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Sample records for broadleaved evergreens

  1. Comparative Study of Carbon Storage and Allocation Characteristics of Mature Evergreen Broad-leaved Forest

    Institute of Scientific and Technical Information of China (English)

    Zhangquan; ZENG; Canming; ZHANGY; Yandong; NIU; Xiquan; LI; Zijian; WU; Jia; LUO

    2014-01-01

    Evergreen broad-leaved forest is an important forest type in China.This paper analyzes the allocation characteristics of vegetation and soil carbon pool of evergreen broad-leaved forest,to understand the current status of research on the carbon storage of evergreen broadleaved forest as well as shortcomings.In the context of global climate change,it is necessary to carry out the long-term research of evergreen broad-leaved forest,in order to grasp the formation mechanism of evergreen broad-leaved forest productivity,and the impact of climate change on the carbon sequestration function of evergreen broad-leaved forest ecosystem.

  2. Change in Species Diversity during Recovering Process of Evergreen Broad-leaved Fo rest

    Institute of Scientific and Technical Information of China (English)

    WenYuanguang; LiuShirong; ChenFang; HeTatping; LiangHongwen

    2005-01-01

    Evergreen broad-leaved forest is one of the most important vegetation types in China. Because of the human activities, evergreen broad-leaved forest has been destroyed extensively, leading to degraded ecosystem. It is urgent to conserve and restore these natural forests in China.tn this paper, the tendency and rate of species diversity restoration of the evergreen broad-lea ved forest in Darning Mountain has been studied. The main results are as follows:(a) in subtropical mid-mountain area, species diversity in degraded evergreen broad-leaved forest can be restored. Through analyzing b diversity index of communities in different time and space, it was found that the species composition of communities tend to be the same as that in the zonal evergreen broad-leaved forest. (b) The restoration rate of evergreen broad-leaved forest was very fast. Planting Chinese fir after clear-cutting and controlled burning of the forest 178 species appeared in a 60Om2, sample area after 20 years"" natural recovering. Among these species, 58 were tree layer and the height of community reached 18m, The survey suggested that it would take only 20 years for the degraded forest to develop into community composed of light demanding broad-leaved pioneer trees and rain-tolerance broad-leaved trees, and it need another 40-80 years to reach the stage consisting of min-tulerance evergreen broad-leaved trees, (c) Species number increased quickly at the early stage (2-20 years) during vegetation recovering process toward the climax, and decreased at the min-stage (50-60 years ), then maintained a relatively stable level at the late-stage (over 150 years).

  3. Litterfall production along successional and altitudinal gradients of subtropical monsoon evergreen broadleaved forests in Guangdong, China

    Science.gov (United States)

    Zhou, G.; Guan, L.; Wei, X.; Zhang, Dongxiao; Zhang, Q.; Yan, J.; Wen, D.; Liu, J.; Liu, S.; Huang, Z.; Kong, G.; Mo, J.; Yu, Q.

    2007-01-01

    Evaluation of litterfall production is important for understanding nutrient cycling, forest growth, successional pathways, and interactions with environmental variables in forest ecosystems. Litterfall was intensively studied during the period of 1982-2001 in two subtropical monsoon vegetation gradients in the Dinghushan Biosphere Reserve, Guangdong Province, China. The two gradients include: (1) a successional gradient composed of pine forest (PF), mixed pine and broadleaved forest (MF) and monsoon evergreen broadleaved forest (BF), and (2) an altitudinal gradient composed of Baiyunci ravine rain forest (BRF), Qingyunci ravine rain forest (QRF), BF and mountainous evergreen broadleaved forest (MMF). Mean annual litterfall production was 356, 861 and 849 g m-2 for PF, MF and BF of the successional gradient, and 1016, 1061, 849 and 489 g m-2 for BRF, QRF, BF and MMF of the altitudinal gradient, respectively. As expected, mean annual litterfall of the pioneer forest PF was the lowest, but rapidly increased over the observation period while those in other forests were relatively stable, confirming that forest litterfall production is closely related to successional stages and growth patterns. Leaf proportions of total litterfall in PF, MF, BF, BRF, QRF and MMF were 76.4%, 68.4%, 56.8%, 55.7%, 57.6% and 69.2%, respectively, which were consistent with the results from studies in other evergreen broadleaved forests. Our analysis on litterfall monthly distributions indicated that litterfall production was much higher during the period of April to September compared to other months for all studied forest types. Although there were significant impacts of some climate variables (maximum and effective temperatures) on litterfall production in some of the studied forests, the mechanisms of how climate factors (temperature and rainfall) interactively affect litterfall await further study. ?? 2006 Springer Science+Business Media B.V.

  4. Habitat fragmentation impacts on biodiversity of evergreen broadleaved forests in Jinyun Mountains,China

    Institute of Scientific and Technical Information of China (English)

    YAN Ming; ZHONG Zhangcheng; LIU Jinchun

    2007-01-01

    The plant communities and their microclimates were surveyed and observed,and the soil fertilities were determined in six plots of evergreen broadleaved forests of different sizes and similar slope aspects on Jinyun Mountains of Chongqing in China from April to October,2003.The relationships of biotic and abiotic factors were analyzed using the Simpson,Shannon-Wiener,and Hill diversity indices,and stepwise multilinear regression analyses techniques.The results showed that compared with continuous evergreen broadleaved forests,five fragmentations had a lower species diversity index,and different life forms showed differences in diversity index.With the decrease in patch areas,the daily differences in air temperature (△Ta),ground surface temperature (△Ts),daily differences in relative humidity (△RH),maximum wind velocity (Vmax),differences in photosynthetic available radiation (△PAR)(at noon)of both edges and interiors,all tended to increase.Maximum wind velocity (Vmax)and photo effective radiation in forest edges were higher than those in interior forest,which presented a stronger temperature-gained edge effect.In all the fragmentations of evergreen broadleaved forests,the depth of the edge effect was the nearest from interior forest in the biggest patch (about 15 meters away from interior forest),while the depth of the edge effect was the farthest from interior forest in the smallest patch (about 25 meters away from interior forest).With regard to the water conservation function,soil water content improved along with increasing species diversity.Some of the nutritional function substances of soil increased with increasing species diversity.The elements of microclimate,such as Ta,△Ta,△Ts,ARH,Vmax,and PAR,changed along with the extent of fragmented forest.

  5. Belowground carbon balance and carbon accumulation rate in the successional series of monsoon evergreen broad-leaved forest

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The balance, accumulation rate and temporal dynamics of belowground carbon in the successional series of monsoon evergreen broadleaved forest are obtained in this paper, based on long-term observations to the soil organic matter, input and standing biomass of litter and coarse woody debris, and dissolved organic carbon carried in the hydrological process of subtropical climax forest ecosystem-monsoon evergreen broad-leaved forest, and its two successional forests of natural restoration-coniferous and broad-leaved mixed forest and Pinus massoniana forest, as well as data of root biomass obtained once every five years and respiration measurement of soil, litter and coarse woody debris respiration for 1 year. The major results include: the belowground carbon pools of monsoon evergreen broad-leaved forest, coniferous and broad-leaved mixed forest, and Pinus massoniana forest are 23191 ± 2538 g·m?2, 16889 ± 1936 g·m?2 and 12680 ± 1854 g·m?2, respectively, in 2002. Mean annual carbon accumulation rates of the three forest types during the 24a from 1978 to 2002 are 383 ± 97 g·m?2·a?1, 193 ± 85 g·m?2·a?1 and 213 ± 86 g·m?2·a?1, respectively. The belowground carbon pools in the three forest types keep increasing during the observation period, suggesting that belowground carbon pools are carbon sinks to the atmosphere. There are seasonal variations, namely, they are strong carbon sources from April to June, weak carbon sources from July to September; while they are strong carbon sinks from October to November, weak carbon sinks from December to March.

  6. [Applicability analysis of spatially explicit model of leaf litter in evergreen broad-leaved forests].

    Science.gov (United States)

    Zhao, Qing-Qing; Liu, He-Ming; Jonard, Mathieu; Wang, Zhang-Hua; Wang, Xi-Hua

    2014-11-01

    The spatially explicit model of leaf litter can help to understand its dispersal process, which is very important to predict the distribution pattern of leaves on the surface of the earth. In this paper, the spatially explicit model of leaf litter was developed for 20 tree species using litter trap data from the mapped forest plot in an evergreen broad-leaved forest in Tiantong, Zhejiang Pro- vince, eastern China. Applicability of the model was analyzed. The model assumed an allometric equation between diameter at breast height (DBH) and leaf litter amount, and the leaf litter declined exponentially with the distance. Model parameters were estimated by the maximum likelihood method. Results showed that the predicted and measured leaf litter amounts were significantly correlated, but the prediction accuracies varied widely for the different tree species, averaging at 49.3% and ranging from 16.0% and 74.0%. Model qualities of tree species significantly correlated with the standard deviations of the leaf litter amount per trap, DBH of the tree species and the average leaf dry mass of tree species. There were several ways to improve the forecast precision of the model, such as installing the litterfall traps according to the distribution of the tree to cover the different classes of the DBH and distance apart from the parent trees, determining the optimal dispersal function of each tree species, and optimizing the existing dispersal function. PMID:25898606

  7. Propagation of Native Tree Species to Restore Subtropical Evergreen Broad-Leaved Forests in SW China

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2016-01-01

    Full Text Available Subtropical evergreen broad-leaved forest (EBLF is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of experiments to study the propagation requirements of indigenous subtropical tree species in Southwest China. Seeds of 21 tree species collected from the natural forest were materials for the experiment. This paper examines the seed germination and seedling growth performance of these species in a nursery environment. Germination percentages ranged from 41% to 96% and were ≥50% for 19 species. The median length of germination time (MLG ranged from 24 days for Padus wilsonii to 144 days for Ilex polyneura. Fifteen species can reach the transplant size (≥15 cm in height within 12 months of seed collection. Nursery-grown seedlings for each species were planted in degraded site. Two years after planting, the seedling survival rate was >50% in 18 species and >80% in 12 species. Based on these results, 17 species were recommended as appropriate species for nursery production in forest restoration projects. Our study contributes additional knowledge regarding the propagation techniques for various native subtropical tree species in nurseries for forest restoration.

  8. Accuracy of LiDAR-based tree height estimation and crown recognition in a subtropical evergreen broad-leaved forest in Okinawa, Japan

    OpenAIRE

    Azita Ahmad Zawawi; Masami Shiba; Noor Janatun Naim Jemali

    2015-01-01

    Aim of study: To present an approach for estimating tree heights, stand density and crown patches using LiDAR data in a subtropical broad-leaved forest. Area of study: The study was conducted within the Yambaru subtropical evergreen broad-leaved forest, Okinawa main island, Japan. Materials and methods: A digital canopy height model (CHM) was extracted from the LiDAR data for tree height estimation and a watershed segmentation method was applied for the individual crown delineation....

  9. Potential Effects of Climate Change on the Distribution of Cold-Tolerant Evergreen Broadleaved Woody Plants in the Korean Peninsula.

    Science.gov (United States)

    Koo, Kyung Ah; Kong, Woo-Seok; Nibbelink, Nathan P; Hopkinson, Charles S; Lee, Joon Ho

    2015-01-01

    Climate change has caused shifts in species' ranges and extinctions of high-latitude and altitude species. Most cold-tolerant evergreen broadleaved woody plants (shortened to cold-evergreens below) are rare species occurring in a few sites in the alpine and subalpine zones in the Korean Peninsula. The aim of this research is to 1) identify climate factors controlling the range of cold-evergreens in the Korean Peninsula; and 2) predict the climate change effects on the range of cold-evergreens. We used multimodel inference based on combinations of climate variables to develop distribution models of cold-evergreens at a physiognomic-level. Presence/absence data of 12 species at 204 sites and 6 climatic factors, selected from among 23 candidate variables, were used for modeling. Model uncertainty was estimated by mapping a total variance calculated by adding the weighted average of within-model variation to the between-model variation. The range of cold-evergreens and model performance were validated by true skill statistics, the receiver operating characteristic curve and the kappa statistic. Climate change effects on the cold-evergreens were predicted according to the RCP 4.5 and RCP 8.5 scenarios. Multimodel inference approach excellently projected the spatial distribution of cold-evergreens (AUC = 0.95, kappa = 0.62 and TSS = 0.77). Temperature was a dominant factor in model-average estimates, while precipitation was minor. The climatic suitability increased from the southwest, lowland areas, to the northeast, high mountains. The range of cold-evergreens declined under climate change. Mountain-tops in the south and most of the area in the north remained suitable in 2050 and 2070 under the RCP 4.5 projection and 2050 under the RCP 8.5 projection. Only high-elevations in the northeastern Peninsula remained suitable under the RCP 8.5 projection. A northward and upper-elevational range shift indicates change in species composition at the alpine and subalpine

  10. Community characteristics of a subtropical evergreen broad-leaved forest in Huangshan, Anhui Province, East China

    Directory of Open Access Journals (Sweden)

    Hui Ding

    2016-08-01

    Full Text Available Located in the subtropical monsoon climate zone, Huangshan is one of the high mountains in eastern China and lies in the transition zone of north-south flora. It is considered a refuge of flora and fauna during the Quaternary maximum glaciation. Zonal vegetation is classified as evergreen broad-leaved forest with a vertical distribution pattern. It is not only one of China’s Biodiversity Conservation Priority Areas, but also one of the World’s Cultural and Natural Heritage Sites and a world famous scenic spot. In 2014, we established a large-scale forest dynamics plot with an area of 10.24 ha in Huangshan based on international protocols (Smithsonian Tropical Research Institute, Center for Tropical Forest Science, CTFS and completed the first field survey. The investigation aimed at revealing community characteristics by analyzing species composition, flora characteristics, diameter class structure, and spatial distribution patterns. We recorded 191 species of vascular plants, belonging to 59 families and 129 genera, in the plot. Among these, trees (DBH ≥ 1 cm belonged to 46 families, 97 genera and 153 species. The number of family and genera with tropical distributions accounted for 65.79% and 45.36% of the total taxa, respectively, while those with temperate distributions accounted for 34.21% and 51.55%, respectively. A number of rare and endangered species occurred in the plots, including six species classified as Class II of State Key Protected Wild Plants, seven threatened species (VU from the China’s Biodiversity Red List: Higher Plant, one species defined in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES (Appendix II, and 64 endemic species to China, indicating their values for protection and research. We also found that the number of species increased sharply with increasing scale when the scale was less than 2,150 m2, while at a higher resolution its rate of increase decreased

  11. Effect of urbanization on the structure and functional traits of remnant subtropical evergreen broad-leaved forests in South China.

    Science.gov (United States)

    Huang, Liujing; Chen, Hongfeng; Ren, Hai; Wang, Jun; Guo, Qinfeng

    2013-06-01

    We investigated the effects of major environmental drivers associated with urbanization on species diversity and plant functional traits (PFTs) in the remnant subtropical evergreen broad-leaved forests in Metropolitan Guangzhou (Guangdong, China). Twenty environmental factors including topography, light, and soil properties were used to quantify the effects of urbanization. Vegetation data and soil properties were collected from 30 400-m(2) plots at 6 study sites in urban and rural areas. The difference of plant species diversity and PFTs of remnant forests between urban and rural areas were analyzed. To discern the complex relationships, multivariate statistical analyses (e.g., canonical correspondence analysis and regression analysis) were employed. Pioneer species and stress-tolerant species can survive and vigorously establish their population dominance in the urban environment. The native herb diversity was lower in urban forests than in rural forests. Urban forests tend to prefer the species with Mesophanerophyte life form. In contrast, species in rural forests possessed Chamaephyte and Nanophanerophyte life forms and gravity/clonal growth dispersal mode. Soil pH and soil nutrients (K, Na, and TN) were positively related to herb diversity, while soil heavy metal concentrations (Cu) were negatively correlated with herb diversity. The herb plant species diversity declines and the species in the remnant forests usually have stress-tolerant functional traits in response to urbanization. The factors related to urbanization such as soil acidification, nutrient leaching, and heavy metal pollution were important in controlling the plant diversity in the forests along the urban-rural gradients. Urbanization affects the structure and functional traits of remnant subtropical evergreen broad-leaved forests.

  12. [Seasonal release characteristics of Ca, Mg and Mn of foliar litter of six tree species in subtropical evergreen broadleaved forest].

    Science.gov (United States)

    Ma, Zhi-liang; Gao, Shun; Yang, Wan-qin; Wu, Fu-zhong

    2015-10-01

    Seasonal release dynamics of Ca, Mg and Mn during decomposition of foliar litter of Pinus massoniana, Cryptomeria fortunei, Cunninghamia lanceolata, Cinnamomum camphora, Toona ciliate, and Quercus acutissima were investigated in subtropical evergreen broad-leaved forest employing the method of litterbag. After one-year decomposition, the release rates of Ca, Mg and Mn in foliar litter of the studied tree species ranged from -13.8% to 92.3%, from 4.0% to 64.8%, and from 41.6% to 81.1%, respectively. Ca dynamics in foliar litter of P. massoniana, C. camphora exhibited the pattern of accumulating early and releasing later, while that of the other four tree species showed direct release. Similarly, the dynamics of Mg released from foliar litter of C. camphora showed the pattern of accumulating early and then releasing, while that of the other five tree species exhibited continuous release. Meanwhile, the dynamics of Mn released from foliar litter of C. fortunei and T. ciliate exhibited early accumulation, and subsequent release, while that of the other four tree species showed continuous release. The releases of Ca, Mg and Mn in foliar litter were greatly influenced by seasonal rainfall, and varied with tree species. Furthermore, the rates and amounts of Ca, Mg and Mn released from foliar litter were higher in rainy season than in dry season. In conclusion, the initial nutrient concentrations and precipitation were two key factors influencing the release dynamics of Ca, Mg and Mn during decomposition of foliar litter in the subtropical evergreen broad-leaved forest. PMID:26995897

  13. Study on successions sequence of evergreen broad-leaved forest in Gutian Mountain of Zhejiang, Eastern China:species diversity

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Using the widely adopted scheme of space-for-time substitution for investigating 16 typical plots distri-buted as a pattern of contiguous grid quadrates within a sampling plot, the expressions of Shannon-Wiener index (H) for species diversity, Pielou index (Jsw, JSI) for evenness and Simpson index (D) for ecological dominance are employed to investigate the species diversity (SD) of four evergreen broadleaved communities in the successions sequence within the Nature Reserve of the Gutian Mountains. Results showed that in the successions process from the coniferous to the mixed coniferous-broadleaved, then to Schima superba and finally to Castanopsis eyrei forest, the arbor layer SD showed the Shannon-Wiener index (H) as 1.9670, 2.4975, 2.6140 and 2.4356, respectively, characterized by their rise before drop and the shrub (herb) layer SD shows the maximum to be in the mixed coniferous-broadleaved (coniferous) forest (H arriving at 2.8625 (1.5334)). In the vertical structure, on the other hand, for the sequenced coniferous forest, coniferous-broad mixed forest and Castnaopsis eyrei forest, the number of SD ranges in a decreasing order from the shrub, arbor to herb layer in contrast to the SD in a decreasing order of Schima superba forest ranging from the arbor to shrub and then to herb layer, and during the succession, the herb layer exhibits the maximum range of SD change among these layers, with its variation coefficients of 0.1572, 0.0806, 0.0899 and 0.1884 for H, Jsw, JSI and D, in order, in sharp contrast to the minimal SD range in the shrub layer, with the corresponding figures of 0.0482, 0.0385, 0.0142, and 0.1553.

  14. Biocycle of nitrogen in a Cyclobalanopsis glauca-dominated evergreen broad-leaved forest in East China

    Institute of Scientific and Technical Information of China (English)

    YU Mingjian; XU Xuehong; LI Minghong; FU Hailong

    2006-01-01

    The nitrogen (N) cycling was elucidated in a 40-year-old subtropical evergreen broad-leaved forest dominated by Cyclobalanopsis glauca growing on red soil in Zhejiang Province,East China.The concentrations of N in the representative species ranged from 0.49% to 1.64%,the order of which in various layers was liana and herb layers>understory layer > tree and subtree layers;in various organs was leaf > branch > root > trunk;and aboveground parts > underground parts.The sequence of the concentrations of N in C.glauca was understory > tree > subtree layer;young and high-growing > old organs;reproductive >vegetative organs.Seasonal dynamics of the concentrations of N in C.glauca in the tree and subtree layers was comparatively stable.It was lower in autumn (October) in root,branch,and leaf in the tree layer,and low in January in the understory.There was no evident change in regularity of the concentrations of N in varying diameter classes.The concentrations of N in the litterfall,precipitation,throughfall,litter layer,and soil were 0.74%-2.30%,0.000,038%,0.000,09%,1.94%,and 0.59%,respectively.The standing crop of N in the plant community was 1,025.28 kg/hm2,accumulation in the litter layer was 224.88 kg/hm2,and reserve in the soil was 55,151 kg/hm2.Annual retention of N was 119.47 kg/hm2,return was about 84.13 kg/hm2,among which litterfall was 78.49 kg/hm2 and throughfall,5.64 kg/hm2.Annual absorption of N was 203.60 kg/hm2.Annual input of N through incident precipitation was 4.88 kg/hm2.Compared with other forest types,cycling rate of N in the community was lower than in deciduous broad-leaved forests,rain forests,and mangroves,and was moderate in evergreen broad-leaved forests.N use efficiency of this forest was moderate among the forest types cited.According to the characteristics of the biocycle of phosphorous,it was concluded that N availability in the soil of this forest was not lower,and phosphorous not N was the limiting factor in the growth

  15. Change in Species Diversity during Recovering Process of Evergreen Broad-leaved Forest%常绿阔叶林恢复过程植物物种多样性的变化

    Institute of Scientific and Technical Information of China (English)

    温远光

    2005-01-01

    Evergreen broad-leaved forest is one of the most important vegetation types in China. Because of the human activities, evergreen broad-leaved forest has been destroyed extensively, leading to degraded ecosystem. It is urgent to conserve and restore these natural forests in China.In this paper, the tendency and rate of species diversity restoration of the evergreen broad-leaved forest in Daming Mountain has been studied. The main results are as follows: (a) In subtropical mid-mountain area, species diversity in degraded evergreen broad-leaved forest can be restored. Through analyzing b diversity index of communities in different time and space, it was found that the species composition of communities tend to be the same as that in the zonal evergreen broad-leaved forest. (b) The restoration rate of evergreen broad-leaved forest was very fast. Planting Chinese fir after clear-cutting and controlled burning of the forest, 178 species appeared in a 600m2 sample area after 20years'natural recovering. Among these species, 58 were tree layer and the height of community reached 18m. The survey suggested that it would take only 20 years for the degraded forest to develop into community composed of light demanding broad-leaved pioneer trees and min-tolerance broad-leaved trees, and it need another 40~80 years to reach the stage consisting of min-tolerance evergreen broad-leaved trees. (c) Species number increased quickly at the early stage (2-20 years) during vegetation recovering process toward the climax, and decreased at the min-stage (50-60 years ), then maintained a relatively stable level at the late-stage (over 150 years).

  16. Characteristics analysis of the evergreen broad-leaved forest in Minxi, Fujian Province%闽西常绿阔叶林群落特征分析

    Institute of Scientific and Technical Information of China (English)

    孔祥海; 黄素华; 陈小红; 邱丰艳

    2009-01-01

    On the base of 1.6 hm~2 cumulative sampling plots community ecological investigation of the evergreen broad-leaved forest in Minxi, and through species composition, areal types, life form spectra, and leaf character statistics analysis, The results showed, 116 families, 235 genera and 398 species of vascular plants were recorded;The dominant seed plant families of the evergreen broad-leaved forest community in Minxi were Lauraceae, Fagaceae, Magnoliaceae, Myrsinaceae, Theaceae, and so on;The flora of the evergreen broad-leaved forest community was obviously tropical and subtropical geographical character in Minxi;The constructive species of the evergreen broad-leaved forest community was abundant, and different community form could be come into being by some constructive species combination which made community diversification;The evergreen broad-leaved forest community was characterized by the evergreen mesophanerophytes and microphanerophytes with simple leathery, entire mesophyllous and microphyllous leaves in Minxi;Comparison of the evergreen broad-leaved forest among Minxi and other regions, the community of the evergreen broad-leaved forest in Minxi had a transitional characteristics from typical subtropical flora to south subtropical at species composition, area type and life form spectrum, as well as the leaf character aspect.%采用群落生态学的方法对闽西常绿阔叶林植被的1.6 hm~2样地调查统计、分析,结果表明,构成闽西常绿阔叶林群落的优势科是樟科、壳斗科、木兰科、紫金牛科和山茶科等;闽西常绿阔叶林群落的植物区系具有明显的热带、亚热带地理性质;闽西常绿阔叶林群落的建群树种多,且部分不同的建群种间可组合构成不同的群丛,群落类型呈现多样化;闽西常绿阔叶林群落的外貌以单叶、革质、全缘和中小型叶为主的常绿中、小高位芽植物组成为特征;闽西常绿阔叶林群落植物在物种组成数量、科属

  17. Role of urban remnant evergreen broad-leaved forests on natural restoration of artificial forests in Chongqing metropolis

    Institute of Scientific and Technical Information of China (English)

    杨永川; 李楠

    2009-01-01

    The effects of urban remnant natural evergreen broad-leaved forest (EBLF) on the restoration of artificial pine forests surrounding it were studied with reference to species composition,biodiversity,dominant species and stand structure on Mt. Tieshanping in Chongqing metropolis,Southwest China. The seeds from the remnant EBLF naturally facilitate the restoration process of artificial Pinus massoniana forests near it. The similarity of species composition between the artificial Pinus massoniana forests and the remnant EBLF and biodiversity index of the artificial Pinus massoniana forests decrease as the distance from the remnant EBLF increases. Castanopsis carlesii var. spinusa is the dominant species in the ground vegetation,shrub layer and sub-tree layer of the Pinus massoniana forests near the remnant EBLF. However,the natural restoration processes of those farther away from the remnant EBLF are restricted for the absence of seed source of the inherent components of the remnant EBLF,and the anthropogenic measures should be taken to facilitate the restoration process.

  18. Effects of Topographic and Soil Factors on Woody Species Assembly in a Chinese Subtropical Evergreen Broadleaved Forest

    Directory of Open Access Journals (Sweden)

    Lijuan Zhao

    2015-03-01

    Full Text Available Evergreen broadleaved forests in subtropical China contain a complicated structure of diverse species. The impact of topographic and soil factors on the assembly of woody species in the forest has been poorly understood. We used Ripley’s K(t function to analyze the spatial patterns and associations of dominant species and residual analysis (RDA to quantify the contribution of topography and soil to species assembly. The 1 ha plot investigated had 4797 stems with a diameter at breast height (dbh larger than 1 cm that belong to 73 species, 55 genera, and 38 families. All stems of the entire forest and four late successional species exhibited a reversed J shape for dbh distribution, while two early successional species showed a unimodal shape. Aggregation was the major spatial pattern for entire forests and dominant species across vertical layers. Spatial associations between inter- and intra-species were mostly independent. Topographic and soil factors explained 28.1% of species assembly. The forest was close to late succession and showed the characteristics of diverse woody species, high regeneration capacity, and aggregated spatial patterns. Topographic and soil factors affected species assembly, but together they could only explain a small part of total variance.

  19. Studies on Material Cycling in Evergreen Broad-Leaved Forest Ecosystem in Hangzhou:I.Precipitation Distribution

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    Through the long-term plot studies plot studies on the precipitation distribution in the evergreen broad-leaved forest ecosystem in Hangzhou for two years,it was indicated that the pattern of precipitation distribution included larger amounts of penetration water and stemflow and a lower amount of interception water.The results revealed that the main factors to infulence the percentages of penetration and stemflow were the air temperature and the leaf area of the forest.The quantity of seepage through the litter layer was much larger than that through the soil layers which decreased sharply with soil depth.The output of water from the ecosystem by surface runoff and deep infiltration through the soil was much lower,only being 5.20 percent of the rainfall,while the water evapotranspiration loss was as large as more than 90 percent of it.The losses by the soil evaporation and plant evapotranspiration were the largest part of output in this forest ecosystem.

  20. Topographic variation in aboveground biomass in a subtropical evergreen broad-leaved forest in China.

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    Dunmei Lin

    Full Text Available The subtropical forest biome occupies about 25% of China, with species diversity only next to tropical forests. Despite the recognized importance of subtropical forest in regional carbon storage and cycling, uncertainties remain regarding the carbon storage of subtropical forests, and few studies have quantified within-site variation of biomass, making it difficult to evaluate the role of these forests in the global and regional carbon cycles. Using data for a 24-ha census plot in east China, we quantify aboveground biomass, characterize its spatial variation among different habitats, and analyse species relative contribution to the total aboveground biomass of different habitats. The average aboveground biomass was 223.0 Mg ha(-1 (bootstrapped 95% confidence intervals [217.6, 228.5] and varied substantially among four topographically defined habitats, from 180.6 Mg ha(-1 (bootstrapped 95% CI [167.1, 195.0] in the upper ridge to 245.9 Mg ha(-1 (bootstrapped 95% CI [238.3, 253.8] in the lower ridge, with upper and lower valley intermediate. In consistent with our expectation, individual species contributed differently to the total aboveground biomass of different habitats, reflecting significant species habitat associations. Different species show differently in habitat preference in terms of biomass contribution. These patterns may be the consequences of ecological strategies difference among different species. Results from this study enhance our ability to evaluate the role of subtropical forests in the regional carbon cycle and provide valuable information to guide the protection and management of subtropical broad-leaved forest for carbon sequestration and carbon storage.

  1. Retention of available P in acid soils of tropical and subtropical evergreen broad-leaved forests

    Institute of Scientific and Technical Information of China (English)

    CHEN Jianhui; ZOU Xiaoming; YANG Xiaodong

    2007-01-01

    Precipitation of mineral phosphate is often recognized as a factor of limiting the availability of P in acidic soils of tropical and subtropical forests.For this paper,we studied the extractable P pools and their transformation rates in soils of a tropical evergreen forest at Xishuangbanna and a subtropical montane wet forest at the Ailao Mountains in order to understand the biogeochemical processes regulating P availability in acidic soils.The two forests differ in forest humus layer;it is deep in the Ailao forest while little is present in the Xishuangbanna forest.The extractable P pools by resin and sodium-bicarbonate decreased when soil organic carbon content was reduced.The lowest levels of extractable P pools occurred in the surface (0-10 era) mineral soils of the Xishuangbanna forest.However,microbial P in the mineral soil of the Xishuangbauna forest was twice that in the Ailao forest.Potential rates of microbial P immobilization were greater than those of organic P mineralization in mineral soils for both forests.We suggest that microbial P immobilization plays an essential role in avoiding mineral P precipitation and retaining available P of plant in tropical acidic soils,whereas both floor mass accumulation and microbial P immobilization function benefit retaining plant available P in subtropical montane wet forests.

  2. CO2 flux evaluation over the evergreen coniferous and broad-leaved mixed forest in Dinghushan, China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>The Dinghushan flux observation site, as one of the four forest sites of ChinaFLUX, aims to acquire long-term measurements of CO2 flux over a typical southern subtropical evergreen coniferous and broad-leaved mixed forest ecosystem using the open path eddy covariance method. Based on two years of data from 2003 to 2004, the characteristics of temporal variation in CO2 flux and its response to environmental factors in the forest ecosystem are analyzed. Provided two-dimensional coordinate rotation, WPL correction and quality control, poor energy-balance and underestimation of ecosystem respiration during nighttime implied that there could be a CO2 leak during the nighttime at the site. Using daytime (PAR > 1.0μmol-1·m-2·s-1) flux data during windy conditions (u* > 0.2 m·s-1), monthly ecosystem respiration (Reco) was derived through the Michaelis-Menten equation modeling the relationship between net ecosystem CO2 exchange (NEE) and photosynthetically active radiation (PAR). Exponential function was employed to describe the relationship between Reco and soil temperature at 5 cm depth (Ts05), then Reco of both daytime and nighttime was calculated respectively by the function. The major results are: (i) Derived from the Michaelis-Menten equation, the apparent quantum yield (α) was 0.0027±0.0011 mgCO2·μmol-1 photons, and the maximum photosynthetic assimilation rate (Amax) was 1.102±0.288 mgCO2·m-2·s-1. Indistinctive seasonal variation of o or Amax was consistent with weak seasonal dynamics of leaf area index (LAI) in such a lower subtropical evergreen mixed forest. (ii) Monthly accumulated Reco was estimated as 95.3±21.1 gC·m-2 mon-1, accounting for about 68% of the gross primary product (GPP). Monthly accumulated NEE was estimated as -43.2±29.6 gC·m-2·mon-1. The forest ecosystem acted as carbon sink all year round without any seasonal carbon efflux period. Annual NEE of 2003 and 2004 was estimated as -563.0 and -441.2 gC·m-2·a-1 respectively

  3. [Characterization of mid-subtropical evergreen broad-leaved forest gap based on light detection and ranging (LiDAR)].

    Science.gov (United States)

    Liu, Feng; Tan, Chang; Wang, Hong; Zhang, Jiang; Wan, Ying; Long, Jiang-ping; Liu, Rui-xi

    2015-12-01

    Light Detection and Ranging (LiDAR) is an active remote sensing technology for acqui- ring three-dimensional structure parameters of vegetation canopy with high accuracy over multiple spatial scales, which is greatly important to the promotion of forest disturbance ecology and the ap- plication on gaps. This paper focused on mid-subtropical evergreen broadleaved forest in Hunan Province, and small footprint LiDAR point data were adopted to identify canopy gaps. and measure geomagnetic characteristics of gaps. The optimal grid model resolution and interpolation methods were chosen to generate canopy height model, and the computer graphics processing was adopted to estimate characteristics of gaps which involved gap size, canopy height and gap shape index, then field investigation was utilized to validate the estimation results. The results showed that the gap rec- ognition rate was 94.8%, and the major influencing factors were gap size and gap maker type. Line- ar correlation was observed between LiDAR estimation and field investigation, and the R² values of gap size and canopy height case were 0.962 and 0.878, respectively. Compared with field investiga- tion, the size of mean estimated gap was 19.9% larger and the mean estimated canopy height was 9.9% less. Gap density was 12.8 gaps · hm⁻² and the area of gaps occupied 13.3% of the forest area. The average gap size, canopy height and gap shape index were 85.06 m², 15.33 m and 1.71, respectively. The study site usually contained small gaps in which the edge effect was not obvious. PMID:27111996

  4. Forest structure, productivity and soil properties in a subtropical evergreen broad-leaved forest in Okinawa, Japan

    Institute of Scientific and Technical Information of China (English)

    XU Xiao-niu; WANG Qin; Hideaki SHIBATA

    2008-01-01

    Structure,species composition,and soil properties of a subtropical evergreen broad-leaved forest in Okinawa,Japan,were examined by establishment of plots at thirty sites.The forest was characterized by a relatively low canopy and a large number of small-diameter trees.Mean canopy height for this forest was 10 m and stands contained an average of 5400 stems·ha-1 (≧ 3.0 cm DBH); 64% of those stems were smaller than 10 cm DBH.The total basal area was 54.4 m 2·ha-1,of which Castanopsis sieboldii contributed 48%.The forest showed high species diversity of trees.80 tree species (≧ 3.0 cm DBH) from 31 families was identified in the thirty sampling plots.C.sieboldii and Schima wallichii were the dominant and subdominant species in terms of importance value.The mean tree species diversity indices for the plots were,3.36 for Diversity index (H'),0.71 for Equitability index (J') and 4.72 for Species richness index (S'),all of which strongly declined with the increase of importance value of the dominant,C.sieboldii.Measures of soil nutrients indicated low fertility,extreme heterogeneity and possible Al toxicity.Regression analysis showed that stem density and the dominant tree height were significantly correlated with soil pH.There was a significant positive relationship between species diversity index and soil exchangeable K+,Ca2+,and Ca2+/Al3+ ratio (all p values <0.001) and a negative relationship with N,C and P.The results suggest that soil property is a major factor influencing forest composition and structure within the subtropical forest in Okinawa.

  5. [Spatial analysis of LAIe of montane evergreen broad-leaved forest in southwest Sichuan, Northwest China, based on image texture].

    Science.gov (United States)

    Zhao, An-Jiu; Yang, Chang-Qing; Liao, Cheng-Yun

    2014-11-01

    Optical remote sensing is still one of the most attractive choices for obtaining leaf area index (LAI) information, but currently may be derived from remotely sensed data with limited accuracy. Effective leaf area index (LAIe) of montane evergreen broad-leaved forest in southwest Sichuan was inventoried and assessed in 83 sample field plots of 20 m x 20 m using different types of image processing techniques, including simple spectral band, simple spectral band ratios and principal component. Texture information was extracted by gray level co-occurrence matrices (GLCM) from different types of processing image. The results showed that there were correlations of different degrees between LAIe and texture parameters, and highly significant correlations were observed between LAIe with the homogeneity of the B1 band, B1/B4 band ratio or principal component PC1. Using texture information of remotely sensed data as auxiliary variables, we developed geostatistics models. Compared with the model based on NDVI auxiliary variable, the accuracy of LAIe were improved, presenting an increase by 5.3% with the homogeneity of the B1 band, 11.0% with the homogeneity B1/B4 band ratio, and 14.5% with the homogeneity principal component PC1, and the statistical errors were also reduced to some extent. The optimal LAIe model of spatial geostatistics was obtained when taking NDVI and homogeneity principal component PC1 as auxiliary variables (R2 = 0.840, RMSE = 0.212). Our results provided a new way to estimate regional spatial distribution of LAI using other auxiliary variables besides the vegetation index.

  6. Genetic differentiation and genetic diversity of Castanopsis (Fagaceae, the dominant tree species in Japanese broadleaved evergreen forests, revealed by analysis of EST-associated microsatellites.

    Directory of Open Access Journals (Sweden)

    Kyoko Aoki

    Full Text Available The broadleaved evergreen forests of the East Asian warm temperate zone are characterised by their high biodiversity and endemism, and there is therefore a need to extend our understanding of its genetic diversity and phylogeographic patterns. Castanopsis (Fagaceae is one of the dominant tree species in the broadleaved evergreen forests of Japan. In this study we investigate the genetic diversity, genetic structure and leaf epidermal morphology of 63 natural populations of C. sieboldii and C. cuspidata, using 32 Expressed Sequence Tag associated microsatellites. The overall genetic differentiation between populations was low (GST = 0.069 in C. sieboldii and GST = 0.057 in C. cuspidata. Neighbor-joining tree and Bayesian clustering analyses revealed that the populations of C. sieboldii and C. cuspidata were genetically clearly differentiated, a result which is consistent with the morphology of their epidermal cell layers. This suggests that C. sieboldii and C. cuspidata should be treated as independent species, although intermediate morphologies are often observed, especially at sites where the two species coexist. The higher level of genetic diversity observed in the Kyushu region (for both species and the Ryukyu Islands (for C. sieboldii is consistent with the available fossil pollen data for Castanopsis-type broadleaved evergreen trees during the Last Glacial Maximum and suggests the existence of refugia for Castanopsis forests in southern Japan. Within the C. sieboldii populations, Bayesian clustering analyses detected three clusters, in the western and eastern parts of the main islands and in the Ryukyu Islands. The west-east genetic differentiation observed for this species in the main islands, a pattern which is also found in several plant and animal species inhabiting Castanopsis forests in Japan, suggests that they have been isolated from each other in the western and eastern populations for an extended period of time, and may

  7. Community Dynamics of Seed Rain in Mixed Evergreen Broad-leaved and Deciduous Forests in a Subtropical Mountain of Central China

    Institute of Scientific and Technical Information of China (English)

    Ze-Hao Shen; Yuan-Yuan Tang; Nan Lü; Jun Zhao; Dao-Xing Li; Gong-Fang Wang

    2007-01-01

    Seed dispersal is a key process within community dynamics. The spatial and temporal variations of seed dispersal and the interspecific differences are crucial for understanding species coexistence and community dynamics. This might also hold for the mixed evergreen broadleaved and deciduous forests in the mountains of subtropical China, but until now little existing knowledge is available for this question. In 2001, we chose to monitor the seed rain process of our mixed evergreen broad-leaved and deciduous forest communities in Mount Dalaoling National Forest Park, Yichang, Hubei Province, China.The preliminary analyses show obvious variations in seed rain density, species compositions and timing of seed rain among four communities. The average seed rain densities of the four communities are 2.43 ± 5.15, 54.13 ±182.75, 10.05 ±19.30and 24.91 ± 58.86 inds./m2, respectively; about one tenth the values in other studies in subtropical forests of China. In each community, the seed production is dominated by a limited number of species, and the contributions from the others are generally minor. Fecundity of evergreen broadleaved tree species is weaker than deciduous species. The seed rain of four communities begins earlier than September, and stops before December, peaking from early September to late October.The beginning date, ending date and peak times of seed rain are extensively varied among the species, indicating different types of dispersal strategies. According to the existing data, the timing of seed rain is not determined by the climate conditions in the same period, while the density of seed rain may be affected by the disturbances of weather variations at a finer temporal resolution.

  8. Temporal dynamics of and effects of an ice storm on litter production in an evergreen broad-leaved forest in Gutianshan National Nature Reserve

    OpenAIRE

    Lei Zhang; Xiaohe Wang; Xiangcheng Mi; Jianhua Chen; Mingjian Yu

    2011-01-01

    To study litter production, composition, temporal dynamics, and the effects of an ice storm on litter production in a 24-ha evergreen broad-leaved forest dynamic plot in Gutianshan National Nature Reserve, Zhejiang, we set up 169 seed traps, and collected litterfall weekly from October 2006 to December 2009. Total annual litter production in 2007 and 2009 was 532.05 g/m2 and 375.17 g/m2, respectively. We attribute the remarkable drop in production due to an ice storm in February 2008. Leaves,...

  9. Study on Restoration of Evergreen Broad-leaved Forest from Pinus massoniana Forest.%马尾松林恢复为常绿阔叶林的研究

    Institute of Scientific and Technical Information of China (English)

    王希华; 宋永昌; 王良衍

    2001-01-01

    High coverage of Pinus massoniana forest on low mountains in Eastern China at present was studied in this paper. This forest is threatened by plant diseases, especially pines wilt, and needs to be restored urgently. Species of later successional stage or climax communities were retained or introduced to the forest through reconstruction according to vegetation ecology theory, so as to restore it quickly to zonal evergreen broad-leaved forest. It formed an evergreen broad-leaved sub-tree layer of 2~3m high dominated by Schima superba from a shrub layer of 57m high after 3 years of reconstruction. The questions of restoration were discussed in this paper.

  10. A climate change-induced threat to the ecological resilience of a subtropical monsoon evergreen broad-leaved forest in Southern China.

    Science.gov (United States)

    Zhou, Guoyi; Peng, Changhui; Li, Yuelin; Liu, Shizhong; Zhang, Qianmei; Tang, Xuli; Liu, Juxiu; Yan, Junhua; Zhang, Deqiang; Chu, Guowei

    2013-04-01

    Recent studies have suggested that tropical forests may not be resilient against climate change in the long term, primarily owing to predicted reductions in rainfall and forest productivity, increased tree mortality, and declining forest biomass carbon sinks. These changes will be caused by drought-induced water stress and ecosystem disturbances. Several recent studies have reported that climate change has increased tree mortality in temperate and boreal forests, or both mortality and recruitment rates in tropical forests. However, no study has yet examined these changes in the subtropical forests that account for the majority of China's forested land. In this study, we describe how the monsoon evergreen broad-leaved forest has responded to global warming and drought stress using 32 years of data from forest observation plots. Due to an imbalance in mortality and recruitment, and changes in diameter growth rates between larger and smaller trees and among different functional groups, the average DBH of trees and forest biomass have decreased. Sap flow measurements also showed that larger trees were more stressed than smaller trees by the warming and drying environment. As a result, the monsoon evergreen broad-leaved forest community is undergoing a transition from a forest dominated by a cohort of fewer and larger individuals to a forest dominated by a cohort of more and smaller individuals, with a different species composition, suggesting that subtropical forests are threatened by their lack of resilience against long-term climate change. PMID:23504896

  11. Phylogeography of Phytophagous Weevils and Plant Species in Broadleaved Evergreen Forests: A Congruent Genetic Gap between Western and Eastern Parts of Japan

    Directory of Open Access Journals (Sweden)

    Kyoko Aoki

    2011-04-01

    Full Text Available The Quaternary climate cycles played an important role in shaping the distribution of biodiversity among current populations, even in warm-temperate zones, where land was not covered by ice sheets. We focused on the Castanopsis-type broadleaved evergreen forest community in Japan, which characterizes the biodiversity and endemism of the warm-temperate zone. A comparison of the phylogeographic patterns of three types of phytophagous weevils associated with Castanopsis (a host-specific seed predator, a generalist seed predator, and a host-specific leaf miner and several other plant species inhabiting the forests revealed largely congruent patterns of genetic differentiation between western and eastern parts of the main islands of Japan. A genetic gap was detected in the Kii Peninsula to Chugoku-Shikoku region, around the Seto Inland Sea. The patterns of western-eastern differentiation suggest past fragmentation of broadleaved evergreen forests into at least two separate refugia consisting of the southern parts of Kyushu to Shikoku and of Kii to Boso Peninsula. Moreover, the congruent phylogeographic patterns observed in Castanopsis and the phytophagous insect species imply that the plant-herbivore relationship has been largely maintained since the last glacial periods. These results reinforce the robustness of the deduced glacial and postglacial histories of Castanopsis-associated organisms.

  12. Carbon of Woody Debris in Plateau-type Karst Evergreen and Deciduous Broad-leaved Mixed Forest of Central Guizhou Province

    Science.gov (United States)

    Wu, Y.; Ni, J.; Liu, L.; Guo, C.

    2014-12-01

    Woody debris (WD) is an essential structural and functional component of forest ecosystems, and plays very significant roles for the biogeochemical cycling of carbon and nutrients. Coarse woody debris (CWD) is considered to be the major part in forest WD and it is primarily composed of logs, snags, stumps and large branches, while fine woody debris (FWD) mainly consists of small twigs. Composition, spatial distribution and carbon storage of WD have been studied in plateau-type karst evergreen and deciduous broad-leaved mixed forest in Tianlong Mountain of central Guizhou Province. Results showed that the carbon storage of WD in karst forests was less than non-karst forests. The major components of WD were fallen trees and snags with 10-20 cm in diameter. Fallen trees and snags with diameter greater than 20 cm were the smallest part of WD. The situation of WD in this region reflects the structural characteristics of WD in mid-late stage of plateau-type karst evergreen and deciduous broad-leaved mixed forest succession. The potential contribution of WD to the regional carbon cycle, and its relationship with climate change were finally discussed. The WD (especially CWD) plays an important role in the carbon cycle of karst forest. Forest WD production and decay rates may partially depend on climatic conditions, the accumulation of CWD and FWD carbon stocks in forests may be correlated with climate. Key words: woody debris, karst forests, carbon storage, spatial distribution, CWD, FWD.

  13. Distribution patterns of the subtropical evergreen broad-leaved forests of southwestern China, as compared with those of the eastern Chinese subtropical regions

    Directory of Open Access Journals (Sweden)

    Tang, C. Q.

    2015-12-01

    Full Text Available This paper analyzes the geographic distribution patterns of the subtropical evergreen broad-leaved forests of southwestern China, and compares with other subtropical regions in the east of China in terms of forest types, pertinent species, and spatial distribution along latitudinal, longitudinal and altitudinal gradients. In general, for both the western and the eastern subtropical regions, the evergreen broad-leaved forests are dominated by species of Castanopsis, Lithocarpus, Cyclobalanopsis (Fagaceae, Machilus, Cinnamomum (Lauraceae, Schima (Theaceae, Manglietia, and Michelia, (Magnoliaceae, while in southwestern China there are more diverse forest types including semi-humid, monsoon, mid-montane moist and humid evergreen broad-leaved forests, but only monsoon and humid forests in the east. The Yunnan area has more varied species of Lithocarpus or Cyclobalanopsis or Castanopsis as dominants than does eastern China, where the chief dominant genus is Castanopsis. The upper limits of the evergreen broad-leaved forests are mainly 2400–2800 m in western Yunnan and western Sichuan, much higher than in eastern China (600–1500, but 2500 m in Taiwan. Also discussed are the environmental effects on plant diversity of the evergreen broad-leaved forest ecosystems exemplified by Yunnan and Taiwan.En este trabajo se analiza los patrones de distribución geográfica de los bosques subtropicales perennifolios de hoja ancha del suroeste de china, y se comparan con los de otras regiones subtropicales del este de China en términos de tipología de bosque, especies relevantes, y distribución espacial a lo largo de un gradiente latitudinal, longitudinal y altitudinal. De manera general, los bosques perennifolios de hoja ancha de la regiones subtropicales tanto orientales como occidentales presentan dominancia de especies de Castanopsis, Lithocarpus, Cyclobalanopsis (Fagaceae, Machilus, Cinnamomum (Lauraceae, Schima (Theaceae, Manglietia y Michelia

  14. Leaf morphology of 40 evergreen and deciduous broadleaved subtropical tree species and relationships to functional ecophysiological traits.

    Science.gov (United States)

    Kröber, W; Heklau, H; Bruelheide, H

    2015-03-01

    We explored potential of morphological and anatomical leaf traits for predicting ecophysiological key functions in subtropical trees. We asked whether the ecophysiological parameters stomatal conductance and xylem cavitation vulnerability could be predicted from microscopy leaf traits. We investigated 21 deciduous and 19 evergreen subtropical tree species, using individuals of the same age and from the same environment in the Biodiversity-Ecosystem Functioning experiment at Jiangxi (BEF-China). Information-theoretic linear model selection was used to identify the best combination of morphological and anatomical predictors for ecophysiological functions. Leaf anatomy and morphology strongly depended on leaf habit. Evergreen species tended to have thicker leaves, thicker spongy and palisade mesophyll, more palisade mesophyll layers and a thicker subepidermis. Over 50% of all evergreen species had leaves with multi-layered palisade parenchyma, while only one deciduous species (Koelreuteria bipinnata) had this. Interactions with leaf habit were also included in best multi-predictor models for stomatal conductance (gs ) and xylem cavitation vulnerability. In addition, maximum gs was positively related to log ratio of palisade to spongy mesophyll thickness. Vapour pressure deficit (vpd) for maximum gs increased with the log ratio of palisade to spongy mesophyll thickness in species having leaves with papillae. In contrast, maximum specific hydraulic conductivity and xylem pressure at which 50% loss of maximum specific xylem hydraulic conductivity occurred (Ψ50 ) were best predicted by leaf habit and density of spongy parenchyma. Evergreen species had lower Ψ50 values and lower maximum xylem hydraulic conductivities. As hydraulic leaf and wood characteristics were reflected in structural leaf traits, there is high potential for identifying further linkages between morphological and anatomical leaf traits and ecophysiological responses.

  15. Mixed Evergreen and Deciduous Broadleaved Forests Interference Characteristics Mulinzi Nature Reserve in Hubei%湖北木林子自然保护区常绿落叶阔叶混交林干扰特征

    Institute of Scientific and Technical Information of China (English)

    汤景明; 翟明普

    2011-01-01

    常绿落叶阔叶混交林是木林子自然保护区的1种主要植被类型。在各种自然干扰和人为干扰的协同作用下,形成了木林子常绿落叶阔叶混交林特有的干扰体系。在常绿落叶阔叶混交林的保护和经营中,要利用封山育林、森林抚育、合理择伐和人工促进天然更新等增益性人工干扰,坚决阻止过渡的森林采伐和毁林开荒等破坏性人工干扰。应参照以自然林窗干扰,采用择伐方式经营常绿落叶阔叶混交林。%The mixed evergreen and deciduous broadleaved forests is one of the main vegetation types of the Mulinzi Nature Reserve.In a variety of natural disturbance and human disturbance of synergies,unique disturbance system of mixed evergreen and deciduous broadleaved forests in Mulinzi was formed.In the protection and management of mixed evergreen and deciduous broadleaved forests should use all kinds of human disturbance of closed forest,forest tending,reasonable selection cutting and artificial natural regeneration of human disturbance such as gain,determined to prevent excessive deforestation and deforestation and other destructive human disturbance.We should refer to the natural forest gap disturbance,operate using selective cutting mixed evergreen and deciduous broad-leaved.

  16. 徐州市城区常绿阔叶树种及其应用调查研究%Investigation and Study of Evergreen Broadleaved Trees Species and Their Landscape Application in Urban Area of Xuzhou

    Institute of Scientific and Technical Information of China (English)

    卢芳; 周瑞玲

    2012-01-01

    The state of the evergreen broadleaved tree species was investigated.The result showed that there are 43 species of evergreen broadleaved species from 32 genera and 22 families in urban gardens and parks of Xuzhou.Their application mainly takes the form of street trees,landscaping trees,basic tree planting,green hedge and land virescence.The present situation of evergreen broadleaved species was analyzed.%对徐州市城区常绿阔叶树种资源现状进行了实地调查。结果表明,在徐州城区园林中应用的能够露地越冬的常绿阔叶树种共计约43种,隶属于22科、32属,应用形式主要有行道树、园景树、基础种植、绿篱、地被。文中还分析了徐州市常绿阔叶树种应用现状。

  17. Studies on Material Cycling in Evergreen Broad-Leaved Forest Ecosystem in Hangzhou:Ⅱ.Dynamics and Decomposition Characteristics of Litter

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    Through the long-term plot study on the litter and its decomposition in the evergreen broad-leaved forest ecosystem in Hangzhou for more than two years,it was resulted that the annual litter production was 5.85 t ha-1,most of which was the fallen leave (79.5 percent) and the withered branches and fruits were far less (7.1 and 13.4 percents respectively).The dynamics of the fallen litter was shown as a curve of two-peak pattern which appeared in April and September each year.The half-life of the litter was 1.59 years.The decay rate of the litter attenuted as an exponential function.The annual amount of the nutrient returned to the ground through the litter was as large as 223.69kg ha-1.The total current amount of the litter on the ground was 7.47t ha-1.The decay rate in the first half of a year was 45.18 percent.This ecosystem remained in the stage of litter increasing with time.

  18. Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

    Science.gov (United States)

    Du, X.; Guo, Q.; Gao, X.; Ma, K.

    2007-01-01

    Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms. We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan, southwestern China. The results showed that: (1) there were marked differences in (mature) seed production between mast (733,700 seeds in 2001) and regular (51,200 and 195,600 seeds in 2002 and 2003, respectively) years for C. fargesii. (2) Most seeds were dispersed in leaf litter, humus and 0-2 cm depth soil in seed bank. (3) Frequency distributions of both DBH and height indicated that C. fargesii had a relatively stable population. (4) Seed rain, seed ground density, seed loss, and leaf fall were highly dynamic and certain quantity of seeds were preserved on the ground for a prolonged time due to predator satiation in both the mast and regular years so that the continuous presence of seed bank and seedling recruitments in situ became possible. Both longer time observations and manipulative experiments should be carried out to better understand the roles of seed dispersal and regeneration process in the ecosystem performance. ?? 2006 Elsevier B.V. All rights reserved.

  19. [Composition and carbon storage of woody debris in moist evergreen broad-leaved forest and its secondary forests in Ailao Mountains of Yunnan Provinve].

    Science.gov (United States)

    Yang, Li-Pan; Liu, Wen-Yao; Yang, Guo-Ping; Ma, Wen-Zhang; Li, Da-Wen

    2007-10-01

    This paper studied the composition and carbon storage of woody debris in the primary moist evergreen broad-leaved forest and its main secondary forests (regenerated Lithocarpus forest, Populus bonatii forest, and Alnus nepalensis forest) in Ailao Moutains of Yunnan Province. The results showed that in the primary forest, the carbon storage of woody debris amounted to 36.56 t x hm(-2). Castanopsis wattii, Lithocarpus xylocarpus and L. chintungensis were the main contributors, and most of them were the logs with larger diameter and at intermediate stage of decay. The unique environment of richer precipitation, higher humidity and lower temperature in the study area, and the decay-resistance of hardwood were favorable to the accumulation of woody debris. The three secondary forests had a carbon storage of 1.2-5.0 t x hm(-2), which decreased in the order of regenerated Lithocaropus forest > P. bonatii forest > A. nepalensis forest, showing a tendency of increasing carbon storage with succession course. PMID:18163291

  20. Nitrogen in soils beneath 18-65 year old stands of subtropical evergreen broad-leaved forests in Laoshan Mountains in Eastern China

    Institute of Scientific and Technical Information of China (English)

    GU Feng; ZHANG Kai; ZHANG Yun-qi; WANG Qin; XU Xiao-niu

    2011-01-01

    Monitoring of soil nitrogen (N) cycling is useful to assess soil quality and to gauge the sustainability of management practices.We studied net N mineralization,nitrification,and soil N availability in the 0-10 cm and 11-30 cm soil horizons in east China during 2006-2007 using an in sito incubation method in four subtropical evergreen broad-leaved forest stands aged 18-,36-,48-,and 65-years.The properties of surface soil and forest floor varied between stand age classes.C:N ratios of surface soil and forest floor decreased,whereas soil total N and total organic C,available P,and soil microbial biomass N increased with stand age.The mineral N pool was small for the young stand and large for the older stands.NO3-N was less than 30% in all stands.Net rates of N mineralization and nitrification were higher in old stands than in younger stands,and higher in the 0-10 cm than in the 11-30 cm horizon.The differences were significant between old and young stands (p <0.031) and between soil horizons (p < 0.005).Relative nitrification was somewhat low in all forest stands and declined with stand age.N transformation seemed to be controlled by soil moisture,soil microbial biomass N,and forest floor C:N ratio.Our results demonstrate that analyses of N cycling can provide insight into the effects of management disturbances on forest ecosystems.

  1. Effect of Slash Burning on Nutrient Removal and Soil Fertility in Chinese Fir and Evergreen Broadleaved Forests of Mid-Subtropical China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A Chinese fir forest (Cunninghamia lanceolata, CF) and an evergreen broadleaved forest (EB) located inFujian Province, southeastern China, were examined following slash burning to compare nutrient capital andtopsoil properties with pre-burn levels. After fire, nutrient (N, P and K) removal from burning residues wasestimated at 302.5 kg ha-1 in the CF and 644.8 kg ha-1 in the EB. Fire reduced the topsoil capitals of totalN and P by about 20% and 10%, respectively, in both forests, while K capital was increased in the topsoils ofboth forests following fire. Total site nutrient loss through surface erosion was 28.4 kg (N) ha-1, 8.4 kg (P)ha-1 and 328.7 kg (K) ha-1 in the CF. In the EB, the losses of total N, P and K were 58.5, 10.5 and 396.3kg ha-1, respectively. Improvement of soil structure and increase in mineralization of nutrients associatedwith increased microbe number and enzyme activities and elevated soil respiration occurred 5 days after fire.However, organic matter and available nutrient contents and most of other soil parameters declined one yearafter fire on the burned CF and EB topsoils. These results suggest that short-term site productivity canbe stimulated immediately, but reduced subsequently by soil and water losses, especially in South China,where high-intensity precipitation, steep slopes and fragile soil can be expected. Therefore, the silviculturalmeasurements should be developed in plantation management.

  2. 亚热带常绿阔叶林和暖温带落叶阔叶林叶片热值比较研究%Comparison of leaf calorific values in subtropical evergreen broad-leaved and warm temperate deciduous broad-leaved forests in China

    Institute of Scientific and Technical Information of China (English)

    田苗; 宋广艳; 赵宁; 何念鹏; 侯继华

    2015-01-01

    Gross calorific value ( GCV) has been introduced to biological research and applied to reflect the capability of plant species to fix solar radiation. Calorific value has also been considered as a coefficient characteristic to evaluate the adaptation strategies of plant species to the external environment. Therefore, understanding the variation in GCV among different ecosystems may provide a basis for assessing energy fixation, transformation, and utilization efficiency. A number of studies have indicated that GCV varies among different geographical locations and ecological categories. Some studies have suggested that the energy contents of alpine plants should be higher than those of tropical plants, and have also shown that energy content differs among different plant life forms, decreasing in the sequence tree >shrub >herb. However, little has been reported on the patterns of GCV in different typical ecosystems ( at the levels of species, life form, and community) across multiple zones. In this study, we compared the leaf calorific values of plant species in two forest ecosystem-subtropical evergreen broad-leaved and warm temperate deciduous broad-leaved forests in China. Field sampling was carried out in early August 2013 at Jiulian Mountain ( Jiangxi Province) and Dongling Mountain ( Beijing Province) , China. Leaf samples of 276 plant species were collected from subtropical evergreen broad-leaved and warm temperate deciduous broad-leaved forests, and the calorific values of these leaves were measured using a PARR 1281 oxygen bomb calorimeter. To explore the variability in GCV, we analyzed the data at the levels of species, life form ( trees, shrubs, and herbs) , and community in the two forest types. Furthermore, trees were subdivided into evergreen and deciduous, and coniferous and broad-leaved. The results showed that the GCV of the subtropical evergreen broad-leaved forest was 17. 83 kJ/g ( n=191) , whereas that of the warm temperate deciduous broad-leaved

  3. Soil animal communities at five succession stages in the litter of the evergreen broad-leaved forest in Tiantong,China

    Institute of Scientific and Technical Information of China (English)

    Yi Lan; You Wenhui; Song Yongchang

    2006-01-01

    Soil animals are abundant in forest litter layer,but little attention has been Paid to the vertical distribution of community structure of soil animals in the layers at different plant community succession stages.The forest litter layer can be divided into fresh litter layer(L),fermentation layer(F)and humus layer(H),which may represent different litter decomposition stages.The aim of the study is to ascertain the vertical distribution features of soil animal communities among the three litter layers and the change in the succession process of the Evergreen Broad-Leaved Forest(EBLF)in Tiantong,Zhejiang Province,China.Soil animal communities in the five plant communities at different succession stages were investigated during the 2003 winter.Soil animals,which were collected by using Tullgren funnels,amounted to a total of 13381 individuals falling into 2 phyla,8 classes and 20 orders.The dominant groups were Acarina and Collembola,accounting for 94.24% of the total individuals,with the number of Acarina individuals 7.66 times than that of Collembola.The common group was Diptera.The results indicated that there was a distinctive vertical distribution of the soil animal communities in the forest litter laver,but it differed from that in soil below the litter layer.In contrast to those in the soil,the soil animals in the litter layer generally tended to increase in both group abundance and density from the top fresh litter layer to the bottom humus layer.Altogether 19 groups and 59.03% of total individuals were found in the bottom layer,while only 8 groups and 5.35% of the total individuals in the top.Moreover,there were some variations in the distribution of the soil animals at different plant succession stages.85.19% of Homoptera and 100% of Symphyla were found in the litter layer at the climax succession stage.while 75.61% of Thysanoptera at the intermediate succession stage.Therefore,these groups might be seen as indicative groups.The total numbers of soil animal

  4. 亚热带阔叶林植物叶片虫食特征研究%Insect herbivory characteristic on leaves of plant species in the evergreen broad-leaved forests

    Institute of Scientific and Technical Information of China (English)

    刘志国; 景军; 李恺; 蔡永立

    2013-01-01

      植物与昆虫是森林生态系统的重要组成成分,两者通过长期的协同进化形成了密切的相互关系,在森林生态系统中发挥着承上启下的作用,连接了初级生产和高级消费,是森林生态系统中重要的动态中心.植物叶片的虫食特征是植物与昆虫相互作用关系的重要表征.选取福建梅花山和浙江天童两地76种常绿阔叶林植物为研究对象,采用野外调查与室内统计分析相结合的方式对植物叶片的虫食率和虫食频度进行了研究,以期了解亚热带常绿阔叶林植物叶片所面临的食叶昆虫取食压力.结果表明:76种植物平均虫食率为7.21%,虫食频度为32.95%.多数植物的叶片虫食率低于10%,叶片虫食频度主要分布在10%~60%之间.乔木种与灌木种、优势植物与伴生植物之间的叶片虫食率和虫食频度均不存在显著差异(P>0.05).超过60%的叶片虫食率和虫食频度发生在展叶期.福建梅花山常绿阔叶林植物的叶片虫食率(P=0.012)和虫食频度(P=0.74)均高于浙江天童.植物幼叶的虫食率随着海拔的升高而下降.以上结果表明,常绿阔叶林植物的叶片虫食强度介于热带雨林(11.1%)和温带森林(7.1%)之间,展叶期是叶片虫食发生的主要阶段,表现出过渡性特征;叶片的虫食在不同生活型和优势程度的植物间存在差异;叶片虫食率随纬度的升高和海拔的上升而降低.%Plants and insect herbivores play a major role in nutrient cycling and energy transfer in forest ecosystem, who formed close relationships through a long term evolution process, and connected with primary production and consumption. For the purpose of determine the patterns of herbivory in subtropical evergreen broad-leaved forest the study investigated herbivory rate and frequency on leaves of 76 evergreen plant species in Mt. Meihuashan, Fujian province and Tiantong National Forest Park, Zhejiang province. In

  5. 云南高黎贡山中山湿性常绿阔叶林的群落特征%Community Characteristics of the Mid-Montane Humid Ever-Green Broad-Leaved Forest in Gaoligong Mountains, Yunnan

    Institute of Scientific and Technical Information of China (English)

    孟广涛; 柴勇; 袁春明; 艾怀森; 李贵祥; 王骞; 李品荣; 蔺汝涛

    2013-01-01

    The dynamic observation of the mid - montane humid evergreen broad-leaved forest and the community characteristics analysis were conducted in a 4 - hm2 permanent plot located in ecological corridor in southern region of Gaoligong Mountains National Nature Reserve during 2009-2010. The results showed that there were 10 546 freestanding individuals with DBH ≥1. 0 cm in the 4 hm plot, belonging to 95 species, 64 genera and 35 families. The species richness was higher and the proportion of rare species was lower in the plot, compared with other plots of the same kind forest. Lauraceae, Theaceae, Araliaceae, Fagaceae, and Symplocaceae were dominant families in the plot and they comprised 44. 21 % of all species and 56. 70% of all individuals. Symplocas ramosissima, Eurya pseudocerasifera , Gordonia longicarpa, Neolitsea lunglingensis, Lithocarpus hancei, and Cyclobalanopsis lamellosa had more importance value in the plot, but no one had obvious advantage, namely the plot did not contain an obviously dominant species. Floristic characteristics of the community indicated that the tropical elements were much more than temperate elements, implying that this area could be an origin of tropics. The minimal area of the community is 1. 32 hm , which could comprise more than 80% of all species. The structure of DBH size class of all species and some dominant species in the plot showed a typical pyramid structure with a wide bottom and a narrow top, implying a good regeneration in the community. The survival curve of most of dominant species tended to be of the Deevey-Ⅲ type, with a high mortality rate at small DHB size class and a low and stable mortality rate at large DBH size class.

  6. Hyperspectral Characteristics of Subtropical Evergreen Broad-Leaved Trees at Different Levels of Simulated Shade%亚热带常绿阔叶树种对模拟遮荫胁迫的高光谱响应

    Institute of Scientific and Technical Information of China (English)

    徐建辉; 江洪

    2014-01-01

    利用 ASD 地物光谱仪,测定不同梯度遮荫胁迫条件下4种亚热带常绿阔叶树种的光谱反射率,应用微分技术处理其反射光谱,并结合 SPAD-502测定的叶绿素相对含量进行分析,研究其在遮荫胁迫情况下的高光谱特征。结果表明:4种树种都具有一定的耐荫性,遮荫处理会影响树种的叶绿素含量,透光率85%的遮荫处理下的叶绿素含量最大;透光率85%的遮荫处理下红边位置发生“红移”现象,但过高的遮荫处理会抑制其生长,出现红边位置“蓝移”现象。不同遮荫梯度下,红边位置对应窄波段范围内的平均一阶微分光谱与叶绿素含量间的相关性较高,R 2大于0.61,相关性显著。本研究通过分析4种亚热带常绿阔叶树种在不同遮荫梯度下的光谱变化特征,以及红边位置对应窄波段范围内平均一阶微分光谱与叶绿素含量的相关性,证明了遮荫影响4种树种的生长,红边位置的一阶微分光谱能有效地监测遮荫对树种的影响,为在大气气溶胶阳伞效应条件下森林植物的生长遥感监测提供了理论依据。%Using the ASD spectrometer to determine the spectral reflectance of four kinds of subtropical evergreen broad-leaved species in different gradient shading stress conditions,the differential technology to process their reflectance spectra,and combining the relative chlorophyll content of SPAD-502 for analysis,this paper studies spectral variation characteristics of four tree species in the shading stress conditions.The results showed that:four kinds of trees have a certain shade tolerance,tree shading will affect chlorophyll content,light transmission rate of 85% shade treatments has maximum chlorophyll content;the red edge position expressed as “red shift”in light transmission rate of 85% shade treatments condition,but excessive shading treatment will inhibit their growth,red edge position expressed as

  7. 帽峰山森林气温与区域气温变化趋势分析%Analysis of Temperature Variation Trends in Maofengshan Mt Subtropical Evergreen Broad-leaves Forest and Guangzhou City

    Institute of Scientific and Technical Information of China (English)

    潘勇军; 王兵; 陈步峰; 史欣; 肖以华

    2011-01-01

    The responses and feedbacks of the forest climate ecosystem into the future global climate change have become very attractive issues. Analysis of historic climate data from 1952 to 2009 of Guangzhou and that from 2004 to 2009 in Maofengshan Mt forest ecosystem by using statistical method and seasonal decomposition additive model confirms that the climate in Guangzhou has recently been warming at a rate of 0.21 °C per decade; The results showed that the temperatures in Guangzhou and Maofengshan Mt were significantly positive correlated, the air temperature change in 2004-2009 had a decreasing trend at a rate of -0.008 ℃ · a-1 and -0.293 ℃ · a -1; The temperature change of Maofengshan Mt subtropical evergreen broad-leaves forest climate ecosystem positively responsed to regional climate change of Guangzhou. Occasionally, its responses appeared negative feedback before the abnormal weather, for example, before the winter-weather disaster in January and February 2008. Climate change is threatening the health of forests around the world. As temperature rises, the negative impacts of climate change are expected to far outweigh any benefits. The advanced fields need to be developed were discussed.%根据广州市1952-2009年和帽峰山2004-2009年气温观测数据,采用统计分析方法和季节分解加法模型,分析了帽峰山森林气温与区域气温变化趋势特征.结果表明:广州市近58年来气温增暖趋势显著,年平均气温的倾向率达0.21℃·a-1;2004-2009年间,广州市和帽峰山气温变化均呈下降趋势,气温倾向率分别为-0.008、-0.293℃·a-1,帽峰山气温下降幅度大于广州市;帽峰山林区气温变化趋势与广州市气温变化趋势基本一致;在区域极端异常天气出现前,森林气温变化趋势出现负反馈.

  8. Ecophysiology of two Sonoran Desert evergreen shrubs during extreme drought

    Science.gov (United States)

    Recent drought across the arid Southwest US may be especially problematic for evergreen desert species that maintain leaves through dry periods. In July, 2002 we compared the ecophysiogical performance of the microphyllous creosotebush (Larrea tridentata) to broadleaved jojoba (Simmondisa chinensis...

  9. Coarse Woody Debris Biomass in a Monsoon Evergreen Broad-leaved Forest in the Dinghushan Nature Reserve, China%鼎湖山粗死木质残体生物量特征

    Institute of Scientific and Technical Information of China (English)

    杨方方; 李跃林

    2011-01-01

    The biomass, types and decay classes of coarse woody debris (CWD) were analyzed in a monsoon evergreen broad-leaved forest (MEBF) in the Dinghushan Nature Reserve, Southeastern China based on long-term data from a I hm2 permanent sample plot. The results showed that: 1) The total CWD biomass was 42.09 t hm2, of which the fallen trees and standing dead trees were 32.81 t hm2 and 9.28 t hm2, respectively. Fallen trees were the main type and accounted for 77.9% of the total CWD biomass, while the percentage of standing dead trees was 22.1%. The average annual increment of CWD was 1.68 thm-2a1-from 1999 to 2010. 2) Castanopsis chinensis was the dominant species of CWD, accounting for 54.0% of the total CWD biomass, and followed by Engelhardtia roxburghiana and Schima superba, with the percentage of 15.1% and 13.9%, respectively. 3) DBH class of the CWD was mainly below 30 cm, though those with DBH more than 30 cm were the main contributor to CWD biomass. 4) The main decay class of CWD was intermediate decay, which accounted for 61.2% of the total CWD biomass. It was also found that the CWD biomass accumulated with time in the forest. Fig 2, Tab 3, Ref 17%对鼎湖山季风常绿阔叶林1 hm2永久性样地内粗死木质残体(Coarse woody debris,简称CWD)的生物量、存在形式及分解状态进行研究.结果表明:1)鼎湖山季风常绿阔叶林CWD的生物量为42.09 t hm-2,其中倒木和枯立木分别为32.81t hm-2、9.28t hm-2,所占比例分别为77.9%、22.1%.1999~2010年间CWD年均输入量为1.68 t hm-2a-1.2)CWD主要优势树种为锥栗(Castanopsis chinensis)、黄杞(Engelhardtia roxbueghiana)和荷木(Schima superba),所占比例分别为54.0%、15.1%和13.9%.3)CWD径级主要分布在30 cm以下,但对CWD生物量贡献最大的径级在30 cm以上.4)CWD 的分解状态主要为中度分解状态,占CWD总生物量的61.2%研究还表明,鼎湖山季风常绿阔叶林的CWD生物量呈逐年增加趋势.图2表3参17

  10. Spatial patterns of dominant species in secondary evergreen broad-leaved forest in central Yunnan, Southwest China.%滇中次生常绿阔叶林优势树种的空间格局

    Institute of Scientific and Technical Information of China (English)

    刘保双; 付登高; 吴晓妮; 王洪娇; 王琪; 段昌群

    2013-01-01

    By using Ripley' s point pattern analysis, the spatial patterns of the dominant species Cyclobalanopsis glaucoides and Keteleeria evelyniana in the secondary evergreen broad-leaved forest in central Yunnan of Southwest China as well as the spatial associations among the individuals of the two species with different DBH classes were analyzed. Overall, the individuals of the two species with different DBH classes were in uniform distribution, indicating that the growth of the two populations was in stable period. The two species and their individuals with different DBH classes had a clumped distribution. With the increase of DBH class, the aggregation degree of C. glaucoides had a decreasing trend, while that of K. evelyniana decreased first, increased then, and decreased at last. A positive or no significant spatial association was observed among the saplings, juvenile trees, and adult trees of the two species. At different spatial scales, the two species of different DBH classes had less association, possibly because of the greater differences in the survival strategies of the two species. It was suggested that in the restoration of the forests in central Yunnan, it would be essential to control the plant population density and attend to the interspecific interaction to build an appropriate structure of the community.%采用Ripley的点格局分析方法对滇中次生常绿阔叶林中优势种滇青冈(Cyclobalanopsis glaucoides)和滇油杉(Keteleeria evelyniana)的分布格局以及不同径级分株之间的相互关系进行了分析.结果表明:(1)总体来看,两个优势物种各径级株数分布较均匀,二者的增长处于稳定期.(2)两个优势物种在总体上及不同径级阶段主要呈聚集分布.随径级的增加,滇青冈种群的聚集程度逐渐降低,而滇油杉种群的聚集程度呈现降低-增加-降低的趋势.两个优势物种的幼树、中树和大树主要呈空间正相关或无空间关联性.(3)两优势种群不同

  11. Ice and Snow Disasters to the Evergreen Broad-leaved Forest in the Jiulianshan Nature Reserve in Jiangxi, China%九连山自然保护区常绿阔叶林冰雪灾害研究

    Institute of Scientific and Technical Information of China (English)

    何俊; 赵秀海; 张春雨; 贾玉; 范娟; 毛双燕; 张自斌; 廖承开

    2011-01-01

    以九连山国家级自然保护区典型常绿阔叶林为对象,研究树木属性、地形因子与冰雪灾害受损程度的关系.结果表明:九连山常绿阔叶林(DBH≥10 cm)以栲属物种占据主要优势.断梢率、腰折率、翻蔸率和平均受损指数(MDI)最高的树种分别为马尾松、米槠、丝栗栲和米槠,最低的树种分别为红楠、丝栗栲、枫香和罗浮柿.断梢率与胸径(DBH)、树高(H)显著正相关(P0.05),坡度30°~ 40°生境中MDI值最高.%The ice and snow damages to the evergreen broad-leaved forest in the Jiulianshan National Nature Reserve in Jiangxi, China were studied, and the correlations between damage degrees with tree characteristics and topographical factors were analyzed.The results showed: The forest was dominated by Castanopsis species (DBH>10 cm), and Pinus massoniana (PM), C.carlesii (CC), C.fargesil (CF), and CC were found highest for top breakage ratio (TOB), trunk breakage ratio (TRB),uprooting ratio (UR) and mean damage index (MDI); while Machilus thunbergii (MT), CF, Liquidambarjormosana (LF),and Diospyros rnorrisiana (DM) were lowest.The TOB had extremely significantly positive correlation with DBH (P<0.01),H (P<0.01), and extremely significantly negative correlation with H/DBH (P<0.01); TRB had extremely significantly negative correlation with DBH (P<0.01); UP had extremely significantly negative correlation with DBH (P<0.01); and MDI was not significantly correlated with DBH, H, and H/DBH (P>0.05).The TOB was the highest under the conditions of DBH≥50 cm, 21≤H<23 m or 20≤H/DBH<40, and the lowest with 10≤DBH<12 cm, 5≤H<7 m or H/DBH≥120; the TRB was the highest under the conditions of 10≤DBH<12 cm, 13≤H<15 m or 100≤H/DBH<110, and the lowest with 42≤DBH<44 cm, 7≤H<9 m or H/DBH ≥120; the UR was the highest under the conditions of 20≤DBH<22 cm, 11≤H<13 m or 90≤H/DBH<100, and the lowest with 36≤DBH<38 cm, DBH≥40

  12. 城乡环境梯度下植物群落的区系成分分析%Floristic Analysis of the Evergreen Broadleaved Forest Community along an Urban-Rural Gradient in Guangzhou

    Institute of Scientific and Technical Information of China (English)

    朱纯; 熊咏梅; 柳泽鑫; 孙东; 苏志尧

    2012-01-01

      分别以白云山、帽峰山、莲塘风水林作为广州市区、城郊和郊区常绿阔叶林群落代表,分析其植物区系组成和多样性特征。结果显示,广州帽峰山常绿阔叶林群落种类最丰富,维管束植物有87科155属212种,优势科为茜草科、大戟科、樟科、禾亚科、芸香科、紫金牛科、壳斗科;白云山维管束植物有72科121属168种,优势科为茜草科、樟科、桑科、禾亚科、大戟科、冬青科;而莲塘风水林森林群落有55科88属102种,优势科为茜草科、樟科、大戟科。从属的地理分布区类型来看,三个群落皆以泛热带分布属的比例最高,其次为旧世界热带分布属和热带亚洲分布属,群落缺乏典型的热带成分,但具有南亚热带植物区系的基本特征。其中白云山的东亚分布类型有3属;帽峰山的东亚分布类型有4属,中国特有分布类型有1属;而莲塘风水林则没有东亚分布和中国特有分布类型。%  Floristic composition of the evergreen broadleaved forest in Maofeng Mountain, Baiyun Mountain, and Liantang, as an urban-to-rural gradient of Guangzhou, was analyzed based on community data. The results indicated that the community in Maofeng Mountain was the richest in species diversity, with 87 families of vascular plants including 155 genera and 212 species, dominant families of the flora were Rubiaceae, Euphorbiaceae, Lauraceae, Agrostidoideae, Rutaceae, Myrsinaceae, and Fagaceae. Vascular plants in Baiyun Mountain plot consisted of 168 species, belonging to 72 families, and 121 genera. Dominant families of the flora were Rubiaceae, Lauraceae, Moraceae, Agrostidoideae, Euphorbiaceae, and Aquifoliaceae. However, Liantang community included only 55 families, 88 genera and 102 species. Dominant families of the flora were Rubiaceae, Lauraceae, and Euphorbiaceae. As for generic distribution, the pantropic areal-type represented the majority of genera

  13. Influence of Different Cutting Intensities on the Structural Stability for Evergreen Broad-leaved Forests in Western Fujian Province%不同采伐强度对闽西常绿阔叶林林分结构稳定性的影响

    Institute of Scientific and Technical Information of China (English)

    罗永福

    2012-01-01

    应用多样性分析方法和改进后的M.Godron稳定性测定方法研究常绿阔叶林5种不同强度采伐(弱度9.8%、中度24.5%、强度46.8%、极强度72.3%和皆伐)作业10 a后林分结构稳定性。结果表明,择伐林地林分处于稳定状态,随着择伐强度的增强,林分的稳定性开始逐渐降低。皆伐林地林分处于不稳定状态。对于常绿阔叶林的科学经营,从稳定性出发,应尽量采取择伐方式,尤其是中低强度的择伐方式。%The structural stability of evergreen broad-leaved forest stand by 5 types of cutting intensity operation(low intensity at 9.8%,middle intensity at 24.5%,high intensity at 46.8%,over-high intensity at 72.3% and clear cutting) after 10 years was studied with methods of diversity analysis and the improved expression of the M.Godron stability measurement.The result showed that the selection cutting was benefit to stability of stand structures,with the enhancement of selection cutting intensity,the stability of the stand began to decrease.Clear cutting woodlands stand was in an unstable state.From the stability of the scientific management of the evergreen broad-leaved forest,selection cutting should be taken,especially the selection cutting at middle-low intensity.

  14. Soil organic matter quantity and quality shape microbial community compositions of subtropical broadleaved forests.

    Science.gov (United States)

    Ding, Junjun; Zhang, Yuguang; Wang, Mengmeng; Sun, Xin; Cong, Jing; Deng, Ye; Lu, Hui; Yuan, Tong; Van Nostrand, Joy D; Li, Diqiang; Zhou, Jizhong; Yang, Yunfeng

    2015-10-01

    As two major forest types in the subtropics, broadleaved evergreen and broadleaved deciduous forests have long interested ecologists. However, little is known about their belowground ecosystems despite their ecological importance in driving biogeochemical cycling. Here, we used Illumina MiSeq sequencing targeting 16S rRNA gene and a microarray named GeoChip targeting functional genes to analyse microbial communities in broadleaved evergreen and deciduous forest soils of Shennongjia Mountain of Central China, a region known as 'The Oriental Botanic Garden' for its extraordinarily rich biodiversity. We observed higher plant diversity and relatively richer nutrients in the broadleaved evergreen forest than the deciduous forest. In odds to our expectation that plant communities shaped soil microbial communities, we found that soil organic matter quantity and quality, but not plant community parameters, were the best predictors of microbial communities. Actinobacteria, a copiotrophic phylum, was more abundant in the broadleaved evergreen forest, while Verrucomicrobia, an oligotrophic phylum, was more abundant in the broadleaved deciduous forest. The density of the correlation network of microbial OTUs was higher in the broadleaved deciduous forest but its modularity was smaller, reflecting lower resistance to environment changes. In addition, keystone OTUs of the broadleaved deciduous forest were mainly oligotrophic. Microbial functional genes associated with recalcitrant carbon degradation were also more abundant in the broadleaved deciduous forests, resulting in low accumulation of organic matters. Collectively, these findings revealed the important role of soil organic matter in shaping microbial taxonomic and functional traits.

  15. 雪灾后粤北山地常绿阔叶林优势树种幼苗更新动态%Dynamics ofdominant tree seedlings in montane evergreen broadleaved forest following a snow disaster in North Guangdong

    Institute of Scientific and Technical Information of China (English)

    区余端; 苏志尧; 解丹丹; 柯娴氡; 李镇魁

    2011-01-01

    Effects of a snowstorm on forest disturbance and the canopy changes caused by forest rehabilitation resulted in changes in tree seedling composition. The species and number of tree seedlings vary with the canopy-density dynamics and are embodied in the future species composition and structure of tree layer. With the aim of revealing the seedling regeneration pattern and its response to canopy changes (as indicated by changes in leaf area index [LAI] ) , a 3-year investigation from 2008 to 2010 was undertaken in Chebaling montane evergreen broadleaved forest. The dominant tree seedling dynamics under the recovering canopy was studied by establishing a 2 hm2 sampling area (comprised of fifty 20 m×20 m plots) following the snow storm in 2008. Data from sampling in 2008 identified the top 12 species ranked by their importance as the dominant tree seedling as follows : Castanopsis carlesii, Schima superba, Castanopsis fargesii, Neolitsea chuii, Styrax suberifolia, Alniphyllum fortunei, Cinnamomum porrectum, Randia canthioides, Machilus chinensis,Rhododendron moulmainense , Cinnamomum austrosinensis and Lithocarpus glaber. Dynamic analysis of these 12 species over the 3 years showed that fluctuation was detected in the ranking of the species' importance values, among which 2009 and 2010 shared similar trends while 2008 showed a different trend. Castanopsis carlesii, Schima superba, Randia canthioides and Rhododendron moulmainense showed an increase in their ranking by importance value, whereas Neolitsea chuii,Lithocarpus glaber , Cinnamomum porrectum and Alniphyllum fortunei showed a decrease in their ranking. Styrax suberifolia ,Cinnamomum austrosinensis and M. chinensis showed a decreased and then increased ranking while Castanopsis fargesii showed the opposite trend. The 12 dominant tree seedling species showed notable responses to canopy recovery.Permutation-based MANOVA (PerMANOVA) indicated that a highly significant difference was found in composition and

  16. 特大冰冻干扰对大明山常绿阔叶林树冠及林冠层状况的影响%Effects of a Severe Ice Storm Disturbance on Crown and Canopy Condition of an Evergreen Broad-leaved Forest in Damingshan National Nature Reserve of Guangxi Province

    Institute of Scientific and Technical Information of China (English)

    温远光; 李婉舒; 朱宏光; 周晓果; 叶铎; 王磊

    2014-01-01

    【目的】通过对大明山南亚热带山地常绿阔叶林72个400m2样地的调查,了解特大冰冻干扰对南亚热带山地常绿阔叶林树冠和林冠状况的影响。【方法】2009年,在大明山海拔934~1223m 的范围内,按上、中、下坡设立3组调查样地,每一组样地包括24个20m×20m样方,对胸径≥5cm的林木进行调查,记录种名、胸径、树高、冠长、冠幅、座标及受损类型等。【结果】经统计,在调查的胸径≥5cm 的2538株林木中,有1714株受到不同程度损伤,占总数的67.53%,其中轻度损伤占47.75%、重度损伤占19.78%。总体上,不同坡位的冠损状况相似,均以轻度损伤为主,但表现有所不同,上坡轻度损伤比例最小(40.94%),严重损伤的比例最高(26.49%);中坡与之相反,轻度损伤比例最大(52.38%),严重损伤比例最小(16.52%);下坡损伤比例最低。胸径影响树木的受损类型和程度,呈现出随着胸径的增加,树冠受损的比例逐渐增大,并在30~40cm 径级(上坡)和40~81cm 径级(中坡和下坡)达到最大值。断枝比例(包括断枝少和断枝多)随胸径增大而增大,而断梢和失冠则随胸径增大而减小。落叶树种比常绿树种受损更重。冰冻灾害后,林冠叶面积指数显著下降,散射透光系数和直射透光系数显著增加。【结论】特大冰冻干扰对大明山常绿阔叶林已造成严重影响,受冰冻灾害的长期影响,大明山常绿阔叶林的树冠和林冠状况发生了显著的变化,由半圆球形树冠演变为狭窄的圆柱形树冠,以适应冰冻干扰和气候变化的影响。%[Objective]Through field investigation of 72 permanent plots (each 400m2 )of the south subtropical montane evergreen broad-leaved forest in Damingshan Nature Reserve of Guangxi province,this paper deals with the effects of a severe ice storm disturbance on the crown and canopy condition of south subtropical

  17. 闽西北地区不同林龄常绿阔叶混交林物种多样性比较%Species diversity of ever-green broad-leaved mixed forest with different forest age in the north-west of Fujian province

    Institute of Scientific and Technical Information of China (English)

    常云妮; 钟全林; 程栋梁; 徐朝斌; 胡波; 张治

    2013-01-01

      基于野外样方数据,按照林龄与垂直分布层次,分别采用Margalef丰富度指数(Dm)、Pielou均匀度指数(J)与生态优势度指数(C)计算式,对闽西北地区主要优势种为米槠(Castanopsis carlesii)、栲树(Castanopsis fargesii)、甜槠(Cadtanopsis eyrei)、青冈(Quercus glauca)等壳斗科植物为主的天然常绿阔叶混交林群落的物种多样性进行了调查与对比分析。结果表明:(1)不同龄组常绿阔叶混交林乔木层的物种多样性存在显著差异(P草本层>灌木层,J值为草本层>乔木层>灌木层。中龄林、近熟林、成熟林的Dm值大小顺序均为:乔木层>灌木层>草本层,J值为灌木层>乔木层>草本层。研究结果可为了解闽西北地区不同龄组常绿阔叶混交林群落结构的物种组成与动态变化特征,探讨常绿阔叶混交林近自然经营及其残次林改造技术,制定其生物多样性的生态保护决策等提供理论依据。%Based on forest age and vertical distribution levels by using typical quadrat sampling method, the species richness index (Dm),evenness (J) and ecological dominance (C) of ten nature ever-green broad-leaved mixed forest communities in the north-west of Fujian province were calculated and analyzed. The dominant species were Castanopsis carlesii、Castanopsis fargesii、Cadtanopsis eyrei、Quercus glauca. The comparative study showed that, (1) The species diversity in different age groups of evergreen broad-leaved mixed forests were significantly different between tree layers (Pherb layer>shrub layer, the J value were herb layer>tree layer>shrub layer;In the half-mature forest, near mature forest and mature forest, the order of the species richness index were tree layer> shrub layer>herb layer, the J value were shrub layer>tree layer>herb layer. The results help to understand species composition and dynamic characteristics of ten nature ever-green broad-leaved mixed

  18. A study on reserves and water holding function of litter in four types of evergreen broadleaved forest in subtropical zone of China%亚热带4种常绿阔叶林林分枯落物储量及持水功能研究

    Institute of Scientific and Technical Information of China (English)

    赵雨虹; 范少辉; 夏晨

    2015-01-01

    In order to explore the litter hydrological functions in four types of forest stands in the process of Phyllostachys edulis expansion to evergreen broadleaved forest in subtropical zone of China, this paper studied the reserves and hydro⁃logical parameters of litter in semi⁃decomposed layer and undecomposed layer such as the maximum water holding capac⁃ity and rate, the water absorption rate and the effective interception amount under four kinds of forest stand: evergreen broad⁃leaved forest, bamboo( 20%)-broadleaf( 80%) mixed forest, bamboo( 80%)-broadleaf( 20%) mixed forest and Mao bamboo pure forest in Dagangshan mountain forest ecological station, Jiangxi Province. The results were shown as follows:① the total litter reserves in four kinds of forest stand could be arranged from high to low as:Mao bamboo pure forest > bamboo(80%)-broadleaf(20%) mixed forest > bamboo(20%)- broadleaf(80%) mixed forest > evergreen broadleaved forest. And litter reserves of semi⁃decomposed layer was higher than that of undecomposed layer. Effective interception rate of bamboo(20%)-broadleaf(80%) mixed forest was the highest, which was 0.78, slightly higher than that of the Mao bamboo forest (0.77). The lowest interception rate was found in broad⁃leaved forest (0.42). ②The wa⁃terholding capacity of litter in different stands with various decomposition rate was consistent. Due to limited reserves, the waterholding quantities in broad⁃leaved forest were the smallest in both undecomposed and semi⁃decomposed layers, which were respectively 0.33 mm and 0.44 mm. ③ The relationship between water holding capacity and immersion time in litter of four forest stands could be shown in the equation:S=aln( t)+b, water holding capacity of litter increased rap⁃idly within the first four hours, then rose slowly. While, the equation of the relationship between water absorption rate and immersion time was:V=atn , and the litter water absorption rate decreased rapidly within

  19. Effects of habitat heterogeneity on community functional diversity of Dinghu Mountain evergreen broad-leaved forest%生境异质性对鼎湖山常绿阔叶林群落功能多样性的影响

    Institute of Scientific and Technical Information of China (English)

    周光霞; 黄立新; 臧晓蔚; 韦霄; 叶万辉; 沈浩

    2016-01-01

    (20 m×20 m) were selected according to the changes of relative elevation and topograph. These 27 subplots can stand for the heterogeneous habitats in Dinghushan ever-green broad-leaved forest. Leaf functional traits of all the trees with DBH (diameter at breast height)≥1 cm in the 27 sub-plots were measured to calculate the functional diversity ( functional dispersion and community weighted mean are caculated as the functional diversity in this paper) during the summer of 2013. The measured traits included morphological traits (spe-cific leaf area, leaf dry matter content, leaf area and leaf lenth to leaf width ratio) and stoichiometric traits (leaf carbon, nitrogen, phosphorus content). Combining with the topographic and soil information, we analysed the main environmental factors that influence the variation of functional diversity. To elucidate the relative importance of environmental filtering and competitive interactions for species co-existence of Dinghushan evergreen broad-leaved forest, we inferred the shifts in func-tional diversity patterns across environmental gradients. The results indicated that functional divergence and community-weighted mean were in close relation with environmental factors, especially elevation, convexity and soil fertility. In the op-timal environmental conditions (high relative elevation, high convexity and higher soil nutrient content), plants adopt the similar (functional divergence decreased) adaptive strategy of efficient conservation of nutrient (low SLA, high LDMC), which suggested that environmental filtering played a stronger role;while in the adverse environmental conditions ( low rela-tive elevation, low convexity and lower soil nutrient content), the traits were various (functional divergence increased) and use fast growing strategy (high SLA, low LDMC), since competitive interactions might play a key role. The functional di-vergence of leaf area and leaf nitrogen contents increased in better environmental conditions

  20. 普洱季风常绿阔叶林次生演替中木本植物幼苗更新特征%Woody seedling regeneration in secondary succession of monsoon broad-leaved evergreen forest in Puer, Yunnan, Southwest China

    Institute of Scientific and Technical Information of China (English)

    李帅锋; 刘万德; 苏建荣; 张志钧; 刘庆云

    2012-01-01

    以时空替代的方法,将针阔混交林、季风常绿阔叶林的次生林与成熟林等3个处于同一空间下的群落作为次生演替进程中的3个阶段,研究云南普洱地区次生演替过程中的木本植物幼苗更新特征,分析了次生演替过程中木本植物幼苗的物种组成、密度、高度级及与环境因子的相关性.结果表明:在8个共144 m2的幼苗样地中调查木本植物幼苗101种2014株,其中乔木幼苗是主要组成.随着次生演替的进行,木本植物幼苗、乔木与藤本幼苗密度逐渐增加,灌木幼苗密度无显著变化;藤本植物幼苗的物种丰富度随着次生演替进行而增加,乔木与灌木幼苗则无显著变化,成熟季风常绿阔叶林中木本植物幼苗ShannonWiener指数要显著小于针阔混交林与次生季风常绿阔叶林.次生与成熟季风常绿阔叶林木本植物幼苗多度随高度级增加而减少,针阔混交林则呈现偏峰曲线,幼苗密度均集中分布在高度20 cm以内,3个群落演替阶段木本植物幼苗物种丰富度随高度级增加呈现偏锋曲线.相似性系数反映出乔木和藤本幼苗的更新来源与群落的物种组成存在着紧密的联系.乔木幼苗密度分布与样地坡度之间存在着显著的负相关,灌木幼苗密度与土壤pH值之间存在着显著正相关.%Seedling, made up of small individuals of woody plant species in the understorey, is an important component of many forests and considered as an important source for natural restoration in forest ecosystems. Simultaneously seedling plays an important role in the regeneration of numerous tree species. Based on space-for-time substitution method, we treated coniferous and broad-leaved mixed forest, secondary monsoon evergreen broad-leaved forest ( MEBF) , primary MEBF in the same area as three different stages of secondary succession of MEBF. Eight sampling plots representing the three different stages distribute in Caiyanghe nature

  1. Effects of Freezing Rain and Snow Disaster on the Plant Diversity in the Subtropical Evergreen Broad-leaved Forest%雨雪冰冻灾害干扰对亚热带常绿阔叶林植物多样性的影响

    Institute of Scientific and Technical Information of China (English)

    刘足根; 袁小兰; 钟梁; 李铭书

    2014-01-01

    2008年雨雪冰冻灾害后,在崇义县选取了4块亚热带常绿阔叶林作为固定样地,分别记为P1,P2,P3和P4,连续5年监测了雨雪冰冻灾害对其植物多样性的影响。结果表明:雨雪冰冻灾害后的5年内,样地内的马尾松、拟赤杨和桤木消失了,增加了杜英;每块样地重要值排第一的树种在雨雪冰冻灾害后,其重要值都减小了,这些树种主要有槠树、栲树和木荷。雨雪冰冻灾害后,乔木层植物丰富度指数P 1和P3样地增大, P4样地减小, P2样地变化较小;植物多样性指数P1样地增大,P2和P3样地变化较小,P4样地减小;植物均匀度指数P1样地增大,P2和P3样地基本未变,P4样地变化较小。林下植物种类数增加了黄瑞木、猕猴桃、白背叶等植物,而黄杨、野甘菊、苦竹等植物消失了,铁芒萁和茅草数量增加较多。从2011年开始,林内郁闭度恢复到了灾害前水平。%After freezing rain and snow disaster in 2008,four fixed sample plots (P1、P2、P3 and P4) were selected to measure the effects on the plant diversity of the subtropical evergreen broad-leaved for-est in Chongyi County from 2008 to 2012.The result showed that Pinus massoniana,Alniphyllum fortunei and Alnus cremastogyne disappeared,and Elaeocarpus decipiens appeared.The important value of tree species which ranked the first before freezing rain and snow disaster was reduced.These tree species in-cluded Oachestnut,castanopsis fargesii,and Schima superba.The important value of Choerospondias axil-laris increased within five years after the freezing rain and snow disaster.P1 and P2 increased,P4 re-duced,P3 changed little for the Margalef index of the arbor layer.P1 increased,P2 and P3 changed lit-tle,P4 reduced for the Shannon-wiener index of the arbor layer.P1 increased,P2 and P3 basically un-changed,P4 reduced for the Pielou index of the arbor layer.The species kinds and the species number increased

  2. 浙江天童常绿阔叶林藤本植物的适应生态学 Ⅰ. 叶片解剖特征的比较%ADAPTIVE ECOLOGY OF LIANAS IN TIANTONG EVERGREEN BROAD-LEAVED FOREST, ZHEJIANG, CHINA I. LEAF ANATOMICAL CHARACTERS

    Institute of Scientific and Technical Information of China (English)

    蔡永立; 宋永昌

    2001-01-01

    The ecological adaptations and leaf characters of ten genera (including eleven species of liana) were studied in evergreen broad-leaved forest of Tiantong Forest Park, Zhejiang province, China. The results are as follows: 1) Despite the mesophyte leaf form of the eleven liana species there were significant differences in leaf anatomical characters among them and some differences among different plants of an individual. These differences are mainly controlled by genetic factors, but environmental factors (mainly light and water or humidity) also had an important influence on them and these may oppose forms required in climbing methods; 2) Based on leaf adaptive characters the 11 species may be divided into three adaptive kinds: sun-adapted taxa or xerophytes (Broussonetia kaempferi, Ficus pumila and F. sarmentosa var. henryi), shade-adapted taxa (Morinda umbellata, Millettia reticulata) and mesophytes (Ampelopsis cantoniensis, Hedera nepalensis var. sinensis, Smilax lanceiofolia var. opaca, Celastrus rosthonianus, Dioscorea cirrhosa, Dalbergia millettii); 3) Rates of variation of different anatomical characters adapting to light or humidity differed among species. The ability to vary these characters, which may be influenced by changing environmental factors during the growth of liana, may be important for liana to adapt to the different environmental conditions it experiences through its life.%利用解剖学方法对浙江天童森林公园常绿阔叶林的10属11种木质藤本叶片的解剖特征进行了比较和因子分析,结果表明:藤本植物叶片结构在不同种类之间具有明显的差异,同种藤本的不同植物体的叶片也存在一定的差异; 这些差异除受遗传因子控制外,环境因子(主要为光照和水分)也有重要作用; 攀援方式对藤本叶片特征有一定影响,但未表现出规律性。尽管叶片的基本结构仍属中生类型,但也表现出一定的趋异适应,根

  3. Adaptive characteristics and behavior of Dalbergia millettii liana in subtropical evergreen broad-leaved forest of eastern China%浙江天童常绿阔叶林香港黄檀的生态适应特征和行为

    Institute of Scientific and Technical Information of China (English)

    蔡永立; 宋永昌

    2001-01-01

    通过对芽的类型和活动、攀援茎的形态、径级分布和格局、攀援能力和立体结构及其与支持木关系的测定分析,探讨了香港黄檀的生态适应特征和行为。结果如下:①芽按活动时间分为春芽和夏芽;两类芽均可形成长枝(攀援枝)或短枝,但在活动持续时间和抽生攀援的长度方面存在明显差异;林内不定芽(主要为春芽)的活动和适应生长是老藤更新的重要途径。②攀援枝的节数和节间长度分别为短枝的7倍和6.5倍,而且易受光照等条件的影响;林缘攀援枝的分枝率是林内的5倍。③径级分布反映出种群随群落演替而老化,香港黄檀属群落早期藤本。④对支持木种类表现出一定的选择性,马尾松是其中被攀援最多的支持木,这主要与香港黄檀的生理、生长要求和马尾松枝型特点等有较大的关系。⑤具有较强的攀援能力,单株在群落中平均可攀援乔木层大树5株,最多可达15株,水平扩展面积平均为54m2,最大可达260m2;藤本通过攀援与支持木形成的空间结构,构成群落的特殊层片,其群落学意义值得进一步研究。%Based on analysis of types and dynamics of buds,morphology and space structure of branches,the ecological adaptation and behavior of Dalbergia millettii liana in the subtropical evergreen broad-leaved forest of eastern China were studied.The results are as follows:(1)Both spring bud and summer bud may form the climbing or short branch,but there are great differences in the activity duration of bud and the branch length formed.Regeneration of old liana trunk will be mainly completed by adaptive growth of adventitious buds on it.(2)Node number and internode leggth of climbing branch are 7 and 6.5 times more than those of short branch,respectively.And they are easily influenced by light.Branching ratio of climbing brance at the edge of forest is 5 times greater than that in the inner

  4. The Composition and Structure of Coarse Woody Debris in the Evergreen Broadleaved Forest After Ice Storm in Northern Guangdong Province%冰灾后粤北常绿阔叶林粗死木质残体的组成与结构

    Institute of Scientific and Technical Information of China (English)

    柳泽鑫; 张璐; 区余端; 孙东; 苏志尧

    2011-01-01

    应用样方调查法,研究冰灾后粤北常绿阔叶林粗死木质残体(coarse woody debris,CWD)的组成和结构特征,比较不同坡向林分的CWD存在形式、种类组成、径级结构、样方分布以及腐烂等级状态.结果表明:冰灾后迎风坡林分的CWD贮量为14.81t/hm2,明显高于背风坡林分5.66t/hm2的CWD贮量;且不同坡向林分的CWD存在形式有较大的差异,迎风坡林分中CWD存在形式以倒木为主,而背风坡林分则以枯立木为主;倒木的分解速度较快,主要处于中度分解状态,而大多数枯立木则处于轻度分解状态;迎风坡林分大径级树种由于积雪作用,形成大量倒木;而背风坡林分小径级树种受低温冻害的影响,大量枯萎死亡.冰灾引起的CWD剧增会严重影响森林演替的进程,其中倒木对森林生态系统结构和功能短期的调节作用比较明显,而枯立木对森林生态系统的影响是一个长期的过程,有必要对其进行长期量化研究.%The composition and structure of the coarse woody debris (CWD) in the evergreen broadleaved forest after ice storm in northern Guangdong Province were studied by means of plot survey to compare the CWD existence form, species composition, DBH structure, and the CWD decay status of the forest stands at different aspects of the hills. The results showed that the CWD storage in the windward stand was 14. 81 t/hm2, which was significantly higher than that of in the leeward stand (5.66 t/hm2) after the ice storm. There was great difference in the CWD existence form in stands at the different aspects. The CWD in the windward stands was mainly in the form of fallen logs, whereas the CWD in the leeward stands was mainly in the form of snags. The decay rate of fallen logs was much faster than that of the snags, so the former was principally in the moderately decomposed state, while the latter was mainly in the slightly decomposed state. The trees in large DBH classes in the windward

  5. Effects of Soil Biological Characteristics on Physiochemical Properties in Evergreen Broad-leaved Forest in Middle Yunnan Plateau, China%滇中高原常绿阔叶林土壤生物学特性对土壤理化性质的影响

    Institute of Scientific and Technical Information of China (English)

    杨媛媛; 黎建强; 陈奇伯; 赵维娜; 刘佩琪; 丁延龙

    2016-01-01

    Soil enzymes activities and soil microbes are the important components of soil ecosystem, particular for forest soil, and also the key factor to determine the soil function. Predicting impacts of soil biological characteristics on physiochemical properties requires a clear understanding of relationship between physicochemical properties and both enzymes activities and soil microbes. In this study, the indices of physicochemical properties, enzymes activities and soil microbes were measured in evergreen broad-leaved forest located in Middle Yunnan Plateau, and the relationship between physicochemical properties and both enzymes activities and soil microbes were analyzed using path analysis. The results showed that: (1) The soil moisture content, field capacity, organic matter, total nitrogen, alkali-hydro nitrogen, total phosphorus, available potassium content were decreased with the increasing of soil depth, and the soil bulk density, pH, total potassium content were increases with increasing of soil depth; (2) Soil urease, catalase, invertase activity and bacteria, actinomyces, fungi is gradually reduce with the increasing of soil depth; (3) Correlation analysis indicated that the physiochemical properties was significantly correlated with both enzymes activities and soil microbes; And (4) the path analyses suggested that soil urease and catalase are the main contributing factors to soil physical properties, and the urease, catalase, invertase and bacteria fungus had significant effects on chemical properties.%土壤酶活性和微生物是构成土壤生态系统的重要组分,也是决定土壤功能的关键因子,研究土壤生物学特性对理化性质的影响可以阐明影响土壤理化性质的因子,从而为林地土壤质量的恢复与保育提供科学依据。文章通过野外调查与室内实验相结合的方法进行样品采集与处理,结合相关分析与通径分析的数据分析方法对云南省玉溪市磨盘山常绿阔

  6. Leaf morphological and anatomical characteristics of epiphytes and their host tress in lower subtropical evergreen broad-leaved forest%南亚热带常绿阔叶林林冠层附生植物及其宿主叶片的形态解剖特征

    Institute of Scientific and Technical Information of China (English)

    江浩; 黄钰辉; 周国逸; 胡晓颖; 刘世忠; 唐旭利

    2011-01-01

    Canopy-dwelling epiphytic plants have been well characterized in terms of the physiological and morphological traits permitting them to thrive in the absence of access to the soil. The ultimate purpose of this paper is to characterize the morphological and anatomical characteristics of major canopy-dwelling epiphytic plants and their host trees in the lower subtropical evergreen broad-leaved forest in the Southern China. Results showed epiphytic plants differed from host trees on leaf morphology and anatomy. Compared with host trees, epiphytic plants have smaller leaf area, larger specific leaf area (SLA), higher leaf water content, higher leaf thickness, higher leaf abaxial and adaxial epidermis thickness, lower stomatal density and stomata size for the uptake and restore of water and nutrients. Difference of leaf morphological and anatomical characters between epiphytes can be largely explained by changes of environmental factors such as photosynthetically active radiation (PAR), temperature and humidity within forest canopy. D. Chinensis and P. Serpens showed special characteristics with high leaf water contents, low stomatal density, thick spongy tissues and thin palisade tissues to adapt to their upper dwelling environment (high temperature, low air humidity and high PAR). F. Glaucescens and P. Hancei have large leaf area, thin leaf, and high stomata size in acclimatizing to the low temperature, high air humidity and low PAR.%选择南亚热带常绿阔叶林中具有代表性的4种林冠层附生植物:白背瓜馥木(Fissistigma glaucescens)、瓜子金(Dischidia chinensis)、蔓九节(Psychotria serpens)、山蒌(Piper hancei)及其主要宿主植物:厚壳桂(Cryptocarya chinensis)、荷木(Schimasuperba)、华润楠(Machilus chinensis)、锥栗(Castanopsis chinensis)为研究对象,对其叶片形态结构和解剖结构特征进行比较.研究结果表明:宿主植物与附生植物的叶片形态结构差异显著.相对于4种宿主植物,4种附生

  7. Ecological Distribution of Collembola in the Litter under Different Ground Cover Treatment of Evergreen Broad-leaved Forest%天童常绿阔叶林砍伐后凋落物层跳虫群落生态学研究

    Institute of Scientific and Technical Information of China (English)

    靳亚丽; 蒋跃

    2016-01-01

    Objective] To understand the effects of ground cover removal on collembola communities in the litter and the community restoration situations. [Method] The collembola community investigation of 4 seasons in an evergreen broad-leaved forest after 7 years since the ground cover removal in Tiantong Region, Zhejiang Province was carried out during Dec. 2019-Sep. 2010. The five treatments in five sites were as follows:(Ⅰ) big trees were removed but sprouts retained;(Ⅱ) ground surface vegetation was removed but litter retained;(Ⅲ) all vegetation and 0–10 cm topsoil were removed;(Ⅳ) undergrowth was removed but big trees retained; and (Ⅴ) a control plot without any disturbance. [Result] The number of collembolan groups did not vary widely. The number of collembola community was as follows:Ⅱ(28. 79%) > Ⅳ(21. 03%) >Ⅰ(20. 75%) > Ⅴ(17. 09%) >Ⅲ(12. 33%) . The community composition vary in different seasons. The number of collembola community was as follows:autumn > summer > spring > winter. The organic carbon, total nitrogen and total phosphorus had obvious differences among the plots. Even after 7 years of restoration, the collembola community traits were obviously different among the treatments. [ Conclusion] Collembola community was very sensitive to the environmental disturbing, which can be used as the indicator species to evaluate the soil environmental dis-turbance.%[目的]了解不同砍伐处理对常绿阔叶林凋落物层跳虫群落结构的影响以及各处理样地跳虫群落恢复状况。[方法]于2009年12月至2010年9月在浙江天童地区常绿阔叶林5个砍伐7年后的恢复样地进行四季采样,对浙江森林公园不同砍伐处理下常绿阔叶林土壤动物优势类群跳虫群落进行调查。样地处理分别为:(Ⅰ)去除大树保留萌枝、(Ⅱ)去除地表植物保留枯枝落叶层、(Ⅲ)去除地表植物和10 cm表土、(Ⅳ)清除下木层保留大树、(Ⅴ)对照。[结果]各处理样地各科

  8. Responses of soil water content to change in plant functional traits in evergreen broadleaved forests in eastern Zhejiang Province%浙东常绿阔叶林植物功能性状对土壤含水量变化的响应

    Institute of Scientific and Technical Information of China (English)

    许洺山; 黄海侠; 史青茹; 杨晓东; 周刘丽; 赵延涛; 张晴晴; 阎恩荣

    2015-01-01

    研究群落演替过程中植物功能性状与土壤含水量的关系,揭示植物对水分供给变化的响应策略,具有重要的生态学意义。该研究以浙江东部天童山、南山和双峰山的3个常绿阔叶林演替系列为对象,旨在探索不同演替阶段常见植物的功能性状与森林群落土壤含水量的相互关系。研究结果显示:森林演替中后期的树木高度、树冠面积、叶片干物质含量显著大于演替前期植物;相反,叶片净光合速率和蒸腾速率随演替进程而降低。随森林演替,表层土壤(0–20 cm)的含水量显著增加,深层土壤(20–40 cm)含水量随演替进程增加但不显著。表层土壤含水量与树木高度、树冠面积和叶片干物质含量显著正相关,与叶片净光合速率和蒸腾速率显著负相关;深层土壤含水量与树冠面积显著正相关,与叶片净光合速率、气孔导度和蒸腾速率显著负相关。树木高度、树冠面积、叶片干物质含量、叶片净光合速率、气孔导度和蒸腾速率均可解释土壤含水量随演替进程的变化趋势,而冠长比对土壤水分变化的响应最为敏感。%Aims Study on the relationships between plant functional traits and soil water content is important for revealing potential impact of vegetation dynamics on soil water dynamics. The objective of this study was to understand the change of soil water content (Ws) through forest succession. MethodsThe study sites are located in Tiantong, Nanshan and Shuangfeng Mountains in eastern Zhejiang Province. We measured 10 functional traits for common plant species andWsin forest plotsrepresentative of three successional stages of evergreen broadleaved forests. The Pearson correlation and the stepwise regression were conducted to determine the quantitative relationships between plant functional traits andWs. Important findings Tree height (H), crown area (CA) and leaf dry matter content (LDMC) were

  9. Niches and interspecific associations of dominant tree populations at different restoration stages of monsoonal broad-leaved evergreen forest%季风常绿阔叶林不同恢复阶段乔木优势种群生态位和种间联结

    Institute of Scientific and Technical Information of China (English)

    李帅锋; 刘万德; 苏建荣; 张志钧

    2011-01-01

    Niche and interspecific association are one of the important contents in community dynamics research. Interspecific interaction affects the restoration and succession of community. In this paper, field investigation was made on the community structure of monsoonal broad-leaved evergreen forest at its different restoration stages ( primary forest, PF; 15 years restoration, 15R; and 30 years restoration, 30R) in Pu ’ er City of Yunnan Province, and the niche breadth, niche overlap, and variance ratio ( VR) as well as the chi-square test and association coefficient (AC) based on 2×2 contingency table were used to analyze the change trend of the dominant tree populations at different restoration stages. In the three communities at different restoration stages, there was a significant positive correlation (P<0. 001 ) between the importance value and corresponding niche breadth. 78. 22% of species pairs at 15R had a niche overlap 0. 4-0. 8, suggesting a strong resource utilization competition in dominant species; while the community structure at PF and 30R was rather stable , and the species with higher niche breadth had a higher niche overlap than those with lower niche breadth , reflecting that the dominant species had stronger competitiveness. At 15R and 30R. there was a positive interspecific association; while at PF, there was a negative association. In the three communities, most species pairs had no significant association, showed stronger independency, and the proportions of positive and negative associations decreased with the process of restoration. There was a significant positive correlation between the association coefficient and niches overlap at different restoration stages, i. e. , the high the niche overlap, the greater the association coefficient.%生态位和种间联结是群落动态研究的重要内容之一,物种间相互作用影响着群落的恢复和演替.本文在对云南普洱地区不同恢复阶段(恢复15年、恢复30年和

  10. 车八岭山地常绿阔叶林冰灾后土壤节肢动物群落的多样性%Soil arthropod diversity following an ice storm in a montane evergreen broadleaved forest in Chebaling National Nature Reserve, China

    Institute of Scientific and Technical Information of China (English)

    区余端; 苏志尧; 李镇魁; 佟富春; 柳泽鑫

    2009-01-01

    2008年初车八岭山地常绿阔叶林受到中国南方80年一遇的冰灾的重创.为了揭示灾后林冠开度的梯度对土壤节肢动物多样性与分布的影响,在受冰灾影响的车八岭山地常绿阔叶林没置2 ha固定样地,按照冠层受损程度选取17个20 m×20 m的样方,用半球面影像技术获取林冠开度,并分凋落物层、0-10 cm和10-20 cm的矿质上层采集凋落物及上壤样品,分析土壤节肢动物多样性.利用双向聚类分析(two-way cluster analysis)对凋落物层的土壤节肢动物和样地进行聚类,以典范对应分析(canonical correspondence analysis)研究冠层开度、土壤有机质、电导率以及自然含水量与0-10 cm表土层土壤节肢动物的关系.结果表明土壤节肢动物的多度、丰富度和多样性随土壤层的加深而下降,具有明显的表聚性;林冠开度与凋落物层的土壤节肢动物类群数量呈负相关;甲螨亚目、中气门亚目和前气门亚目动物对光照的适应范围广;膜翅目、鞘翅目幼虫、综合纲和伪蝎目动物具有明显的避光性;土壤节肢动物类群的分布与林冠开度、土壤自然含水量、电导率和有机质关系密切.因此可以推论,冰灾对车八岭山地常绿阔叶林冠层的破坏及土壤因子的变化会进一步影响土壤节肢动物群落的组成和分布.本项研究还表明,土壤节肢动物群落能有效地表征它们所栖息的生态系统的特点,可用于监测冰灾后森林恢复和演替动态.而双向聚类分析和典范对应分析对于揭示土壤节肢动物的空间异质性及其与环境因子的相互关系具有理想的效果.%In 2008, an ice storm caused extensive damage to the montane evergreen broadleaved forest in Chebaling National Nature Reserve, Guangdong Province, China. To assess the response of soil arthropod diversity and distribution to a gradient of canopy openness following the ice storm, 17 plots, each 400 m~2, were selected

  11. Distribution patterns and carbon and nitrogen contents of Castanopsis platyacantha fine roots, the constructive species of evergreen broad-leaved secondary forest in Wawushan Mountain of Sichuan Province%瓦屋山常绿阔叶次生林建群种扁刺栲的细根分布及其碳氮特征

    Institute of Scientific and Technical Information of China (English)

    彭勇; 陈冠陶; 梁政; 李顺; 彭天驰; 涂利华

    2016-01-01

    The Wawushan Mountain National Forest Park in Sichuan Province, where there is relatively intact Castanopsis platyacantha-Schima sinensis formations, is a typical representative of the mid-subtropical moist evergreen broad-leaved forest in West China. Using the soil core method, this study investigated the fine root distribution and characteristics of carbon and nitrogen of sample C. platyacantha which is the main constructive species in this formation. The results were as follows: (1) The total fine root biomass of C. platyacantha was 173.62 g·m?2 and the total biomass of live fine roots was 135.29 g·m?2. (2) The fine root biomass, root length density, root surface area and specific root length decreased with the increase of soil depth, and their proportions in 0-30 cm layers were 67.23%, 69.53%, 69.48%and 57.20%, respectively; root length density, root surface area and specific root length decreased significantly with increasing root diameter, and 58.84%, 52.59%and 51.36%of them were in the roots that diameter was less than 1 mm, respectively. (3) Root extinction coefficient in biomass, length and surface area of C. platyacantha fine root increased with the rise of the root diameter. (4) In the first soil layer, the roots C content increased significantly with the rising root diameter, but there was no significant difference in other soil layers;the C content of the roots whose diameter was less than 2 mm in the first soil layer was significantly lower than other soil layers, while the differences of roots C content of greater than 2 mm among soil layers was insignificant. (5) The roots N content decreased with the increase of soil depth and root diameter, while the C/N ratio value was opposite. These results reflected the vertical distribution of the secondary forest underground fine root system and nutrient characteristics, which would provided some basic data for revealing the subsurface ecological processes and the effects of environmental change on

  12. Soil microbial functional diversity in a montane evergreen broadleaved forest of Chebaling Following the Huge Ice Storm in South China%车八岭山地常绿阔叶林冰灾后土壤微生物群落功能多样性

    Institute of Scientific and Technical Information of China (English)

    区余端; 苏志尧; 彭桂香; 刘刚

    2009-01-01

    研究了我国南方冰灾后常绿阔叶林林冠开度及土壤养分的空间异质性对土壤微生物功能多样性的影响.在受冰灾影响的粤北车八岭山地常绿阔叶林2 hm~2固定样地中按照冠层受损程度选取16个20 m×20 m的样方,用半球面影像技术获取林冠开度,并取0~20 cm的表层土壤混合样品分析土壤的理化性质,同时应用Biolog技术分析微生物功能多样性.按林冠开度梯度对各样方土壤微生物群落利用单一碳源的分析发现,林冠开度大的样方土壤微生物的活性、丰富度、多样性和均匀度都较低,反之则较高.聚类分析的结果与林冠开度的梯度有高度的一致性.主成分分析表明各样方土壤微生物功能多样性具有显著差异(第一轴p<0.005;第二轴p<0.001),其结果与聚类结果基本吻合.冗余分析揭示了土壤全磷、全钾、全氮、速效氮、有机碳、容重、总孔隙度和林冠开度的综合作用对土壤微生物功能多样性有显著影响(p<0.005),其中林冠开度与土壤微生物群落功能多样性的关系最密切.土壤微生物功能多样性受土壤养分的影响,具体表现为:与土壤有机碳呈明显的正相关;与全氮正相关;与速效氮、全磷负相关.研究说明冰灾所造成林冠开度和土壤养分的空间异质性会影响到土壤微生物功能多样性,而土壤微生物功能多样性可用于对生境恢复的指示和评价.%Effect of spatial heterogeneity in canopy openness and soil nutrients on soil microbial functional diversity was investigated following a huge ice storm in south China. Sixteen plots, each 400 m~2, were selected for this study according to the damage degrees of the canopy within a 2 hm~2 permanent plot, which had been set up within the storm-hit montane evergreen broadleaved forest in Chebaling National Nature Reserve. Canopy openness was estimated with hemispherical photography, and a composite sample of surface soil (0-20 cm

  13. Five Little Evergreens

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Five Little Evergreens outside in a row.The first one said,"Let's look at the snow."The second one said,"Oh-oh,it's getting cold."The third one said,"Chiristmas is coming so I'm told."The4fourth one said,"I hope someone decorates me."The fifth one said,"We'll just have to wait and see."Five Little Evergreens

  14. 南亚热带常绿阔叶林林冠不同部位藤本植物的光合生理特征及其对环境因子的适应%Photosynthetic characteristics of canopy-dwelling vines in lower subtropical evergreen broad-leaved forest and response to environmental factors

    Institute of Scientific and Technical Information of China (English)

    江浩; 周国逸; 黄钰辉; 刘世忠; 唐旭利

    2011-01-01

    Aims Vines are important floristic and ecological elements in forests of tropical and subtropical areas; however,few studies have provided information on the photosynthetic characteristics of vines. Our purpose is to characterize the photosynthetic traits of major canopy-dwelling vines in the lower subtropical evergreen broad-leaved forest in southern China.Methods We compared the photosynthetic characteristics of two upper-canopy vines (Dischidia chinensis and Psychotria serpens) and two lower-canopy vines (Fissistigma glaucescens and Piper hancei) in Dinghushan Nature Reserve. We measured maximum photosynthetic rate (Amax), light saturation point (Lsp), light compensation point (lcp), respiration in light (Rday), convexity (K), apparent quantum yield (φ), transpiration rate (Tr) and water utilization efficiency ( WUE) using a LI-6400 system. We also determined environmental factors inside and outsidethe canopy.Important findings Differences of photosynthetic characteristics between the upper and lower canopy-dwelling vines can be largely explained by differences in environmental factors such as photosynthetic active radiation (PAR), temperature and humidity within the forest canopy. Vines located in the upper canopy have lower annual mean Amax and LSP compared with those located in the lower canopy. Amax values of the upper canopy vines D. chinensis and Psychotria serpens are (2.9 ± 0.6) and (6.3 ± 1.3) μmol CO2m-2 ·S-1 , respectively, and their LSP values are (168.5 ± 83.4) and (231.4 ± 147.8) μmol·m-2·s-1, respectively. The Amax values of F. glaucescens and Piper hancei are (8.9 ± 2.9) and (8.6 ± 2.3) μmol CO2·m-2·s-1, respectively, and the LSP values are (491.6 ± 230.8) and (402.3 ± 112.8) μmol·m-2·s-1, respectively. The lower canopy vines have lower LCP compared with the upper canopy vines. The LCP values are (5.6 ± 1.9) and (5.4 ± 1.7) μmol·m-2·s-1 for F. glaucescens and Piper hancei,respectively and (16.1 ± 5.9) and (10.1 ± 5.7)

  15. Acclimation in Leaf Morphological and Eco-physiological Characteristics of Different Canopy-dwelling Epiphytes in a Lower Subtropical Evergreen Broad-leaved Forest%亚热带常绿阔叶林冠层附生植物叶片形态结构及生理功能特征的适应性研究

    Institute of Scientific and Technical Information of China (English)

    江浩; 黄钰辉; 周国逸; 胡晓颖; 刘世忠; 唐旭利

    2012-01-01

    著的差异,并致使各自的生理生态功能发生了相应的适应,是植物适应环境条件的重要表现.%Epiphytes have been well characterized in terms of the morphological and eco-physiological traits that permit them to thrive in the complex forest canopy. Our aim was to characterize and analyze the morphological and eco-physiological traits of different canopy-dwelling epiphytes in a lower subtropical evergreen broad-leaved forest in Southern China.Results showed that the differences in morphological and eco-physiological characteristics between the upper and lower canopy-dwelling epiphytes were largely explained by changes in environmental factors such as photosynthetic active radiation (PAR) .temperature,and humidity within the complex forest canopy. Two epiphytes, Dischidia chinensis and Psychotria ser-pens located in the upper canopy had low Tr (0.17 ±0. 02 mmol H2O and 0. 34 ±0. 05 mmol H2O,respectively) and low Pmax(2. 2 ±0.1 μmol CO2·m-2·S-1 and 3.2 ±0.4 μmol CO2·m-2-s-1,respectively) associated with thick leaf (558 ±63 μm and 217.1 ±33.1 μm, respectively) and small stomata size (185. 7 ±3. 7 pm2 and 225.4 ±5. 2 pm2 .respectively) to adapt to their upper dwelling environments (high temperature,low air humidity and high PAR). At the same time,the special structures led to high WUE (11. 35 ±0. 87 μmol CO2/mmol H2O and 7.88 ± 1.31 μmol CO2/mmol H2O,respectively). However,the lower canopy-dwelling epiphytes Fis-sistigma glaucescens and Piper hancei had thin leaf (90. 8 ± 9. 9 μm and 114. 9 ± 18.2 μm, respectively) and large stomata size (260. 6 ±6. 3 μm2 and 362. 5 ±8. 7 μm2 .respectively). The ratios of palisade to spongy tissues thickness (P/S) ,the thickness of leaf epidermis thickness and other structures also changed with various canopy-dwelling heights. In comparison with Dischidia chinensis and Psychotria serpens located at upper canopy-dwelling conditions, Fissistigma glaucescens and Piper hancei showed high

  16. Inter- and intra-specific variation in stemflow for evergreen species and deciduous tree species in a subtropical forest

    Science.gov (United States)

    Su, Lei; Xu, Wenting; Zhao, Changming; Xie, Zongqiang; Ju, Hua

    2016-06-01

    Quantification of stemflow is necessary for the assessment of forest ecosystem hydrological effects. Nevertheless, variation of stemflow among plant functional groups is currently not well understood. Stemflow production of co-occurring evergreen broadleaved trees (Cyclobalanopsis multinervis and Cyclobalanopsis oxyodon) and deciduous broadleaved trees (Fagus engleriana and Quercus serrata var. brevipetiolata) was quantified through field observations in a mixed evergreen and deciduous broadleaved forest. The research results revealed that stemflow increased linearly with increasing rainfall magnitude, with precipitation depths of 6.9, 7.2, 10.0 and 14.8 mm required for the initiation of stemflow for C. multinervis, C. oxyodon, F. engleriana and Q. serrata, respectively. Stemflow percentage and funneling ratio (FR) increased with increasing rainfall in a logarithmic fashion. Stemflow percentage and FR tended to grow rapidly with increasing rainfall magnitude up to a rainfall threshold of 50 mm, above which, further rainfall increases brought about only small increases. For C. multinervis, C. oxyodon, F. engleriana and Q. serrata, FR averaged 19.8, 14.8, 8.9 and 2.8, respectively. The stemflow generating rainfall thresholds for evergreen species were smaller than for deciduous species. Furthermore, stemflow percentage and FR of the former was greater than the latter. For both evergreen species and deciduous species, overall funneling ratio (FRs) decreased with increasing basal area. We concluded that: (1) although stemflow partitioning represented a fairly low percentage of gross rainfall in mixed evergreen and deciduous broadleaved forests, it was capable of providing substantial amount of rainwater to tree boles; (2) the evergreen species were more likely to generate stemflow than deciduous species, and directed more intercepted rainwater to the root zone; (3) small trees were more productive in funneling stemflow than larger trees, which may provide a favorable

  17. A comparison of 137Cs radioactivity in localized evergreen and deciduous plant species

    International Nuclear Information System (INIS)

    A vegetation study at the Comanche Peak Steam Electric Station (CPSES) near Glen Rose, Texas was conducted in 1991 and 1992. The CPSES is a commercial nuclear power plant owned and operated by Texas Utilities Electric of Dallas, Texas. The US Nuclear Regulatory Commission (USNRC) requires the CPSES to routinely sample broadleaf vegetation in place of milk samples. Few commercial dairies exist in the vicinity. Broadleaf tree species are scarce because the climate and local limestone geology have produced a dry rolling hill topography. An evergreen juniper is the dominant tree species. Few broadleaves during the winter season have hindered year-round sampling. This study compares the environmental 137Cs concentrations between broadleaf and evergreen foliage at CPSES. Soil 137Cs concentrations from each vegetation location were also compared to the foliage 137Cs concentrations. The study's objective was to determine if the deciduous and evergreen vegetation 137Cs concentrations are statistically the same

  18. A comparison of {sup 137}Cs radioactivity in localized evergreen and deciduous plant species

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, R.C.

    1996-05-01

    A vegetation study at the Comanche Peak Steam Electric Station (CPSES) near Glen Rose, Texas was conducted in 1991 and 1992. The CPSES is a commercial nuclear power plant owned and operated by Texas Utilities Electric of Dallas, Texas. The US Nuclear Regulatory Commission (USNRC) requires the CPSES to routinely sample broadleaf vegetation in place of milk samples. Few commercial dairies exist in the vicinity. Broadleaf tree species are scarce because the climate and local limestone geology have produced a dry rolling hill topography. An evergreen juniper is the dominant tree species. Few broadleaves during the winter season have hindered year-round sampling. This study compares the environmental {sup 137}Cs concentrations between broadleaf and evergreen foliage at CPSES. Soil {sup 137}Cs concentrations from each vegetation location were also compared to the foliage {sup 137}Cs concentrations. The study`s objective was to determine if the deciduous and evergreen vegetation {sup 137}Cs concentrations are statistically the same.

  19. Solar Physics at Evergreen

    Science.gov (United States)

    Zita, E. J.; Bogdan, T. J.; Carlsson, M.; Judge, P.; Heller, N.; Johnson, M.; Petty, S.

    2004-05-01

    We have recently established a solar physics research program at The Evergreen State College. Famed for its cloudy skies, the Pacific Northwest is an ideal location for solar physics research activities that do not require local observations. Collaborators from the High Altitude Observatory (HAO) at the National Center for Atmospheric Research have shared solar data from satellite-borne instruments such as TRACE and SUMER. HAO colleagues also share data from computer simulations of magneto-hydrodynamics (MHD) in the chromosphere, generated by the Institute for Theoretical Astrophysics (ITA) at the University of Oslo. Evergreen students and faculty learned to analyze data from satellites and simulations, in Boulder and Oslo, and established an infrastructure for continuing our analyses in Olympia. We are investigating the role of magnetic waves in heating the solar atmosphere. Comparing data from satellites and simulations shows that acoustic oscillations from the photosphere cannot effectively propagate into the chromosphere, but that magnetic waves can carry energy up toward the hot, thin corona. We find that acoustic waves can change into magnetic waves, especially near the magnetic "canopy," a region where the sound speed is comparable to magnetic wave speeds. Understanding MHD wave transformations and their role in energy transport can help answer outstanding questions about the anomalous heating of the solar atmosphere. Ref: Waves in the magnetized solar atmosphere II: Waves from localized sources in magnetic flux concentrations. Bogdan et al., 2003, ApJ 597

  20. [Frost-resistance of subtropical evergreen woody plants: an evaluation based on plant functional traits].

    Science.gov (United States)

    Xu, Yi-Lu; Yang, Xiao-Dong; Xu, Yue; Xie, Yi-Ming; Wang, Liang-Yan; Yan, En-Rong

    2012-12-01

    Evaluating the frost-resistance of evergreen woody plants is of significance in guiding the species selection in forest management in subtropical region. In this paper, an investigation was made on the functional traits (including specific leaf area, stem wood density, leaf area, leaf dry matter content, leaf relative electrical conductance, and twig wood density) of 64 common evergreen broad-leaved and coniferous woody plant species in the Ningbo region of Zhejiang Province, East China, after a severe snowstorm in early 2008, aimed to select the evergreen woody plants with high ability of freeze-tolerance, and to establish a related evaluation system. By using a hierarchy analysis approach, the weight values of the functional traits of each species were determined, and an index system for evaluating the plants tolerance ability against freeze and mechanical damage was established. Based on this system, 23 evergreen plant species with high tolerance ability against freeze and mechanical damage, such as Cyclobalanopsis gilva, Cyclobalanopsis nubium, Neolitsea aurata, and Vacciniuim mandarinorum, were selected. In the meantime, on the basis of the ordering with each of the functional traits, the ordering of the tolerance ability of the 64 plant species against freeze and mechanical damage was made, and a list for the frost-resistance ability of the subtropical evergreen woody plant species in Ningbo region was constituted. PMID:23479868

  1. 地形和土壤特性对亚热带常绿阔叶林内植物功能性状的影响%Effects of topographic variations and soil characteristics on plant functional traits in a subtropical evergreen broad-leaved forest

    Institute of Scientific and Technical Information of China (English)

    丁佳; 吴茜; 闫慧; 张守仁

    2011-01-01

    To elucidate the driving factors behind plant functional traits, especially in mountainous areas, we explored how variation in topography and soil characteristics affects ecophysiological and morphological traits of woody plants within the Gutianshan 24-ha plot in Zhejiang Province. This site is in a typical subtropical broad-leaved forest. During the summers of 2008 and 2009, we measured three ecophysiological traits (chlorophyll content, chlorophyll fluorescence parameters Fy/Fro and PIABS, and stem sapwood xylem specific hydraulic conductivity) and four morphological traits (stomata density, specific leaf area, leaf thickness, and ratio of leaf length to leaf width) among 115 woody species in the field. Redundancy analysis was conducted to identify the most influential environmental factors from our topographical factors (mean elevation, convexity, slope, and aspect) and five soil parameters (moisture, total nitrogen content, total phosphorus content, total carbon content, and pH). Leaf chlorophyll content was negatively correlated with elevation and convexity, but positively correlated with soil moisture and total nitrogen content. The two chlorophyll fluorescence parameters (Fv/Fm and PlABS) were strongly negatively correlated with soil total nitrogen and phosphorus content; these variables were likely interrelated with low soil pH values. Stem sapwood xylem specific hydraulic conductivity was positively correlated with soil moisture and specific leaf area was positively correlated with elevation. Topographical variables explained 10.4% of total variation in functional traits;mean elevation was the most powerful explanatory variable, followed by convexity, slope and finally, aspect.Soil parameters explained 13.9% of the total functional trait variation; and soil moisture was the most powerful factor, followed by total nitrogen content, pH value, total phosphorous content, total carbon content and the ratio of nitrogen and phosphorous. At this scale and at

  2. Effects of moso bamboo encroachment into native, broad-leaved forests on soil carbon and nitrogen pools

    Science.gov (United States)

    Bai, Shangbin; Conant, Richard T.; Zhou, Guomo; Wang, Yixiang; Wang, Nan; Li, Yanhua; Zhang, Kaiqiang

    2016-01-01

    Across southern China, Moso bamboo has been encroaching on most neighboring secondary broad-leaved forests and/or coniferous plantations, leading to the land cover changes that alter abiotic and biotic conditions. Little is known about how this conversion alters soil carbon (C) and nitrogen (N). We selected three sites, each with three plots arrayed along the bamboo encroachment pathway: moso bamboo forest (BF); transition zone, mixed forest plots (MF); and broad-leaved forest (BLF), and examined how bamboo encroachment affects soil organic C (SOC), soil total N, microbial biomass C (MBC), microbial biomass N (MBN), water-soluble organic C (WSOC), and water-soluble organic N (WSON) in three forests. Over nine years, moso bamboo encroachment leads to a decrease in SOC and total soil N, an increase in MBC and WSOC, and a decrease in MBN and WSON. Changes in soil C and N occurred mainly in the topsoil. We conclude that moso bamboo encroachment on broadleaved forest not only substantially altered soil C and N pools, but also changed the distribution pattern of C and N in the studied forest soils. Continued bamboo encroachment into evergreen broadleaved forests seems likely to lead to net CO2 emissions to the atmosphere as ecosystem C stocks decline. PMID:27526781

  3. The phylogenetic signal of functional traits and their effects on community structure in an evergreen broad-leaved forest

    Directory of Open Access Journals (Sweden)

    Ke Cao

    2013-09-01

    Full Text Available The phylogenetic conservatism of plant functional traits and its association with community structure are important topics in ecological research. Plant functional traits are simultaneously affected by their evolutionary background, local habitat conditions and large-scale climate. In this study we asked whether functional traits have a significant phylogenetic signal and significantly affect species abundance in a community. For this objective, we used data from a 24 ha Gutianshan forest plot, which included species abundance and six functional traits of 156 woody species: leaf nitrogen content, leaf phosphorus content, leaf area, wood density, specific leaf area and seed mass. We found that all functional traits showed significant phylogenetic signal, suggesting that all functional traits are significantly affected by their evolutionary history. We also found that species abundance was correlated with leaf nitrogen content, leaf phosphorus content, leaf area, woody density and specific leaf area except seed mass, suggesting that resource acquisition significantly affects species abundance distribution in a community, and that these functional traits impact community structure in different ways.

  4. 'Linkage' pharmaceutical evergreening in Canada and Australia

    OpenAIRE

    Faunce, Thomas A; Lexchin, Joel

    2007-01-01

    'Evergreening' is not a formal concept of patent law. It is best understood as a social idea used to refer to the myriad ways in which pharmaceutical patent owners utilise the law and related regulatory processes to extend their high rent-earning intellectual monopoly privileges, particularly over highly profitable (either in total sales volume or price per unit) 'blockbuster' drugs. Thus, while the courts are an instrument frequently used by pharmaceutical brand name manufacturers to prolong...

  5. Analysis on community diversity in coniferous-broadleaved mixed forests in Wuyi Mountain%武夷山针阔混交林的群落多样性

    Institute of Scientific and Technical Information of China (English)

    张炜琪; 陈辉; 林文俊; 董建文; 陈世品; 赵伟村

    2016-01-01

    通过测定群落内乔木层的重要值、灌木层的Shannon-Wiener(H′)指数和Pielou(J)均匀度指数,以及郑元润改进后的M. Godron稳定性指数,对武夷山4个不同类型的针阔混交林群落进行所处演替阶段的分析和群落稳定性研究。结果表明:(1)群落A(杉木Cunninghamia lanceolata Hook.、马尾松Pinus massoniana Lamb.+赤杨叶Alniphyllum fortunei Makino.)处于从针叶林向针阔混交林演替阶段的中期;群落B(马尾松+细柄蕈树Altingia gracilipes Merr.)处于从阔叶马尾松林向阔叶混交林演替的中期;群落C(马尾松+甜槠Castanopsis eyrei Tutch.)处于从针阔混交林向阔叶混交林演替的中后期;群落D (杉木+赤杨叶)处于从针阔混交林向阔叶混交林演替的初期;(2)群落内灌木层的物种构成及多样性将影响并决定群落演替的方向;(3)4个针阔混交林乔木层仍有大量针叶树种存在,稳定性测定坐标值远离20/80这个点,表明这些森林群落均未达到顶级群落阶段,处于不稳定状态。%To measure the community succession stages and stability for four coniferous and broadleaf mixed forests communities with different forest types ( A, B, C, and D) in Wuyi Mountain, community analysis was conducted according to four indices: tree layer′s important values ( IV) , shrub′s Shannon-Wiener index ( H′) , Pielou index ( J) and M. Godron′s stability index improved by Zheng yuanrun. Our results showed as follows: ( 1 ) Community A ( Cunninghamia lanceolata Hook. and Pinus massoniana Lamb.+Alniphyllum fortunei Makino.) was in the middle successional stage from the coniferous forest to the coniferous-broadleaved mixed forest, community B ( Pinus massoniana Lamb.+Altingia gracilipes Merr.) was in the middle stage of secondary succession from Pinus-broadleaved mixed forest to evergreen broadleaved forest. Meanwhile, community C( Pinus massoniana Lamb.+Castanopsis eyrei Tutch.) was in the late stage of

  6. Chinese Localisation of Evergreen: An Open Source Integrated Library System

    Science.gov (United States)

    Zou, Qing; Liu, Guoying

    2009-01-01

    Purpose: The purpose of this paper is to investigate various issues related to Chinese language localisation in Evergreen, an open source integrated library system (ILS). Design/methodology/approach: A Simplified Chinese version of Evergreen was implemented and tested and various issues such as encoding, indexing, searching, and sorting…

  7. The transitional semi-evergreen bushland in Ethiopia

    DEFF Research Database (Denmark)

    van Breugel, Paulo; Friis, Ib; Sebsebe, Demissew

    2016-01-01

    Question: Evergreen bushlands in Ethiopia have been inadequately studied and mapped. We address the question whether there is a transitional semi-ever-green bushland on the eastern escarpment of the Ethiopian Highlands, with unique floristic characteristics that distinguish it from the evergreen...... bushlands in other parts of Ethiopia and eastern Africa. Methods: Based on a review of the recent descriptions of evergreen bushlands in Ethiopia, we hypothesize that there is a distinct zone of natural semi-ever-green bushland, which is restricted to the eastern and southeastern escarpment of the Ethiopian...... Highlands. In contrast, evergreen bushlands in other parts of Ethiopia are considered to be of a secondary nature. To test this hypothesis, we carried out qualitative vegetation surveys in 354 locations across Ethiopia and classified the vegetation in these locations based on the occurrences of indicator...

  8. An old-growth subtropical Asian evergreen forest as a large carbon sink

    Science.gov (United States)

    Tan, Zheng-Hong; Zhang, Yi-Ping; Schaefer, Douglas; Yu, Gui-Rui; Liang, Naishen; Song, Qing-Hai

    2011-03-01

    Old-growth forests are primarily found in mountain ranges that are less favorable or accessible for land use. Consequently, there are fewer scientific studies on old-growth forests. The eddy covariance method has been widely used as an alternative approach to studying an ecosystem's carbon balance, but only a few eddy flux sites are located in old-growth forest. This fact will hinder our ability to test hypotheses such as whether or not old-growth forests are carbon neutral. The eddy covariance approach was used to examine the carbon balance of a 300-year-old subtropical evergreen broadleaved forest that is located in the center of the largest subtropical land area in the world. The post-QA/QC (quality assurance and control) eddy covariance based NEP was ˜ 9 tC ha -1 yr -1, which suggested that this forest acts as a large carbon sink. The inventory data within the footprint of the eddy flux show that ˜6 tC ha -1 yr -1 was contributed by biomass and necromass. The large-and-old trees sequestered carbon. Approximately 60% of the biomass increment is contributed by the growth of large trees (DBH > 60 cm). The high-altitude-induced low temperature and the high diffusion-irradiation ratio caused by cloudiness were suggested as two reasons for the large carbon sink in the forest we studied. To analyze the complex structure and terrain of this old-growth forest, this study suggested that biometric measurements carried out simultaneously with eddy flux measurements were necessary.

  9. Sustainable cultivation of broadleaved trees in a recycling community

    International Nuclear Information System (INIS)

    In the future, with problems of global warming and acidification and with an increasing need to recirculate wastes of the community in an ecologically acceptable and economically sound manner, the cultivation of broadleaved species (birch, aspen, poplar, alder and willow in particular) on suitable forest land and on former agricultural land is of utmost interest if following the recycling philosophy. The wood produced could be used primarily for short fibres and for energy. Also of interest is the production of methanol, biogas and electricity, chipboard and laminates, in the context of a forest industry concerned with the further development of the raw materials. The main advantages of cultivating fast-growing, broadleaved trees on former agricultural land are that: * in Sweden it has been shown possible to produce 10-12 tonnes of dry matter of woody biomass per hectare and year by cultivating willows and hybrid poplars, * in such plantations, the energy efficiency ratio will be 1 to 15-20, meaning that for every energy unit used, 15-20 can be harvested, and * some residual products from society, such as sludges, ashes, and wastewaters can be used as fertilizers in such plantations. 16 refs

  10. Evergreen broadleaf forest transition zone changes in Japan from 1961 to 2008 detected by aerial ortho-photos

    Science.gov (United States)

    Nakazono, Etsuko; Tanaka, Nobuyuki; Yasuda, Masatsugu; Daimaru, Hiromu; Takeuchi, Wataru

    2016-06-01

    In order to detect the distribution change of evergreen broad-leaved trees (EBTs) in a old-growth forest on the transitional zone of cool-temperate and warm-temperate zones, we used the ortho-photo data conversed from the aerial photos. Comparing the crown map of EBTs in the 1-ha verification plot with the ground truth data of individual tree inventory, 14 out of 17 (82%) upper layer trees were found to be visually read on the aerial photo We chose two indices for detecting the distribution change of EBTs, crown number and total crown area. We made crown maps of the 20-ha plot based on ortho-photos in 1961, 1975, 1985, 2003, 2005 and 2008, and calculated crown number and total crown area for each photos. The crown number increased at a rate 0.18/year/ha from 1961 to 2000’s, and total crown area also increased at a rate 0.21% for the 20-ha plot. The total crow area increase was highly probable because errors of area in orthophotos were smaller than secular changes of the area.

  11. Spatial and temporal variation in the soil CO2 efflux in a subtropical broadleaved forest in Okinawa, Japan

    Science.gov (United States)

    Matsumoto, Kazuho; Terasawa, Kei; Taniguchi, Shingo; Takashima, Atsushi; Katayama, Ayumi; Ohashi, Mizue

    2016-04-01

    Soil CO2 efflux (Rs) is a major component of the carbon emissions from terrestrial ecosystems. The spatiotemporal variation in Rs and its dependency on biotic and abiotic factors have been clarified in various ecosystems. It is thought that subtropical ecosystem RS values are slightly higher than those of temperate ecosystems, but much smaller than those of tropical ecosystems (Bond-Lamberty & Thomson, 2010), but compared with temperate and tropical ecosystems there are limited relevant data. This study examined spatial (within stand-scale) and temporal (hourly to seasonal) variation in Rs in a subtropical evergreen broad-leaved forest on Okinawa Island, Japan. We measured Rs using a closed dynamic chamber at 60 locations within a 0.15-ha plot once a month in 2013 and 2014. In addition, Rs was measured continuously using automated chambers at two locations within the same plot in 2015. The annual average Rs value (5.5 μmol m-2 s-1) obtained from the monthly manual measurements was comparable with values reported for tropical rainforests and larger than those for temperate forests. At our site, Rs showed clear seasonal variation depending on soil temperature, unlike in tropical rainforests, which lack seasonality. The spatial variation in Rs was positively correlated with the ratio of litter cover area per unit soil area, which was larger on the ridge and smaller on the slope. We propose that the amount of litter, as a material for heterotrophic respiration, largely characterises the spatial variation in Rs at this site, with a relatively small contribution from autotrophic respiration by plant roots. The results clarify that Rs values in subtropical forests in Okinawa have characteristics between those of temperate forests (seasonality) and tropical rainforests (large Rs).

  12. 29 CFR 780.1016 - Use of evergreens and forest products.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Use of evergreens and forest products. 780.1016 Section 780... Labor Provisions Under Section 13(d) Requirements for Exemption § 780.1016 Use of evergreens and forest products. Harvesting of evergreens and other forest products is exempt only when these products will...

  13. An Instructional Guide for Ethnic Studies at Evergreen Valley College.

    Science.gov (United States)

    Chavez, Mauro

    Guidelines and conceptual parameters are presented for ethnic studies courses at Evergreen Valley College (EVC). Introductory material discusses the requirement that all associate degree students complete three units of ethnic studies; presents general guidelines for ethnic studies; defines "ethnic-racial minority"; and suggests criteria for…

  14. A Student Government Guidebook for Evergreen Valley College.

    Science.gov (United States)

    Chavez, Mauro

    Designed to help develop informed and capable student leadership in student affairs at Evergreen Valley College (EVC), this student government guide and text for Government 91 focuses on the major leadership needs and objectives of student government within a participatory framework. After an explanation of course objectives and requirements,…

  15. Contrasting ozone sensitivity in related evergreen and deciduous shrubs

    Energy Technology Data Exchange (ETDEWEB)

    Calatayud, Vicent, E-mail: vicent@ceam.e [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain); Marco, Francisco; Cervero, Julia [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain); Sanchez-Pena, Gerardo [SPCAN, Dir. Gral. de Medio Natural y Politica Forestal, Ministerio de Medio Ambiente, y Medio Rural y Marino, Rios Rosas 24, 28003 Madrid (Spain); Sanz, Maria Jose [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain)

    2010-12-15

    Plant responses to enhanced ozone levels have been studied in two pairs of evergreen-deciduous species (Pistacia terebinthus vs. P. lentiscus; Viburnum lantana vs. V. tinus) in Open Top Chambers. Ozone induced widespread visible injury, significantly reduced CO{sub 2} assimilation and stomatal conductance (g{sub s}), impaired Rubisco efficiency and regeneration capacity (V{sub c,max,}J{sub max}) and altered fluorescence parameters only in the deciduous species. Differences in stomatal conductance could not explain the observed differences in sensitivity. In control plants, deciduous species showed higher superoxide dismutase (SOD) activity than their evergreen counterparts, suggesting metabolic differences that could make them more prone to redox imbalances. Ozone induced increases in SOD and/or peroxidase activities in all the species, but only evergreens were able to cope with the oxidative stress. The relevancy of these results for the effective ozone flux approach and for the current ozone Critical Levels is also discussed. - Mediterranean evergreen shrubs have a constitutively higher capacity to tolerate ozone stress than their deciduous relatives.

  16. A gap-filling model for eddy covariance latent heat flux: Estimating evapotranspiration of a subtropical seasonal evergreen broad-leaved forest as an example

    Science.gov (United States)

    Chen, Yi-Ying; Chu, Chia-Ren; Li, Ming-Hsu

    2012-10-01

    SummaryIn this paper we present a semi-parametric multivariate gap-filling model for tower-based measurement of latent heat flux (LE). Two statistical techniques, the principal component analysis (PCA) and a nonlinear interpolation approach were integrated into this LE gap-filling model. The PCA was first used to resolve the multicollinearity relationships among various environmental variables, including radiation, soil moisture deficit, leaf area index, wind speed, etc. Two nonlinear interpolation methods, multiple regressions (MRS) and the K-nearest neighbors (KNNs) were examined with random selected flux gaps for both clear sky and nighttime/cloudy data to incorporate into this LE gap-filling model. Experimental results indicated that the KNN interpolation approach is able to provide consistent LE estimations while MRS presents over estimations during nighttime/cloudy. Rather than using empirical regression parameters, the KNN approach resolves the nonlinear relationship between the gap-filled LE flux and principal components with adaptive K values under different atmospheric states. The developed LE gap-filling model (PCA with KNN) works with a RMSE of 2.4 W m-2 (˜0.09 mm day-1) at a weekly time scale by adding 40% artificial flux gaps into original dataset. Annual evapotranspiration at this study site were estimated at 736 mm (1803 MJ) and 728 mm (1785 MJ) for year 2008 and 2009, respectively.

  17. Effects of simulated acid rain on soil and soil solution chemistry in a monsoon evergreen broad-leaved forest in southern China.

    Science.gov (United States)

    Qiu, Qingyan; Wu, Jianping; Liang, Guohua; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2015-05-01

    Acid rain is an environmental problem of increasing concern in China. In this study, a laboratory leaching column experiment with acid forest soil was set up to investigate the responses of soil and soil solution chemistry to simulated acid rain (SAR). Five pH levels of SAR were set: 2.5, 3.0, 3.5, 4.0, and 4.5 (as a control, CK). The results showed that soil acidification would occur when the pH of SAR was ≤3.5. The concentrations of NO₃(-)and Ca(2+) in the soil increased significantly when the pH of SAR fell 3.5. The concentration of SO₄(2-) in the soil increased significantly when the pH of SAR was acidity of SAR. The releases of soluble Al and Fe were SAR pH dependent, and their net exports under pH 2.5 treatment were 19.6 and 5.5 times, respectively, higher than that under CK. The net export of DOC was reduced by 12-29% under SAR treatments as compared to CK. Our results indicate the chemical constituents in the soil are more sensitive to SAR than those in the soil solution, and the effects of SAR on soil solution chemistry depend not only on the intensity of SAR but also on the duration of SAR addition. The soil and soil solution chemistry in this region may not be affected by current precipitation (pH≈4.5) in short term, but the soil and soil leachate chemistry may change dramatically if the pH of precipitation were below 3.5 and 3.0, respectively. PMID:25893761

  18. Artificial Promoting Coppice for Developing Evergreen Broad-leaved Forests%人工促进萌芽更新发展常绿阔叶林

    Institute of Scientific and Technical Information of China (English)

    廖土发; 周炳金

    2009-01-01

    从宏观的经济效益和社会效益角度出发,做到经济、社会、生态三大效益相统一,让森林发挥出最大的综合效益,做到青山常在,永续利用,是林场经营必须遵循的科学法则.在营造林工作中,采用人工促进萌芽更新方法,以管为主,营造、封、改为辅.以片带网点相结合,大力发展次生常绿阔叶林.

  19. Effects of micro-topographies on stand structure and tree species diversity in an old-growth evergreen broad-leaved forest, southwestern Japan

    Directory of Open Access Journals (Sweden)

    Tran Van Do

    2015-07-01

    Full Text Available Stand structure and species diversity were studied in correspondence with micro-topographies in an old-growth forest in southwestern Japan. The study was conducted in a 200×200m2 permanent plot, which were divided into 400 subplots using grids of 10m×10m. Subplots were categorized to four micro-topographies as crest slope (CS, head hollow (HH, upper slope (US and lower slope (LS, basing on slope of forest floor and plot position, and to two elevational zones as below 450 m and above 450 m. Tree censuses for all individuals with diameter at breast height (DBH ⩾ 5 cm were conducted in 2009 and 2013. The results indicated that CS had subplot means of living stems, dead stems, DBH, basal area (G, and basal area increment (▵G significantly higher than that in LS. While, means of recruited stems and Shannon diversity index were significantly lower. Comparing between below and above 450 m elevational zones indicated the significantly higher parameters of stand structure and species diversity in above 450 m elevational zone. The differences of edaphic conditions led to difference of density of living stems, species density, DBH, G, and ▵G among micro-topographies. Therefore, crest slope, upper slope, and higher elevational zones should be encouraged for the purposes of carbon accumulation and storage. While, the lower elevational zones should be used for the purposes of species diversity conservation.

  20. Vegetation Composition and Community Structure of Typical Mid-Mountain Broad-Leaved Forest in Jiangxi Wuyishan%江西武夷山典型中山阔叶林的植被组成与群落结构

    Institute of Scientific and Technical Information of China (English)

    雷平; 袁荣斌; 兰文军; 邹思成; 徐新宇

    2013-01-01

    以江西武夷山典型中山阔叶林为研究对象,在30 km2固定样地设置16个样方,其中13个常绿阔叶林群落、3个落叶阔叶林群落.群落乔灌层物种丰富,占物种生活型的83%.共调查到植物58科112属186种,以壳斗科、山矾科、蔷薇科、山茶科、樟科物种数最多,建群种主要为多脉青冈、闽皖八角、白檀、枫香树等,灌木层以山矾科、山茶科、禾本科为主.物种科属分布区类型以热带性质为主,具有典型的中亚热带地区特点.常绿阔叶林群落和落叶阔叶林群落均具有较高的多样性,单因素方差结果显示这2种林型在多样性指数上不存在差异显著性,乔、草优势种重要值亦不存在差异显著性,只有灌木层重要值存在差异显著性.%Set 16 plots in 30km2 fixed sample area of typical mid-mountain broad-leaved forest in Jiangxi Wuyishan,including 13 evergreen broad-leaved forest communities and 3 deciduous broad-leaved forest communities.The communities have rich species in tree layer and shrub layer,which accounting for 83% of species' life forms.A total of 186 vascular plant species,belonging to 112 genera and 58 families,were recorded,and the largest number of species is Fagaceae,Symplocaceae,Rosaceae,Theaceae and Lauraceae.The mainly constructive species are Cyclobalanopsis multiervis,Illicium minwanense,Symplocos paniculata and Liquidambar formosana etc.,and the shrub layer dominant families are Symplocaceae,Theaceae and Gramineae.Areal distribution type of species suggests that the forest is typical characteristics in subtropical regions and highly related to tropic components.Evergreen broad-leaved forest community and deciduous broad-leaved forest communities both have high species diversity; one-way ANOVA results showed that there is no significant difference on the diversity index of the two forest types,so do the important values of tree layer and herbaceous layer,but there is significant difference on the

  1. Humus forms in two secondary semi-evergreen tropical forests

    OpenAIRE

    Loranger, Gladys; PONGE, Jean-François; Lavelle, Patrick

    2003-01-01

    International audience The dynamics and function of humus forms in tropical forests are still poorly understood. Humus profiles in two secondary semi-evergreen woodlands in Guadeloupe (French West Indies) were analysed micromorphologically. The humus forms are described under the canopy of five dominant tree species at two sites: under Pisonia subcordata and Bursera simaruba in a secondary forest on a Leptosol (Rendzina), and under Swietenia macrophylla, Tabebuia heterophylla and B. simaru...

  2. Invariant community structure of soil bacteria in subtropical coniferous and broadleaved forests.

    Science.gov (United States)

    Wang, Xiaoli; Wang, Xiaoling; Zhang, Weixin; Shao, Yuanhu; Zou, Xiaoming; Liu, Tao; Zhou, Lixia; Wan, Songze; Rao, Xingquan; Li, Zhian; Fu, Shenglei

    2016-01-01

    Soil bacteria may be influenced by vegetation and play important roles in global carbon efflux and nutrient cycling under global changes. Coniferous and broadleaved forests are two phyletically distinct vegetation types. Soil microbial communities in these forests have been extensively investigated but few studies have presented comparable data regarding the characteristics of bacterial communities in subtropical forests. We investigated soil bacterial biomass and community composition in three pairs of coniferous and broadleaved forests across a subtropical climatic gradient. We found that bacterial biomass differed between the coniferous and broadleaved forests across the subtropical climate gradient; however, this difference disappeared at some individual sites. In contrast, the same 90 bacterial genera were found in both forest types, and their relative abundances didn't differ between the forest types, with the exception of one genus that was more abundant in broadleaved forests. Soil nitrogen or moisture was associated with bacterial groups in the coniferous and broadleaved forests, respectively. Thus, we inferred that these forests can respond differently to future changes in nitrogen deposition or precipitation. This study highlights soil bacterial invariant community composition in contrasting subtropical forests and provides a new perspective on the potential response and feedback of forests to global changes. PMID:26754326

  3. A robot to detect and control broad-leaved dock (Rumex obtusifolius L.) in grassland

    NARCIS (Netherlands)

    Evert, van F.K.; Samsom, J.; Polder, G.; Vijn, M.P.; Dooren, van H.J.C.; Lamaker, E.J.J.; Heijden, van der G.W.A.M.; Kempenaar, C.; Zalm, van der A.J.A.; Lotz, L.A.P.

    2011-01-01

    Broad-leaved dock is a common and troublesome grassland weed with a wide geographic distribution. In conventional farming the weed is normally controlled by using a selective herbicide, but in organic farming manual removal is the best option to control this weed. The objective of our work was to de

  4. Resistance to wildfire and early regeneration in natural broadleaved forest and pine plantation

    Science.gov (United States)

    Proença, Vânia; Pereira, Henrique M.; Vicente, Luís

    2010-11-01

    The response of an ecosystem to disturbance reflects its stability, which is determined by two components: resistance and resilience. We addressed both components in a study of early post-fire response of natural broadleaved forest ( Quercus robur, Ilex aquifolium) and pine plantation ( Pinus pinaster, Pinus sylvestris) to a wildfire that burned over 6000 ha in NW Portugal. Fire resistance was assessed from fire severity, tree mortality and sapling persistence. Understory fire resistance was similar between forests: fire severity at the surface level was moderate to low, and sapling persistence was low. At the canopy level, fire severity was generally low in broadleaved forest but heterogeneous in pine forest, and mean tree mortality was significantly higher in pine forest. Forest resilience was assessed by the comparison of the understory composition, species diversity and seedling abundance in unburned and burned plots in each forest type. Unburned broadleaved communities were dominated by perennial herbs (e.g., Arrhenatherum elatius) and woody species (e.g., Hedera hibernica, Erica arborea), all able to regenerate vegetatively. Unburned pine communities presented a higher abundance of shrubs, and most dominant species relied on post-fire seeding, with some species also being able to regenerate vegetatively (e.g., Ulex minor, Daboecia cantabrica). There were no differences in diversity measures in broadleaved forest, but burned communities in pine forest shared less species and were less rich and diverse than unburned communities. Seedling abundance was similar in burned and unburned plots in both forests. The slower reestablishment of understory pine communities is probably explained by the slower recovery rate of dominant species. These findings are ecologically relevant: the higher resistance and resilience of native broadleaved forest implies a higher stability in the maintenance of forest processes and the delivery of ecosystem services.

  5. 78 FR 45288 - Frank Sherman, Evergreen Trails, Inc., Cabana Coaches, LLC, TMS West Coast, Inc. and FSCS...

    Science.gov (United States)

    2013-07-26

    ... Surface Transportation Board Frank Sherman, Evergreen Trails, Inc., Cabana Coaches, LLC, TMS West Coast... Trails, Inc. (Evergreen), Cabana Coaches, LLC (Cabana), TMS West Coast, Inc. (TMS), and FSCS Corporation... shareholder of noncarrier holding companies FSCS and TMS. Cabana is owned directly by FSCS and Evergreen...

  6. Fragmentation patterns of evergreen oak woodlands in Southwestern Iberia

    DEFF Research Database (Denmark)

    Costa, A.; Madeira, M.; Lima Santos, J.;

    2014-01-01

    Mediterranean evergreen oak woodlands (composed of Quercus suber L. and Quercus rotundifolia Lam.) are becoming increasingly fragmented in the human-modified landscapes of Southwestern Portugal and Spain. Previous studies have largely neglected to assess the spatial changes of oak woodlands in re...... patterns of oak recruitment and therefore, its study may be helpful in highlighting future baselines for the sustainable management of oak woodlands....... in relation to their surrounding landscape matrix, and to characterize and quantify woodland boundaries and edges. The present study aims to fill this gap by analyzing fragmentation patterns of oak woodlands over a 50-year period (1958-2007) in three landscapes. Using archived aerial imagery from 1958, 1995...... by shrubland and by new afforestation areas in the oak woodland landscape surrounding matrix, led to the highest values for edge contrast length trends of 5.0 and 12.3, respectively. Linear discriminant analysis was performed to delineate fragmented woodland structures and identify metric variables...

  7. Solar Physics at Evergreen: Solar Dynamo and Chromospheric MHD

    Science.gov (United States)

    Zita, E. J.; Maxwell, J.; Song, N.; Dikpati, M.

    2006-12-01

    We describe our five year old solar physics research program at The Evergreen State College. Famed for its cloudy skies, the Pacific Northwest is an ideal location for theoretical and remote solar physics research activities. Why does the Sun's magnetic field flip polarity every 11 years or so? How does this contribute to the magnetic storms Earth experiences when the Sun's field reverses? Why is the temperature in the Sun's upper atmosphere millions of degrees higher than the Sun's surface temperature? How do magnetic waves transport energy in the Sun’s chromosphere and the Earth’s atmosphere? How does solar variability affect climate change? Faculty and undergraduates investigate questions such as these in collaboration with the High Altitude Observatory (HAO) at the National Center for Atmospheric Research (NCAR) in Boulder. We will describe successful student research projects, logistics of remote computing, and our current physics investigations into (1) the solar dynamo and (2) chromospheric magnetohydrodynamics.

  8. Forest Typification to Characterize the Structure and Composition of Old-growth Evergreen Forests on Chiloe Island, North Patagonia (Chile)

    OpenAIRE

    Jan R. Bannister; Pablo J. Donoso

    2013-01-01

    The Evergreen forest type develops along the Valdivian and North-Patagonian phytogeographical regions of the south-central part of Chile (38° S–46° S). These evergreen forests have been scarcely studied south of 43° S, where there is still a large area made up of old-growth forests. Silvicultural proposals for the Evergreen forest type have been based on northern Evergreen forests, so that the characterization of the structure and composition of southern Evergreen forests, e.g., their typific...

  9. [Effects of conversion of natural broad-leaved forest to Chinese fir plantation on soil respiration in subtropical China].

    Science.gov (United States)

    Zhang, Rui; Bai, Yang; Liu, Juan; Jiang, Pei-kun; Zhou, Guo-mo; Wu, Jia-sen; Tong, Zhi-peng; Li, Yong-fu

    2015-10-01

    Soil CO2 effluxes in natural broad-leaved forest and the conversed Chinese fir plantation in Linglong Mountains Scenic of Zhejiang Province were evaluated by using static closed chamber and gas chromatography method. The results showed that soil CO2 efflux showed consistent seasonal dynamics in natural broad-leaved forest and Chinese fir plantation, with the maximums observed in summer and autumn, the minimums in winter and spring. Soil CO2 effluxes were 20.0-111.3 and 4.1-118.6 mg C . m-2 . h-1 in natural broad-leaved forest and Chinese fir plantation, respectively. The cumulative soil CO2 emission of natural broad-leaved forest (16.46 t CO2 . hm-2 . a-1) was significantly higher than that of Chinese fir plantation (11.99 t CO2 . hm-2 . a-1). Soil moisture did not affect soil CO2 efflux. There was a significant relationship between soil CO2 efflux and soil temperature at 5 cm depth. There was no significant relationship between soil CO2 efflux of natural broad-leaved forest and water soluble organic carbon content, while water soluble organic carbon content affected significantly soil CO2 efflux in Chinese fir plantation. Converting the natural broad-leaved forest to Chinese fir plantation reduced soil CO2 efflux significantly but improved the sensitivity of soil respiration to environmental factors. PMID:26995901

  10. Storage dynamics of fallen trees in a mixed broadleaved and Korean pine forest

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A study of the storage dynamics in the mixed broadleaved and Korean pine forests was carried out in the Changbai Mountains, Jilin Province, P. R. China. The modifying law of fallen trees was the storage dynamics of the existing fallen trees and the annual input in the mixed broadleaved and Korean pine forest. The current storage of fallen trees was 16.25 t?hm-2 in the initially, but after 100 years, 85% of the storage in dry weight was decomposed, and little material was left after 300 years. The average annual input of fallen trees was 0.6 t?hm-2and it increased with time to 31.0 t?hm-2after 200 years, which was maintained until the climax community ended. The total storage of fallen trees increased in the early stage. The decomposition of fallen trees eventually reached equilibrium with storage being identical with the annual input of fallen trees.

  11. Microbial biomass and N mineralization in mixed plantations of broadleaves and nitrogen-fixing species

    OpenAIRE

    Pereira, Ermelinda; SANTOS, Sónia A.P.; Arrobas, Margarida; Claro, Ana Marília; Patrício, Maria do Sameiro

    2010-01-01

    The present study was conducted in a 10-year-old trial of mixed plantation located in the Northeast of Portugal. This study was developed in the three following treatments: pure of Robinia pseudoacacia; pure of Prunus avium and mixed of Prunus avium × Robinia pseudoacacia. To better understand the benefit of the consociation of an N-fixing species (Robinia pseudoacacia) with broadleaves quality timber production (Prunus avium), we compared the soil microbial biomass carbon and nitrogen, soil ...

  12. Evergreen sclerophyllous Quercus forests in northwestern Yunnan, China as compared to the Mediterranean evergreen Quercus forests in California, USA and northeastern Spain

    Directory of Open Access Journals (Sweden)

    C. Q. Tang

    2006-12-01

    Full Text Available Evergreen sclerophyllous Quercus forests in NW Yunnan (China were studied and compared with the Mediterranean evergreen sclerophyllous Quercus forests in central coastal California (USA and Catalonia (NE Spain. Forests of Q. aquifolioides, Q. pannosa, Q. longispica of NW Yunnan, Q. agrifolia of California and Q. ilex of NE Spain were analyzed as representative communities. The similarities and differences at the community level in the contemporary vegetation of the sclerophyllous Quercus forest found in the three regions are clarified. The general patterns of the evergreen Quercus forest in the three regions were similar, though different assemblages of species were involved. The species diversity in all three regions was rather low. The species richness did not significantly differ among the forests, although in the Q. longispica forest it is somewhat higher than the others. The three representative species of evergreen Quercus in NW Yunnan reached the greatest maximum height, while Q. agrifolia of California had the largest basal area per ha. The Q. ilex forest of Spain had the lowest values for maximum tree height and dbh and the highest density per ha. Frequency of dbh size classes indicated that Q. aquifolioides, Q. pannosa, and Q. agrifolia had potentially good regeneration of the sporadic type with highest values for the intermediate size classes, and the regeneration of Q. longispica and Q. ilex was strong as indicated by a reverse-J pattern. Still, in each area, most regeneration was from sprouting. In all three regions the evergreen Quercus species have adapted to environmental changes, for instance by development of sprouting and rooting abilities to resist drought, cold conditions and various disturbances. The evergreen Quercus forests in NW Yunnan were structurally more similar to the Q. agrifolia forest of central coastal California than to the Q. ilex forest of NE Spain.

  13. Hydroponic Screening for Iron Deficiency Tolerance in Evergreen Azaleas

    Directory of Open Access Journals (Sweden)

    Sonia DEMASI

    2015-04-01

    Full Text Available Evergreen azaleas grow in acid soil and suffer from iron deficiency when cultivated in substrate with pH higher than 6.0. In order to select tolerant plants, 11 azalea genotypes were tested for 21 days in alkaline solution (pH 9, buffered with sodium hydrogen carbonate (1 g·l-1. Leaf damage, root length and mortality rate were recorded. While leaf damage and mortality rate allowed to discriminate genotypes, root development appeared not directly linked to iron deficiency tolerance. Rhododendron ‘Juko’, R. scabrum, R. macrosepalum ‘Hanaguruma’, R. x pulchrum ‘Oomurasaki’, and R. x pulchrum ‘Sen-e-oomurasaki’ resulted iron efficient genetic resources, useful for azalea cultivation and gardening in calcareous soils. On the contrary, R. obtusum ‘Kirin’, R. tosaense, R.x mucronatum ‘Fujimanyo’ and R. obtusum ‘Susogo-no-ito’ resulted iron deficiency sensitive genotypes. R. x mucronatum ‘Ryukyushibori’ and R. indicum ‘Kinsai’ showed intermediate responses.

  14. 叶山林场次生阔叶林乔木树种多样性及种间关联分析%Analysis of tree species diversity and interspecific association of tree layer in secondary broad-leaved forest in Yeshan forest-farm

    Institute of Scientific and Technical Information of China (English)

    郝耀锋; 樊丙玉; 吴开华; 黄庆丰

    2012-01-01

    通过铜陵叶山林场次生落叶阔叶林样地调查,对乔木层物种丰富度指数、植物多样性指数、Pielou均匀度指数、生态优势度指数、重要值和种间关联进行分析.结果表明,在12块样地中共有乔木树种19种,平均植物多样性指数、均匀度指数和生态优势度指数分别为1.25、0.70和0.37.优势树种麻栎重要值为105.3,伴生树种化香、枫香和国槐重要值分别为65.1、36.3和18.6.该森林类型为麻栎落叶阔叶混交林.19个树种之间共存在171对相关,但正关联树种对少于负关联树种对,正负关联比小于1,说明该群落类型还处于演替阶段,即由落叶阔叶林向常绿与落叶阔叶混交林过渡阶段.%Based on the investigation of plots, the indexes of species richness, plant diversity, Pielou evenness and ecological dominance, important value and interspecific association of tree layer in secondary broad-leaved forest were calculated and analyzed in Yeshan forest-farm of Tongling county. The results showed that there are 19 tree species in the 12 plots. Mean indexes of plant diversity, evenness and ecological dominance are 1.25, 0.70 and 037, respectively. The important value of dominant tree, Quercus acutissima, is 105.3, and the companion tree species, Platycarya strobilacea, Liquidambar formosana and Sophorajaponica, are 65.1, 36.3 and 18.6, respectively. This forest type is Quercus acutissima deciduous broadleaved mixed forest. One hundred and seventy-one tree species coexist correlation among 19 tree species, but the pairs of the positive associated tree species are less than the negative ones. The ratio between the positive and negative association is less than 1, which mean that this community type is still in successive stage, namely the transition stage from the deciduous broadleaved forest to the evergreen and deciduous broadleaved mixed forest.

  15. Different Patterns of Changes in the Dry Season Diameter at Breast Height of Dominant and Evergreen Tree Species in a Mature Subtropical Forest in South China

    Institute of Scientific and Technical Information of China (English)

    Jun-Hua Yan; Guo-Yi Zhou; De-Qiang Zhang; Xu-Li Tang; Xu Wang

    2006-01-01

    Information on changes in diameter at breast height (DBH) is important for net primary production (NPP)estimates, timing of forest inventory, and forest management. In the present study, patterns of DBH change were measured under field conditions during the dry season for three dominant and native tree species in a monsoon evergreen broad-leaved forest in the Dinghushan Biosphere Reserve. For each tree species,different patterns of DBH change were observed. In the case of the fast-growing tree species Castanopsis chinensis Hance, large diurnal fluctuations occur, with a peak DBH in the early morning (around 05:00 h) that decreases to a minimum by about 14:00 h. Both Schima superba Gardn. et Chemp and Cryptocarya chinensis (Hance) Hemsl. exhibited less diurnal swelling and shrinkage. Diurnal fluctuations for these species were observed on a few occasions over the period of observation. Graphical comparisons and statistical analysis of changes in DBH with meteorological variables indicate that for different trees, the different changes in DBH observed responded to different meteorological variables. Large stem changes were found to occur for Ca. chinensis trees that were associated with variations in solar radiation. However, both S. superba and Cr. chinensis were found to be less sensitive to solar radiation. Changes in the DBH of these two species were found to be controlled mainly by soil temperature and soil moisture. During the later dry season, with a lower soil temperature and soil moisture, all three tree species stopped growing and only negligible shrinkage, expansion, or fluctuation occurred, suggesting that the optimum time to measure tree growth in the Dinghushan Biosphere Reserve is the later dry season.

  16. Manipulation of VOC emissions with methyl jasmonate and carrageenan in the evergreen conifer Pinus sylvestris and evergreen broadleaf Quercus ilex.

    Science.gov (United States)

    Semiz, G; Blande, J D; Heijari, J; Işik, K; Niinemets, U; Holopainen, J K

    2012-03-01

    Plant defence can be induced by exposing plants to the plant hormone jasmonic acid (JA) or its volatile ester, methyl jasmonate (MeJA). Carrageenans (Carr) - sulphated D-galactans extracted from red algae - can also induce plant defences. In this study, the effects of exogenous MeJA and Carr application (concentration 300 and 12.7 μmol, respectively) on volatile emissions from two widespread evergreen woody species, Pinus sylvestris (nine Turkish and one Finnish provenance) and Quercus ilex (Italian provenance) were investigated. We collected headspace samples from seedlings and analysed the quality and quantity of volatile compounds emitted by treated and control plants. In total, 19 monoterpenes, 10 sesquiterpenes, 10 green leaf volatiles (GLVs) and two aromatic compounds were emitted by P. sylvestris from all the provenances studied. Foliar MeJA application clearly affected the volatile profiles of trees from all the provenances. Effects of Carr were genotype specific. In Q. ilex, emissions of sesquiterpenes, GLVs and the homoterpene (E)-DMNT were all induced by MeJA application. However, emissions of most constitutively emitted monoterpenes were significantly reduced. Carr application also led to a significant reduction in monoterpene emissions, but without corresponding increases in other emissions. Our results indicate that exogenously applied MeJA and Carr can both significantly modify the volatile profiles of P. sylvestris and Q. ilex, but also that there are important provenance- and species-specific differences in the overall degree of elicitation and compositions of elicited compounds. PMID:21973325

  17. Protected areas: mixed success in conserving East Africa's evergreen forests.

    Directory of Open Access Journals (Sweden)

    Marion Pfeifer

    Full Text Available In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs are intended to conserve habitats and species. Variability in PA effectiveness and 'leakage' (here defined as displacement of deforestation may lead to different trends in forest loss within, and adjacent to, existing PAs. Here, we quantify spatial variation in trends of evergreen forest coverage in East Africa between 2001 and 2009, and test for correlations with forest accessibility and environmental drivers. We investigate PA effectiveness at local, landscape and national scales, comparing rates of deforestation within park boundaries with those detected in park buffer zones and in unprotected land more generally. Background forest loss (BFL was estimated at -9.3% (17,167 km(2, but varied between countries (range: -0.9% to -85.7%; note: no BFL in South Sudan. We document high variability in PA effectiveness within and between PA categories. The most successful PAs were National Parks, although only 26 out of 48 parks increased or maintained their forest area (i.e. Effective parks. Forest Reserves (Ineffective parks, i.e. parks that lose forest from within boundaries: 204 out of 337, Nature Reserves (six out of 12 and Game Parks (24 out of 26 were more likely to lose forest cover. Forest loss in buffer zones around PAs exceeded background forest loss, in some areas indicating leakage driven by Effective National Parks. Human pressure, forest accessibility, protection status, distance to fires and long-term annual rainfall were highly significant drivers of forest loss in East Africa. Some of these factors can be addressed by adjusting park management. However, addressing close links between livelihoods, natural capital and poverty remains a fundamental challenge in East Africa's forest conservation efforts.

  18. Protected areas: mixed success in conserving East Africa's evergreen forests.

    Science.gov (United States)

    Pfeifer, Marion; Burgess, Neil D; Swetnam, Ruth D; Platts, Philip J; Willcock, Simon; Marchant, Robert

    2012-01-01

    In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs) are intended to conserve habitats and species. Variability in PA effectiveness and 'leakage' (here defined as displacement of deforestation) may lead to different trends in forest loss within, and adjacent to, existing PAs. Here, we quantify spatial variation in trends of evergreen forest coverage in East Africa between 2001 and 2009, and test for correlations with forest accessibility and environmental drivers. We investigate PA effectiveness at local, landscape and national scales, comparing rates of deforestation within park boundaries with those detected in park buffer zones and in unprotected land more generally. Background forest loss (BFL) was estimated at -9.3% (17,167 km(2)), but varied between countries (range: -0.9% to -85.7%; note: no BFL in South Sudan). We document high variability in PA effectiveness within and between PA categories. The most successful PAs were National Parks, although only 26 out of 48 parks increased or maintained their forest area (i.e. Effective parks). Forest Reserves (Ineffective parks, i.e. parks that lose forest from within boundaries: 204 out of 337), Nature Reserves (six out of 12) and Game Parks (24 out of 26) were more likely to lose forest cover. Forest loss in buffer zones around PAs exceeded background forest loss, in some areas indicating leakage driven by Effective National Parks. Human pressure, forest accessibility, protection status, distance to fires and long-term annual rainfall were highly significant drivers of forest loss in East Africa. Some of these factors can be addressed by adjusting park management. However, addressing close links between livelihoods, natural capital and poverty remains a fundamental challenge in East Africa's forest conservation efforts. PMID:22768074

  19. Monitoring Spring Recovery of Photosynthesis and Spectral Reflectance in Temperate Evergreen and Mixed Deciduous Forests

    Science.gov (United States)

    Wong, C. Y.; Arain, M. A.; Ensminger, I.

    2015-12-01

    Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which characterizes their photosynthetic activity with high activity in the growing season and downregulation during the winter season. Monitoring the timing of the transitions in evergreens is difficult since it's a largely invisible process, unlike deciduous trees that have a visible budding and senescence sequence. Spectral reflectance and the photochemical reflectance index (PRI), often used as a proxy for photosynthetic light-use efficiency, provides a promising tool to track the transition of evergreens between inactive and active photosynthetic states. To better understand the relationship between PRI and photosynthetic activity and to contrast this relationship between plant functional types, the spring recovery of an evergreen forest and mixed deciduous forest was monitored using spectral reflectance, chlorophyll fluorescence and gas exchange. All metrics indicate photosynthetic recovery during the spring season. These findings indicate that PRI can be used to observe the spring recovery of photosynthesis in evergreen conifers but may not be best suited for deciduous trees. These findings have implications for remote sensing, which provides a promising long-term monitoring system of whole ecosystems, which is important since their roles in the carbon cycle may shift in response to climate change.

  20. Uptake of perfluoroalkyl acids in the leaves of coniferous and deciduous broad-leaved trees.

    Science.gov (United States)

    Zhang, Huanhuan; Liu, Wei; He, Xin; Wang, Yu; Zhang, Qian

    2015-07-01

    Analytical methods for determining perfluoroalkyl acids (PFAAs) in leaves were developed to quantify a suite of analytes in both coniferous and deciduous broad-leaved trees. Sodium hydroxide-methanol and solid-phase extraction was selected as the extracting and cleanup strategy for PFAA analysis. Ten perfluorocarboxylic acids (PFCAs) and 4 perfluorosulfonic acids (PFSAs) were monitored in 7 kinds of leaves grown in the urban areas of Dalian, China. The results show that coniferous tree leaves take up more PFAAs than broad-leaved tree leaves, with the highest amount of 150 ng/g in pine needles. Leaf PFCA levels were much higher than PFSAs level. Short carbon-chain PFCAs with 3 to 6 perfluorinated carbons account for approximately 40% to 80% of the total leaf PFAAs, where uptake decreased with increasing carbon chain length. Temporal observation of leaf PFAAs revealed no significant variation of concentrations in the leaves over a weekly interval and the absence of significant seasonal change in pine needles and sophora. The present study provides some evidence for the accumulation of PFAAs in leaves, which is valuable for understanding their environmental behavior and the development of alternative bioindicator.

  1. 76 FR 51367 - China Shipping Container Lines Co., Ltd.; COSCO Container Lines Company Limited; Evergreen Line A...

    Science.gov (United States)

    2011-08-18

    ... From the Federal Register Online via the Government Publishing Office FEDERAL MARITIME COMMISSION China Shipping Container Lines Co., Ltd.; COSCO Container Lines Company Limited; Evergreen Line A Joint... Container Lines Co., Ltd.; COSCO Container Lines Company Limited; Evergreen Line A Joint Service...

  2. 75 FR 76727 - Evergreen Wind Power III, LLC; Supplemental Notice that Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2010-12-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Evergreen Wind Power III, LLC; Supplemental Notice that Initial Market-Based... supplemental notice in the above-referenced proceeding of Evergreen Wind Power III, LLC's application...

  3. Silvicultural interpretation of natural vegetation dynamics in ageing Scots pine stands for their conversion into mixed broadleaved stands

    NARCIS (Netherlands)

    Kint, V.; Geudens, G.; Mohren, G.M.J.; Lust, N.

    2006-01-01

    In many West-European regions there is principal consensus on the conversion of homogeneous even-aged Scots pine plantations into mixed broadleaved stands. In recent years, interest is growing for conversion management in which managers try to maximise the use of natural processes by steering or acc

  4. A Study of Full-Time Faculty Burnout at Evergreen Valley College.

    Science.gov (United States)

    Johnson, Tanya

    In fall 1988, a study of full-time faculty and staff was conducted at Evergreen Valley College (EVC) to identify factors contributing to burnout and to create opportunities to allievate the problem. The Maslach Burnout Inventory (MBI) was used to assess the level of burnout among full-time faculty, administrators, and classified staff at EVC and…

  5. A Listening Laboratory Designed from Cognitive Learning Principles at Evergreen Valley College.

    Science.gov (United States)

    Johnson, Tanya

    A listening laboratory was developed at Evergreen Valley College (EVC) in accordance with procedures used at the college's individualized instruction laboratory. Steps taken in developing the laboratory included: (1) the director of the Learning Center Instructional Laboratory was interviewed to determine the procedure for establishing the…

  6. Developing an Interlibrary Loan Borrowing Policy for Evergreen Valley College Library Patrons. Governance and Management.

    Science.gov (United States)

    Poehlmann, Ruth I.

    The increased use of interlibrary loan (ILL) services at the Evergreen Valley College (EVC) library which resulted from joining OCLC automated Interlibrary Loan subsystem in 1979 led to the development of an Interlibrary Loan Borrowing Policy by the EVC library staff. The policy is designed to explain to library patrons the limitations on…

  7. An Assessment of the Level of Faculty Burnout at Evergreen Valley College.

    Science.gov (United States)

    Johnson, Tanya

    A study was conducted at Evergreen Valley College (EVC), California, to assess the level of faculty burnout and to determine the need for personal and organizational interventions to reduce burnout and improve morale. The Maslach Burnout Inventory (MBI) was administered to all 105 full-time faculty at EVC, and scores for the MBI subscales of…

  8. Why Do Some Evergreen Species Keep Their Leaves for a Second Winter, While Others Lose Them?

    Directory of Open Access Journals (Sweden)

    Peter J. Grubb

    2014-10-01

    Full Text Available In subtropical montane semi-moist forest in SW China (SMSF, a large majority of evergreen tree and tall shrub species was found to have only one cohort of old leaves in early spring. In contrast, almost all species of evergreen tree and tall shrub in warm temperate rain forest (WTRF in Japan and sclerophylls in Mediterranean-climate forest (MSF of the Mediterranean Basin have two or more cohorts of old leaves in early spring; they drop their oldest cohort during or soon after leaf outgrowth in spring. Japanese WTRF has no dry season and MSF a dry summer. SMSF has a dry winter. On four evergreen Rhododendron species from SW China with only one cohort of old leaves in spring when in cultivation in Scotland, the majority of leaves in the senescing cohort fell by the end of December. We hypothesize that with dry winters, there is an advantage to dropping older leaves in autumn, because there is a low chance of appreciable positive assimilation in winter and a high chance of desiccation, reducing the resorption of dry mass and mineral nutrients from ageing leaves. Our hypothesis may be extended to cover evergreens at high altitude or high latitude that experience cold soils in winter.

  9. Comparative study on active soil organic matter in Chinese fir plantation and native broad-leaved forest in subtropical China

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-kui; WANG Si-long; DENG Shi-jian

    2005-01-01

    Active soil organic matter (ASOM) has a main effect on biochemical cycles of soil nutrient elements such as N, P and S, and the quality and quantity of ASOM reflect soil primary productivity. The changes of ASOM fractions and soil nutrients in the first rotation site and the second rotation site of Chinese fir plantation and the native broad-leaved forest were investigated and analyzed by soil sampling at the Huitong Experimental Station of Forestry Ecology (at latitude 26°48′N and longitude 109°30′E under a subtropical climate conditions), Chinese Academy of Sciences in March, 2004. The results showed that values of ASOM fractions for the Chinese fir plantations were lower than those for the broad-leaved forest. The contents of easily oxidisable carbon (EOC), microbial biomass carbon (MBC), water soluble carbohydrate (WSC) and water-soluble organic carbon (WSOC) for the first rotation of Chinese fir plantation were 35.9%, 13.7%, 87.8% and 50.9% higher than those for the second rotation of Chinese fir plantation, and were 15.8%, 47.3%, 38.1% and 30.2% separately lower than those for the broad-leaved forest. For the three investigated forest sites, the contents of MBC and WSOC had a larger decrease, followed by WSC, and the change of EOC was least. Moreover, soil physico-chemistry properties such as soil nutrients in Chinese fir plantation were lower than those in broad-leaved forest. It suggested that soil fertility declined after Chinese fir plantation replaced native broad-leaved forest through continuous artificial plantation.

  10. 叶山次生落叶阔叶林主要树种空间结构特征%Spatial structure characteristics of main tree species in secondary deciduous broad-leaved forest in Yeshan

    Institute of Scientific and Technical Information of China (English)

    樊丙玉; 郝耀锋; 吴开华; 黄庆丰

    2012-01-01

    deciduous broadleaved forest to the evergreen and deciduous broadleaved mixed forest.

  11. [Soil moisture dynamics under broad-leaved Korean pine forest in Changbai Mountains].

    Science.gov (United States)

    Yang, Hong; Pei, Tiefan; Guan, Dexin; Jin, Changjie; Wang, Anzh

    2006-04-01

    The located observation on the soil moisture dynamics under broad-leaved Korean pine forest in Changbai Mountains in 1990 - 1992 and 2003 showed that the seasonal variation of soil moisture content could be divided into five periods, i. e., gathering water stage in spring, consuming water stage in arid season, holding water stage in rainy season, losing water stage in autumn, and relatively stable stage of soil moisture in winter-spring. By using standard deviation and variation coefficient, the vertical layers of soil moisture were divided into rapid change layer, active layer, and sub-active layer. Correlation analysis was applied to analyze the relationships of moisture content among different soil layers and the correlation between soil moisture and precipitation in the same period. PMID:16836083

  12. Modeling diameter distribution of the broadleaved-Korean pine mixed forest on Changbai Mountains of China

    Institute of Scientific and Technical Information of China (English)

    WANG Shunzhong; DAI Limin; LIU Guohua; YUAN Jianqiong; ZHANG Hengmin; WANG Qingli

    2006-01-01

    The broadleaved-Korean pine mixed forest is a native vegetation in the Changbai Mountains, northeast China. The probability density functions including the normal, negative exponential, Weibull and finite mixture distribution, were used to describe the diameter distributions of the species groups and entire forest stand. There is a strong correlation between parameters and mean DBH except the shape parameters in the mixture distribution. The diameter classes of species and entire forest stand showed not negative exponential but normal and "S" distribution. The mixture function was better than normal and Weibull to describe the model distribution. The location parameter had an effect on the estimated frequency in the first diameter class, when the estimated location parameter was bigger than the lower limit of the first diameter class.

  13. Forest Typification to Characterize the Structure and Composition of Old-growth Evergreen Forests on Chiloe Island, North Patagonia (Chile

    Directory of Open Access Journals (Sweden)

    Jan R. Bannister

    2013-11-01

    Full Text Available The Evergreen forest type develops along the Valdivian and North-Patagonian phytogeographical regions of the south-central part of Chile (38° S–46° S. These evergreen forests have been scarcely studied south of 43° S, where there is still a large area made up of old-growth forests. Silvicultural proposals for the Evergreen forest type have been based on northern Evergreen forests, so that the characterization of the structure and composition of southern Evergreen forests, e.g., their typification, would aid in the development of appropriate silvicultural proposals for these forests. Based on the tree composition of 46 sampled plots in old-growth forests in an area of >1000 ha in southern Chiloé Island (43° S, we used multivariate analyses to define forest groups and to compare these forests with other evergreen forests throughout the Archipelago of North-Patagonia. We determined that evergreen forests of southern Chiloé correspond to the North-Patagonian temperate rainforests that are characterized by few tree species of different shade tolerance growing on fragile soils. We discuss the convenience of developing continuous cover forest management for these forests, rather than selective cuts or even-aged management that is proposed in the current legislation. This study is a contribution to forest classification for both ecologically- and forestry-oriented purposes.

  14. Correlations between canopy gaps and species diversity in broad-leaved and Korean pine mixed forests

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiuhai; ZHANG Chunyu; ZHENG Jingming

    2006-01-01

    Regeneration of tree species associated with canopy gaps in broad-leaved Korean pine forests was investigated.Species diversity in gaps and under closed canopy was compared,the relationship between biodiversity and gap structure was analyzed.Results indicate that there were significant differences between tree species diversity in gaps and that under canopy (p<0.01).In terms of Shannon-Wiener index,evenness index,and abundance index,the biodiversity in gap community were higher than those under forest canopy in regeneration layer.In terms of Simpson's dominance index,the dominance of certain species in the regeneration layer increased from gaps to closed canopy (p<0.01).In contrast,trends of biodiversity changes of succession layer in gaps and under closed canopy were opposite.Tree species diversity of different layers reacted directly to the change of gap size class.For example,Shannon-Wiener index and abundance index is higher and Simpson's dominance index is the lowest in succession layer of medium-size gap (100-250 m2) in the broad-leaved Korean pine forest of Changbai Mountains.Shannon-Wiener index reached the highest in a size of≥250 m2 and<100 m2,reached the lowest in a size of 200-250 m2 in the regeneration layer.Simpson's dominance index reached its maximum when the gap size was between 200 and 250m2.Generally,species of different layers reacted differently to the changes of gap size classes.The gap size class with more seedlings did not correspond to size class containing more medium-size trees.Tree species diversity indices in the two layers behaved reciprocally during the development process of forest gaps.

  15. The impact of boreal deciduous and evergreen forests on atmospheric CO2 seasonality

    Science.gov (United States)

    Welp, L.; Graven, H. D.; Keeling, R. F.; Bi, J.

    2015-12-01

    The seasonal cycle of atmospheric CO2 is largely controlled by the terrestrial biosphere. It is well known that the seasonal amplitude of net ecosystem productivity (NEP) is the largest in the far north, where forest productivity is compressed into a short growing season. Since 1960, the seasonal amplitude of atmospheric CO2 north of 45N has increased by 35-55%. The increase in the seasonal amplitude is a difficult benchmark for coupled climate-carbon models to replicate. In fact, the models vary widely in their mean seasonal cycle representation. The boreal region has a strong influence on CO2 seasonality at Barrow. Deciduous and evergreen plant functional types (PFTs) have different patterns of NEP. We identified four pairs of nearby deciduous and evergreen forest PFTs with eddy covariance measurements. Evergreen forests show an early peak in NEP in May-June, while deciduous forests have a larger peak in NEP later in June-July. The influence of each PFT on the seasonal cycle at Barrow was computed from atmospheric transport results. We normalized the amplitude influence by the growing season NEP of the tower-based PFT flux and found that deciduous forests have 1.4 to 1.8 times more influence (per unit of growing season NEP) at Barrow than evergreen PFT. This diagnosis depends on the timing of the sharp seasonal draw-down at Barrow, which occurs too late to be explained by evergreen forests. The cycle at Barrow therefore appears to be strongly influenced by deciduous PFT, despite the dominance of evergreen PFTs in boreal forests. This paradoxical conclusion is also reached when examining the seasonality of land surface fluxes calculated using atmospheric inverse methods. We examine how these different PFTs, and possible trends in relative abundance, affect the seasonality of atmosphere CO2 using FluxNet data and atmospheric transport modelling. Our results highlight the importance of parameterizing multiple PFTs or individual species within grid cells in models in

  16. 常绿阔叶林中栲树展叶期叶片的虫食格局%INSECT HERBIVORY PATTERNS ON LEAVES OF CASTANOPSIS FARGESII DURING LEAF EXPANSION IN EVERGREEN BROAD-LEAVED FOREST IN EASTERN CHINA

    Institute of Scientific and Technical Information of China (English)

    刘志国; 蔡永立; 李恺; 杨乐; 孙灿

    2009-01-01

    叶片的虫食主要发生在展叶期.虽然展叶期短暂,它却可能是了解植食性昆虫和植物之间相互关系的关键.为了解栲树(Castanopsis fargesii)在展叶期叶片的虫食格局和展叶方式对叶片虫食的影响,研究了栲树展叶期内的虫食动态变化,结果表明:栲树展叶的两个阶段(折叠期和打开期),虫食叶片的格局存在较大的差异,打开阶段的日虫食频度和日虫食率显著高于折叠阶段(F1,32=8.97,P=0.005 4;F1,32=12.38,P=0.001 4),展叶期最终叶片虫食频度为50.72%,叶片虫食率为8.25%.折叠期叶片主要受到低强度的虫食,打开期叶片虫食则以较大强度的虫食为主.展叶期叶片的虫食主要发生在夜间,夜间虫食率显著高于日间虫食率(t=2.51,p=0.017),变化趋势与日虫食率一致.栲树叶片在展叶的两个阶段可能采用了不同的防御对策.

  17. 凋落叶空间扩散模型在常绿阔叶林的适用性分析%Applicability analysis of spatially explicit model of leaf litter in evergreen broad-leaved forests

    Institute of Scientific and Technical Information of China (English)

    赵青青; 刘何铭; Mathieu Jonard; 王樟华; 王希华

    2014-01-01

    利用凋落叶空间扩散模型研究单株植物的凋落叶扩散过程,这对预测凋落叶在地表的分布格局有重要意义.本文依据浙江天童20 hm2动态监测样地植被调查数据和叶凋落量数据,分别对20种目标树种进行凋落叶空间扩散模型的拟合,以及模型适用性分析.模型假设叶凋落量和植株胸径之间服从异速生长关系,并且叶凋落量随距离呈指数降低,通过极大似然法估计模型参数.结果表明:所有树种实际叶凋落量和理论叶凋落量相关性显著;但树种间的模型预测精度相差较大,各树种理论叶凋落量解释实际叶凋落量变异的百分比为16.0% ~ 74.0%,平均为49.3%.模型预测精度与叶凋落量数据的标准差、树种平均胸径、树种平均叶片干质量呈显著正相关.根据各树种的分布格局,使凋落物筐覆盖到不同胸径母树周围不同距离处,确定各树种的最优扩散函数,以及不断改进已有的扩散函数可以提高模型的预测精度.

  18. Storm damage in a montane evergreen broadleaved forest of Chebaling National Nature Reserve, South China%车八岭山地常绿阔叶林冰灾后林木受损的生态学评估

    Institute of Scientific and Technical Information of China (English)

    苏志尧; 刘刚; 区余端; 戴朝晖; 李镇魁

    2010-01-01

    从植物生态学的角度对2008年初南方冻雨冰雪灾害对典型的亚热带山地常绿阔叶林造成的损害情况做了研究.对12个优势种和亚优势种的受灾情况做了对比分析,对不同径级和不同地形因子下林木抵抗冻雨灾害的差异做了对比.统计检验结果显示林木受损程度存在显著的种间差异、径级差异和地形级差异.优势种米槠(Castanopsis carlesii)比多数亚优势种受害更严重;各树种抗冻雨灾害能力以山茶科和樟科的种较强,而壳斗科的多个种,如米槠、栲(C. fargesii)受灾较为严重;林木的受损比例随着胸径(diameter at breast height,DBH)增加而增大;在未受灾的各级林木中,超过70%的个体集中在最小一级径阶(1-5 cm).X~2检验显示坡度、坡向、坡位等地形因子对林木受损状况有显著的影响,随着坡位上升,林木受损程度逐渐加重,上坡位的林木受损比例最大,下坡位最小,这可能与随着坡位升高,迎风面降温效果更迅速有关.对于坡向和坡度而言,位于半阳坡的林木受灾比例显著高于半阴坡,位于坡度级Ⅲ(15°-25°)、Ⅳ(25°-35°)、Ⅴ(35°-45°)上的林木受灾最严重.该研究结果对于亚热带常绿阔叶林的保育和应对未来可能再次发生的冰雪,火害有重要意义; 同时对于森林恢复和演替、乡土阔叶树种的选育及森林经营等方面的研究和应用也有重要的参考价值.

  19. DETECTING EFFECT OF PHYLOGENETIC DIVERSITY ON SEEDLING MORTALITY IN AN EVERGREEN BROAD-LEAVED FOREST IN CHINA%常绿阔叶林谱系多样性对幼苗存活率的影响

    Institute of Scientific and Technical Information of China (English)

    陈英

    2009-01-01

    密度制约机制对于维护生物多样性有非常重要的作用.随着对密度制约机制的深入研究,人们逐渐认识到:不仅在种内存在密度制约效应,亲缘关系相近的物种之间也可能表现出密度制约效应.webb在2000年提山的NRI(净种间亲缘关系指数)、NTI(净最近种间亲缘关系指数)考虑了比较全面的谱系信息,获得了广泛的应用.该文采用NRI、NTI来代表种间关系,并用Logistic回归模犁来分析了谱系因子对浙江省开化县古田山自然保护区24hm~2永久监测样地中501个幼苗样方死亡率的影响.通过对6次幼苗调查数据的分析表明:不仅相同物种密度对于幼苗的死亡率有显著影响,当密度达到一定水平时,谱系因子同样也对幼苗的死亡率有显著影响苗区中个体间的亲缘关系越近,幼苗个体的死亡率越高.%Aims Negative density dependence plays an important role in maintaining forest biodiversity. Ecologists found this mechanism operates not only between conspecifics but also between closely related heterospecifics. Our objective was to determine whether phylogenetic diversity affects seedling mortality at different scales.Methods We used net relatedness index (NRI) and nearest taxon index (NTI) to represent phylogenetic diversity and employed logistic regression modeling. We analyzed the relationship between seedling mortality and phylogenetic diversity using the seedling dynamic data from six seedling censuses of 507 seedling plots at Gutianshan Nature Reserve during May 2006 and November 2007. Important findings We found that higher density of conspecifics resulted in higher seedling mortality, and phylogenetic diversity was responsible for seedling mortality when seedling density was high (>3.46 individuals·m~(-2)).

  20. Transformation of Carbon and Nitrogen by Earthworms in the Decomposition Processes of Broad-leaved Litters

    Institute of Scientific and Technical Information of China (English)

    DONG Weihua; YIN Xiuqin

    2007-01-01

    Earthworms are the important constituents in the decayed food web and the main ecological conditioners in the process of decomposition and nutrient mineralization. The transformation of organic carbon (C) and total nitrogen (N) in the broad-leaved litters ingested by earthworms was researched by means of a laboratory experiment. Experimental samples were collected from broad-leaved Korea Pine mixed forest in Liangshui National Natural Reserve (47°10'50"N, 128°53'20"E) in the northeastern Xiao Hinggan Mountains of Northeast China. The contents of organic C and total N in earthworms, leaf litters and earthworm faeces were analyzed. Results show that the organic C content was in the following order: leaf litters>faeces>earthworms, while total N content was contrary to that of the organic C. The organic C contents in the different leaf litters were in the following order: Tilia amurensis>Betula costata>Acer mono, whereas the total N contents in the different leaf litters were: Betula costata>Tilia amurensis>Acer mono. The contents of organic C and total N in the faeces from the different leaf litters were almost consistent with the contents of the leaf litters. After the leaf litters were ingested by earthworms, the organic C, which was transformed to increase earthworms' weights, accounted for 3.90%-13.31% of the total ingestion by earthworms, while that in the earthworm faeces accounted for 6.14%-13.70%. The transformed organic C through the other metabolism (e.g., respiration) of earthworms accounted for 75.04%-89.92%. The ingested organic C by earthworms was mostly used for metabolic activities. The N ingested by earthworms was less than organic C. It is estimated that 37.08% of total N was transformed to increase the earthworm's weight, 19.97% into earthworm faeces and 47.86% for the consumption of the earthworm's activities. The earthworms not only increased the content of organic C and total N in the soil, but also decreased the values of C/N in

  1. Estimate of productivity in ecosystem of the broad-leaved Korean pine mixed forest in Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>We measured soil, stem and branch respiration of trees and shrubs, foliage photosynthesis and respiration in ecosystem of the needle and broad-leaved Korean pine forest in Changbai Mountain by LI-6400 CO2 analysis system. Measurement of forest microclimate was conducted simultaneously and a model was found for the relationship of soil, stem, leaf and climate factors. CO2 flux of different components in ecosystem of the broad-leaved Korean pine forest was estimated based on vegetation characteristics. The net ecosystem exchange was measured by eddy covariance technique. And we studied the effect of temperature and photosynthetic active radiation on ecosystem CO2 flux. Through analysis we found that the net ecosystem exchange was affected mainly by soil respiration and leaf photosynthesis. Annual net ecosystem exchange ranged from a minimum of about -4.671μmol·m-2·s-1 to a maximum of 13.80μmol·m-2·s-1, mean net ecosystem exchange of CO2 flux was -2.0μmol·m-2·s-1 and 3.9μmol·m-2·s-1 in winter and summer respectively (mean value during 24 h). Primary productivity of tree, shrub and herbage contributed about 89.7%, 3.5% and 6.8% to the gross primary productivity of the broad-leaved Korean pine forest respectively. Soil respiration contributed about 69.7% CO2 to the broad-leaved Korean pine forest ecosystem, comprising about 15.2% from tree leaves and 15.1% from branches. The net ecosystem exchange in growing season and non-growing season contributed 56.8% and 43.2% to the annual CO2 efflux respectively. The ratio of autotrophic respiration to gross primary productivity (Ra:GPP) was 0.52 (NPP:GPP=0.48). Annual carbon accumulation underground accounted for 52% of the gross primary productivity, and soil respiration contributed 60% to gross primary productivity. The NPP of the needle and broad-leaved Korean pine forest was 769.3 gC·m-2·a-1. The net ecosystem exchange of this forest ecosystem (NEE) was 229.51 gC·m-2·a-1. The NEE of this forest ecosystem

  2. Unmanned aerial survey of fallen trees in a deciduous broadleaved forest in eastern Japan.

    Science.gov (United States)

    Inoue, Tomoharu; Nagai, Shin; Yamashita, Satoshi; Fadaei, Hadi; Ishii, Reiichiro; Okabe, Kimiko; Taki, Hisatomo; Honda, Yoshiaki; Kajiwara, Koji; Suzuki, Rikie

    2014-01-01

    Since fallen trees are a key factor in biodiversity and biogeochemical cycling, information about their spatial distribution is of use in determining species distribution and nutrient and carbon cycling in forest ecosystems. Ground-based surveys are both time consuming and labour intensive. Remote-sensing technology can reduce these costs. Here, we used high-spatial-resolution aerial photographs (0.5-1.0 cm per pixel) taken from an unmanned aerial vehicle (UAV) to survey fallen trees in a deciduous broadleaved forest in eastern Japan. In nine sub-plots we found a total of 44 fallen trees by ground survey. From the aerial photographs, we identified 80% to 90% of fallen trees that were >30 cm in diameter or >10 m in length, but missed many that were narrower or shorter. This failure may be due to the similarity of fallen trees to trunks and branches of standing trees or masking by standing trees. Views of the same point from different angles may improve the detection rate because they would provide more opportunity to detect fallen trees hidden by standing trees. Our results suggest that UAV surveys will make it possible to monitor the spatial and temporal variations in forest structure and function at lower cost.

  3. Microenvironmental heterogeneity of physical soil properties in a broad-leaved Pinus koraiensis forest gap

    Institute of Scientific and Technical Information of China (English)

    Wenbiao DUAN; Jing WANG; Yan LI

    2009-01-01

    Microenvironmental heterogeneity of soil phy-sical properties in 0-20 cm and 20-40 cm soil layers in a broad-leaved Pinus koraiensis forest gap in Xiao Xing'anl-ing Mountains were analyzed by geostatistical method.The results show that the amount of soil water, saturation water capacity, capillary water capacity and porosity in the top layer were greater than those in the lower layer, except for bulk density, where the opposite applied. Soil physical properties in the top soil layer had relatively higher ranges and coefficients of variation. The total and auto correlation spatial heterogeneity of soil physical properties in the top layer were larger than those in the lower layer. The soil water had a strong anisotropic structure in an easterly and northerly direction, but porosity shows isotropy in the same directions. With increasing spatial distance, the other three physical factors exhibited anisotropic structures. The mutual effect between semi-variograms of soil physical properties in the top layer within the spatial autocorrelation range was not significant. For spatial distribution of physical properties within different layers, the patches at the middle and lower ranks in the forest gap dominated.Patches at higher rank were only distributed in the 0-20 cm soil layer and were located north of the forest gap center.

  4. [Energy balance and evapotranspiration in broad-leaved Korean pine forest in Changbai Mountains].

    Science.gov (United States)

    Zhang, Xin-jian; Yuan, Feng-hui; Chen, Ni-na; Deng, Jun-li; Yu, Xiao-zhou; Sheng, Xue-jiao

    2011-03-01

    Based on the continuous measurements of an open-path eddy covariance system, this paper analyzed the characteristics of energy balance components and evapotranspiration in a broad-leaved Korean pine forest in Changbai Mountains in 2008, as well as the differences of energy balance components and evapotranspiration between growth season and dormant season. For the test forest, the year-round energy balance closure was 72%, being at a medium level, compared to the other studies in the Fluxnet community. The energy balance components had significant differences in their diurnal and seasonal variations. In growth season, turbulent energy exchange was dominated by upward latent heat flux, accounting for 66% of available energy; while in dormant season, the turbulent energy exchange was dominated by upward sensible heat flux, accounting for 63% of available energy. The accumulated annual evapotranspiration in the study site in 2008 was 484.7 mm, occupying 87% of the precipitation at the same time period (558.9 mm), which demonstrated that evapotranspiration was the main water loss item in temperate forests of northern China.

  5. Pollen flux and vertical dispersion in coniferous and deciduous broadleaved mixed forest in the Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    XU QingHai; LI YueCong; ZHOU LiPing; LI YiYin; ZHANG ZhenQing; LIN FengYou

    2007-01-01

    The pollen flux in coniferous and deciduous broadleaved mixed forest in the Changbai Mountains is presented in one year's experiments. The results indicate that arboreal pollen percentages are more than 65% and pollen flux is higher than 5000 grain·cm-2·a-1, while less than 2% and lower than 1000 grain·cm-2·a-1 for shrubby pollen, and less than 20% and lower than 3000 grain·cm-2·a-1 for herbaceous pollen for most samples at different heights. The pollen assemblages are similar to those in the samples under 8 m height where Pinus and Quercus are dominant and followed by the few non-local pollen types, and Fraxinus percentages are high with a few non-local pollen types at 16 m to 32 m height as well as non-local pollen clearly increased at 40 m height. Comparisons between pollen assemblages and vegetation composition suggest that similarities are higher for pollen trap samples than for surface moss samples.

  6. [Macropore characteristics and its relationships with the preferential flow in broadleaved forest soils of Simian Mountains].

    Science.gov (United States)

    Wang, Wei; Zhang, Hong-jiang; Cheng, Jin-hua; Wu, Yu-he; Du, Shi-cai; Wang, Ran

    2010-05-01

    Brilliant blue dyeing and water breakthrough curve were applied to study the number and distribution of macropores and their relations to the preferential flow in typical sub-tropic broad-leaved forest soils of Simian Mountains. The radii of the macropores were mainly between 0. 3 and 3.0 mm, with the macroporosities in the range of 6.3% to 10.5%, and the macropores were always distributed in aggregation with increasing soil depth. The number of the macropores in each radius interval of dye-stained areas was tenfold increase than that of blank areas. The number of the macropores with radius larger than 0.3 mm, especially larger than 1.5 mm, was the most important factor affecting the occurrence of preferential flow. Significant correlations were found between the number of macropores and the water steady effluent volume, with the highest correlation coefficients of 0.842 and 0.879 for the radii intervals of 0.7-1.5 mm and 1.5-3.0 mm, respectively. Macro-pore continuity in dye-stained areas was better than that in blank areas, especially in the radius interval of 1.5-3.0 mm, with the biggest difference of 78.31%. In dye-stained areas, the number of macropores decreased gradually with soil depth. The filler-like distribution of macropores formed an effective water pressure gradient, which resulted in the preferential transport of water. PMID:20707104

  7. Contrasting seasonal leaf habits of canopy trees between tropical dry-deciduous and evergreen forests in Thailand.

    Science.gov (United States)

    Ishida, Atsushi; Diloksumpun, Sapit; Ladpala, Phanumard; Staporn, Duriya; Panuthai, Samreong; Gamo, Minoru; Yazaki, Kenichi; Ishizuka, Moriyoshi; Puangchit, Ladawan

    2006-05-01

    We compared differences in leaf properties, leaf gas exchange and photochemical properties between drought-deciduous and evergreen trees in tropical dry forests, where soil nutrients differed but rainfall was similar. Three canopy trees (Shorea siamensis Miq., Xylia xylocarpa (Roxb.) W. Theob. and Vitex peduncularis Wall. ex Schauer) in a drought-deciduous forest and a canopy tree (Hopea ferrea Lanessan) in an evergreen forest were selected. Soil nutrient availability is lower in the evergreen forest than in the deciduous forest. Compared with the evergreen tree, the deciduous trees had shorter leaf life spans, lower leaf masses per area, higher leaf mass-based nitrogen (N) contents, higher leaf mass-based photosynthetic rates (mass-based P(n)), higher leaf N-based P(n), higher daily maximum stomatal conductance (g(s)) and wider conduits in wood xylem. Mass-based P(n) decreased from the wet to the dry season for all species. Following onset of the dry season, daily maximum g(s) and sensitivity of g(s) to leaf-to-air vapor pressure deficit remained relatively unchanged in the deciduous trees, whereas both properties decreased in the evergreen tree during the dry season. Photochemical capacity and non-photochemical quenching (NPQ) of photosystem II (PSII) also remained relatively unchanged in the deciduous trees even after the onset of the dry season. In contrast, photochemical capacity decreased and NPQ increased in the evergreen tree during the dry season, indicating that the leaves coped with prolonged drought by down-regulating PSII. Thus, the drought-avoidant deciduous species were characterized by high N allocation for leaf carbon assimilation, high water use and photoinhibition avoidance, whereas the drought-tolerant evergreen was characterized by low N allocation for leaf carbon assimilation, conservative water use and photoinhibition tolerance. PMID:16452078

  8. Whole-plant allocation to storage and defense in juveniles of related evergreen and deciduous shrub species.

    Science.gov (United States)

    Wyka, T P; Karolewski, P; Żytkowiak, R; Chmielarz, P; Oleksyn, J

    2016-05-01

    In evergreen plants, old leaves may contribute photosynthate to initiation of shoot growth in the spring. They might also function as storage sites for carbohydrates and nitrogen (N). We hence hypothesized that whole-plant allocation of carbohydrates and N to storage in stems and roots may be lower in evergreen than in deciduous species. We selected three species pairs consisting of an evergreen and a related deciduous species: Mahonia aquifolium (Pursh) Nutt. and Berberis vulgaris L. (Berberidaceae), Prunus laurocerasus L. and Prunus serotina Ehrh. (Rosaceae), and Viburnum rhytidophyllum Hemsl. and Viburnum lantana L. (Adoxaceae). Seedlings were grown outdoors in pots and harvested on two dates during the growing season for the determination of biomass, carbohydrate and N allocation ratios. Plant size-adjusted pools of nonstructural carbohydrates in stems and roots were lower in the evergreen species of Berberidaceae and Adoxaceae, and the slope of the carbohydrate pool vs plant biomass relationship was lower in the evergreen species of Rosaceae compared with the respective deciduous species, consistent with the leading hypothesis. Pools of N in stems and roots, however, did not vary with leaf habit. In all species, foliage contained more than half of the plant's nonstructural carbohydrate pool and, in late summer, also more than half of the plant's N pool, suggesting that in juvenile individuals of evergreen species, leaves may be a major storage site. Additionally, we hypothesized that concentration of defensive phenolic compounds in leaves should be higher in evergreen than in deciduous species, because the lower carbohydrate pool in stems and roots of the former restricts their capacity for regrowth following herbivory and also because of the need to protect their longer-living foliage. Our results did not support this hypothesis, suggesting that evergreen plants may rely predominantly on structural defenses. In summary, our study indicates that leaf habit has

  9. Is Patent "Evergreening" Restricting Access to Medicine/Device Combination Products?

    Directory of Open Access Journals (Sweden)

    Reed F Beall

    Full Text Available Not all new drug products are truly new. Some are the result of marginal innovation and incremental patenting of existing products, but in such a way that confers no major therapeutic improvement. This phenomenon, pejoratively known as "evergreening", can allow manufacturers to preserve market exclusivity, but without significantly bettering the standard of care. Other studies speculate that evergreening is especially problematic for medicine/device combination products, because patents on the device component may outlast expired patents on the medicine component, and thereby keep competing, possibly less-expensive generic products off the market.We focused on four common conditions that are often treated by medicine/device product combinations: asthma and chronic obstructive pulmonary disease (COPD, diabetes, and severe allergic reactions. The patent data for a sample of such products (n = 49 for treating these conditions was extracted from the United States Food and Drug Administration's Orange Book. Additional patent-related data (abstracts, claims, etc were retrieved using LexisNexis TotalPatent. Comparisons were then made between each product's device patents and medicine patents.Unexpired device patents exist for 90 percent of the 49 medicine/device product combinations studied, and were the only sort of unexpired patent for 14 products. Overall, 55 percent of the 235 patents found by our study were device patents. Comparing the last-to-expire device patent to that of the last-to-expire active ingredient patent, the median additional years of patent protection afforded by device patents was 4.7 years (range: 1.3-15.2 years.Incremental, patentable innovation in devices to extend the overall patent protection of medicine/device product combinations is very common. Whether this constitutes "evergreening" depends on whether these incremental innovations and the years of extra patent protection they confer are proportionately matched by

  10. The effect of wind velocity on transpiration in a mixed broadleaved deciduous forest

    Science.gov (United States)

    Kim, D.; Oren, R.; Oishi, A. C.; Hsieh, C.; Phillips, N. G.; Novick, K. A.; Stoy, P. C.

    2013-12-01

    Wind velocity (U) within and above forest canopies can alter the coupling between the vapor-saturated sub-stomatal airspace and the drier atmosphere aloft, thereby influencing transpiration rates. In practice, however, the actual increase in transpiration with increasing U depends on the aerodynamic resistance (RA) to vapor transfer compared to canopy resistance to water vapor flux out of leaves (RC, dominated by stomatal resistance, Rstom), and the rate at which RA decreases with increasing U. We investigated the effect of U on transpiration at the canopy scale using filtered meteorological data and sap flux measurements gathered from six diverse species of a mature broadleaved deciduous forest. Only under high light conditions, stand transpiration (EC) increased slightly (6.5%) with increasing U ranging from ~0.7 to ~4.7 m s-1. Under other conditions, sap flux density (Js) and EC responded weakly or did not change with U. RA, estimated from Monin-Obukhov similarity theory, decreased with increasing U, but this decline was offset by increasing RC, estimated from a rearranged Penman-Monteith equation, due to a concurrent increase in vapor pressure deficit (D). The increase of RC with D over the observed range of U was consistent with increased Rstom by ~40% based on hydraulic theory. Except for very rare half-hourly values, the proportion of RA to total resistance (RT) remained accounting for the effects of U-D relationship on Rstom would reduce the uncertainty of modeling canopy gas exchange more than accounting for the direct effect of U on RA.

  11. Callus formation impedes adventitious rhizogenesis in air layers of broadleaved tree species

    Directory of Open Access Journals (Sweden)

    Sanjay Singh

    2014-07-01

    Full Text Available Callusing and root induction in air layering was evaluated aiming at evolution of procedure for mass clonal propagation of mature ortets of five tropical broadleaf species differing in their potential for adventitious root formation in shoot cuttings as: Anogiessus latifolia < Boswellia serrata < Dalbergia latifolia < Gmelina arborea < Dalbergia sissoo. Two experiments were conducted in rainy season during consecutive years; without application of growth regulators in the first year and with growth regulators (T1 - water, T2- 100 ppm indole-3-acetic acid, T3-100 ppm thiamine-HCl and T4 -combination of T2 + T3 in the next year. Air layered branches were detached from the trees to record percentage of alive airlayers, callusing and rooting (% as well as root number and root length. Response to air layering was found to be highly variable in five tree species but appeared to be feasible procedure for clonal propagation of mature ortets of B. serrata and D. sissoo with 100% (in auxin + thiamine treatment and 83.3% (in auxin treatment success, respectively. Maximum callusing (% was found in D. latifolia while no callusing was observed in D. sissoo, which is most easy-to-root among all five species. Callus formation impedes adventitious rhizogenesis in air layers as significant negative correlation of callusing (% and adventitious root formation was recorded in air layers of five tropical broadleaved tree species. Application of exogenous auxin alone or in combination with thiamine circumvents callusing to ensure direct development of roots for successful air layering.

  12. Long-term forest dynamics at Gribskov, eastern Denmark with early-Holocene evidence for thermophilous broadleaved tree species

    DEFF Research Database (Denmark)

    Overballe-Petersen, Mette V; Nielsen, Anne Birgitte; Hannon, Gina E.;

    2012-01-01

    thermophilous broadleaved trees, including Quercus sp., Tilia sp. and Ulmus sp. The macrofossils contribute to the vegetation reconstruction with evidence for local presence of species with low pollen productivity or easily degraded pollen types such as Populus. The charcoal record shows frequent burning during...... no clear indication of post-depositional disturbance, although a possible short-lived hiatus occurs around 6500 cal. BP. The early pollen record from thermophilous trees could indicate that there may have been some downwash following sediment desiccation through wood peat layers deposited between c. 6500...

  13. The seasonality of butterflies in a semi-evergreen forest: Gibbon Wildlife Sanctuary, Assam, northeastern India

    Directory of Open Access Journals (Sweden)

    Arun P. Singh

    2015-01-01

    Full Text Available A study spanning 3.7 years on the butterflies of Gibbon Wildlife Sanctuary GWS (21km2, a semi-evergreen forest, in Jorhat District of Assam, northeastern India revealed 211 species of butterflies belonging to 115 genera including 19 papilionids and seven ‘rare’ and ‘very rare’ species as per Evans list of the Indian sub-continent (Great Blue Mime Papilio paradoxa telearchus; Brown Forest BobScobura woolletti; Snowy Angle Darpa pteria dealbatahas; Constable Dichorragia nesimachus; Grey Baron Euthalia anosia anosia; Sylhet Oakblue Arhopala silhetensis; Branded Yamfly Yasoda tripunctata. The butterflies showed a strong seasonality pattern in this forest with only one significant peak during the post monsoon (September-October when 118 species were in flight inside the forest which slowly declined to 92 species in November-December. Another peak (102 species was visible after winter from March to April. Species composition showed least similarity between pre-monsoon (March-May and post-monsoon (October-November seasons. The number of papilionid species were greater from July to December as compared from January to June. The findings of this study suggest that the pattern of seasonality in a semi-evergreen forest in northeastern India is distinct from that of the sub-tropical lowland forest in the Himalaya. Favourable logistics and rich diversity in GWS points to its rich potential in promoting ‘butterfly inclusive ecotourism’ in this remnant forest.

  14. Fine Root Productivity and Turnover of Ectomycorrhizal and Arbuscular Mycorrhizal Tree Species in a Temperate Broad-Leaved Mixed Forest.

    Science.gov (United States)

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2016-01-01

    Advancing our understanding of tree fine root dynamics is of high importance for tree physiology and forest biogeochemistry. In temperate broad-leaved forests, ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) tree species often are coexisting. It is not known whether EM and AM trees differ systematically in fine root dynamics and belowground resource foraging strategies. We measured fine root productivity (FRP) and fine root turnover (and its inverse, root longevity) of three EM and three AM broad-leaved tree species in a natural cool-temperate mixed forest using ingrowth cores and combined the productivity data with data on root biomass per root orders. FRP and root turnover were related to root morphological traits and aboveground productivity. FRP differed up to twofold among the six coexisting species with larger species differences in lower horizons than in the topsoil. Root turnover varied up to fivefold among the species with lowest values in Acer pseudoplatanus and highest in its congener Acer platanoides. Variation in root turnover was larger within the two groups than between EM and AM species. We conclude that the main determinant of FRP and turnover in this mixed forest is species identity, while the influence of mycorrhiza type seems to be less important. PMID:27617016

  15. Microelement contents of litter, soil fauna and soil in Pinus koralensis and mixed broad-leaved forest

    Institute of Scientific and Technical Information of China (English)

    LI Jinxia; YIN Xiuqin; DONG Weihua

    2007-01-01

    The Mn,Zn and Cu contents of litter,soil fauna and soil in Pinus koraiensis and mixed broad-leaved forest in Liangshui Nature Reserve of Xiaoxing'an Mountains were analyzed in this paper,results showed that the tested microelement contents in the litter,soil fauna and soil followed the order:Mn>Zn>Cu,but varied with environmental components,for Mn the order is soil>litter>soil fauna,for Zn is soil fauna>litter and soil,and for Cu is soil fauna>soil>litter.The change range of the tested microelement contents in litter was larger in broad-leaved forest than those in coniferous forest.Different soil fauna differed in their microelementenrichment capability,the highest content of Mn,Zn and Cu existed in earthworm,centipede and diplopod,respectively.The contents of the tested microelements in soil fauna had significant correlations with their environmental background values,litter decomposition rate,food habit of soil fauna,and its absorbing selectively and enrichment to microelements.The microelements contained in 5-20 cm soil horizon were more than those in 0-5 cm humus layer,and their dynamics differed in various horizons.

  16. Constructing seasonal LAI trajectory by data-model fusion for global evergreen needle-leaf forests

    Science.gov (United States)

    Wang, R.; Chen, J.; Mo, G.

    2010-12-01

    For decades, advancements in optical remote sensors made it possible to produce maps of a biophysical parameter--the Leaf Area Index (LAI), which is critically necessary in regional and global modeling of exchanges of carbon, water, energy and other substances, across large areas in a fast way. Quite a few global LAI products have been generated since 2000, e.g. GLOBCARBON (Deng et al., 2006), MODIS Collection 5 (Shabanov et al., 2007), CYCLOPES (Baret et al., 2007), etc. Albeit these progresses, the basic physics behind the technology restrains it from accurate estimation of LAI in winter, especially for northern high-latitude evergreen needle-leaf forests. Underestimation of winter LAI in these regions has been reported in literature (Yang et al., 2000; Cohen et al., 2003; Tian et al., 2004; Weiss et al., 2007; Pisek et al., 2007), and the distortion is usually attributed to the variations of canopy reflectance caused by understory change (Weiss et al., 2007) as well as by the presence of ice and snow on leaves and ground (Cohen, 2003; Tian et al., 2004). Seasonal changes in leaf pigments can also be another reason for low LAI retrieved in winter. Low conifer LAI values in winter retrieved from remote sensing make them unusable for surface energy budget calculations. To avoid these drawbacks of remote sensing approaches, we attempt to reconstruct the seasonal LAI trajectory through model-data fusion. A 1-degree LAI map of global evergreen needle-leaf forests at 10-day interval is produced based on the carbon allocation principle in trees. With net primary productivity (NPP) calculated by the Boreal Ecosystems Productivity Simulator (BEPS) (Chen et al., 1999), carbon allocated to needles is quantitatively evaluated and then can be further transformed into LAI using the specific leaf area (SLA). A leaf-fall scheme is developed to mimic the carbon loss caused by falling needles throughout the year. The seasonally maximum LAI from remote sensing data for each pixel

  17. A Comparative Analysis To Determine the Value in Producing Higher Achievement in a Social Studies Course at Evergreen Valley College.

    Science.gov (United States)

    Griffin, Jerome J.

    The major purpose of this study was to determine if students enrolled in an "Eyes on the Prize" telecourse performed better academically in utilizing a study guide than students who did not utilize the study guide. "Eyes on the Prize," a course offered at Evergreen Valley College (EVC), fulfills a two-year ethnic studies requirement for graduation…

  18. Report on the Visit to the Evergreen State College, Olympia, Washington. May, 1974. Unified Studies Report No. I:1.

    Science.gov (United States)

    Greeley, Warren; And Others

    The Evergreen State College seems to be working well as a nontraditional college committed to educational change and innovation. It provides a model for interdisciplinary education, developing basic cognitive skills and drawing all disciplines in probing specific problems. The necessary ingredients for a stimulating learning environment based on…

  19. Differential responses of carbon and water vapor fluxes to climate among evergreen needleleaf forests in the USA

    Science.gov (United States)

    Understanding of differences in carbon and water vapor fluxes of spatially distributed evergreen needle leaf forests (ENFs) is crucial to accurately estimating regional carbon and water budgets and when predicting the responses of ENFs to future climate. We investigated cross-site variability in car...

  20. CARBON DYNAMICS OF MEXICAN TROPICAL EVERGREEN FORESTS: INFLUENCE OF FOREST MANAGEMENT OPTIONS AND REFINEMENT OF CARBON-FLUX ESTIMATES

    Science.gov (United States)

    Tropical evergreen forests (TEF) of southeast Mexico experienced a deforestation rate of approximately 206,000 ha/yr and an efflux of nearly 21 TgC/yr between 1980 and the present. and formerly occupied by these forests have potential to mitigate greenhouse gas emissions. his pap...

  1. Leaf development and demography explain photosynthetic seasonality in Amazon evergreen forests.

    Science.gov (United States)

    Wu, Jin; Albert, Loren P; Lopes, Aline P; Restrepo-Coupe, Natalia; Hayek, Matthew; Wiedemann, Kenia T; Guan, Kaiyu; Stark, Scott C; Christoffersen, Bradley; Prohaska, Neill; Tavares, Julia V; Marostica, Suelen; Kobayashi, Hideki; Ferreira, Mauricio L; Campos, Kleber Silva; da Silva, Rodrigo; Brando, Paulo M; Dye, Dennis G; Huxman, Travis E; Huete, Alfredo R; Nelson, Bruce W; Saleska, Scott R

    2016-02-26

    In evergreen tropical forests, the extent, magnitude, and controls on photosynthetic seasonality are poorly resolved and inadequately represented in Earth system models. Combining camera observations with ecosystem carbon dioxide fluxes at forests across rainfall gradients in Amazônia, we show that aggregate canopy phenology, not seasonality of climate drivers, is the primary cause of photosynthetic seasonality in these forests. Specifically, synchronization of new leaf growth with dry season litterfall shifts canopy composition toward younger, more light-use efficient leaves, explaining large seasonal increases (~27%) in ecosystem photosynthesis. Coordinated leaf development and demography thus reconcile seemingly disparate observations at different scales and indicate that accounting for leaf-level phenology is critical for accurately simulating ecosystem-scale responses to climate change.

  2. Responses of evergreen and deciduous Quercus species to enhanced ozone levels

    Energy Technology Data Exchange (ETDEWEB)

    Calatayud, Vicent, E-mail: calatayud_viclor@gva.e [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Cervero, Julia; Calvo, Esperanza [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Garcia-Breijo, Francisco-Jose [Laboratorio de Anatomia e Histologia Vegetal ' Julio Iranzo' , Jardin Botanico, Universitat de Valencia, c/Quart 80, 46008 Valencia (Spain); Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Reig-Arminana, Jose [Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Sanz, Maria Jose [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain)

    2011-01-15

    Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD{sub 1.6}) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. - Ozone tolerance overlapped with leaf traits in four Quercus species.

  3. Leaf development and demography explain photosynthetic seasonality in Amazon evergreen forests

    Science.gov (United States)

    Wu, Jin; Albert, Lauren; Lopes, Aline; Restrepo-Coupe, Natalia; Hayek, Matthew; Wiedemann, Kenia T.; Guan, Kaiyu; Stark, Scott C.; Christoffersen, Bradley; Prohaska, Neill; Tavares, Julia V.; Marostica, Suelen; Kobayashi, Hideki; Ferreira, Maurocio L.; Campos, Kleber Silva; da Silva, Rodrigo; Brando, Paulo M.; Dye, Dennis G.; Huxman, Travis E.; Huete, Alfredo; Nelson, Bruce; Saleska, Scott

    2016-01-01

    In evergreen tropical forests, the extent, magnitude, and controls on photosynthetic seasonality are poorly resolved and inadequately represented in Earth system models. Combining camera observations with ecosystem carbon dioxide fluxes at forests across rainfall gradients in Amazônia, we show that aggregate canopy phenology, not seasonality of climate drivers, is the primary cause of photosynthetic seasonality in these forests. Specifically, synchronization of new leaf growth with dry season litterfall shifts canopy composition toward younger, more light-use efficient leaves, explaining large seasonal increases (~27%) in ecosystem photosynthesis. Coordinated leaf development and demography thus reconcile seemingly disparate observations at different scales and indicate that accounting for leaf-level phenology is critical for accurately simulating ecosystem-scale responses to climate change.

  4. Critical loads of nitrogen deposition and critical levels of atmospheric ammonia for mediterranean evergreen woodlands

    Science.gov (United States)

    Pinho, P.; Theobald, M. R.; Dias, T.; Tang, Y. S.; Cruz, C.; Martins-Loução, M. A.; Máguas, C.; Sutton, M.; Branquinho, C.

    2011-11-01

    Nitrogen (N) has emerged in recent years as a key factor associated with global changes, with impacts on biodiversity, ecosystems functioning and human health. In order to ameliorate the effects of excessive N, safety thresholds have been established, such as critical loads (deposition fluxes) and levels (concentrations). For Mediterranean ecosystems, few studies have been carried out to assess these parameters. Our objective was therefore to determine the critical loads of N deposition and long-term critical levels of atmospheric ammonia for Mediterranean evergreen woodlands. For that we have considered changes in epiphytic lichen communities, which have been shown to be one of the most sensitive to excessive N. Based on a classification of lichen species according to their tolerance to N we grouped species into response functional groups, which we used as a tool to determine the critical loads and levels. This was done under Mediterranean climate, in evergreen cork-oak woodlands, by sampling lichen functional diversity and annual atmospheric ammonia concentrations and modelling N deposition downwind from a reduced N source (a cattle barn). By modelling the highly significant relationship between lichen functional groups and N deposition, the critical load was estimated to be below 26 kg (N) ha-1 yr-1, which is within the upper range established for other semi-natural ecosystems. By modelling the highly significant relationship of lichen functional groups with annual atmospheric ammonia concentration, the critical level was estimated to be below 1.9 μg m-3, in agreement with recent studies for other ecosystems. Taking into account the high sensitivity of lichen communities to excessive N, these values should be taken into account in policies that aim at protecting Mediterranean woodlands from the initial effects of excessive N.

  5. Critical loads of nitrogen deposition and critical levels of atmospheric ammonia for mediterranean evergreen woodlands

    Directory of Open Access Journals (Sweden)

    P. Pinho

    2011-11-01

    Full Text Available Nitrogen (N has emerged in recent years as a key factor associated with global changes, with impacts on biodiversity, ecosystems functioning and human health. In order to ameliorate the effects of excessive N, safety thresholds have been established, such as critical loads (deposition fluxes and levels (concentrations. For Mediterranean ecosystems, few studies have been carried out to assess these parameters. Our objective was therefore to determine the critical loads of N deposition and long-term critical levels of atmospheric ammonia for Mediterranean evergreen woodlands. For that we have considered changes in epiphytic lichen communities, which have been shown to be one of the most sensitive to excessive N. Based on a classification of lichen species according to their tolerance to N we grouped species into response functional groups, which we used as a tool to determine the critical loads and levels. This was done under Mediterranean climate, in evergreen cork-oak woodlands, by sampling lichen functional diversity and annual atmospheric ammonia concentrations and modelling N deposition downwind from a reduced N source (a cattle barn. By modelling the highly significant relationship between lichen functional groups and N deposition, the critical load was estimated to be below 26 kg (N ha−1 yr−1, which is within the upper range established for other semi-natural ecosystems. By modelling the highly significant relationship of lichen functional groups with annual atmospheric ammonia concentration, the critical level was estimated to be below 1.9 μg m−3, in agreement with recent studies for other ecosystems. Taking into account the high sensitivity of lichen communities to excessive N, these values should be taken into account in policies that aim at protecting Mediterranean woodlands from the initial effects of excessive N.

  6. Seasonal photosynthetic activity in evergreen conifer leaves monitored with spectral reflectance

    Science.gov (United States)

    Wong, C. Y.; Gamon, J. A.

    2013-12-01

    Boreal evergreen conifers must maintain photosynthetic systems in environments where temperatures vary greatly across seasons from high temperatures in the summer to freezing levels in the winter. This involves seasonal downregulation and photoprotection during periods of extreme temperatures. To better understand this downregulation, seasonal dynamics of photosynthesis of lodgepole (Pinus contorta D.) and ponderosa pine (Pinus ponderosa D.) were monitored in Edmonton, Canada over two years. Spectral reflectance at the leaf and stand scales was measured weekly and the Photochemical Reflectance Index (PRI), often used as a proxy for chlorophyll and carotenoid pigment levels and photosynthetic light-use efficiency (LUE), was used to track the seasonal dynamics of photosynthetic activity. Additional physiological measurements included leaf pigment content, chlorophyll fluorescence, and gas exchange. All the metrics indicate large seasonal changes in photosynthetic activity, with a sharp transition from winter downregulation to active photosynthesis in the spring and a more gradual fall transition into winter. The PRI was a good indicator of several other variables including seasonally changing photosynthetic activity, chlorophyll fluorescence, photosynthetic LUE, and pigment pool sizes. Over the two-year cycle, PRI was primarily driven by changes in constitutive (chlorophyll:carotenoid) pigment levels correlated with seasonal photosynthetic activity, with a much smaller variation caused by diurnal changes in xanthophyll cycle activity (conversion between violaxanthin & zeaxanthin). Leaf and canopy scale PRI measurements exhibited parallel responses during the winter-spring transition. Together, our findings indicate that evergreen conifers photosynthetic system possesses a remarkable degree of resilience in response to large temperature changes across seasons, and that optical remote sensing can be used to observe the seasonal effects on photosynthesis and

  7. [Effects of precipitation variation on growing seasonal dynamics of soil microbial biomass in broadleaved Korean pine mixed forest].

    Science.gov (United States)

    Wang, Ning; Wang, Mei-ju; Li, Shi-lan; Wang, Nan-nan; Feng, Fu-juan; Han, Shi-jie

    2015-05-01

    Broadleaved Korean pine mixed forest is the zonal climax vegetation in Northeast China and it plays a significant role in maintaining the ecological security. Changbai Mountains is a suitable region to study the positive and negative feedback mechanisms of temperate forest for precipitation variation. This study analyzed responses of soil microbial biomass carbon (SMBC) and microbial biomass nitrogen (SMBN) to precipitation variation (± 30%) in original broadleaved Korean pine mixed forest of Changbai Mountains. The results showed that, during the growing seasons (from May to September), the averages of SMBC and SMBN were 879.09 and 100.03 mg · kg(-1), respectively. Moreover, both of these two parameters gradually decreased with the soil depth. The contents of SMBC and SMBN all increased with the increasing precipitation, and the changes of SMBC and SMBN in the 0-5 cm soil layer were stronger than in the 5-10 cm soil layer. The value of SMBC/SMBN declined with the increase of precipitation. The precipitation variation significantly influenced the means of SMBC and SMBN. Compared with precipitation reduction, precipitation enhancement affected the indices much significantly. Both SMBC and SMBN showed similar seasonal patterns, which were the lowest in May, and after that, they increased and then decreased and increased again, showing 1-2 peaks in the growing season. However, the value and occurring time of the peaks varied with the precipitation and soil layer, and the seasonal variations of SMBC and SMBN in the 0-5 cm soil layer were higher than in the 5-10 cm soil layer. SMBC and SMBN had significant positive correlation with organic matter and total nitrogen content. The variances of soil physical and chemical properties caused by precipitation variation were closely related with the difference in spatial-temporal patterns of the soil microbial biomass in the forest. In conclusion, the precipitation variations could cause the change of the soil microbial

  8. Diurnal Variations of Greenhouse Gas Fluxes from Mixed Broad-leaved and Coniferous Forest Soil in Dinghushan

    Institute of Scientific and Technical Information of China (English)

    ZHOUCunyu; ZHANGDeqiang; WANGYuesi; ZHOUGuoyi; LIUShizhong; TANGXuli

    2005-01-01

    The subtropical mixed broad-leaved and coniferous forest, a typical successional monsoon forest, is one of the major forests in the subtropics of China. Therefore, it is very important to estimate the fluxes of the greenhouse gases from the forest soil in order to evaluate the impact of subtropical forests on the greenhouse gas emissions or absorptions. This study investigated the diurnal variations of fluxes of three greenhouse gases (CO2, CH4, and N2O) from a mixed broad-leaved and coniferous forest soil. A static chamber-gas chromatograph technique was used to measure the fluxes of three greenhouse gases. By using the improved gas chromatography sampling system, the fluxes were analyzed with a single injection. In order to find out the effects of litter and seedling on the emissions or absorptions of these greenhouse gases, three treatments were set in the fleld:(1)bare soil surface (litter was removed previously); (3) litter + soil; (3) seedling + litter + soil. The experimental results demonstrated that the forest soil was a source of CO2, N2O and a weak sink of CH4.The daily fluxes of CO2, CH4, and N2O from the soil surface were in the range of 488.99~700.57, 0.049~0.108 and -0.025~ -0.053 mg/(m2·h ), respectively. CO2 from the litter decomposition accounted for about 1/3 of the total CO2 emission from the soil surface, while the litter and seedling had no significant effect on the fluxes of CH4 and N2O. The fluxes of CO2 and N2O measured at 9:00 -11:00 a.m. were significantly different from their daily averages. Therefore, caution must be taken if the CO2 and N2O fluxes measured within 9:00-11:00 a.m. are used for extrapolation.

  9. An impacts of logging operations on understory plants for the broadleaved/Korean pine mixed forest on Changbai Mountain, China

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; SHAO Guo-fan; DAI Li-min; XU Dong; GU Hui-yan; WANG Fei

    2005-01-01

    Natural regeneration of tree species is important to the sustainability of native forest ecosystems in the temperate zone of northeast China. This study compared the densities and heights of seedlings and the diversities of shrubs and herbs on three sites of logging operations: log-skidding trails (LST), logging gaps (LG) and log landing sites (LLS). Sites undisturbed by logging gaps operations were sampled as control. The species, counts and height of tree seedlings and the species, counts, height and percentage coverage of shrubs and herbs were recorded in the field. The highest density and greatest height of regeneration trees were observed at LG and LST. The effects of LST on the densities of broadleaved trees were greater than those of coniferous trees. The difference in seedling density between LLS and control was significant (p=0.05). There was no significant difference in average seedling height for all the tree species between the disturbed sites and control. There were more shrub and herb species at the disturbed sites than at control. The diversity of understory plants at LG was the highest among all the sites. LST and LLS were different in shrub diversity, so were LLS and control. Both LG and LLS were different from control in herb diversity. Active measures need to be taken on the operation sites to protect the coniferous trees and the diversities of understory plants for sustaining the structure and composition of the broadleaved-Korean pine mixed forest on Changbai Mountain of China. Since different operation sites have different effects on different tree species, site-dependent actions must be taken to assure the regeneration of ecologically important tree species.

  10. Growing up with stress - carbon sequestration and allocation dynamics of a broadleaf evergreen forest

    Science.gov (United States)

    Griebel, Anne; Bennett, Lauren T.; Arndt, Stefan K.

    2016-04-01

    Evergreen forests have the potential to sequester carbon year-round due to the presence of leaves with a multi-year lifespan. Eucalypt forests occur in warmer climates where temperature and radiation are not imposing a strong seasonality. Thus, unlike deciduous or many coniferous trees, many eucalypts grow opportunistically as conditions allow. As such, many eucalypts do not produce distinct growth rings, which present challenges to the implementation of standard methods and data interpretation approaches for monitoring and explaining carbon allocation dynamics in response to climatic stress. As a consequence, there is a lack of detailed understanding of seasonal growth dynamics of evergreen forests as a whole, and, in particular, of the influence of climatic drivers on carbon allocation to the various biomass pools. We used a multi-instrument approach in a mixed species eucalypt forest to investigate the influence of climatic drivers on the seasonal growth dynamics of a predominantly temperate and moisture-regulated environment in south-eastern Australia. Ecosystem scale observations of net ecosystem exchange (NEE) from a flux tower in the Wombat forest near Melbourne indicated that the ecosystem is a year-round carbon sink, but that intra-annual variations in temperature and moisture along with prolonged heat waves and dry spells resulted in a wide range of annual sums over the past three years (NEE ranging from ~4 to 12 t C ha-1 yr-1). Dendrometers were used to monitor stem increments of the three dominant eucalypt species. Stem expansion was generally opportunistic with the greatest increments under warm but moist conditions (often in spring and autumn), and the strongest indicators of stem growth dynamics being radiation, vapour pressure deficit and a combined heat-moisture index. Differences in the seasonality of stem increments between species were largely due to differences in the canopy position of sampled individuals. The greatest stem increments were

  11. [Effect of climate change on net primary productivity of Korean pine (Pinus koraiensis) at different successional stages of broad-leaved Korean pine forest].

    Science.gov (United States)

    Qiu, Yang; Gao, Lu-Shuang; Zhang, Xue; Guo, Jing; Ma, Zhi-Yuan

    2014-07-01

    Pinus koraiensis in broad-leaved Korean pine forests of Changbai Mountain at different successional stages (secondary poplar-birch forest, secondary coniferous and broad-leaved forest and the primitive Korean pine forest) were selected in this paper as the research objects. In this research, the annual growth of net primary productivity (NPP) (1921-2006) of P. koraiensis was obtained by combining the tree-ring chronology and relative growth formulae, the correlation between NPP of P. koraiensis and climatic factors was developed, and the annual growth of NPP of P. koraiensis at different successional stages in relation to climatic variation within different climate periods were analyzed. The results showed that, in the research period, the correlations between climatic factors and NPP of P. koraiensis at different successional stages were different. With increasing the temperature, the correlations between NPP of P. koraiensis in the secondary poplar-birch forest and the minimum temperatures of previous and current growing seasons changed from being significantly negative to being significantly positive. The positive correlation between NPP of P. koraiensis in the secondary coniferous and broad-leaved forest and the minimum temperature in current spring changed into significantly positive correlation between NPP of P. koraiensis and the temperatures in previous and current growing seasons. The climatic factors had a stronger hysteresis effect on NPP of P. koraiensis in the secondary coniferous and broad-leaved forest, but NPP of P. koraiensis in the primitive Korean pine forest had weaker correlation with temperature but stronger positive correlation with the precipitation of previous growing season. The increases of minimum and mean temperatures were obvious, but no significant variations of the maximum temperature and precipitation were observed at our site. The climatic variation facilitated the increase of the NPP of P. koraiensis in the secondary poplar

  12. Evergreen shrub traits and peatland carbon cycling under high nutrient load

    Science.gov (United States)

    Larmola, Tuula; Bui, Vi; Bubier, Jill L.; Wang, Meng; Murphy, Meaghan; Moore, Tim R.

    2016-04-01

    The reactive nitrogen (N) assimilated by plants is usually invested in chlorophyll to improve light harvesting capacity and in soluble proteins such as Rubisco to enhance carbon (C) assimilation. We studied the effects of simulated atmospheric N deposition on different traits of two evergreen shrubs Chamaedaphne calyculata and Rhododendron groenlandicum in a nutrient-poor Mer Bleue Bog, Canada that has been fertilized with N as NO3 and NH4 (2-8 times ambient annual wet deposition) with or without phosphorus (P) and potassium (K) for 7-12 years. We examined how nutrient addition influences the plant performance at leaf and canopy level and linked the trait responses with ecosystem C cycling. At the leaf level, we measured physiological and biochemical traits: CO2 exchange and chlorophyll fluorescence, an indicator of plant stress in terms of light harvesting capacity; and to study changes in photosynthetic nutrient use efficiency, we also determined the foliar chlorophyll, N, and P contents. At the canopy level, we examined morphological and phenological traits: growth responses and leaf longevity during two growing seasons. Regardless of treatment, the majority of leaves showed no signs of stress in terms of light harvesting capacity. The plants were N saturated: with increasing foliar N content, the higher proportion of N was not used in photosynthesis. Foliar net CO2 assimilation rates did not differ significantly among treatments, but the additions of N, P, and K together resulted in higher respiration rates. The analysis of the leaf and canopy traits showed that the two shrubs had different strategies: C. calyculata was more responsive to nutrient additions, more deciduous-like, whereas R. groenlandicum maintained evergreen features under nutrient load, shedding its leaves even later in the season. In all, simulated atmospheric N deposition did not benefit the photosynthetic apparatus of the dominant shrubs, but resulted in higher foliar respiration

  13. Root productivity of deciduous and evergreen species identified using a molecular approach

    Science.gov (United States)

    Ellsworth, P.; Sternberg, L. O.

    2012-12-01

    The linkage between leaf traits and root structure may explain how plants integrate above and belowground traits into whole plant adaptations to environmental stresses. In dry seasonal forests, the lack of dry season precipitation dries out the relatively nutrient-rich shallow soil, leaving shallow soil water and nutrients inaccessible to uptake until the wet season. In tropical or subtropical seasonal dry forests, deciduousness may allow for the survival of shallow fine roots during the dry season. Losing leaves during the dry season reduces aboveground plant water demand, and a greater proportion of water extracted from deep soil can be used to maintain shallow roots until the wet season. Higher shallow root survival through the dry season than evergreen species means that deciduous species can take advantage of the nutrient pulse associated with the onset of the wet season. To test the above hypothesis, fine roots were collected from soil cores in a seasonally dry forest during the dry season, onset of the wet season, and the wet season and were identified to selected evergreen and deciduous study species. The fine roots of two of the selected species (Lyonia ferruginea and Carya floridana) could be identified from visual characteristics. The other three study species, which were all from the genus Quercus (Q. geminata, Q. myrtifolia, and Q. laevis), were impossible to separate visually. We developed a PCR-based restriction fragment length polymorphism (PCR-RFLP) technique, which provided a quick, simple, low-cost way to identify the species of all fine roots of our study species. We extracted DNA from all roots that were not visually identified, amplified the internal transcribed spacer region (ITS), digested the ITS region with the restriction enzyme TaqαI, and used gel electrophoresis to separate DNA fragments. Using a PCR-RFLP based root identification key that we developed for the species at Archbold Biological Station, all species that could not be

  14. Boeing and EGAT Unveil World's First Large Cargo Freighter——Evergreen Aviation Technologies transforms Boeing747-400 for 787 Dreamliner cargo

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Evergreen Aviation Technologies Corporation (EGAT), a subsidiary of the Evergreen Group, and The Boeing Company unveiled the first of three Boeing 747-400 Large Cargo Freighters (LCF) modified to exacting specifications to transport giant-sized Boeing 787 "Dreamliner" assemblages.Boeing selected EGAT to perform the specialized aircraft conversions and work began in 2005. The three-aircraft conversion program will be completed in 2007.

  15. Carbon-based Payments for Tropical Forest Conservation – A Case Study for Evergreen Forest in Cambodia

    OpenAIRE

    Sasaki, Nophea

    2010-01-01

    As negotiations to include reduced emissions from deforestation and degradation (REDD) in the post-Kyoto agreements are underway, study on carbon payments for the REDD projects become urgently important. Having experienced rapid degradation and deforestation, Cambodia’s highly stocked evergreen forest is the first priority forest to be conserved if carbon payments are available. Using inventory data and timber royalties in Cambodia, we analyze the costs for and revenues from timber harvesting...

  16. Seasonal variations of gas exchange and water relations in deciduous and evergreen trees in monsoonal dry forests of Thailand.

    Science.gov (United States)

    Ishida, Atsushi; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Sasrisang, Amornrat; Kaewpakasit, Kanokwan; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Gamo, Minoru; Diloksumpun, Sapit; Puangchit, Ladawan; Ishizuka, Moriyoshi

    2010-08-01

    This study compared leaf gas exchange, leaf hydraulic conductance, twig hydraulic conductivity and leaf osmotic potential at full turgor between two drought-deciduous trees, Vitex peduncularis Wall. and Xylia xylocarpa (Roxb.) W. Theob., and two evergreen trees, Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels, at the uppermost canopies in tropical dry forests in Thailand. The aims were to examine (i) whether leaf and twig hydraulic properties differ in relation to leaf phenology and (ii) whether xylem cavitation is a determinant of leaf shedding during the dry season. The variations in almost all hydraulic traits were more dependent on species than on leaf phenology. Evergreen Hopea exhibited the lowest leaf-area-specific twig hydraulic conductivity (leaf-area-specific K(twig)), lamina hydraulic conductance (K(lamina)) and leaf osmotic potential at full turgor (Ψ(o)) among species, whereas evergreen Syzygium exhibited the highest leaf-area-specific K(twig), K(lamina) and Ψ(o). Deciduous Xylia had the highest sapwood-area-specific K(twig), along with the lowest Huber value (sapwood area/leaf area). More negative osmotic Ψ(o) and leaf osmotic adjustment during the dry season were found in deciduous Vitex and evergreen Hopea, accompanied by low sapwood-area-specific K(twig). Regarding seasonal changes in hydraulics, no remarkable decrease in K(lamina) and K(twig) was found during the dry season in any species. Results suggest that leaf shedding during the dry season is not always associated with extensive xylem cavitation. PMID:20581012

  17. Study on carbon-fixing,oxygen-releasing,temperature-reducing and humidity-increasing effects of evergreen plants in south highway

    OpenAIRE

    Liu, Minmin; HUANG Manhong; YANG Zhenqian

    2014-01-01

    Li-6400 portable photosynthesis system,was used to test the diurnal variations of photosynthetic rate and stomatal conductance of evergreen plants in Southern Highway,and to calculate their ability of absorbing carbon dioxide and releasing oxygen and to calculate the transpiring water volume and absorbing heat quantity of plants.Results showed that Euonymus fortunei Hand-Mazz,Hedera helix.Aucuba eriobotryaefolia had better carbon-fixing and oxygen-releasing effects,while Photinia serrulata,T...

  18. Effects of coffee management intensity on composition, structure and regeneration status of Ethiopian moist evergreen Afromontane forests

    OpenAIRE

    Hundera, Kitessa; Aerts, Raf; Fontaine, M; Mechelen, M. van; Gijbels, Pieter; Honnay, Olivier; Muys, Bart

    2013-01-01

    The effect of arabica coffee management intensity on composition, structure and regeneration of moist evergreen Afromontane forests was studied in three traditional coffee management systems of Southwest Ethiopia: semi-plantation coffee (SPC), semi-forest coffee (SFC) and forest coffee (FC). Vegetation and environmental data were collected in 84 plots from forests varying in intensity of coffee management. After controlling for environmental variation (altitude, aspect, slope, soil nutrient a...

  19. Assessing atmospheric concentration of polychlorinated biphenyls by evergreen Rhododendron maximum next to a contaminated stream.

    Science.gov (United States)

    Dang, Viet D; Walters, David M; Lee, Cindy M

    2016-09-01

    Conifers are often used as an air passive sampler, but few studies have focused on the implication of broadleaf evergreens to monitor atmospheric semivolatile organic compounds such as polychlorinated biphenyls (PCBs). In the present study, the authors used Rhododendron maximum (rhododendron) growing next to a contaminated stream to assess atmospheric PCB concentrations. The present study area was located in a rural setting and approximately 2 km downstream of a former capacitor plant. Leaves from the same mature shrubs were collected in late fall 2010 and winter and spring 2011. Polychlorinated biphenyls were detected in the collected leaves, suggesting that rhododendron can be used as air passive samplers in rural areas where active sampling is impractical. Estimated ΣPCB (47 congeners) concentrations in the atmosphere decreased from fall 2010 to spring 2011 with concentration means at 3990 pg m(-3) , 2850 pg m(-3) , and 931 pg m(-3) in fall 2010, winter 2011, and spring 2011, respectively. These results indicate that the atmospheric concentrations at this location continue to be high despite termination of active discharge from the former industrial source. Leaves had a consistent pattern of high concentrations of tetra-CBs and penta-CBs similar to the congener distribution in polyethylene passive samplers deployed in the water column, suggesting that volatilized PCBs from the stream were the primary source of contaminants in rhododendron leaves. Environ Toxicol Chem 2016;35:2192-2198. © 2016 SETAC. PMID:26889751

  20. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam.

    Science.gov (United States)

    Nam, Vu Thanh; van Kuijk, Marijke; Anten, Niels P R

    2016-01-01

    Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB) and root biomass (RB) based on 300 (of 45 species) and 40 (of 25 species) sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH) and tree height (H), wood density (WD) was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam. PMID:27309718

  1. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam.

    Directory of Open Access Journals (Sweden)

    Vu Thanh Nam

    Full Text Available Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB and root biomass (RB based on 300 (of 45 species and 40 (of 25 species sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH and tree height (H, wood density (WD was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam.

  2. Assessing atmospheric concentration of polychlorinated biphenyls (PCBs) by evergreen Rhododendron maximum next to a contaminated stream

    Science.gov (United States)

    Dang, Viet D.; Walters, David; Lee, Cindy M.

    2016-01-01

    Conifers are often used as an “air passive sampler”, but few studies have focused on the implication of broadleaf evergreens to monitor atmospheric semivolatile organic compounds such as polychlorinated biphenyls (PCBs). In this study, we used Rhododendron maximum (rhododendron) growing next to a contaminated stream to assess atmospheric PCB concentrations. The study area was located in a rural setting and approximately 2 km downstream of a former Sangamo-Weston (S-W) plant. Leaves from the same mature shrubs were collected in late fall 2010, and winter and spring 2011. PCBs were detected in the collected leaves suggesting that rhododendron can be used as air passive samplers in rural areas where active sampling is impractical. Estimated ΣPCB (47 congeners) concentrations in the atmosphere decreased from fall 2010 to spring 2011 with concentration means at 3990, 2850, and 931 pg m-3 in fall 2010, winter 2011, and spring 2011, respectively. These results indicate that the atmospheric concentrations at this location continue to be high despite termination of active discharge from the former S-W plant. Leaves had a consistent pattern of high concentrations of tetra- and penta-CBs similar to the congener distribution in polyethylene (PE) passive samplers deployed in the water column suggesting that volatilized PCBs from the stream were the primary source of contaminants in rhododendron leaves.

  3. Composition and diversity of tree species in transects of location lowland evergreen forest of Ecuador

    Directory of Open Access Journals (Sweden)

    Jorge Caranqui A.

    2015-09-01

    Full Text Available The study was conducted in 9 transects 1000m2 of lowland evergreen forest, located in two locations on the coast and one in eastern Ecuador. It was to contribute to knowledge of the diversity and composition of woody plants over 10 cm diameter at breast height (DBH plus infer the state of conservation of forests based on the composition, the number of species, indices diversity and importance value (IV, found in 9 transects of 1000 m² of forest: 156 species, 107 genera and 39 families distributed in 9 transects, in each one the Simpson diversity index is of 0.92 to 0.95, in this case are diversity because all approaches 1. Most were found species aren´t present in all transects, the index value in each transect does not exceed 40%. Grouping transects match three locations exception made to transect 5 and 8 were conducted in disturbed sites, the most transects are intermediate disturbance that their high levels of diversity.

  4. Effects of mixture and thinning in a tree farming valuable broadleaves plantation more than 20 years after the establishment.

    Directory of Open Access Journals (Sweden)

    Alessio Corazzesi

    2010-12-01

    Full Text Available The results of peduncolate Oak plantation trials where the Oak is mixed to wild Cherry and narrow-leaf Ash per line and per close mixture with different proportions (25% and 50% of N-fixing species (Black Locust and Italian Alder are described in the paper. The plantation, carried out in winter 1988-89, was framed into a reafforestation plan for spoil banks restoration. On a share of the plantation area, free thinnings foreseeing the release of about 70 target trees per hectare, were undertaken in 2001 and 2003; 21% and 27% of basal area were removed, respectively. In the latter trial, the crowns of target trees were completely isolated by felling all the surrounding trees. The performances of valuable timber broadleaves, the effects of intercropping and thinning on the growth of Oak target trees were analysed. Three inventories (2001, 2004 and 2008 and the annual monitoring of target trees growth were performed at the purpose. The two peduncolate Oak and narrow-leaf Ash trees showed the best performances among the set of valuable broadleaves, whilst wild cherry resulted not suited to local site conditions. A higher tree mortality occurred in the mixture with Black Locust. The mixture with both Nfixing species provided a stimulus to the Oak growth both in terms of dbh and tree height. Italian Alder resulted anyway less competitive and easy to manage, considering its progressive self-thinning, while Black Locust was aggressive enough to necessitate the control of its development by pollarding 7 years after the plantation. In the thinned plots, target trees showed significant diameter increments in comparison with control plots; maintaining year by year constant dbh increments of about 1 cm and crown’s diameter increment of about 50 cm. Intercropping with Italian Alder showed to be more effective than thinning on growth of the target trees. st1\\:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso

  5. Potential of two submontane broadleaved species (Acer opalus, Quercus pubescens) to reveal spatiotemporal patterns of rockfall activity

    Science.gov (United States)

    Favillier, Adrien; Lopez-Saez, Jérôme; Corona, Christophe; Trappmann, Daniel; Toe, David; Stoffel, Markus; Rovéra, Georges; Berger, Frédéric

    2015-10-01

    Long-term records of rockfalls have proven to be scarce and typically incomplete, especially in increasingly urbanized areas where inventories are largely absent and the risk associated with rockfall events rises proportionally with urbanization. On forested slopes, tree-ring analyses may help to fill this gap, as they have been demonstrated to provide annually-resolved data on past rockfall activity over long periods. Yet, the reconstruction of rockfall chronologies has been hampered in the past by the paucity of studies that include broadleaved tree species, which are, in fact, quite common in various rockfall-prone environments. In this study, we test the sensitivity of two common, yet unstudied, broadleaved species - Quercus pubescens Willd. (Qp) and Acer opalus Mill. (Ao) - to record rockfall impacts. The approach is based on a systematic mapping of trees and the counting of visible scars on the stem surface of both species. Data are presented from a site in the Vercors massif (French Alps) where rocks are frequently detached from Valanginian limestone and marl cliffs. We compare recurrence interval maps obtained from both species and from two different sets of tree structures (i.e., single trees vs. coppice stands) based on Cohen's k coefficient and the mean absolute error. A total of 1230 scars were observed on the stem surface of 847 A. opalus and Q. pubescens trees. Both methods yield comparable results on the spatial distribution of relative rockfall activity with similar downslope decreasing recurrence intervals. Yet recurrence intervals vary significantly according to tree species and tree structure. The recurrence interval observed on the stem surface of Q. pubescens exceeds that of A. opalus by > 20 years in the lower part of the studied plot. Similarly, the recurrence interval map derived from A. opalus coppice stands, dominant at the stand scale, does not exhibit a clear spatial pattern. Differences between species may be explained by the bark

  6. Uncertainty analysis of CO2 flux components in subtropical evergreen coniferous plantation

    Institute of Scientific and Technical Information of China (English)

    LIU Min; HE HongLin; YU GuiRui; LUO YiQi; SUN XiaoMin; WANG HuiMin

    2009-01-01

    We present an uncertainty analysis of ecological process parameters and CO2 flux components (Reco, NEE and gross ecosystem exchange (GEE)) derived from 3 years continuous eddy covariance meas-urements of CO2 fluxes at subtropical evergreen coniferous plantation, Qianyanzhou of ChinaFlux. Daily-differencing approach was used to analyze the random error of CO2 fluxes measurements and bootstrapping method was used to quantify the uncertainties of three CO2 flux components. In addition, we evaluated different models and optimization methods in influencing estimation of key parameters and CO2 flux components. The results show that: (1) Random flux error more closely follows a dou-ble-exponential (Laplace), rather than a normal (Gaussian) distribution. (2) Different optimization meth-ods result in different estimates of model parameters. Uncertainties of parameters estimated by the maximum likelihood estimation (MLE) are lower than those derived from ordinary least square method (OLS). (3) The differences between simulated Rrco, NEE and GEE derived from MLE and those derived for a given parameter optimization method, e temperature-dependent model (T_model) and the models methods are more important than the ecological models in influencing uncertainty in estimated carbon fluxes. (4) The relative uncertainty of CO2 flux derived from OLS is higher than that from MLE, and the uncertainty is related to timescale, that is, the larger the timescale, the smaller the uncertainty. The relative uncertainties of Reco, NEE and GEE are 4%-8%, 7%-22% and 2%-4% respectively at annual timescale.

  7. Modern pollen-rain characteristics of tall terra firme moist evergreen forest, southern Amazonia

    Science.gov (United States)

    Gosling, William D.; Mayle, Francis E.; Tate, Nicholas J.; Killeen, Timothy J.

    2005-11-01

    The paucity of modern pollen-rain data from Amazonia constitutes a significant barrier to understanding the Late Quaternary vegetation history of this globally important tropical forest region. Here, we present the first modern pollen-rain data for tall terra firme moist evergreen Amazon forest, collected between 1999 and 2001 from artificial pollen traps within a 500 × 20 m permanent study plot (14°34'50″S, 60°49'48″W) in Noel Kempff Mercado National Park (NE Bolivia). Spearman's rank correlations were performed to assess the extent of spatial and inter-annual variability in the pollen rain, whilst statistically distinctive taxa were identified using Principal Components Analysis (PCA). Comparisons with the floristic and basal area data of the plot (stems ≥10 cm d.b.h.) enabled the degree to which taxa are over/under-represented in the pollen rain to be assessed (using R-rel values). Moraceae/Urticaceae dominates the pollen rain (64% median abundance) and is also an important constituent of the vegetation, accounting for 16% of stems ≥10 cm d.b.h. and ca. 11% of the total basal area. Other important pollen taxa are Arecaceae (cf. Euterpe), Melastomataceae/Combretaceae, Cecropia, Didymopanax, Celtis, and Alchornea. However, 75% of stems and 67% of the total basal area of the plot ≥10 cm d.b.h. belong to species which are unidentified in the pollen rain, the most important of which are Phenakospermum guianensis (a banana-like herb) and the key canopy-emergent trees, Erisma uncinatum and Qualea paraensis.

  8. Life-history traits in an evergreen Mediterranean oak respond differentially to previous experimental environments

    Directory of Open Access Journals (Sweden)

    J. M. Rey Benayas

    2008-06-01

    Full Text Available Living organisms respond both to current and previous environments, which can have important consequences on population dynamics. However, there is little experimental evidence based on long-term field studies of the effects of previous environments on the performance of individuals. We tested the hypothesis that trees that establish under different environmental conditions perform differently under similar post-establishment conditions. We used the slow-growing, evergreen Mediterranean oak Quercus ilex subsp. rotundifolia as target species. We analyzed the effects of previous environments, competition effects and tradeoffs among life-history traits (survival, growth, and reproduction. We enhanced seedling establishment for three years by reducing abiotic environmental harshness by means of summer irrigation and artificial shading in 12 experimental plots, while four plots remained as controls. Then these treatments were interrupted for ten years. Seedlings under ameliorated environmental conditions survived and grew faster during early establishment. During the post-management period, previous treatments 1 did not have any effect on survival, 2 experienced a slower above-ground growth, 3 decreased root biomass as indicated from reflectivity of Ground Penetration Radar, 4 increased acorn production mostly through a greater canopy volume and 5 increased acorn production effort. The trees exhibited a combination of effects related to acclimation for coping with abiotic stress and effects of intra-specific competition. In accordance with our hypothesis, tree performance overall depended on previous environmental conditions, and the response was different for different life-history traits. We recommend early management because it increased plot cover, shortened the time to attain sexual maturity and increased the amount of acorn production. Plots such as those assessed in this study may act as sources of propagules in deforested

  9. Canopy structure, vertical radiation profile and photosynthetic function in a Quercus ilex evergreen forest

    International Nuclear Information System (INIS)

    The studied evergreen forest dominated by Quercus ilex showed a leaf area index (LAI) of 4.5, of which 61 % was accumulated within the tree layer, 30 % within the shrub layer, and 9 % within the herb layer. The leaves of all the species were ± horizontally oriented (41°), absorbing a relevant percentage of incident irradiance. The high LAI drastically modified the quality and quantity of solar radiation on the forest underground. The spectral distribution of the radiation under the forest was markedly deficient in blue and red wavelengths. The maximum absorption in these spectral bands was found in spring, when net photosynthetic rate (P N ) was at its maximum, and in summer, when new leaves reached 90 % of their definitive structure. The vertical radiation profile showed an evident reduction of the red-far red ratio (R/FR). Radiation quality and quantity influenced leaf physiology and morphology. Clear differences in leaf size, leaf water content per area (LWC) and specific leaf area (SLA) on the vertical profile of the forest were observed. All the shrub species showed similar SLA (12.02 m2 kg-1, mean value). The ability to increase SLA whilst simultaneously reducing leaf thickness maximized the carbon economy. The high chlorophyll (Chl) content of shrub layer leaves (1.41 g kg-1, mean value) was an expression of shade adaptation. Both leaf morphology and leaf physiology expressed the phenotypic plasticity. Q. ilex, Phillyrea latifolia and Pistacia lentiscus of the forest shrub layer showed wide differences in leaf structure and function with respect to the same species developing under strong irradiance (low maquis): a 57 % mean increase of SLA and a 86 % mean decrease of PN. They showed high leaf plasticity. Leaf plasticity implies that the considered sclerophyllous species has an optimum developmental pattern achieving adaptation to environments. (author)

  10. The impact of broadleaved woodland on water resources in lowland UK: III. The results from Black Wood and Bridgets Farm compared with those from other woodland and grassland sites

    Directory of Open Access Journals (Sweden)

    J. Roberts

    2005-01-01

    Full Text Available In the United Kingdom the planting of broadleaved woodland has led to concerns about the impact on water resources. Comparative studies, typically using soil water measurements, have been established to compare water use of broadleaved woodland and grassland. The diversity of outcomes from these studies makes it difficult to make any consistent prediction of the hydrological impact of afforestation. Most studies have shown greater drying of soils under broadleaved woodland than under grass. However, two studies in a beech wood growing on shallow soils above chalk at Black Wood, Micheldever, Hampshire showed little overall difference between broadleaved woodland and grass, either in soil water abstraction or in evaporation. Two factors are thought to contribute to the different results from Black Wood. It is known that evaporation can be considerably enhanced at the edges of woodlands or in small areas of woodlands. The studies at Black Wood were made well within a large area of fairly uniform woodland. Other studies in which a difference occurred in soil drying between broadleaved woodland and grass used measurements made in small areas of woodlands or at woodland edges. Another important difference between comparison of woodland at Black Wood and grassland growing nearby, also on shallow soils above Chalk, compared to other broadleaved woodland/grass comparisons, growing on other geologies, is the influence of the Chalk. Although vegetation such as grass (and woodland does not populate the chalk profusely with roots, water can be removed from the Chalk by the roots which proliferate at the soil/chalk interface and which can generate upward water movement within the Chalk. Published work showed that only in a very dry summer did the evaporation from grass growing on shallow soils above chalk fall below potential. In broadleaved woodland/grass comparisons on non-chalky soils it is possible that moisture deficits in the soil below the grass may

  11. [Spatiotemporal distribution pattern of photosynthetic photon flux density in forest gaps of Korean pine broadleaved mixed forest].

    Science.gov (United States)

    Li, Meng; Duan, Wen-biao; Chen, Li-xin

    2011-04-01

    Taking the forest gaps of natural Pinus koraiensis broadleaved mixed forest in Xiao Xing'an Mountains as test object, and by the method of grids, the photosynthetic photon flux density (PPFD) in the gaps was continuously measured during growth season, and the spatiotemporal distribution patterns of the PPFD were analyzed by fundamental statistics and geostatistics methods. In the forest gaps, the high-value region of PPFD presented an obvious diurnal change, with the maximum PPFD appeared at 12:00 and in the northern part of the gaps. The mean monthly PPFD was the highest in June, and then decreased in the sequence of July, August, and September, with the largest coefficient of variation at different locations occurred in July and the medium variability in all the months. In different months, the intensity and the scale of PPFD spatial heterogeneity in the gaps differed, with the variation degree being the highest in June and the sill and proportion being the largest in July. The complex degree of the monthly PPFD patches also differed, with the maximum located in the northeast part of the gaps. The variation sequence of the mean monthly PPFD in understory and open ground was consistent with that in gap, and the mean monthly PPFD was the highest in open ground, medium in forest gap, and the lowest in understory.

  12. Exploring Conservation Options in the Broad-Leaved Korean Pine Mixed Forest of the Changbai Mountain Region

    Directory of Open Access Journals (Sweden)

    Lin Ma

    2015-05-01

    Full Text Available The broad-leaved Korean pine (Pinus koraiensis mixed forest (BKPF is one of the most biodiverse zonal communities in the northern temperate zone. Changbai Mountain in northeastern China contains one of the largest BKPFs in the region. The government of China has established a network of 23 nature reserves to protect the BKPF and the species that depend on it for habitat, including the endangered Siberian tiger (Panthera tigris altaica. This study used the conservation planning software C-Plan to calculate the irreplaceability value of each unit to assess how efficiently and comprehensively the existing conservation network supports biodiversity and to identify gap areas that, if integrated into the network, would expand its protection capability. Results show a number of high-conservation-value planning units concentrated along certain ridges. The existing conservation network is structured such that the habitats of only 24 species (out of a total of 75 achieve established conservation targets. Of the other 51 species, 20 achieve less than 50% of their conservation targets. However, expanding the network to include high-conservation-value gap areas could achieve conservation targets for 64 species and could provide different degrees of protection to the other 11 species. Using C-Plan software can guide decision-making to expand the conservation network in this most precious of mountainous ecological zones.

  13. Optimisation of hot-water application technology for the control of broad-leaved dock (Rumex obtusifolius

    Directory of Open Access Journals (Sweden)

    Roy Latsch

    2014-12-01

    Full Text Available In organic farming, the control of broad-leaved dock (Rumex obtusifolius via hot-water treatment of the upper root region (hypocotyl is a new alternative to the current standard control method involving manual digging-out of the roots. This comparative study looks at five different hot-water application techniques. The aim is to optimise the control method in terms of water and energy requirement to obtain a mortality rate of the treated plants of at least 80%. The studied parameters were the application, the amount of water, the water temperature, the soil moisture content and the soil type. In total, 813 plants of varying size were treated (120-225 plants per treatment. The success of each treatment was rated 12 weeks after it was applied. Based on the results, the preferred treatment in terms of water and energy requirement was a commercially available rotary nozzle. With this nozzle, for example, at 40 vol.-% soil moisture, 1.6 L of water at a temperature of 90°C was necessary for successful Rumex control. The rotary nozzle could be used as a non-contact system, and was therefore the most user-friendly of the application techniques examined.

  14. [Spatial heterogeneity of soil inorganic nitrogen in a broadleaved-Korean pine mixed forest in Changbai Mountains of northeast China].

    Science.gov (United States)

    Xu, Yuan; Zhang, Jun-hui; Han, Shi-jie; Wang, Shu-tang; Wang, Cun-guo; Wang, Shu-qi

    2010-07-01

    Geostatistic methods were applied to study the spatial heterogeneity of top soil (0 - 10 cm) ammonium N and nitrate N in a broadleaved-Korean pine mixed forest of Changbai Mountains, Northeast China. The semi-variogram of soil ammonium N and nitrate N could be well fitted by spherical or Gaussian model. The spatial distribution of soil ammonium N and nitrate N all exhibited moderate autocorrelation, with the structural ratio being 0.70% - 41.47% and 32.26% - 52.66%, and the autocorrelation degree of soil ammonium N was smaller than that of soil nitrate N, with the variation distance being 8.87 and 9.76 m, respectively. Spatially, soil ammonium N and nitrate N were distributed in patches, and the spatial heterogeneity of soil ammonium N was higher than that of soil nitrate N. There was a significant negative correlation between soil nitrate N and soil moisture content, while soil ammonium N had less correlation with soil moisture. PMID:20879516

  15. Net water vapour exchange over a mixed needle and broad-leaved forest in Changbai Mountain during autumn

    Institute of Scientific and Technical Information of China (English)

    HANShijie; WENXuefa; YUGuirui; SUNXiaomin; LIQingkang; RENChuanyou

    2003-01-01

    Water vapour and CO2 fluxes were measured by the eddy-covariance technique above a mixed needle and broad-leaved forest with affiliated meteorological measurements in Changbai Mountain as part of China's FLUX projects since late August in 2002. Net water vapour exchange and environmental control over the forest were examined from September 1 to October 31 in 2002. To quantify the seasonal dynamics, the transition period was separated into leafed, leaf falling and leafless stages according to the development of leaf area. The results showed that (a) seasonal variation of water vapour exchange was mainly controlled by net radiation (Rn) which could account for 78.5%, 63.4% and 56.6% for leafed, leaf falling and leafless stages, respectively, while other environmental factors' effects varied evidently; (b) magnitude of water vapour flux decreased remarkably during autumn and daily mean of water vapour exchange was 24.2 mg m-2 s-1 (100%), 14.8 mg m-2 s-1 (61.2%) and 10.3 mg m-2 s-1 (42.6%) for leafed, leaf falling and leafless stage, respectively; and (c) the budget of water vapour exchange during autumn was estimated to be 87.1 kg H2O m2, with a mean of 1427.2 g H2O d-1 varying markedly from 3104.0 to 227.5 g H2O m-2d-1.

  16. Diurnal and seasonal carbon sequestration potential of seven broadleaved species in a mixed deciduous forest in India

    Science.gov (United States)

    Biswas, Soumyajit; Bala, Sanjay; Mazumdar, Asis

    2014-06-01

    The objective of the study was to measure annual carbon sequestration rate of mixed deciduous forest by measuring that of seven young broadleaved tree species (6 years age) as well as selection of better carbon sequestered plant species for future plantation. The diurnal net assimilation rate of Carbon dioxide (CO2) at leaf level was measured with LI-6400 Portable Photosynthesis System at daytime on seasonal basis in a man-made forest at Budge Budge (N 22°28‧ E 88°08‧) of South 24 Parganas, West Bengal, INDIA. Net assimilation rate of carbon at canopy level was calculated by measuring Leaf Area Index with LAI-2200 and using analytical model with non-rectangular hyperbolic light response curve. The average net assimilation rate of CO2 at leaf level was found maximum in Albizzia lebbek (8.13 μmol m-2 s-1) and that of canopy level in Eucalyptus spp. (4.851 g h-1). The minimum was found for Swietenia mahagoni (1.058 g h-1). The annual carbon sequestration rate of the mixed forest in natural condition was estimated 6.01 t ha-1 year-1 by consolidating the potential of all seven species.

  17. Meteorological control on CO2 flux above broad-leaved Korean pine mixed forest in Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    GUAN; Dexin; WU; Jiabing; YU; Guirui; SUN; Xiaomin; ZHAO; X

    2005-01-01

    The impacts of temperature, photosynthetic active radiation (PAR) and vapor pressure deficit (VPD) on CO2 flux above broad-leaved Korean pine mixed forest in the Changbai Mountains were studied based on eddy covariance and meteorological factors measurements.The results showed that, daytime CO2 flux was mainly controlled by PAR and they fit Michaelis-Menten equation. Meanwhile VPD also had an influence on the daytime flux. Drier air reduced the CO2 assimilation of the ecosystem, the drier the air, the more the reduction of the assimilation. And the forest was more sensitive to VPD in June than that in July and August. The respiration of the ecosystem was mainly controlled by soil temperature and they fit exponential equation. It was found that this relationship was also correlated with seasons; respiration from April to July was higher than that from August to November under the same temperature. Daily net carbon exchange of the ecosystem and the daily mean air temperature fit exponential equation. It was also found that seasonal trend of net carbon exchange was the result of comprehensive impacts of temperature and PAR and so on. These resulted in the biggest CO2 uptake in June and those in July and August were next. Annual carbon uptake of the forest ecosystem in 2003 was -184 gC. m-2.

  18. Satellite chlorophyll fluorescence measurements reveal large-scale decoupling of photosynthesis and greenness dynamics in boreal evergreen forests.

    Science.gov (United States)

    Walther, Sophia; Voigt, Maximilian; Thum, Tea; Gonsamo, Alemu; Zhang, Yongguang; Köhler, Philipp; Jung, Martin; Varlagin, Andrej; Guanter, Luis

    2016-09-01

    Mid-to-high latitude forests play an important role in the terrestrial carbon cycle, but the representation of photosynthesis in boreal forests by current modelling and observational methods is still challenging. In particular, the applicability of existing satellite-based proxies of greenness to indicate photosynthetic activity is hindered by small annual changes in green biomass of the often evergreen tree population and by the confounding effects of background materials such as snow. As an alternative, satellite measurements of sun-induced chlorophyll fluorescence (SIF) can be used as a direct proxy of photosynthetic activity. In this study, the start and end of the photosynthetically active season of the main boreal forests are analysed using spaceborne SIF measurements retrieved from the GOME-2 instrument and compared to that of green biomass, proxied by vegetation indices including the Enhanced Vegetation Index (EVI) derived from MODIS data. We find that photosynthesis and greenness show a similar seasonality in deciduous forests. In high-latitude evergreen needleleaf forests, however, the length of the photosynthetically active period indicated by SIF is up to 6 weeks longer than the green biomass changing period proxied by EVI, with SIF showing a start-of-season of approximately 1 month earlier than EVI. On average, the photosynthetic spring recovery as signalled by SIF occurs as soon as air temperatures exceed the freezing point (2-3 °C) and when the snow on the ground has not yet completely melted. These findings are supported by model data of gross primary production and a number of other studies which evaluated in situ observations of CO2 fluxes, meteorology and the physiological state of the needles. Our results demonstrate the sensitivity of space-based SIF measurements to light-use efficiency of boreal forests and their potential for an unbiased detection of photosynthetic activity even under the challenging conditions interposed by evergreen

  19. Temporal variability in the sources and fluxes of CO2 in a residential area in an evergreen subtropical city

    Science.gov (United States)

    Weissert, L. F.; Salmond, J. A.; Turnbull, J. C.; Schwendenmann, L.

    2016-10-01

    Measurements of CO2 fluxes in temperate climates have shown that urban areas are a net source of CO2 and that photosynthetic CO2 uptake is generally not sufficient to offset local CO2 emissions. However, little is known about the role of vegetation in cities where biogenic CO2 uptake is not limited to a 2-8 months growing season. This study used the eddy covariance technique to quantify the atmospheric CO2 fluxes over a period of 12 months in a residential area in subtropical Auckland, New Zealand, where the vegetation cover (surface cover fraction: 47%) is dominated by evergreen vegetation. Radiocarbon isotope measurements of CO2 were conducted at three different times of the day (06:00-09:00, 12:00-15:00, 01:00-04:00) for four consecutive weekdays in summer and winter to differentiate anthropogenic sources of CO2 (fossil fuel combustion) from biogenic sources (ecosystem respiration, combustion of biofuel/biomass). The results reveal previously unreported patterns for CO2 fluxes, with no seasonal variability and negative (net uptake) CO2 midday fluxes throughout the year, demonstrating photosynthetic uptake by the evergreen vegetation all year-round. The winter radiocarbon measurements showed that 85% of the CO2 during the morning rush hour was attributed to fossil fuel emissions, when wind was from residential areas. However, for all other time periods radiocarbon measurements showed that fossil fuel combustion was not a large source of CO2, suggesting that biogenic processes likely dominate CO2 fluxes at this residential site. Overall, our findings highlight the importance of vegetation in residential areas to mitigate local CO2 emissions, particularly in cities with a climate that allows evergreen vegetation to maintain high photosynthetic rates over winter. As urban areas grow, urban planners need to consider the role of urban greenspace to mitigate urban CO2 emissions.

  20. A cold-tolerant evergreen interspecific hybrid of Ocimum kilimandscharicum and Ocimum basilicum: analyzing trichomes and molecular variations.

    Science.gov (United States)

    Dhawan, Sunita Singh; Shukla, Preeti; Gupta, Pankhuri; Lal, R K

    2016-05-01

    Ocimum (Lamiaceae) is an important source of essential oils and aroma chemicals especially eugenol, methyl eugenol, linalool, methyl chavicol etc. An elite evergreen hybrid has been developed from Ocimum kilimandscharicum and Ocimum basilicum, which demonstrated adaptive behavior towards cold stress. A comparative molecular analysis has been done through RAPD, AFLP, and ISSR among O. basilicum and O. kilimandscharicum and their evergreen cold-tolerant hybrid. The RAPD and AFLP analyses demonstrated similar results, i.e., the hybrid of O. basilicum and O. kilimandscharicum shares the same cluster with O. kilimandscharicum, while O. basilicum behaves as an outgroup, whereas in ISSR analysis, the hybrid genotype grouped in the same cluster with O. basilicum. Ocimum genotypes were analyzed and compared for their trichome density. There were distinct differences on morphology, distribution, and structure between the two kinds of trichomes, i.e., glandular and non-glandular. Glandular trichomes contain essential oils, polyphenols, flavonoids, and acid polysaccharides. Hair-like trichomes, i.e., non-glandular trichomes, help in keeping the frost away from the living surface cells. O. basilicum showed less number of non-glandular trichomes on leaves compared to O. kilimandscharicum and the evergreen cold-tolerant hybrid. Trichomes were analyzed in O. kilimandscharicum, O. basilicum, and their hybrid. An increased proline content at the biochemical level represents a higher potential to survive in a stress condition like cold stress. In our analysis, the proline content is quite higher in tolerant variety O. kilimandscharicum, low in susceptible variety O. basilicum, and intermediate in the hybrid. Gene expression analysis was done in O. basilicum, O. kilimandscharicum and their hybrid for TTG1, GTL1, and STICHEL gene locus which regulates trichome development and its formation and transcription factors WRKY and MPS involved in the regulation of plant responses to freezing

  1. Uncertainty analysis of CO2 flux components in subtropical evergreen coniferous plantation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    We present an uncertainty analysis of ecological process parameters and CO2 flux components (Reco, NEE and gross ecosystem exchange (GEE)) derived from 3 years’ continuous eddy covariance meas-urements of CO2 fluxes at subtropical evergreen coniferous plantation, Qianyanzhou of ChinaFlux. Daily-differencing approach was used to analyze the random error of CO2 fluxes measurements and bootstrapping method was used to quantify the uncertainties of three CO2 flux components. In addition, we evaluated different models and optimization methods in influencing estimation of key parameters and CO2 flux components. The results show that: (1) Random flux error more closely follows a dou-ble-exponential (Laplace), rather than a normal (Gaussian) distribution. (2) Different optimization meth-ods result in different estimates of model parameters. Uncertainties of parameters estimated by the maximum likelihood estimation (MLE) are lower than those derived from ordinary least square method (OLS). (3) The differences between simulated Reco, NEE and GEE derived from MLE and those derived from OLS are 12.18% (176 g C·m-2·a-1), 34.33% (79 g C·m-2·a-1) and 5.4% (92 g C·m-2·a-1). However, for a given parameter optimization method, a temperature-dependent model (T_model) and the models derived from a temperature and water-dependent model (TW_model) are 1.31% (17.8 g C·m-2·a-1), 2.1% (5.7 g C·m-2·a-1), and 0.26% (4.3 g C·m-2·a-1), respectively, which suggested that the optimization methods are more important than the ecological models in influencing uncertainty in estimated carbon fluxes. (4) The relative uncertainty of CO2 flux derived from OLS is higher than that from MLE, and the uncertainty is related to timescale, that is, the larger the timescale, the smaller the uncertainty. The relative uncertainties of Reco, NEE and GEE are 4%-8%, 7%-22% and 2%-4% respectively at annual timescale.

  2. Dynamics of the evergreen understory at Coweeta Hydrologic Laboratory, North Carolina

    Science.gov (United States)

    Dobbs, Marion Mcnamara

    Much attention today is directed toward vegetation dynamics and related issues of biotic diversity. Both environmental gradients and disturbance/land use history are important determinants of both the distributional pattern and the dynamics of many plant species. The southern Appalachian Mountains constitute a region of high plant and animal diversity and rapidly increasing development pressure with its consequent changes in land use. The remaining forested areas commonly include a significant evergreen understory (undergreen) composed of ericaceous shrubs, predominately Rhododendron maximum , which is believed to be expanding and exerting an inhibitory effect on the establishment of other species, thus impacting forest structure and composition. This study was an attempt to characterize this forest component, temporally and spatially, at the Coweeta Hydrologic Laboratory, North Carolina, in terms of a variety of topographic gradients as well as long-term (century) and short-term (decade) disturbance history, verify expansion, develop a surrogate soil moisture index for use in an explanatory model for undergreen pattern, and examine the feasibility of predicting the pattern of undergreen at one time based on knowledge of topographic relationships gained at an earlier time. A GIS was used for visual and areal comparisons; logistic regression was used for developing spatiotemporal explanatory models. Results indicate that aspect, stream proximity, and elevation are all important in explaining distributional pattern and dynamics of the undergreen at Coweeta, with R. maximum showing preference for moister areas and its common associate, Kalmia latifolia found more frequently in drier areas. The influence of these environmental factors differs between the larger Coweeta Basin, the site of experimental manipulations at the small watershed level since the 1930's, and the physically similar Dryman Fork Basin, relatively undisturbed since that time. There is an apparent

  3. [Biogeographic regionalization of the mammals of tropical evergreen forests in Mesoamerica].

    Science.gov (United States)

    Olguin-Monroy, Hector C; Gutiérrez-Blando, Cirene; Rios-Muñoz, César A; León-Paniagua, Livia; Navarro-Sigüenza, Adolfo G

    2013-06-01

    Mesoamerica is a biologically complex zone that expands from Southern Mexico to extreme Northern Colombia. The biogeographical patterns and relationships of the mammalian fauna associated to the Mesoamerican Tropical Evergreen Forest (MTEF) are poorly understood, in spite of the wide distribution of this kind of habitat in the region. We compiled a complete georeferenced database of mammalian species distributed in the MTEF of specimens from museum collections and scientific literature. This database was used to create potential distribution maps through the use of environmental niche models (ENMs) by using the Genetic Algorithm for Rule-Set Production (GARP) using 22 climatic and topographic layers. Each map was used as a representation of the geographic distribution of the species and all available maps were summed to obtain general patterns of species richness in the region. Also, the maps were used to construct a presence-absence matrix in a grid of squares of 0.5 degrees of side, that was analyzed in a Parsimony Analysis of Endemicity (PAE), which resulted in a hypothesis of the biogeographic scheme in the region. We compiled a total of 41 527 records of 233 species of mammals associated to the MTEF. The maximum concentration of species richness (104-138 species) is located in the areas around the Isthmus of Tehuantepec, Northeastern Chiapas-Western Guatemala, Western Honduras, Central Nicaragua to Northwestern Costa Rica and Western Panama. The proposed regionalization indicates that mammalian faunas associated to these forests are composed of two main groups that are divided by the Isthmus of Tehuantepec in Oaxaca in: a) a Northern group that includes Sierra Madre of Chiapas-Guatemala and Yucatan Peninsula; and b) an austral group, that contains the Pacific slope of Chiapas towards the South including Central America. Some individual phylogenetic studies of mammal species in the region support the relationships between the areas of endemism proposed, which

  4. Environmental Drivers of Whole-Ecosystem Methane Fluxes from a Lowland Evergreen Forest

    Science.gov (United States)

    Shoemaker, J. K.; Keenan, T. F.; Hollinger, D. Y.; Richardson, A. D.

    2013-12-01

    Forests dominate the global carbon cycle, but their role in methane (CH4) biogeochemistry remains uncertain. Limitations in mesoscale sampling approaches has led to gaps in our knowledge of the dynamics of CH4 uptake and release from forested ecosystems and the environmental drivers that control these fluxes. Methane, a more potent greenhouse gas than carbon dioxide (CO2) over short timescales, may have an important role to play in determining the total climate influence of a forest system. Here we examine a time series of methane fluxes, obtained over 2 years by eddy flux covariance, from a lowland evergreen forest in central Maine, USA. During 2011, a wetter than average year, the forest was a net source of CH4 from the beginning of the measurement period in July through October. In 2012, a drier than average year, the forest was a small source only from early June through mid-July after which it transitioned to a weak sink for the remainder of the year. Using both a multiple linear regression and an artificial neural network approach, we find gross primary productivity (GPP, estimated from eddy covariance CO2 fluxes) to provide the strongest correlation with the seasonal trend in CH4 flux. While GPP alone provides the majority of the models' correlation during 2011, including soil moisture at 10cm significantly improves the fit of the model during 2012. Using a linear model of GPP and soil moisture, combined with Monte-Carlo resampling, we estimate that the total annual CH4 fluxes for 2011 and 2012 at Howland forest were 6900 +/- 4600 and -18000 +/- 2700 umol m-2 yr-1, respectively (means +/- 1sd). While these fluxes are very small compared to the annual CO2 consumption at this site (~300 g m-2 yr-1), these forest CH4 fluxes may contribute significantly to both short- and long-term variability in regional CH4 emissions. Understanding how environmental drivers influence CH4 fluxes at the landscape scale is critical to developing appropriate model structures for

  5. Relationship and its ecological significance between plant species diversity and ecosystem function of soil conservation in semi-humid evergreen forests, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    WANG Zhenhong; YANG Chengbo; YANG Limei; ZHOU Zizong; RAO Jing; YUAN Li; LI Ju

    2007-01-01

    In recent years,the relationship between biodiversity and ecosystem stability,productivity,and other ecosystem functions has been extensively studied by using theoretical approaches,experimental investigations,andobservations in natural ecosystems;however,results are controversial.For example,simple systems were more stable than complex systems in theoretical studies,and higher productivity was observed in human-made ecosystems with poorer species composition,etc.The role of biodiversity in the ecosystem,such as its influence on sustainability,stability,and productivity,is still not understood.Because accelerated soil-erosion in various ecosystems has caused a decrease of primary productivity,a logical way used in the study of the relationship between biodiversity and ecosystem function can be used to study the relationship between plant species diversity and soil conservation.In addition,biodiversity is a product of evolutionary history,and soil erosion is a key factor controlling the evolution of modern environment on the surface of the Earth.A study on the relationship between biodiversity and soil-erosion processes could help us understand the environmental evolution of Earth.Fifteen 10m × 40m standard nmoffplots were established to measure surface runoff,soil erosion,and total P loss in different secondary communities of semi-humid evergreen broad-leaved forests that varied in composition,diversity,and level of disturbance and soil erosion.The following five communities were studied:AEI (Ass.Elsholtzia fruticosa+Imperata cylindrical),APMO (Ass.Pinus yunnanensis + Myrsine africana + Oplismenus compsitus), APLO (Ass.Pinus yunnanensis + Lithocarpus confines + Oplismenus compsitus),AEME (Ass.Eucalyptus smith + Myrsine africana +Eupatorium adenophorum),and ACKV (Ass.Cyclobalanopsis glaucoides + Keteleeria evelyniana + Viola duelouxii).Tree density,the diameter of the tree at breast height,and the hygroscopic volume of plant leaves were determined in each plot

  6. [Characteristics of evaporation over broadleaved Korean pine forest in Changbai Mountains, Northeast China during snow cover period in winter].

    Science.gov (United States)

    Li, Hui-dong; Guan, De-xin; Wang, An-zhi; Wu, Jia-Bing; Jin, Chang-jie; ShiI, Ting-ting

    2013-04-01

    Based on the measurement data of water vapor flux by open-path eddy covariance system and of the micrometeorological factors in broad-leaved Korean pine forest in Changbai Mountains during the snow cover period from 2002 to 2005, this paper analyzed the dynamics of snow cover evaporation and the relationships between the evaporation and meteorological factors. The energy balanced ratio during the snow cover period was 79. 9% , and the latent heat flux accounted for 21. 4% of net radiation. The diurnal variation of the evaporation presented a single-peak curve, and the evaporation rate during snow-melting period was higher than that during stable snow cover period. The half-hour evaporation presented liner relationship with net radiation and quadratic relationship with air temperature. The daily evaporation presented quadratic relationship with net radiation and exponential relationship with air temperature. The daily evaporation presented a dynamic trend of decreasing-stable-increasing, with the maximum at increasing stage and the minimum at stable stage. The maximum value of the daily evaporation was 0.73 mm d-1, and the minimum value was 0. 004 mm d-1. During the snow cover periods of 2002-2003, 2003-2004 and 2004-2005, the annual evaporation was 27.6, 25.5, and 22.9 mm, accounting for 37.9% , 19.5% , and 30. 0% of the precipitation in the same periods, respectively. The mean value of the daily evaporation in the three periods was 0. 17, 0. 19, and 0. 17 mm d-1, respectively.

  7. The impact of broadleaved woodland on water resources in lowland UK: I. Soil water changes below beech woodland and grass on chalk sites in Hampshire

    Directory of Open Access Journals (Sweden)

    J. Roberts

    2005-01-01

    Full Text Available The possible effects of broadleaved woodland on recharge to the UK Chalk aquifer have led to a study of evaporation and transpiration from beech woodland (Black Wood and pasture (Bridgets Farm, growing in shallow soils above chalk in Hampshire. Eddy correlation measurements of energy balance components above both the forest and the grassland enabled calculation of latent heat flux (evaporation and transpiration as a residual. Comparative measurements of soil water content and soil water potential in 9 m profiles under both forest and grassland found changes in soil water content down to 6 m at both sites; however, the soil water potential measurements showed upward movement of water only above a depth of about 2 m. Below this depth, water continued to drain and the soil water potential measurements showed downward movement of water at both sites, notwithstanding significant negative soil water potentials in the chalk and soil above. Seasonal differences occur in the soil water content profiles under broadleaved woodland and grass. Before the woodland foliage emerges, greater drying beneath the grassland is offset in late spring and early summer by increased drying under the forest. Yet, when the change in soil water profiles is at a maximum, in late summer, the profiles below woodland and grass are very similar. A comparison of soil water balances for Black Wood and Bridgets Farm using changes in soil water contents, local rainfall and evaporation measured by the energy balance approach allowed drainage to be calculated at each site. Although seasonal differences occurred, the difference in cumulative drainage below broadleaved woodland and grass was small.

  8. Ecological Function of Mixed Conifer-Broadleaved Forest%人工针阔混交林生态作用分析

    Institute of Scientific and Technical Information of China (English)

    曹世刚

    2015-01-01

    通过对人工针阔混交林生态作用的调查与分析,结果表明:日本落叶松+色赤杨混交林比日本落叶松纯林植物种类多,乔木层、灌木层、草本层中的多样性能指标占优势,针阔混交林的分解速度明显高于纯林,其营养元素(N、P、K )的释放率均在50%左右,而日本落叶松纯林营养元素(N、P、K )的释放率低于31%。培育人工针阔混交林,能提高物种的多样性,加速枯落物的分解,增强营养元素释放效率,提高土壤肥力。%Ecological function of mixed conifer‐broadleaved forest was analyzed .Plant species of Larix kaempferi+ mixed forest of Alnussibirica are more than that of pure forest of Larix kaempferi ;diversity indices in tree layer , shrub layer ,herb layer are in a dominant position;the decomposition rate of mixed conifer‐broadleaved forest is sig‐nificantly higher than that of pure forest ,the release rate of its nutrients (N ,P ,K ) being 50% ;the release rate of pure forest of nutrients (N ,P ,K) for Larix kaempferi is less than 31% .Cultivating mixed conifer‐broadleaved for‐est ,can increase the diversity of species ,accelerate the decomposition of litter and release nutrients to enhance effi‐ciency ,and improve soil fertility .

  9. Observations on arbuscular mycorrhiza associated with important edible tuberous plants grown in wet evergreen forest in Assam, India

    Directory of Open Access Journals (Sweden)

    RAJA RISHI

    2013-10-01

    Full Text Available Kumar R, Tapwal A, Pandey S, Rishi R, Borah D. 2013. Observations on arbuscular mycorrhiza associated with important edible tuberous plants grown in wet evergreen forest in Assam, India. Biodiversitas 14: 67-72. Non-timber forest products constitute an important source of livelihood for rural households from forest fringe communities across the world. Utilization of wild edible tuber plants is an integral component of their culture. Mycorrhizal associations influence the establishment and production of tuber plants under field conditions.The aim of present study is to explore the diversity and arbuscular mycorrhizal (AMF colonization of wild edible tuber plants grown in wet evergreen forest of Assam, India. A survey was conducted in 2009-10 in Sunaikuchi, Khulahat, and Bura Mayong reserved forest of Morigaon district of Assam to determine the AMF spore population in rhizosphere soils and root colonization of 14 tuberous edible plants belonging to five families. The results revealed AMF colonization of all selected species in all seasons. The percent colonization and spore count was less in summer, moderate in winter and highest in rainy season. Seventeen species of arbuscular mycorrhizal fungi were recorded in four genera viz. Acaulospora (7 species, Glomus (5 species, Sclerocystis (3 species and Gigaspora (2 species.

  10. Reconciling species-level vs plastic responses of evergreen leaf structure to light gradients: shade leaves punch above their weight.

    Science.gov (United States)

    Lusk, Christopher H; Onoda, Yusuke; Kooyman, Robert; Gutiérrez-Girón, Alba

    2010-04-01

    *When grown in a common light environment, the leaves of shade-tolerant evergreen trees have a larger leaf mass per unit area (LMA) than their light-demanding counterparts, associated with differences in lifespan. Yet plastic responses of LMA run counter to this pattern: shade leaves have smaller LMA than sun leaves, despite often living longer. *We measured LMA and cell wall content, and conducted punch and shear tests, on sun and shade leaves of 13 rainforest evergreens of differing shade tolerance, in order to understand adaptation vs plastic responses of leaf structure and biomechanics to shade. *Species shade tolerance and leaf mechanical properties correlated better with cell wall mass per unit area than with LMA. Growth light environment had less effect on leaf mechanics than on LMA: shade leaves had, on average, 40% lower LMA than sun leaves, but differences in work-to-shear, and especially force-to-punch, were smaller. This was associated with a slightly larger cell wall fraction in shade leaves. *The persistence of shade leaves might reflect unattractiveness to herbivores because they yield smaller benefits (cell contents per area) per unit fracture force than sun leaves. In forest trees, cell wall fraction and force-to-punch are more robust correlates of species light requirements than LMA.

  11. 贡嘎山阔叶木本植物叶片解剖结构及其生存策略分析%An Analysis of the Foliar Anatomical Structures of Broadleaved Woody Plants in the Gongga Mountains and Their Survival Strategy

    Institute of Scientific and Technical Information of China (English)

    刘艳芳; 张艳茹; 陈红

    2015-01-01

    对68种贡嘎山阔叶木本植物的叶片解剖结构特征进行了研究 ,结果表明:① 叶片各解剖结构在不同物种间存在很大的差异 ,其中海绵组织厚度和栅海比的变异系数较大 ,是生态适应性状 ;而叶片厚度、上表皮厚度、栅栏组织厚度以及栅栏细胞层数的变异系数较小 ,是系统演替性状 .② 落叶植物有较大的光合速率 ,而对叶片组织结构的投入较低 ,采取了积极型的生存策略 ;常绿植物具有较小的光合速率 ,并对叶片组织结构有较高的投入 ,采取了保守型的生存策略 .%In a study reported in the present paper ,the leaf structural characters of 68 broadleaved woody species of the Gongga Mountains were investigated .The results were as follows :① Great interspecific differences were observed in various anatomical structures .Sponge tissue thickness and palisade spongy ra-tio had larger coefficient of variation (CV) ,suggesting that they were ecologically adaptive traits ,while blade thickness ,upper epidermis thickness ,palisade tissue thickness and palisade cell layers had smaller CV ,indicating that they were system succession traits .② Deciduous plants had higher photosynthetic rate and lower investment in leaf tissue structures ,which was a positive survival strategy ;while evergreen plants had lower photosynthetic rate and higher investment in the organizational structures of blades , w hich suggested that they adopted a conservative strategy for survival .

  12. Simulating the exchanges of carbon dioxide, water vapor and heat over Changbai Mountains temperate broad-leaved Korean pine mixed forest ecosystem

    Institute of Scientific and Technical Information of China (English)

    WANG; Qiufeng; NIU; Dong; YU; Guirui; REN; Chuanyou; WEN; X

    2005-01-01

    A process-based ecosystem productivity model BEPS (Boreal Ecosystem Productivity Simulator) was updated to simulate half-hourly exchanges of carbon, water and energy between the atmosphere and terrestrial ecosystem at a temperate broad-leaved Korean pine forest in the Changbai Mountains, China. The BEPSh model is able to capture the diurnal and seasonal variability in carbon dioxide, water vapor and heat fluxes at this site in the growing season of 2003. The model validation showed that the simulated net ecosystem productivity (NEP), latent heat flux (LE), sensible heat flux (Hs) are in good agreement with eddy covariance measurements with an R2 value of 0.68, 0.86 and 0.72 for NEP, LE and Hs, respectively. The simulated annual NEP of this forest in 2003 was 300.5 gC/m2, and was very close to the observed value. Driving this model with different climate scenarios, we found that the NEP in the Changbai Mountains temperate broad-leaved Korean pine mixed forest ecosystem was sensitive to climate variability, and the current carbon sink will be weakened under the condition of global warming. Furthermore, as a process-based model, BEPSh was also sensitive to physiological parameters of plant, such as maximum Rubisco activity (Vcmax) and the maximum stomatal conductance (gmax), and needs to be carefully calibrated for other applications.

  13. Patterns and determinants of potential carbon gain in the C3 evergreen Yucca glauca (Liliaceae) in a C4 grassland.

    Science.gov (United States)

    Maragni, L A; Knapp, A K; McAllister, C A

    2000-02-01

    Yucca glauca is a C(3) evergreen rosette species locally common in the C(4)-dominated grasslands of the central Great Plains. Most congeners of Y. glauca are found in deserts, and Y. glauca's morphological similarities to desert species (steeply angled leaves, evergreen habit) may be critical to its success in grasslands. We hypothesized that the evergreen habit of Y. glauca, coupled with its ability to remain physiologically active at cool temperatures, would allow this species to gain a substantial portion of its annual carbon budget when the C(4) grasses are dormant. Leaf-level gas exchange was measured over an 18-mo period at Konza Prairie in northeast Kansas to assess the annual pattern of potential C gain. Two short-term experiments also were conducted in which nighttime temperatures were manipulated to assess the cold tolerance of this species. The annual pattern of C gain in Y. glauca was bimodal, with a spring productive period (maximum monthly photosynthetic rate = 21.1 ± 1.97 μmol·m·s) in March through June, a period of midseason photosynthetic depression, and a fall productive period in October (15.6 ± 1.25 μmol·m·s). The steeply angled leaves resulted in interception of photon flux density at levels above photosynthetic saturation throughout the year. Reduced photosynthetic rates in the summer may have been caused by low soil moisture, but temperature was strongly related (r = 0.37) to annual variations in photosynthesis, with nocturnal air temperatures below -5°C in the late fall and early spring, and high air temperatures (>32°C) in the summer, limiting gas exchange. Overall, 31% of the potential annual carbon gain in Y. glauca occurred outside the "frost-free" period (April-October) at Konza Prairie and 43% occurred when the dominant C(4) grasses were dormant. Future climates that include warmer minimum temperatures in the spring and fall may enhance the success of Y. glauca relative to the C(4) dominants in these grasslands. PMID:10675310

  14. Impact of evergreening on patients and health insurance: a meta analysis and reimbursement cost analysis of citalopram/escitalopram antidepressants

    Directory of Open Access Journals (Sweden)

    Alkhafaji Ali A

    2012-11-01

    Full Text Available Abstract Background "Evergreening" refers to the numerous strategies whereby owners of pharmaceutical products use patent laws and minor drug modifications to extend their monopoly privileges on the drug. We aimed to evaluate the impact of evergreening through the case study of the antidepressant citalopram and its chiral switch form escitalopram by evaluating treatment efficacy and acceptability for patients, as well as health insurance costs for society. Methods To assess efficacy and acceptability, we performed meta-analyses for efficacy and acceptability. We compared direct evidence (meta-analysis of results of head-to-head trials and indirect evidence (adjusted indirect comparison of results of placebo-controlled trials. To assess health insurance costs, we analyzed individual reimbursement data from a representative sample of the French National Health Insurance Inter-regime Information System (SNIIR-AM from 2003 to 2010, which allowed for projecting these results to the whole SNIIR-AM population (53 million people. Results In the meta-analysis of seven head-to-head trials (2,174 patients, efficacy was significantly better for escitalopram than citalopram (combined odds ratio (OR 1.60 (95% confidence interval 1.05 to 2.46. However, for the adjusted indirect comparison of 10 citalopram and 12 escitalopram placebo-controlled trials, 2,984 and 3,777 patients respectively, efficacy was similar for the two drug forms (combined indirect OR 1.03 (0.82 to 1.30. Because of the discrepancy, we could not combine direct and indirect data (test of inconsistency, P = 0.07. A similar discrepancy was found for treatment acceptability. The overall reimbursement cost burden for the citalopram, escitalopram and its generic forms was 120.6 million Euros in 2010, with 96.8 million Euros for escitalopram. Conclusions The clinical benefit of escitalopram versus citalopram remains uncertain. In our case of evergreening, escitalopram represented a substantially

  15. Seasonal and annual variation of CO2 flux above a broad-leaved Korean pine mixed forest

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>Long-term measurement of carbon metabolism of old-growth forests is critical to predict their behaviors and to reduce the uncertainties of carbon accounting under changing climate. Eddy covariance technology was applied to investigate the long-term carbon exchange over a 200 year-old Chinese broad-leaved Korean pine mixed forest in the Changbai Mountains (128°28’E and 42°24’N, Jilin Province, P. R. China) since August 2002. On the data obtained with open-path eddy covariance system and CO2 profile measurement system from Jan. 2003 to Dec. 2004, this paper reports (i) annual and seasonal variation of FNEE, FGPP and Re; (ii) regulation of environmental factors on phase and amplitude of ecosystem CO2 uptake and release Corrections due to storage and friction velocity were applied to the eddy carbon flux. Lal and soil temperature determined the seasonal and annual dynamics of FGPP and RE separately. VPD and air temperature regulated ecosystem photosynthesis at finer scales in growing seasons. Water condition at the root zone exerted a significant influence on ecosystem maintenance carbon metabolism of this forest in winter. The forest was a net sink of atmospheric CO2 and sequestered -449 g C·m-2 during the study period; -278 and -171 gC·m-2 for 2003 and 2004 respectively. FGPP and FRE over 2003 and 2004 were -1332, -1294 g C·m-2. and 1054, 1124 g C·m-2 respectively. This study shows that old-growth forest can be a strong net carbon sink of atmospheric CO2. There was significant seasonal and annual variation in carbon metabolism. In winter, there was weak photosynthesis while the ecosystem emitted CO2. Carbon exchanges were active in spring and fall but contributed little to carbon sequestration on an annual scale. The summer is the most significant season as far as ecosystem carbon balance is concerned. The 90 days of summer contributed 66.9, 68.9% of FGPp, and 60.4, 62.1% of RE of the entire year.

  16. Maintenance of an abrupt boundary between needle-leaved and broad-leaved forests in a wetland near coast

    Institute of Scientific and Technical Information of China (English)

    Shiro Tsuyuzaki; Akira Haraguchi

    2009-01-01

    There is an abrupt boundary between two well-developed wetland forests, a stand consisting of a broad-leaved, nitrogen-fixer Alnus japonica and a stand of the needle-leaved Picea glehnii Masters, in eastern Hokkaido, Japan. To clarify maintenance mechanisms, we studied the forest profile, water level, groundwater and precipitation chemistry, seedling establishment patterns in relation to microhabitats, and seed migration. The profile of groundwater level insufficiently explained the abrupt boundary formation, while the groundwater chemistry differed significantly between the two forests; i.e., EC, Na+, K+, Mg2+, Ca2+ and Cl- were higher in P. glehnii forest and pH was lower. Precipitation in P. glehnii forest contained richer Na+, Ca2+ and Cl-, indicating that the differences in surface-water chemistry were mostly derived from precipitation. Solar radiation was less than 2.2 MJ·m-2·d-1 on P. glehnii forest in late June, while that was patchily distributed in A. japonica forest with a range from 1.0 to 3.7 MJ·m-2·d-1. Moss cover on the soil surface, most of which were made of Sphagnum spp., was 60% in P. glehnii forest, but was 10% in A. japonica forest. Surface water chemistry represented by pH was considered to determine the development of Sphagnum moss. About 70% of P. glehnii seedlings < 1.3 m in height established on moss cover. Seed-sowing experiments suggested that seed germination and seedling survival for both species were significantly higher in P. glehnii forest. Therefore, the regeneration of P. glehnii in A. japonica forest was negligible, owing to the paucity of favorable microhabitats and low seedling establishment. A. japonica regenerated only by resprouting, and the seedlings were few in both forests. In addition, A. japonica seed migration into the P. glehnii forests was greatly restricted, and low solar radiation in the P. glehnii forest contributed to low seedling survival. Based on those results, we concluded that Picea glehnii and Alnus

  17. Soil properties in forest gaps and under canopy in broad-leaved Pinus koraiensis forests in Changbai Mountainous Region, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chunyu; ZHAO Xiuhai

    2007-01-01

    The species composition and diversities,and soil properties under canopy gaps in broad-leaved Pinus koraiensis forests were studied in the Changbai Mountains.The results indicated that the species composition and diversifies in gap were different from those under canopy.The Shannon-Wiener index,evenness index,and abundance index in gap were higher than those under canopy in the seedling layer,while the community dominance in the seedling layer increased in closed canopy.The physicochemical properties of soil changed with the change of space and resource availability in gaps.The thickness,standing crop,and water holding capacity of the litter layer under canopy were significantly (p < 0.01) higher than those in gap.The content of total nitrogen and total potassium of litter in gap were 10.47% and 20.73% higher than those under canopy,however,the content of total phosphorus and organic carbon under canopy were 15.23% and 12.66% more than those under canopy.The water content of 0-10 cm and 10-20 cm of soil layer in gap were 17.65% and 16.17% more than those under canopy.The soil buck density of 0-10 cm were slightly higher under canopy than that in gaps,but there was no significant difference in the soil buck density of the 10-20 cm soil layer.The soil pH values were 5.80 and 5.85 in gap and under canopy,respectively,and were not significantly different.The content of soil organic matter,total nitrogen,and total potassium in gap were 12.85%,7.67%,and 2.38% higher than those under canopy.The content of NH4+-N,available phosphorus,available potassium,and total phosphorus in soil under canopy were 13.33%,20.04%,16.52%,and 4.30% higher than those in gap.

  18. Species diversity of natural evergreen broadleaf forest community in Danxia landform area of Langshan Mountain%良山丹霞地貌区天然常绿阔叶林群落物种多样性研究

    Institute of Scientific and Technical Information of China (English)

    旷建军; 旷柏根; 彭珍宝; 谢振华; 刘玲; 袁正科; 王海昀

    2011-01-01

    Using the sampling method to collect data, the important values for measure indicators, and using richness the index D2, Simpsom index D1, Shannon-Wiener index H', Sheldon evenness index JSW and Pielou evenness index E as the measurement index, the community species diversity of 14 natural evergreen broad-leaved forest in Danxia landform area of Langshan Mountain were studied. The results showed that: 1 ) In similar habitat, along with the syngenesis to the subclimax stage, the change tendency of species diversity is increasable. In the climax community, the change tendency of species diversity of shrubs and herbs was increasable, but arbor have no obvious change. 2) Community species diversity was changed with elevation change, besides general common change pattern, but also presents one kind of bimodal curve pattern. 3 ) H' and E have higher sensitivity than D1 and JSW. There is a significant similar function among with descries species diversity of arbors, shrubs, and herbs with D1 and H', and descries species diversity of arbors with H' and E, D1, and E, JSW and E, and descries species diversity of herb with JSW and E. It was concluded that elevation, habitat and succession affect community species diversity in Danxia landform, H'、D1 、JSW and E can individually express Danxia landform community species diversity.%采用样方法采集数据,以重要值为测度指标,以丰富度指数D2、Simpsom指数D1、Shannon.Wiener指数H'、Sheldon均匀度指数Jsw和Pielou均匀度指数E为测度指数,研究了崀山丹霞地貌14个天然常绿阔叶林群落物种多样性.结果表明:1)在相似生境中,随着群落演替至亚顶极阶段,物种多样性的变化趋势是增加的,顶极群落中,生境变优,灌、草层物种多样性的变化趋势为增加,而乔木层无明显变化规律;2)群落物种多样性随海拔的变化,除一般常见的变化模式外,还出现一种双峰曲线模式;3)H'较D1,E较Jsw具有较高的敏感度.D1与H'在

  19. Elevated ozone negatively affects photosynthesis of current-year leaves but not previous-year leaves in evergreen Cyclobalanopsis glauca seedlings

    International Nuclear Information System (INIS)

    To assess the effects of leaf age/layer on the response of photosynthesis to chronic ozone (O3), Cyclobalanopsis glauca seedlings, a dominant evergreen broadleaf tree species in sub-tropical regions, were exposed to either ambient air (AA) or elevated O3 (AA + 60 ppb O3, E-O3) for two growing seasons in open-top chambers. Chlorophyll content, gas exchange and chlorophyll a fluorescence were investigated three times throughout the 2nd year of O3 exposure. Results indicated that E-O3 decreased photosynthetic parameters, particularly light-saturated photosynthesis rate, stomatal conductance and effective quantum yield of PSII photochemistry of current-year leaves but not previous-year leaves. Stomatal conductance of plants grown under ambient conditions partially contributed to the different response to E-O3 between leaf layers. Light radiation or other physiological and biochemical processes closely related to photosynthesis might play important roles. All suggested that leaf ages or layers should be considered when assessing O3 risk on evergreen woody species. -- Highlights: • Response of evergreen Cyclobalanopsis glauca to O3 was investigated. • Elevated O3 significantly reduced photosynthesis of current-year leaves. • Previous-year leaves showed little response to O3. • Stomatal conductance contributes to the response difference to O3 among leaf ages. -- Impacts of elevated O3 on photosynthesis of evergreen woody species depend on leaf ages

  20. Influences of evergreen gymnosperm and deciduous angiosperm tree species on the functioning of temperate and boreal forests

    DEFF Research Database (Denmark)

    Augusto, Laurent; De Schrijver, An; Vesterdal, Lars;

    2015-01-01

    It has been recognized for a long time that the overstorey composition of a forest partly determines its biological and physical-chemical functioning. Here, we review evidence of the influence of evergreen gymnosperm (EG) tree species and deciduous angiosperm (DA) tree species on the water balance...... and processes that require further research. Relatively larger amounts of nutrients enter the soil-plant biogeochemical cycle under the influence of EGs than DAs, but recycling of nutrients appears to be slightly enhanced by DAs. Understanding the mechanisms underlying forest ecosystem functioning is essential...... of their tissues, higher soil moisture and favourable conditions for earthworms. Forest floors consequently tend to be thicker in EG forests compared to DA forests. Many factors, such as litter lignin content, influence litter decomposition and it is difficult to identify specific litter-quality parameters...

  1. Estimation of above ground biomass by using multispectral data for Evergreen Forest in Phu Hin Rong Kla National Park, Thailand

    International Nuclear Information System (INIS)

    Tropical forest is the most important and largest source for stocking CO2 from the atmosphere which might be one of the main sources of carbon emission, global warming and climate change in recent decades. There are two main objectives of this study. The first one is to establish a relationship between above ground biomass and vegetation indices and the other is to evaluate above ground biomass and carbon sequestration for evergreen forest areas in Phu Hin Rong Kla National park, Thailand. Random sampling design based was applied for calculating the above ground biomass at stand level in the selected area by using Brown and Tsutsumi allometric equations. Landsat 7 ETM+ data in February 2009 was used. Support Vector Machine (SVM) was applied for identifying evergreen forest area. Forty-three of vegetation indices and image transformations were used for finding the best correlation with forest stand biomass. Regression analysis was used to investigate the relationship between the biomass volume at stand level and digital data from the satellite image. TM51 which derived from Tsutsumi allometric equation was the highest correlation with stand biomass. Normalized Difference Vegetation Index (NDVI) was not the best correlation in this study. The best biomass estimation model was from TM51 and ND71 (R2 =0.658). The totals of above ground biomass and carbon sequestration were 112,062,010 ton and 56,031,005 ton respectively. The application of this study would be quite useful for understanding the terrestrial carbon dynamics and global climate change. (author)

  2. Modeling the early-phase redistribution of radiocesium fallouts in an evergreen coniferous forest after Chernobyl and Fukushima accidents

    Energy Technology Data Exchange (ETDEWEB)

    Calmon, P.; Gonze, M.-A.; Mourlon, Ch.

    2015-10-01

    Following the Chernobyl accident, the scientific community gained numerous data on the transfer of radiocesium in European forest ecosystems, including information regarding the short-term redistribution of atmospheric fallout onto forest canopies. In the course of international programs, the French Institute for Radiological Protection and Nuclear Safety (IRSN) developed a forest model, named TREE4 (Transfer of Radionuclides and External Exposure in FORest systems), 15 years ago. Recently published papers on a Japanese evergreen coniferous forest contaminated by Fukushima radiocesium fallout provide interesting and quantitative data on radioactive mass fluxes measured within the forest in the months following the accident. The present study determined whether the approach adopted in the TREE4 model provides satisfactory results for Japanese forests or whether it requires adjustments. This study focused on the interception of airborne radiocesium by forest canopy, and the subsequent transfer to the forest floor through processes such as litterfall, throughfall, and stemflow, in the months following the accident. We demonstrated that TREE4 quite satisfactorily predicted the interception fraction (20%) and the canopy-to-soil transfer (70% of the total deposit in 5 months) in the Tochigi forest. This dynamics was similar to that observed in the Höglwald spruce forest. However, the unexpectedly high contribution of litterfall (31% in 5 months) in the Tochigi forest could not be reproduced in our simulations (2.5%). Possible reasons for this discrepancy are discussed; and sensitivity of the results to uncertainty in deposition conditions was analyzed. - Highlights: • Transfer of radiocesium atmospheric fallout in evergreen forests was modeled. • The model was tested using observations from Chernobyl and Fukushima accidents. • Model predictions of canopy interception and depuration agree with measurements. • Unexpectedly high contribution of litterfall for the

  3. Structure and floristic composition of old-growth wet evergreen forests of Nelliampathy Hills, Southern Western Ghats

    Institute of Scientific and Technical Information of China (English)

    V.S.Ramachandran; K.Swarupanandan

    2013-01-01

    We analyze the structure and composition of old-growth wet evergreen forest of Nelliampathy hills,the chain of hills lying immediately south of Palghat Gap,in the southern Western Ghats of India.We sampled 30 plots of 0.1 ha each (50 m × 20 m) at six locations enumerating all plants ≥ 10 cm girth at breast height.We pooled the data and computed various structural parameters.There were 152 species of 120genera and 51 families of the study area.Of these,118 (77%) were trees,24 were climbers (16%) and 10 were shrubs (7%).Species richness varied from 58-99 per 0.5 ha sample and Shannon indices of diversity ranged from 4.4 to 5.2.Fifty-nine per cent (89 species) of the species were Indian Sub-continent elements and 34% (51 species) are endemic to the Western Ghats.Fifteen species are listed in various threat categories.Aglaia and Litsea were the most species-rich genera.Numbers of families ranged from 27-43 per 0.5 ha sample.Euphorbiaceae and Lauraceae were the most species-rich families.Stand density varied from 1714 to 2244 stems·ha-1 and basal area from 53.6 to 102.1 m2·ha-1.The vegetation was dominated by 3-6 species and six dominance patterns characterized the species composition within the hill complex.The old-growth evergreen forests of Nelliampathy exist as small fragments rich in biodiversity and can be used as benchmarks for comparison with disturbed forests.

  4. Critical loads of nitrogen deposition and critical levels of atmospheric ammonia for semi-natural Mediterranean evergreen woodlands

    Science.gov (United States)

    Pinho, P.; Theobald, M. R.; Dias, T.; Tang, Y. S.; Cruz, C.; Martins-Loução, M. A.; Máguas, C.; Sutton, M.; Branquinho, C.

    2012-03-01

    Nitrogen (N) has emerged in recent years as a key factor associated with global changes, with impacts on biodiversity, ecosystems functioning and human health. In order to ameliorate the effects of excessive N, safety thresholds such as critical loads (deposition fluxes) and levels (concentrations) can be established. Few studies have assessed these thresholds for semi-natural Mediterranean ecosystems. Our objective was therefore to determine the critical loads of N deposition and long-term critical levels of atmospheric ammonia for semi-natural Mediterranean evergreen woodlands. We have considered changes in epiphytic lichen communities, one of the most sensitive comunity indicators of excessive N in the atmosphere. Based on a classification of lichen species according to their tolerance to N we grouped species into response functional groups, which we used as a tool to determine the critical loads and levels. This was done for a Mediterranean climate in evergreen cork-oak woodlands, based on the relation between lichen functional diversity and modelled N deposition for critical loads and measured annual atmospheric ammonia concentrations for critical levels, evaluated downwind from a reduced N source (a cattle barn). Modelling the highly significant relationship between lichen functional groups and annual atmospheric ammonia concentration showed the critical level to be below 1.9 μg m-3, in agreement with recent studies for other ecosystems. Modelling the highly significant relationship between lichen functional groups and N deposition showed that the critical load was lower than 26 kg (N) ha-1 yr-1, which is within the upper range established for other semi-natural ecosystems. Taking into account the high sensitivity of lichen communities to excessive N, these values should aid development of policies to protect Mediterranean woodlands from the initial effects of excessive N.

  5. The impact of changes in the amount and timing of precipitation on the herbaceous understorey of Mediterranean evergreen oak woodlands

    Science.gov (United States)

    Jongen, Marjan; Lecomte, Xavier; Pereira, João. S.

    2010-05-01

    In the Iberian Peninsula, the evergreen oak woodlands, called montados in Portugal and dehesas in Spain, are of great ecological and socio-economic importance. Dominated by evergreen Quercus species, these savanna-type woodlands are characterized by a widely separated tree stratum associated with an herbaceous understorey, dominated by C3 annual species. The productivity and biogeochemical cycles of the herbaceous layer are highly dependent on timing and magnitude of precipitation. Climate change scenarios for the region suggest not only increasing air temperatures, but also the possibility of decreasing spring precipitation, accompanied by an increase in the interval between precipitation events, which might cause drought conditions to occur. To understand the impact of hydrological changes on productivity and ecosystem processes of the herbaceous understorey in these ecosystems, water manipulation experiments are being carried out in Portugal. In autumn 2009, large (30 m2) rain-out shelters were constructed near Coruche (Portugal), with the aim of studying the effect of precipitation variability on the understorey vegetation in a managed cork oak woodland. Initially, the two treatments in the rain-out shelters will be: (1) ambient precipitation quantity, with a dry period of 7 days, and (2) ambient precipitation quantity with a dry period of 21 days. The 'ambient precipitation quantity' is based on historical precipitation data for the experimental site, with average annual precipitation of 680 mm. In addition to the above two treatments, there will be non-sheltered reference plots, receiving natural rainfall patterns. In the future we aim to reduce the precipitation quantity (-30%) with similar length of the dry periods as above. From February 2010 onwards, we will gather a full data set for environmental variables, as well as productivity, species composition, soil CO2 flux, soil nitrogen and photosynthesis. Preliminary results will be presented.

  6. Critical loads of nitrogen deposition and critical levels of atmospheric ammonia for semi-natural Mediterranean evergreen woodlands

    Directory of Open Access Journals (Sweden)

    P. Pinho

    2012-03-01

    Full Text Available Nitrogen (N has emerged in recent years as a key factor associated with global changes, with impacts on biodiversity, ecosystems functioning and human health. In order to ameliorate the effects of excessive N, safety thresholds such as critical loads (deposition fluxes and levels (concentrations can be established. Few studies have assessed these thresholds for semi-natural Mediterranean ecosystems. Our objective was therefore to determine the critical loads of N deposition and long-term critical levels of atmospheric ammonia for semi-natural Mediterranean evergreen woodlands. We have considered changes in epiphytic lichen communities, one of the most sensitive comunity indicators of excessive N in the atmosphere. Based on a classification of lichen species according to their tolerance to N we grouped species into response functional groups, which we used as a tool to determine the critical loads and levels. This was done for a Mediterranean climate in evergreen cork-oak woodlands, based on the relation between lichen functional diversity and modelled N deposition for critical loads and measured annual atmospheric ammonia concentrations for critical levels, evaluated downwind from a reduced N source (a cattle barn. Modelling the highly significant relationship between lichen functional groups and annual atmospheric ammonia concentration showed the critical level to be below 1.9 μg m−3, in agreement with recent studies for other ecosystems. Modelling the highly significant relationship between lichen functional groups and N deposition showed that the critical load was lower than 26 kg (N ha−1 yr−1, which is within the upper range established for other semi-natural ecosystems. Taking into account the high sensitivity of lichen communities to excessive N, these values should aid development of policies to protect Mediterranean woodlands from the initial effects of excessive N.

  7. DNA Barcode Authentication of Wood Samples of Threatened and Commercial Timber Trees within the Tropical Dry Evergreen Forest of India

    Science.gov (United States)

    Nithaniyal, Stalin; Newmaster, Steven G.; Ragupathy, Subramanyam; Krishnamoorthy, Devanathan; Vassou, Sophie Lorraine; Parani, Madasamy

    2014-01-01

    Background India is rich with biodiversity, which includes a large number of endemic, rare and threatened plant species. Previous studies have used DNA barcoding to inventory species for applications in biodiversity monitoring, conservation impact assessment, monitoring of illegal trading, authentication of traded medicinal plants etc. This is the first tropical dry evergreen forest (TDEF) barcode study in the World and the first attempt to assemble a reference barcode library for the trees of India as part of a larger project initiated by this research group. Methodology/Principal Findings We sampled 429 trees representing 143 tropical dry evergreen forest (TDEF) species, which included 16 threatened species. DNA barcoding was completed using rbcL and matK markers. The tiered approach (1st tier rbcL; 2nd tier matK) correctly identified 136 out of 143 species (95%). This high level of species resolution was largely due to the fact that the tree species were taxonomically diverse in the TDEF. Ability to resolve taxonomically diverse tree species of TDEF was comparable among the best match method, the phylogenetic method, and the characteristic attribute organization system method. Conclusions We demonstrated the utility of the TDEF reference barcode library to authenticate wood samples from timber operations in the TDEF. This pilot research study will enable more comprehensive surveys of the illegal timber trade of threatened species in the TDEF. This TDEF reference barcode library also contains trees that have medicinal properties, which could be used to monitor unsustainable and indiscriminate collection of plants from the wild for their medicinal value. PMID:25259794

  8. DNA barcode authentication of wood samples of threatened and commercial timber trees within the tropical dry evergreen forest of India.

    Directory of Open Access Journals (Sweden)

    Stalin Nithaniyal

    Full Text Available BACKGROUND: India is rich with biodiversity, which includes a large number of endemic, rare and threatened plant species. Previous studies have used DNA barcoding to inventory species for applications in biodiversity monitoring, conservation impact assessment, monitoring of illegal trading, authentication of traded medicinal plants etc. This is the first tropical dry evergreen forest (TDEF barcode study in the World and the first attempt to assemble a reference barcode library for the trees of India as part of a larger project initiated by this research group. METHODOLOGY/PRINCIPAL FINDINGS: We sampled 429 trees representing 143 tropical dry evergreen forest (TDEF species, which included 16 threatened species. DNA barcoding was completed using rbcL and matK markers. The tiered approach (1st tier rbcL; 2nd tier matK correctly identified 136 out of 143 species (95%. This high level of species resolution was largely due to the fact that the tree species were taxonomically diverse in the TDEF. Ability to resolve taxonomically diverse tree species of TDEF was comparable among the best match method, the phylogenetic method, and the characteristic attribute organization system method. CONCLUSIONS: We demonstrated the utility of the TDEF reference barcode library to authenticate wood samples from timber operations in the TDEF. This pilot research study will enable more comprehensive surveys of the illegal timber trade of threatened species in the TDEF. This TDEF reference barcode library also contains trees that have medicinal properties, which could be used to monitor unsustainable and indiscriminate collection of plants from the wild for their medicinal value.

  9. Cachar tropical semi–evergreen forest type of Northeast India: status of species diversity, distribution and population structure

    Directory of Open Access Journals (Sweden)

    Koushik Majumdar

    2015-09-01

    Full Text Available Conservation of threatened species in most cases is difficult because of incomplete knowledge about their actual distribution, population and habitat ecology. Quantitative vegetation inventory was applied to analyse phytosociological structure of Cachar tropical semi-evergreen forest type in Northeast India, which is consider as a rare forest sub-type. Total 9, 500 by 10m (0.5 ha sized line transects were laid in Tripura. Overall 3,391 individuals of woody species were measured in 4.5 ha analysis, which represented total 167 species. Out of 167 species, 138 species were tree, 14 were shrubs, 10 woody climbers, 3 bamboos and 2 palm species. Again, taxonomically out of 167 species only 6 species was monocot; deciduous and evergreen ratio was 98: 69. Further, out of 167 species 95 species showed aggregated distribution than 72 random distributions. Stem density was ranged 566-964 ha-1, basal area 19.22-52.82 m2ha-1; but most species listed with very low Important Value Index (IVI, where 51 species identified as very rare (0.05 from predominant to very rare population group (r2adj is adjusted correlation co-efficient. Stem density-girth relation was significantly quadratic and showed highest coefficient value for sapling (r2adj=0.99; p<0.05 than adult density (r2adj=0.96; p<0.001; however, stem density was declined across the height classes (r2adj=0.56; p<0.05. Present findings demonstrate the high conservation value of this habitat, as umbrella species (Dipterocarpus turbinatus was red listed as critically endangered by International Union for Conservation of Nature and Natural Resources (IUCN with 13 globally threatened plants. Present analysis offers easy scope for effective habitat management and strategies for species conservation and restoration through ecological niche modeling tool.

  10. Photoprotection of evergreen and drought-deciduous tree leaves to overcome the dry season in monsoonal tropical dry forests in Thailand.

    Science.gov (United States)

    Ishida, Atsushi; Yamazaki, Jun-Ya; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Maruta, Emiko; Diloksumpun, Sapit; Puangchit, Ladawan

    2014-01-01

    In tropical dry forests, uppermost-canopy leaves of evergreen trees possess the ability to use water more conservatively compared with drought-deciduous trees, which may result from significant differences in the photoprotective mechanisms between functional types. We examined the seasonal variations in leaf gas exchange, chlorophyll fluorescence and the amounts of photosynthetic pigments within lamina of the uppermost-canopy leaves of three drought-deciduous trees (Vitex peduncularis Wall., Xylia xylocarpa (Roxb.) W. Theob., Shorea siamensis Miq.), a semi-deciduous tree (Irvingia malayana Miq.) and two evergreen trees (Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels) in Thailand. Area-based maximum carbon assimilation rates (Amax) decreased during the dry season, except in S. siamensis. The electron transport rate (ETR) remained unchanged in deciduous trees, but decreased during the dry season in evergreen and semi-deciduous trees. In the principal component analysis, the first axis (Axis 1) accounted for 44.3% of the total variation and distinguished deciduous from evergreen trees. Along Axis 1, evergreen trees were characterized by a high Stern-Volmer non-photochemical quenching coefficient (NPQ), high xanthophyll cycle pigments/chlorophyll and a high de-epoxidation state of the xanthophyll cycle, whereas the deciduous trees were characterized by a high ETR, a high quantum yield of PSII (ΦPSII = (Fm(') -F)/Fm(')) and a high mass-based Amax under high-light conditions. These findings indicate that drought-deciduous trees showing less conservative water use tend to dissipate a large proportion of electron flow through photosynthesis or alternative pathways. In contrast, the evergreens showed more conservative water use, reduced Amax and ETR and enhanced NPQ and xanthophyll cycle pigments/chlorophyll during the dry season, indicating that down-regulated photosynthesis with enhanced thermal dissipation of excess light energy played an important role in

  11. Photoprotection of evergreen and drought-deciduous tree leaves to overcome the dry season in monsoonal tropical dry forests in Thailand.

    Science.gov (United States)

    Ishida, Atsushi; Yamazaki, Jun-Ya; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Maruta, Emiko; Diloksumpun, Sapit; Puangchit, Ladawan

    2014-01-01

    In tropical dry forests, uppermost-canopy leaves of evergreen trees possess the ability to use water more conservatively compared with drought-deciduous trees, which may result from significant differences in the photoprotective mechanisms between functional types. We examined the seasonal variations in leaf gas exchange, chlorophyll fluorescence and the amounts of photosynthetic pigments within lamina of the uppermost-canopy leaves of three drought-deciduous trees (Vitex peduncularis Wall., Xylia xylocarpa (Roxb.) W. Theob., Shorea siamensis Miq.), a semi-deciduous tree (Irvingia malayana Miq.) and two evergreen trees (Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels) in Thailand. Area-based maximum carbon assimilation rates (Amax) decreased during the dry season, except in S. siamensis. The electron transport rate (ETR) remained unchanged in deciduous trees, but decreased during the dry season in evergreen and semi-deciduous trees. In the principal component analysis, the first axis (Axis 1) accounted for 44.3% of the total variation and distinguished deciduous from evergreen trees. Along Axis 1, evergreen trees were characterized by a high Stern-Volmer non-photochemical quenching coefficient (NPQ), high xanthophyll cycle pigments/chlorophyll and a high de-epoxidation state of the xanthophyll cycle, whereas the deciduous trees were characterized by a high ETR, a high quantum yield of PSII (ΦPSII = (Fm(') -F)/Fm(')) and a high mass-based Amax under high-light conditions. These findings indicate that drought-deciduous trees showing less conservative water use tend to dissipate a large proportion of electron flow through photosynthesis or alternative pathways. In contrast, the evergreens showed more conservative water use, reduced Amax and ETR and enhanced NPQ and xanthophyll cycle pigments/chlorophyll during the dry season, indicating that down-regulated photosynthesis with enhanced thermal dissipation of excess light energy played an important role in

  12. Functions of Biodiversity of Artificial Broadleaved-Coniferous Mixed Forest%人工针阔混交林生物多样性功能分析

    Institute of Scientific and Technical Information of China (English)

    卢志华

    2015-01-01

    通过对红松、刺楸人工针阔混交林和红松人工纯林生物多样性功能的试验分析,结果表明:针阔混交林能增加蚯蚓的数量,林龄25年时,混交林的蚯蚓数量比人工纯林高48.4%;人工针阔混交林招引各种鸟类达33种,每天食虫量达1500条,抑制了森林虫害的发生;人工针阔混交林日平均气温0.5 m和1.8 m处分别比红松纯林低2.4~1.0℃,相对湿度0.5 m处比红松纯林提高24%,绝对湿度提高2.3%,1.8 m处混交林相对湿度比纯林提高11%,绝对湿度比纯林提高5.2%;混交林比纯林能降低风速0.7~1.2 m s-1。针阔混交林的各项功能指标都优于纯林。%The functions of the biodiversity of the artificial pure forest for Pinus koraiensis and the artificial broad-leaved-coniferous mixed forest of Pinus koraiensis and Kalopanax septemlobus were analyzed.Result shows that:broadleaved-coniferous mixed forest can increase the number of earthworms;the numbers of earthworm in the mixed forest are 48.4% higher than that of the artificial forests while the forest age being 25 years;the broadleaved-conif-erous mixed forest can attract 33 kinds of birds,and the insectivorous number are 1 500 per day,which inhibit the occurrence of forest pests;the daily average temperature of the broadleaved-coniferous mixed forest at 0.5 m and 1.8 m is 2.4 ℃ and 1.0℃ respectively lower than that of the pure forest of Pinuskoraiensis;the relative humidity and the absolute humidity is 24% and 2.3% higher than that of the pure forest at the height of 0.5 m respectively;the relative humidity and the absolute humidity is 1 1% and 5 .2% higher than that of the pure forest at the height of 1.8 m respectively;the mixed forest can reduce the wind speed by 0.7-1.2 m s-1 than that of the pure forest.The func-tion indicators of the broadleaved-coniferous mixed forest are superior to that of the pure forest.

  13. Temperature profiles from XBT casts from the EVERGREEN, GRESHAM, and HAMILTON from Ocean Weather Station E (OWS-E) and H (OWS-H) in the North Atlantic Ocean from 06 December 1970 to 01 September 1971 (NODC Accession 7101267)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the EVERGREEN, GRESHAM, and HAMILTON within a 1-mile radius of Ocean Weather Station E (3500N 04800W), H (3800N 07100W),...

  14. Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC EVERGREEN in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 23 January 1979 to 10 February 1979 (NODC Accession 7900115)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USCGC EVERGREEN in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Coast Guard from...

  15. Changes in structure and composition of evergreen forests on an altitudinal gradient in the Venezuelan Guayana shield.

    Science.gov (United States)

    Hernández, Lionel; Dezzeo, Nelda; Sanoja, Elio; Salazar, Leandro; Castellanos, Hernán

    2012-03-01

    There have been several ecological studies in forests of the Guayana Shield, but so far none had examined the changes in structure and composition of evergreen forests with altitude. This study describes and analyzes the structure, species composition and soil characteristics of forest stands at different altitudinal zones in Southeastern Venezuelan Guayana, in order to explain the patterns and the main factors that determine the structure and composition of evergreen forests along the altitudinal gradient. Inventories of 3 948 big (>10cm DBH) and 1 328 small (5-10cm DBH) woody stems were carried out in eleven plots, ranging from 0.1 to 1.0ha, along a 188km long transect with elevations between 290 and 1 395masl. It has been found that 1) hemiepihytes become more dominant and lianas reduce their dominance with increasing altitude and 2) the forest structure in the study area is size-dependent. Five families and 12 genera represented only 9% of the total number of families and genera, respectively, recorded troughout the gradient, but the two groups of taxa comprised more than 50% of the Importance Value (the sum of the relative density and the relative dominance) of all measured stems. Moreover, the results suggest that low species richness seems to be associated with the dominance of one or few species. Stand-level wood density (WD) of trees decreased significantly with increasing elevation. WD is an indicator of trees'life history strategy. Its decline suggests a change in the functional composition of the forest with increasing altitude. The Canonical Correspondence Analysis (CCA) indicated a distinction of the studied forests on the basis of their altitudinal levels and geographic location, and revealed different ecological responses by the forests, to environmental variables along the altitudinal gradient. The variation in species composition, in terms of basal area among stands, was controlled primarily by elevation and secondarily by rainfall and soil

  16. Soil fauna abundance and diversity in a secondary semi-evergreen forest in Guadeloupe (Lesser Antilles): influence of soil type and dominant tree species

    OpenAIRE

    Loranger-Merciris, Gladys; Imbert, Daniel; Bernhard-Reversat, France; PONGE, Jean-François; Lavelle, Patrick

    2007-01-01

    International audience The importance of secondary tropical forests regarding the maintenance of soil fauna abundance and diversity is poorly known. The aims of this study were (1) to describe soil fauna abundance and diversity and (2) to assess the determinants of soil fauna abundance and diversity in two stands of a tropical semi-evergreen secondary forest. Soil macrofauna and microarthropod abundance and soil macrofauna diversity were described at two sites developed on different soils ...

  17. New forms of evergreening in Australia: misleading advertising, enantiomers and data exclusivity: Apotex v Servier and Alphapharm v Lundbeck.

    Science.gov (United States)

    Faunce, Thomas; Vines, Tim; Gibbons, Helen

    2008-10-01

    Two recent decisions of the Federal Court of Australia have provided interesting insights into the ongoing struggle between originator drug manufacturers and the public interest in Australia. In Apotex Pty Ltd (formerly GenRx Pty Ltd) v Les Laboratoires Servier (No 2) [2008] FCA 607 the court held that an advertising campaign by an originator pharmaceutical company, which sought to persuade doctors to issue prescriptions prohibiting substitution of "a-flagged" generics, constituted misleading and deceptive conduct under s 52 of the Trade Practices Act 1974 (Cth). The decision of the court in Alphapharm Pty Ltd v H Lundbeck A/S (2008) 76 IPR 618; [2008] FCA 559 limits the ability of the manufacturer of a drug based on a purified racemate enantiomer to claim a later registration date on the Australian Register of Therapeutic Goods and subsequently obtain an extension of its intellectual monopoly privileges as well as an exclusivity period for the data it had submitted to safety regulators. Importantly, this case is one of the first to consider recent allegedly pro- and anti-"evergreening" changes to the Therapeutic Goods Act 1989 (Cth) and Patents Act 1990 (Cth) as impacted by the intellectual property chapter (Ch 17) of the Australia-United States Free Trade Agreement. PMID:19010001

  18. Study on carbon-fixing,oxygen-releasing,temperature-reducing and humidity-increasing effects of evergreen plants in south highway

    Directory of Open Access Journals (Sweden)

    LIU Minmin

    2014-04-01

    Full Text Available Li-6400 portable photosynthesis system,was used to test the diurnal variations of photosynthetic rate and stomatal conductance of evergreen plants in Southern Highway,and to calculate their ability of absorbing carbon dioxide and releasing oxygen and to calculate the transpiring water volume and absorbing heat quantity of plants.Results showed that Euonymus fortunei Hand-Mazz,Hedera helix.Aucuba eriobotryaefolia had better carbon-fixing and oxygen-releasing effects,while Photinia serrulata,Trachycarpus fortunei,Radix Ophiopogonis had worse carbon-fixing and oxygen-releasing effects.Radix Ophiopogonis,Photinia glabra,Euonymus fortunei Hand.-Mazz had higher cooling and humidification ability,while Photinia serrulata,Trachycarpus fortunei did not act as well as them.Euonymus fortunei Hand.-Mazz and Hedera helix had higher leaf chlorophyll in per unit mass,values are 12.91、10.34、9.93 mg·g-1.Radix Ophiopogonis、Cinnamomum camphora(Linn. Presl and Trachycarpus fortunei had lower leaf chlorophyll in per unit mass,value is 3.55、2.67、2.06 mg·g-1.Releasing oxygen,fixing carbon,net assimilation and chlorophyll content has good correlation(P<0.05.

  19. Soil microbial activity and nutrients of evergreen broad-leaf forests in mid-subtropical region of China

    Institute of Scientific and Technical Information of China (English)

    Zhangquan Zeng; Silong Wang; Canming Zhang; Hong Tang; Xiquan Li; Zijian Wu; Jia Luo

    2015-01-01

    To better understand the effects of forest suc-cession on soil microbial activity, a comparison of soil microbial properties and nutrients was conducted between three forest types representing a natural forest succession chronosequence. The study compared a pine (Pinus mas-soniana) forest (PF), a pine and broadleaf mixed forest (MF) and an evergreen broadleaf forest (BF), in the Yingzuijie Biosphere Reserve, Hunan Province, China. Results showed that soil nutrients in the MF and BF plots were higher than in the PF plots. The range in microbial biomass carbon followed a similar pattern with BF having the greatest values, 522–1022 mg kg-1, followed by MF 368–569 mg kg-1, and finally, PF 193–449 mg kg-1. Soil nutrients were more strongly correlated with microbial biomass carbon than basal respiration or metabolic quo-tient. Overall, forest succession in the study site improved soil microbial properties and soil fertility, which in turn can increase primary productivity and carbon sequestration.

  20. Fragmentation and Management of Ethiopian Moist Evergreen Forest Drive Compositional Shifts of Insect Communities Visiting Wild Arabica Coffee Flowers

    Science.gov (United States)

    Berecha, Gezahegn; Aerts, Raf; Muys, Bart; Honnay, Olivier

    2015-02-01

    Coffea arabica is an indigenous understorey shrub of the moist evergreen Afromontane forest of SW Ethiopia. Coffee cultivation here occurs under different forest management intensities, ranging from almost no intervention in the `forest coffee' system to far-reaching interventions that include the removal of competing shrubs and selective thinning of the upper canopy in the `semi-forest coffee' system. We investigated whether increasing forest management intensity and fragmentation result in impacts upon potential coffee pollination services through examining shifts in insect communities that visit coffee flowers. Overall, we netted 2,976 insect individuals on C. arabica flowers, belonging to sixteen taxonomic groups, comprising 10 insect orders. Taxonomic richness of the flower-visiting insects significantly decreased and pollinator community changed with increasing forest management intensity and fragmentation. The relative abundance of honey bees significantly increased with increasing forest management intensity and fragmentation, likely resulting from the introduction of bee hives in the most intensively managed forests. The impoverishment of the insect communities through increased forest management intensity and fragmentation potentially decreases the resilience of the coffee production system as pollination increasingly relies on honey bees alone. This may negatively affect coffee productivity in the long term as global pollination services by managed honey bees are expected to decline under current climate change scenarios. Coffee agroforestry management practices should urgently integrate pollinator conservation measures.

  1. Moisture availability constraints on the leaf area to sapwood area ratio: analysis of measurements on Australian evergreen angiosperm trees

    Science.gov (United States)

    Togashi, Henrique; Prentice, Colin; Evans, Bradley; Forrester, David; Drake, Paul; Feikema, Paul; Brooksbank, Kim; Eamus, Derek; Taylor, Daniel

    2014-05-01

    The leaf area to sapwood area ratio (LA:SA) is a key plant trait that links photosynthesis to transpiration. Pipe model theory states that the sapwood cross-sectional area of a stem or branch at any point should scale isometrically with the area of leaves distal to that point. Optimization theory further suggests that LA:SA should decrease towards drier climates. Although acclimation of LA:SA to climate has been reported within species, much less is known about the scaling of this trait with climate among species. We compiled LA:SA measurements from 184 species of Australian evergreen angiosperm trees. The pipe model was broadly confirmed, based on measurements on branches and trunks of trees from one to 27 years old. We found considerable scatter in LA:SA among species. However quantile regression showed strong (0.2

  2. Assessing the "two water worlds hypothesis", and water sources for native and exotic evergreen species in south-central Chile

    Science.gov (United States)

    Hervé Fernández, Pedro; Oyarzún, Carlos; Huyghens, Dries; Verhoest, Niko; Boeckx, Pascal

    2016-04-01

    Recent studies using water stable isotopes (δ2H and δ18O) have described an ecohydrological separation of water between streams and trees indicated as the "two water world hypothesis". In this study, we monitored water compartments at two catchments near Valdivia (Chile) covered by old growth native evergreen forest (NF) and a Eucalyptus nitens stand covered catchment (or EP), throughout approximately 1.5 years. Our results showed that precipitation, stream and suction lysimeter water plots approximately along the δ2H/δ18O slope of local precipitation inputs (LMWL). However, bulk soil and xylem water plots below the LMWL, supporting the "two water worlds hypothesis". This suggests that trees are using water that is not contributing to stream water. However, we also found evidence of connectivity between the two water worlds, potentially caused by heavy rainfall events, for a brief period (autumn and winter) especially in EP. Our results also suggests that precipitation falling during autumn-winter period is the main water supply for streamflow and bulk soil water, which share a similar precipitation source as Aetoxicon punctatum (in NF) and 4 years old Eucalyptus nitens stand (in EP). We conclude that the "two water worlds hypothesis" applies under certain environmental conditions.

  3. Insect herbivory patterns on leaves of 11 plant species in the evergreen broad-leaved forests of Tiantong National Forest Park, Zhejiang%浙江天童常绿阔叶林中11种常绿乔灌木叶片虫食状分析

    Institute of Scientific and Technical Information of China (English)

    王宏伟; 蔡永立; 李恺; 江红; 田玉鹏

    2006-01-01

    为探讨昆虫对植物叶片的取食行为和伤害方式,作者选择浙江天童常绿阔叶林内的11种常绿乔灌木为对象,对叶片虫食状类型和格局进行分析.结果如下:(1)共发现16种虫食状类型,每种植物叶片虫食状类型数在10-13种之间,每种虫食状出现频率在0.5-28.7%之间.缘食状出现频率最高(28.7%),虫瘿和泡状出现频率最低(0.5%).(2)叶片虫食状分布格局可分为3种类型,即一种虫食状占绝对优势的单优格局,如马银花(Rhododendron ovatum)和檵木(Loropetalum chinense);两种虫食状(缘食状和顶食状)共占优势的双优格局,仅有木荷(Schima superba);3种及3种以上虫食状占优势的多优格局(其余8种植物).(3)叶片虫食状多样性指数变化在1.57-2.23之间,最高为苦槠(Castanopsis sclerophylla),最低为马银花;乔木的多样性指数(2.040)高于灌木(1.882),优势种多样性指数高于伴生种,但差异均不显著;多样性指数反映了虫食状类型和出现频率的综合差异.(4)16种虫食状类型中有8对显著正相关,4对显著负相关,可能反映出不同类型昆虫取食植物的趋同和差异.

  4. 福建梅花山17种常绿阔叶植物叶片虫食状况%Insect Herbivory Patterns on Leaves of 17 Plant Species in the Evergreen Broad-leaved Forests of Mt. Meihuashan, Fujian Province

    Institute of Scientific and Technical Information of China (English)

    陈凌; 蔡永立; 李恺; 王宏伟; 田玉鹏; 叶倩

    2008-01-01

    从福建梅花山自然保护区海拔450m和1 200m的常绿阔叶林中选取17种常绿乔、灌木,对其叶片虫食状和取食强度进行分析,结果如下:(1)17种植物叶片共有15种虫食状类型,每种叶片虫食状类型为8~14;虫食状出现频率0.02%~37.01%,其中缘食状出现频率最高(37.01%),叶中脉食状出现频率最低(0.02%).(2)木荷(Schima superba)的取食强度最大(9.60%),栲树(Castanopsis fargesii)次之(6.61%),油茶(Camellia Oleifera)最小(0.34%).(3)15种虫食状类型中有6对虫食状呈显著正相关, 2对呈显著负相关.(4)海拔1 200m处的甜槠(Castanopsis eyrei)、木荷、栲树和连蕊茶(Camellia fraterna)比海拔450m处的同种植物叶片的虫食强度高,其中木荷差异最大,从13.81%降至2.93%.

  5. 鼎湖山南亚热带常绿阔叶林20公顷样地群落特征研究%COMMUNITY STRUCTURE OF A 20 HM2 LOWER SUBTROPICAL EVERGREEN BROADLEAVED FOREST PLOT IN DINGHUSHAN, CHINA

    Institute of Scientific and Technical Information of China (English)

    叶万辉; 曹洪麟; 黄忠良; 练琚愉; 王志高; 李林; 魏识广; 王章明

    2008-01-01

    鼎湖山南亚热带常绿阔叶林是北回归线附近保存较完好的地带性植被,是在南亚热带季风湿润型气候条件下发育的植被类型,具有热带向亚热带的过渡性质,群落结构相对复杂,组成种类相对丰富.参照巴拿马巴洛科罗拉多岛(Barm Colorado Island,BCI)50 hm2热带雨林样地的技术规范,采用中国森林生物多样性监测网络的统一调查研究方法,于2005年在鼎湖山南亚热带常绿阔叶林建立了20 hm2固定监测样地,调查并鉴定了样方内胸径(Diameter at beast heighht,DBH)大于1 cm的木本植物.首次调查结果表明,群落内共有木本植物210种,71 617个活的个体,分属于56科119属.从乔木区系的组成及其特点可以看出,其南亚热带的区系成分占绝对优势,并呈现出由亚热带向热带过渡的趋势.群落垂直结构复杂,地上成层现象较明显,乔木可分为3层,其中重要值最大的锥(Castrnopsis chinensis)、木荷(Schima superba)和黄杞(Engelhardtia roxburghiana)均是乔木上层的优势种;中层是群落的主要层,由厚壳桂(Cryptocarya chinensis)、黄叶树(Xanthophyllum hainanense)和华润楠(Machilus chinensis)等中生和耐阴树种组成;下层成分较复杂,物种多样性高,不同地段的物种组成差异较大.样地内物种十分丰富,种.面积曲线拟合显示其物种数量接近于BCI.稀有种比例极高,有110种,占总物种数的52.38%,其中有45%的稀有种源于物种本身的特性,有20%源于区系交汇,人为或自然干扰造成的稀有种占30%以上.样地中所有个体的径级分布(以1cm等级排列)明显呈倒"J"形,表示群落稳定与正常生长状态.根据对优势种径级结构的分布分析,将各树种的径级结构归纳为4种类型:1)峰型(中径级个体储备型),此类物种为乔木上层优势种;2)倒"J"型(正常型),此类物种为乔木中层的优势种;3)类倒"J"型(偏正常型),此类物种占据乔木的中、下层;4)"L"型(灌木型),此类物种分布于乔木下层和灌木层.点格局分析得出优势种在各个层上的绝大部分尺度都是聚集分布的,而不同径级的空间分布随物种的不同而呈现出明显的差异性,点格局显示了优势种在相同径级的分布(特别是DBH=10~40 cm)具有一定的空间互补性.对大径级(DBH>40 cm)的504个个体进行空间分布格局分析,结果表明,所有这些个体随机分布于整个样地,但不同的物种在空间分布上存在一定的规律.

  6. Observation on Feeding Habit of Dominant Birds and Forage Sites in an Evergreen Broadleaved Forest, Tiantong Forest Park, Zhejiang%天童常绿阔叶林样地中优势鸟类食性与采食地点植物的关系

    Institute of Scientific and Technical Information of China (English)

    陈宇; 王军馥; 张航; 丁虎林; 唐思贤

    2012-01-01

    Based on observation of food habit of common birds was observed at a 20 hm2 plot from October 2010 to September 2011 in Tiantong Forest Park, Zhejiang, we analyzed the relation between birds and tree species. Among the 3 130 birds of 32 species observed that belong to 5 families and 12 orders 5 species Alcippe morrisonia, Aegithalos concinnus, Parus major, Hemixos castanonotus and Pycnonotus sinensis were dominant. The species of trees perched by birds were correspondingly related to bird species by similarity index and Spearman correlation analysis. Birds Parus major and Aegithalos concinnus more likely foraged on or near trees of Diospyros gtaucifolia, bird Pycnonotus sinensis was near trees of Vaccinium trichocladum and Schoepfia jasminodora in autumn, while birds Hemixos castanonotus selected their forage site near trees of Eurya muricata in summer and autumn.%2010年10月至2011年9月,在浙江天童国家森林公园内的天童20 hm2样地中对鸟类食性进行观察,并对鸟类与植物物种间分布关系进行研究.调查观察到鸟类5目12科32种3 130只次,其中优势种类为灰眶雀鹛(Alcippe morrisonia)、红头[长尾]山雀(Aegithalos concinnus)、大山雀(Parus major)、栗背短脚鹎(Hemixos castanonotus)和白头鹎(Pycnonotus sinensis).采用Sorensen相似性指数和Spearman相关性分析对优势种鸟类与植被分布的关系进行分析,结果显示鸟类分布与植物分布呈对应关系:大山雀和红头[长尾]山雀在同一时期与浙江柿(Diospyros glaucifolia)有相关性,白头鹎同时期与刺毛越橘(Vaccinium trichocladum)和青皮木(Schoepfia jasminodora)相关,栗背短脚鹎在不同时期与同种植物格药柃( Eurya muricata)相关.

  7. 哀牢山中山湿性常绿阔叶林枯立木数量及分配规律%Quantity and Distribution of Standing Dead Trees in Montane Moist Evergreen Broad-leaved Forest in Ailao Mountain,Yunnan

    Institute of Scientific and Technical Information of China (English)

    张树斌; 郑征

    2009-01-01

    以三棵树、锅底塘、山门口和簸箕坝4块样地调查资料为基础,研究了云南哀牢山国家级自然保护区内中山湿性常绿阔叶林枯立木的数量组成、分配格局和生物量特征.结果表明:哀牢山中山湿性常绿阔叶林内枯立木的密度为(68.5±18.0)株/hm2,枯立木占全部乔木的(5.7±0.6)%.枯立木胸径(DBH)分配以小径级为主(5≤DBH<20 cm),此径级的枯立木显著高于另外2个级别(20≤DBH<40 cm和DBH≥40 cm,P<0.05).哀牢山中山湿性常绿阔叶林枯立木的物种组成极其丰富,分属于14科32种,树种组成以壳斗科的腾冲栲(Castanopsis wattii)、硬壳柯(Lithocarpus hancei)和木果柯(Lithocarpus xylocarpus),越桔科的云南越桔(Vaccinium duclouxii),杜鹃花科的珍珠花(Lyonia ovalifolia)和薄叶杜鹃(Rhododendron leptothrium)为主.哀牢山中山湿性常绿阔叶林枯立木贮量较高为(3.9±0.7)t*hm-2,生物量的树种分配以腾冲栲(Castanopsis wattii)和木果柯(Lithocarpus xylocarpus)为主.

  8. 八大公山常绿落叶阔叶混交林枯立木物种组成、大小级与分布格局%Species composition, size class, and spatial patterns of snags in the Badagongshan (BDGS) mixed evergreen and deciduous broad-leaved forest in central China

    Institute of Scientific and Technical Information of China (English)

    卢志军; 刘福玲; 吴浩; 江明喜

    2015-01-01

    枯立木是森林生态系统的重要组成部分,对其数量特征(如物种组成和大小级)与分布格局的研究是认识这个特殊类群的起点.本文以湖南八大公山25 ha森林动态监测样地常绿落叶阔叶混交林为研究对象,以该样地第一次木本植物(DBH≥1 cm)调查数据为基础,分析了枯立木的物种组成、径级结构、分布格局以及生境关联.结果表明,样地内共有枯立木(DBH≥1 cm,高度≥130 cm,完全死亡)8,947株.其中,1 cm≤ DBH <5 cm枯立木4,258株(47.59%),5 cm ≤ DBH <10 cm枯立木2,132株(23.84%),10 cm ≤ DBH <30 cm枯立木2,377株(26.57%),DBH≥30 cm枯立木180株(2%);平均DBH为8.0 cm,最大DBH为83.5 cm.从分布格局来看,0-50 m的尺度上,样地内枯立木主要呈现聚集分布,但在接近40 m的尺度上,逐渐变为随机分布.利用多元回归树(multivariate regression tree,MRT)将样地生境分为3类,运用Torus转换比较某类生境中枯立木密度与物种零分布模型中的期望密度,结果显示枯立木在山谷中分布较少,山脊较多,而在山坡生境则呈现随机分布.鉴定到种的枯立木有724株(8.1%),隶属于26科84种;其中,杜鹃花科、壳斗科和樟科枯立木最多.在物种水平上,多脉青冈(Cyclobalanopsis multinervis)、长蕊杜鹃(Rhododendron stamineum)和黄丹木姜子(Litsea elongata)枯立木最多;而优势树种亮叶水青冈(Fagus lucida)的枯立木并不多见.

  9. 普洱季风常绿阔叶林次生演替中木本植物幼苗更新特征%Woody seedling regeneration in secondary succession of monsoon broad-leaved evergreen forest in Puer, Yunnan, Southwest China

    Institute of Scientific and Technical Information of China (English)

    李帅锋; 刘万德; 苏建荣; 张志钧; 刘庆云

    2012-01-01

    以时空替代的方法,将针阔混交林、季风常绿阔叶林的次生林与成熟林等3个处于同一空间下的群落作为次生演替进程中的3个阶段,研究云南普洱地区次生演替过程中的木本植物幼苗更新特征,分析了次生演替过程中木本植物幼苗的物种组成、密度、高度级及与环境因子的相关性.结果表明:在8个共144 m2的幼苗样地中调查木本植物幼苗101种2014株,其中乔木幼苗是主要组成.随着次生演替的进行,木本植物幼苗、乔木与藤本幼苗密度逐渐增加,灌木幼苗密度无显著变化;藤本植物幼苗的物种丰富度随着次生演替进行而增加,乔木与灌木幼苗则无显著变化,成熟季风常绿阔叶林中木本植物幼苗ShannonWiener指数要显著小于针阔混交林与次生季风常绿阔叶林.次生与成熟季风常绿阔叶林木本植物幼苗多度随高度级增加而减少,针阔混交林则呈现偏峰曲线,幼苗密度均集中分布在高度20 cm以内,3个群落演替阶段木本植物幼苗物种丰富度随高度级增加呈现偏锋曲线.相似性系数反映出乔木和藤本幼苗的更新来源与群落的物种组成存在着紧密的联系.乔木幼苗密度分布与样地坡度之间存在着显著的负相关,灌木幼苗密度与土壤pH值之间存在着显著正相关.

  10. Seedling regeneration of the primary semi-humid evergreen broadleaved forest and its secondary succession communities in Xishan, Kunming%昆明西山半湿润常绿阔叶林及其次生演替群落的更新特征

    Institute of Scientific and Technical Information of China (English)

    李小双; 宋亮; 陈军文; 袁春明; 张良

    2012-01-01

    对昆明西山国家森林公园处于不同演替阶段的云南油杉林、云南油杉-滇青冈混交林和滇青冈林内木本植物幼苗的种类组成、数量及更新方式等进行了调查分析.结果表明:在所调查的共144个25 m2的样方中,共记录到木本植物幼苗32科45属共49种.随着演替的进行,幼苗总密度表现出先增加后降低的趋势,处于演替中期的云南油杉-滇青冈混交林内幼苗最丰富,平均密度达80株·25 m-2.在不同演替阶段各植被类型中,实生和萌生两种更新方式同时存在,单一的更新方式可能使群落的更新面临较大的风险.幼苗发生了顶死或梢枯后,从其根颈处生出多个萌枝形成多干基株的更新方式结合了实生和萌生更新各自的优点,是幼苗在与环境长期作用过程中进化出的一种有效对策.%Woody plant seedlings in Keteleeria evelyniana community,Keteleeria evelyniana-Cyclobalanopsis glaucoides community,and C. glaucoides community in Xishan National Forest Park, Kunming, were surveyed and analyzed to determine their regeneration characteristics including species composition, density, regeneration mode, and etc. In all the 144 plots(5 m×5 m each) ,49 woody plants seedling belonging to 45 genera,32 families are recorded. The total density of seedling showed a unimodal change in response to the forest succession progress, with the highest density in the K. evelyniana-C. glaucoides community(80 stems·25 m-2). Seedling regeneration and sprouting regeneration coexisted in communities at different succession stages;single regeneration mode may increase the risk of unsuccessful regeneration of communities. However,seedling re-sprouting regeneration,which had been formed during the long-term interaction between seedlings and their environment,seems to be an effective strategy as it combined the advantages of both modes.

  11. Mite species (Acari: Mesostigmata new and rare to Polish fauna, inhabiting the soil of broadleaved forests dominated by small-leaved lime (Tilia cordata Mill. in Kwidzyn Forest District (N Poland

    Directory of Open Access Journals (Sweden)

    FALEŃCZYK-KOZIRÓG KATARZYNA

    2014-06-01

    Full Text Available During a two-year study on mites of the order Mesostigmata in broadleaved forest stands dominated by small-leaved lime (Tilia cordata Mill., 117 mite species were identified. Among them, 3 had been so far rarely recorded in Poland (Haemogamasus nidi, Stylochirus rovenensis and Eugamasus crassitarsis and 2 were classified as new to the Polish fauna (Veigaia sibirica and Digamasellus perpusillus.

  12. Effects of Mixture Silviculture of Larix kaempferi and Natural-Regenerated Broad-Leaved Trees%日本落叶松与天然萌芽阔叶树人工混交培育效果的分析

    Institute of Scientific and Technical Information of China (English)

    田永霞

    2016-01-01

    通过对日本落叶松与天然萌生阔叶树人工混交林的调查分析,结果表明:日本落叶松与天然萌芽阔叶树人工混交培育降低了培育成本,提高了生态效益,混交林培育28 a 后,林分生长稳定,生产力较高;混交林中的植物种类丰富,数量较多,各层次的物种多样性指数均好于人工营造的日本落叶松与白桦针阔混交林和日本落叶松纯林;日本落叶松与天然萌生阔叶树人工混交林,对恢复森林生态原始林貌有一定促进作用。%Mixture plantation of Larix kaempferi and natural-regenerated broad-leaved trees were investigated.Re-sult shows that silviculture of Larix kaempferi and natural-regenerated broad-leaved trees reduce costs and improve the eco-efficiency,growth of the stand is stable after silviculturing mixed forest for 28 years and the productivity is more higher;plant species of mixed forest is abundant ,the number are larger;all levels of species diversity index are optimal than that of Larix kaempferi ,coniferous and broad-leaved mixed forest and pure forest of Larix kaempferi .Larix kaempferi and natural-regenerated broad-leaved trees have a certain promotion role in restoring original appearance of forest ecology.

  13. Irradiance in young stands of Picea abies (L.) Karst. and Pinus sylvestris L. and the possibilities to prevent suckers of broad-leaved trees

    International Nuclear Information System (INIS)

    Incoming shortwave global radiation (Qg) and photosynthetically active radiation (PAR;Qpa) as a fraction of full daylight, relative irradiance (%Q), were measured at the same time in young stands of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). Measurements were made on three levels above ground: 20 cm above ground and 50 and 75% of stand height. Stands of three heights (75, 150 and 300 cm) were studied during two months. The stands were created by arranging young trees cut from natural stands, in nine quadratic spacings: 0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 1.0, 1.4, and 2.0 m. The leaf area index (L) was estimated. Differences in %Q-values for Qpa and Qg in the same species at the same stand height and level of light measurements above ground were significant only in 150 and 300 cm stands. In 75 cm high stands of Scots pine, the %Q was less than 60% at spacings less than 0.2 m and in 75 cm high stands of Norway spruce, the %Q was less than 60% at spacings less than 0.3 m. Only at 0.1 x 0.1-0.3 x 0.3 m, %Q was less than 20% in Norway spruce stands. In 150 cm stands %Q less than 20% was measured at spacings less than 0.7 m in Norway spruce and less than 0.5 in Scots pine. In 300 cm stands of Norway spruce it was measured up to 1.2 and in Scots pine less than 1.1 m. Light extinction coefficients, K and Kg for spruce and pine stands were 0.17-0.40 and 0.16-0.31 respectively. Some practical implications of the study are presented. Lack of light (%Q less than 10%) as a single factor of seriously suppressed growth and development of broad-leaved plants and suckers by competition in young stands of spruce and pine only occur in dense stands 0.3 x 0.3-1.1 x 1.1 m (8000-100000 stems per hectare). Competition by light on a regenerated area generally occurs in the level of 50% of tree height (150-300 cm) and higher due to the rapid growth of broad-leaved trees (sprouts) compared with planted conifers but the light intensity at these levels %Q greater

  14. Leaf biomechanics, morphology, and anatomy of the deciduous mesophyte Prunus serrulata (Rosaceae) and the evergreen sclerophyllous shrub Heteromeles arbutifolia (Rosaceae).

    Science.gov (United States)

    Balsamo, Ronald A; Bauer, Aaron M; Davis, Stephen D; Rice, Benita M

    2003-01-01

    Leaf tensile properties were compared between the mesic deciduous tree Prunus serrulata (var. "Kwanzan") and the xeric and sclerophyllous chaparral evergreen shrub Heteromeles arbutifolia (M. Roem). All values for biomechanical parameters for H. arbutifolia were significantly greater than those of P. serrulata. The fracture planes also differed between the two species with P. serrulata fracturing along the secondary veins, while H. arbutifolia most often fractured across the leaf irrespective of the vein or mesophyll position, thus yielding qualitative differences in the stress-strain curves of the two species. Anatomically, P. serrulata exhibits features typical for a deciduous mesophytic leaf such as a thin cuticle, a single layer of palisade mesophyll, isodiametric spongy mesophyll, and extensive reticulation of the laminar veins. Heteromeles arbutifolia leaves, however, are typically two- to three-fold thicker with a 35% higher dry mass/fresh mass ratio. The vascular tissue is restricted to the interface of the palisade and spongy mesophyll near the center of the leaf. Both epidermal layers have a thick cuticle. The palisade mesophyll is tightly packed and two to three layers thick. The spongy mesophyll cells are ameboid in shape and tightly interlinked both to other spongy cells as well as to the overlying palisade layer. We conclude that the qualitative and quantitative biomechanical differences between the leaves of these two species are likely due to a complex interaction of internal architectural arrangement and the physical/chemical differences in the properties of their respective cell walls. These studies illustrate the importance that morphological and anatomical correlates play with mechanical behavior in plant material and ultimately reflect adaptations present in the leaves of chaparral shrubs that are conducive to surviving in arid environments.

  15. Photosynthetic capacity and nitrogen partitioning in foliage of the evergreen shrub Daphniphyllum humile along a natural light gradient.

    Science.gov (United States)

    Katahata, Shin-Ichiro; Naramoto, Masaaki; Kakubari, Yoshitaka; Mukai, Yazuru

    2007-02-01

    We examined the effects of leaf age and mutual shading on the morphology, photosynthetic properties and nitrogen (N) allocation of foliage of an evergreen understory shrub, Daphniphyllum humile Maxim, growing along a natural light gradient in a deciduous Fagus crenata-dominated forest in Japan. Seedlings in high-light environments were subject to greater mutual shading and 1-year-old foliage survival was lower than in seedlings in low-light environments, indicating that the survival rates of foliage were related to the degree of mutual shading. Although specific leaf area (SLA) in current- and 1-year-old foliage was curvilinearly related to daily photosynthetic photon flux (PPF), SLA was unaffected by leaf age, indicating that foliage in D. humile may not acclimate morphologically to annual changes in light caused by mutual shading. Light-saturated net photosynthetic rates (Pmax) were correlated with daily PPF in current-year foliage. In addition, a strong, positive relationship was found between nitrogen concentration per unit leaf area and Pmax. In contrast, the relationship among PPF, N and photosynthetic parameters in 1-year old foliage was weak because of the strong remobilization of N from older leaves to current-year foliage in plants growing in high light. However, the relationship between daily PPF and both photosynthetic N-use efficiency and the ratio of maximum electron transport rate to maximum carboxylation rate did not differ between current-year and 1-year-old foliage, suggesting that these responses help maintain a high photosynthetic efficiency even in older foliage. We conclude that D. humile maximizes whole-plant carbon gain by maintaining a balance among photosynthetic functions across wide ranges of leaf ages and light environments.

  16. Rainfall Controls on Land Surface Phenology over "Never-green" and "Ever-green" Lands in Africa

    Science.gov (United States)

    Yan, D.; Zhang, X.; Yu, Y.; Guo, W.

    2015-12-01

    The characteristics of land surface phenology (LSP) in the "Never-green" Sahara desert and the "Ever-green" equatorial Congo Basin were rarely discussed due to the extremely low seasonal greenness variations across the Sahara desert and the prolonged cloud cover over the Congo Basin. Based on 30-minute observations acquired by the Spinning Enhanced Visible and Infrared Imager onboard the METEOSAT geostationary satellites, we generated a three-day angularly corrected Two-band Enhanced Vegetation Index (EVI2) time series for each year between 2006 and 2013. We further reconstructed EVI2 temporal trajectories and retrieved LSP transitions using the Hybrid Piecewise Logistic Model. We associated the LSP transitions with the rainy season transitions derived from the Tropical Rainfall Measurement Mission Product 3B42. Results show that LSP within both the Sahara Desert and the Congo Basin was strongly controlled by the rainfall seasonality. Specially, although there is no vegetation growth in most part of the Sahara Desert, recurring LSP was spatially detected in irrigation agriculture and the geomorphological regions of wadis, dayas, chotts/sebkhas and rocky hills. These geomorphological features are able to store moisture in soil to keep plants growing during the long dry seasons after vegetation greenup is triggered by rainfall events. The spatial shift of phenological timing is controlled by the Mediterranean rainfall regime in the north and the rainfalls brought by the Intertropical Convergence Zone (ITCZ) in the south. Across the equatorial Congo Basin, EVI2 time series reveals that canopy greenness cycles (CGC) of the seasonal leaf variation occur in tropical rainforests, which differs from the commonly termed "growing season" with complete leafless canopies. The seasonal EVI2 amplitude is very small and represents the gradual "leaf-exchange" processes. Two annual CGC are found and their spatial shifts closely follow the seasonal migration of ITCZ precipitation.

  17. Climatic envelope of evergreen sclerophyllous oaks and their present distribution in the eastern Himalaya and Hengduan Mountains

    Institute of Scientific and Technical Information of China (English)

    Qing-Song YANG; Wen-Yun CHEN; Ke XIA; Zhe-Kun ZHOU

    2009-01-01

    Evergreen sclerophyllous oaks (the E.S. oaks, Quercus section Heterobalanus) are the dominant species of the local ecosystem in the eastern Himalaya and the Hengduan Mountains, southwest China. In this study, we document the climatic envelope of the seven E.S. oak species and examine the relationships between climate and their distribution. This was done using a principal components analysis (PCA) and multiple regression analysis (MRA) of nine climatic indices. The main climatic envelope of the E.S. oaks were: mean temperature of the warmest month (MTW)=12.0-19.5 ℃, warmth index (WI) = 33.2-88.9 ℃ month, annual biotemperature (BT)=-6.9- -0.3 ℃, coldness index (CI)=-30.4- -10.1 ℃ month, mean temperature of the coldest month (MTC)=-3.7-3.0 ℃ and annual precipitation (AP)=701-897 mm at the lower limits; and MTW=8.3-16.1 ℃, WI=15.7-59.1 ℃ month, BT=3.6-8.9 ℃, CI=-55.4--19.3 ℃ month, MTC=8.3-16.1 ℃ and AP=610-811 mm at the upper limits. The climatic range of the E.S. oaks is wide and includes two climatic zones, the cool-temperature zone and the subpolar zone. The PCA and MRA results suggest that the thermal climate plays a major role and precipitation plays a secondary role in controlling the large-scale distribution of the E.S. oaks, except Quercus monimotricha. In thermal regimes, BT and/or MTW are most important for both lower and upper limits of the E.S. oaks. Furthermore, our results indicate that the upper distribution limits of the E.S. oaks are less determined by low temperatures and their duration (CI) than by other factors.

  18. First and second sets of shoots in five evergreen woody species from Tiantong National Forest Park of Zhejiang, China%浙江天童国家森林公园5种常绿阔叶植物的一次和二次抽枝进程

    Institute of Scientific and Technical Information of China (English)

    夏洋洁; 唐坚强; 张光富; 黄超; 蒙凤群; 孙书存

    2013-01-01

    第二次抽枝中的叶片虫食率、现叶速率和展叶速率都不小于第一次抽枝,而第二次抽枝小枝投资总量较小,这些可能是物种对相对较大的昆虫取食压力和即将来临的冬天不利条件等的适应.%Aims Some woody species of subtropical evergreen broad-leaved forests in Eastern China form a second set of shoots in late summer or autumn after a first set in spring. Our objective is to elucidate features of this second set of shoots, including their adaptive significance. Methods We investigated differences between the first and second sets of shoots for five evergreen woody species {Symplocos lancifolia, Loropetalum chinense, Eurya rubiginosa var. attenuata, Myrica rubra, and Castanop-sis fargesii) from an evergreen broad-leaved forest in Tiantong National Forest Park of Zhejiang, China. Herbivore damage of leaves was estimated, leaf emergence rate, leaf expansion rate and duration were calculated, and twig investment (leaf number and individual leaf area within twigs, twig stem length and diameter) was measured for both sets of shoots. Important findings Leaves of M. rubra and C. fargesii suffered greater herbivore damage to the second shoots compared with the first, and no significant difference was found in damage between the two sets of shoots for S. lancifolia, L. chinense and E. rubiginosa var. attenuata. The first and second sets of shoots shared the same leaf emergence pattern. Symplocos lancifolia, L. chinense, E. rubiginosa var. attenuata, and M. rubra showed a succeeding type of leaf emergence, and C. fargesii showed a flushing type of leaf emergence. However, duration of leaf emergence was much shorter in the second set of shoots for S. lancifolia, E. rubiginosa var. attenuata and M. rubra than in the first but not for the other two species. Leaf expansion rate was significantly higher for the second set of shoots for S. lancifolia, L. chinense and E. rubiginosa var. attenuata and was indistinguishable for M

  19. Root biomass and underground C and N storage of the primitive Korean pine and broad-leaved forest and its different succession stages in Changbai Mountain, northeast China

    Institute of Scientific and Technical Information of China (English)

    YANG Liyun; LUO Tianxiang; WU Songtao

    2006-01-01

    This paper studied root biomass and underground carbon (C) and nitrogen (N) storage of a more than 200-year-old primitive Korean pine and broad-leaved forest and its two 20- and 80-year-old secondary Populus davidiana and Betula platyphylla forests in Changbai Mountain,northeast China.The results showed that with forest succession,the root biomass of 20-year-old,80-year-old,and primitive forests was 2.437,2.742,and 4.114 kg/m2,respectively.The root C storage was 1.113,1.323,and 2.023kg/m2,soil C storage was 11.911,11.943,and 12.587 kg/m2,and underground C storage was 13.024,13.266,and 14.610kg/m2,respectively,while the root N storage was 0.035,0.032,and 0.038 kg/m2,soil N storage was 1.208,1.222,and 0.915 kg/m2,and underground N storage was 1.243,1.254,and 0.955 kg/m2,respectively,which indicated that along with forest succession,the forest underground became a potential"carbon sink,"whereas underground N storage did not change obviously.

  20. Response Of Wheat (Triticum aestivum L. Crop And Broad-Leaved Weeds To Different Water Requirements And Weed Management In Sandy Soils

    Directory of Open Access Journals (Sweden)

    El-Metwally Ibrahim M.

    2015-03-01

    Full Text Available Water scarcity is a major cause of crops yield reduction in many parts of the world. So, a more rational use of irrigation water should be adapted and deficit irrigation principles should be accepted with a certain level of reduction in yield level. To study the efficiency of four water requirements (100% whole season, 75% whole season, 50% whole season and 100% whole season while 50% at grain-filling stage and five weed-control treatments (three postemergence herbicides i.e., metosulam, tribenuron-methyl, and bromoxynil, hand weeding and unweeded check, and their interactive effects, two field experiments on wheat crop were conducted in two successive seasons at the agricultural experimental station of the National Research Centre, Nubaria, Egypt. Bromoxynil, tribenuron-methyl came in the first order for controlling total broad-leaved weeds. Application of 100% water requirement recorded the highest values compared to all other irrigation water treatments in term of flag-leaf area, chlorophyll content, plant height, number of spike/m2, spike weight, grains number/spike, weight of 1,000 grains, yield and yield attributes of wheat. Metosulam followed by bromoxynil, tribenuron-methyl and hand-weeding treatments gave higher values of grain yield/ha. The highest grain yield, protein and carbohydrates percentages of wheat grains were obtained from addition of 100% water requirement with metosulam treatment was used followed by 75% of water requirement combined with metosulam treatment without significant difference among these treatments.

  1. Short-Term Responses of Ground-Dwelling Beetles to Ice Storm-Induced Treefall Gaps in a Subtropical Broad-Leaved Forest in Southeastern China.

    Science.gov (United States)

    Yu, Xiao-Dong; Liu, Chong-Ling; Lü, Liang; Luo, Tian-Hong; Zhou, Hong-Zhang

    2016-02-01

    Periodic natural disturbances shape the mosaic character of many landscapes and influence the distribution and abundance of organisms. In this study, we tested the effect of ice storm-induced treefall gaps on ground-dwelling beetle assemblages in different-aged successional stands of subtropical broad-leaved forest in southeastern China. We evaluated the relative importance of gap-phase microhabitat type (within gap, gap edge, and interior shaded) within different stand ages (regenerating stands and mature stands) as determinants of changes in beetle diversity and community structure. At 18 replicate sites sampled during 2009-2010, no significant differences were found in species richness and the abundances of the most common beetle species captured in pitfall traps among the three gap-phase microhabitat types, but the abundances of total beetles, as well as fungivorous and phytophagous species groups, were significantly lower in gap microhabitats than in interior shaded microhabitats in mature stands. Beetle assemblage composition showed no significant differences among the three microhabitat types, and only the fauna of gap plots slightly diverged from those of edge and shaded plots in mature stands. Cover of shrubs and stand age significantly affected beetle assemblage structure. Our results suggest that beetle responses to gap-phase dynamics in early successional forests are generally weak, and that effects are more discernible in the mature stands, perhaps due to the abundance responses of forest-specialist species. PMID:26377249

  2. Impact of the 2013-2015 weather variability on seasonal growth dynamics and daily stem-size changes of three coexisting broadleaved tree species

    Science.gov (United States)

    van der Maaten, Ernst; Pape, Jonas; van der Maaten Theunissen, Marieke; Scharnweber, Tobias; Smiljanic, Marko; Wilmking, Martin

    2016-04-01

    Dendrometers are measurement devices that continuously monitor stem-size changes of trees without invasive sampling of the cambium. Dendrometers record both irreversible tree growth as well as reversible signals of stem water storage and depletion, making them important tools for studying tree water status, tree physiology and short-term growth responses of trees to weather fluctuations. In this study, a three-year dendrometer dataset (2013-2015) is used to study seasonal growth dynamics and daily stem-size changes of three coexisting broadleaved tree species (common hornbeam (Carpinus betulus L.), European beech (Fagus sylvatica L.), and pedunculate oak (Quercus robur L.)), growing in an unmanaged forest in northeastern Germany. Seasonal growth patterns (i.e. growth onset, cessation and duration) are analyzed in relation to environmental conditions, and forest meteorological factors driving daily stem-size changes are identified. Following dry conditions in 2014, especially the growth of beech was reduced. Oak was less affected, and displayed a distinct early growth onset for all study years.

  3. [Simulation of the effects of climate change on canopy transpiration over a broad-leaved Korean pine forest in Changbai Mountains].

    Science.gov (United States)

    Chen, Ni-Na; Yuan, Feng-Hui; Wang, An-Zhi; Wu, Jia-Bing; Jin, Chang-Jie; Guan, De-Xin; Shi, Ting-Ting

    2011-02-01

    To investigate the effects of climate change on canopy transpiration, a process-based carbon and water coupling multi-layer model was verified, and used to simulate the canopy transpiration over a broad-leaved Korean pine forest in Changbai Mountains. This multi-layer model could well estimate canopy transpiration. The simulated values fitted well with the measured data based on eddy covariance method. The simulation of the responses of canopy transpiration to climate change indicated that the latent heat flux (LE) increased with increasing air temperature, and decreased with the decline of soil water content or the increase of air CO2 concentration. Under the climate scenarios in this study, the LE was most sensitive to the associated variation of 10% reduction of soil water content in 0-20 cm layer and 190 micromol x mol(-1) increase of CO2 concentration, but not sensitive to the synchronous variation of 10% reduce of soil water content and 3.6 degrees C increase of air temperature.

  4. Carbon storage in evergreen broad-leaf forests in mid-subtropical re-gion of China at four succession stages

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhang-quan; WANG Si-long; ZHANG Can-ming; GONG Chao; HU Qing

    2013-01-01

    To better understand the effect of forest succession on carbon sequestration, we investigated carbon stock and allocation of evergreen broadleaf forest, a major zonal forest in subtropical China. We sought to quantify the carbon sequestration potential. We sampled four forest types, shrub (SR), pine (Pinus massoniana) forest (PF), pine and broadleaf mixed forest (MF) and evergreen broadleaf forest (BF). A regression equation was constructed using tree height and diameter at breast height (DBH) and elements of total tree biomass. The equation was subse-quently utilized to estimate tree carbon storage. The carbon storage of understory, litter, and soil was also estimated. Carbon storage in biomass increased significantly from the early succession stage SR (6.21 t⋅ha-1) to the late stage BF (134.87 t⋅ha-1). The biomass carbon stock of forest layers generally increased with succession except for the understory. The soil organic carbon storage for the total profile increased with forest succession, from 51.16 to 90.49 t⋅ha-1, but the contribution of SOC to the carbon stock of the forest ecosystem declined from 89.18% to 40.15%. The carbon stock at ecosystem scale increased significantly with succes-sion from SR (57.37 t⋅ha-1), to PF (154.20 t⋅ha-1), to MF (170.96 t⋅ha-1) and to BF (225.36 t⋅ha-1), with carbon stock of BF 3.93 times that of SR. The forests in our study have great potential for increasing carbon se-questration, and large areas of secondary or degraded evergreen broad-leaf forests in the subtropical zone of China could be a great carbon sink in future.

  5. Two-year tree growth patterns investigated from monthly girth records using dendrometer bands in a wet evergreen forest in India

    OpenAIRE

    Pélissier, Raphaël; Pascal, J.P.

    2000-01-01

    With the aim of characterizing tree growth patterns, this paper reexamines the growth data of 100 selected trees belonging to 24 species that were recorded monthly in a 0.2-ha plot of a wet evergreen forest in the Western Ghats of India during the period 1980-82 using dendrometer bands. The mean growth profile, combining all of the selected trees, showed : (a) a significantly lower annual growth rate during the second year of survey which seemed to be negatively related to monsoon precipitati...

  6. PHYTOSOCIOLOGICAL STRUCTURE OF THE TREE COMPONENT OF TWO SEASONAL EVERGREEN FOREST AREAS, RIO DAS PACAS BASIN, QUERÊNCIA, MATO GROSSO STATE, BRAZIL

    Directory of Open Access Journals (Sweden)

    Sustanis Horn Kunz

    2014-03-01

    Full Text Available http://dx.doi.org/10.5902/1980509813317This study aimed to describe the tree component structure of two patches of Evergreen Seasonal Forest in Pacas River Basin in Querência municipality in Mato Grosso state, Brazil. The point-centered quarter method was applied to systematically distribute 200 points in pristine forest and 100 points in managed forest. In each quarter, the nearest tree to the sampling point with diameter at breast height equal or greater than 10 cm was included. Estimates of local species richness were obtained with the Jackknife 1 and the Jaccard index was used to determinate floristic similarity between the patches. Although the two forest patches have had distinct historical uses, with tree component structure distinct, the areas presented high floristic similarity (Cj=0.67, the local species richness was alike (57 species in pristine forest and 52 in managed forest and the species with the highest importance value was the same in the both patches - Ocotea leucoxylon (Sw. Laness. Despite the anthropogenic disturbances in the past, it is possible to conclude that the managed forest is in an advanced stage of regeneration as expected for the evergreen seasonal forests pattern since this forest is naturally less diverse than the Amazon ombrophilous forests.

  7. Variability in radial sap flux density patterns and sapwood area among seven co-occurring temperate broad-leaved tree species.

    Science.gov (United States)

    Gebauer, Tobias; Horna, Viviana; Leuschner, Christoph

    2008-12-01

    Forest transpiration estimates are frequently based on xylem sap flux measurements in the outer sections of the hydro-active stem sapwood. We used Granier's constant-heating technique with heating probes at various xylem depths to analyze radial patterns of sap flux density in the sapwood of seven broad-leaved tree species differing in wood density and xylem structure. Study aims were to (1) compare radial sap flux density profiles between diffuse- and ring-porous trees and (2) analyze the relationship between hydro-active sapwood area and stem diameter. In all investigated species except the diffuse-porous beech (Fagus sylvatica L.) and ring-porous ash (Fraxinus excelsior L.), sap flux density peaked at a depth of 1 to 4 cm beneath the cambium, revealing a hump-shaped curve with species-specific slopes. Beech and ash reached maximum sap flux densities immediately beneath the cambium in the youngest annual growth rings. Experiments with dyes showed that the hydro-active sapwood occupied 70 to 90% of the stem cross-sectional area in mature trees of diffuse-porous species, whereas it occupied only about 21% in ring-porous ash. Dendrochronological analyses indicated that vessels in the older sapwood may remain functional for 100 years or more in diffuse-porous species and for up to 27 years in ring-porous ash. We conclude that radial sap flux density patterns are largely dependent on tree species, which may introduce serious bias in sap-flux-derived forest transpiration estimates, if non-specific sap flux profiles are assumed.

  8. Seasonal and yearly variations in light use and nitrogen use by seedlings of four deciduous broad-leaved tree species invading larch plantations.

    Science.gov (United States)

    Kitaoka, Satoshi; Koike, Takayoshi

    2005-04-01

    Several deciduous broad-leaved tree species, differing in leaf phenology, invade larch (Larix kaempferii (Lamb.) Carrière) plantations in Japan. The understory light environment of larch forests changes drastically between the leafy and leafless periods. To determine how the invading seedlings exploit the changing light environment, and if phenological differences reflect the light- and nitrogen-use traits of the seedlings, we measured leaf phenology, seasonal changes in light-saturated photosynthetic rate (P(sat)), leaf nitrogen (N) content (N(area)), chlorophyll/nitrogen ratio (Chl/N), specific leaf area (SLA) and N remobilization rate (NRMR) over 3 years. The mid-successional or gap-phase species, Magnolia hypoleuca Siebold & Zucc., had a short leafy period and high P(sat) and NRMR. In contrast, two late-successional tree species, Prunus ssiori Friedr. Schmidt, which undergoes leaf flush before larch, and Carpinus cordata Blume, which maintains green leaves until frost, both had low P(sat) and NRMR but exploited the opportunity for growth during the period when the larch canopy trees were leafless. Quercus mongolica Fisch. ex Ledeb. var. crispula (Blume) Ohashi, a mid-late-successional species that underwent leaf flush at the same time as the overstory larch, had values of photosynthetic parameters between those of the gap-phase and late-successional species. Among species, M. hypoleuca and Q. mongolica had higher photosynthetic rates and photosynthetic N-use efficiencies. In all species, the relationship between N(area) and P(sat) showed species-specific yearly fluctuations; however, there was no yearly fluctuation in the relationship between N(area) and P(sat) at CO2 saturation. Yearly fluctuations in the N(area)-P(sat) relationship appeared to be induced by changes in SLA and N-use characteristics, which in turn are affected by climatic variations.

  9. [Composition and seasonal dynamics of litter falls in a broad-leaved Korean pine (Pinus koraiensis) mixed forest in Changbai Mountains, Northeast China].

    Science.gov (United States)

    Yuan, Zuo-qiang; Li, Bu-hang; Bai, Xue-jiao; Lin, Fei; Shi, Shuai; Ye, Ji; Wang, Xu-gao; Hao, Zhan-qing

    2010-09-01

    In order to understand the composition and spatiotemporal dynamics of the litter falls at community level in a broad-leaved Korean pine mixed forest in Changbai Mountains, litter falls were collected from 150 containers in a 25 hm2 permanent plot in 2008. The leaf litters in the containers were from 35 tree species, accounting for 67.3% of the total number (52) of the tree species with DBH > or =1 cm in the plot. The litter falls had a weight 29.39 kg, equivalent to 3918.4 kg x hm(-2) among which, broad leaves, miscellany, needle leaves, and branches occupied 61.7%, 18.0%, 11.7%, and 8.6%, respectively. About 83.8% of the broad leaves were from Tilia amurensis, Fraxinus mandshurica, Quercus mongolica, Acer mono, and Ulmus japonica. The litter falls showed an evident seasonal dynamics, with the peaks occurred from 13 September to 10 October, e.g., the litter falls from T. amurensis and Pinus koraiensis peaked in 13-26 September, while those from Q. mongolica, U. japonica, and A. pseudo-sieboldianum peaked in 27 September to 10 October. There was a great difference in the mass of the litter falls among the containers, e.g., with 150-200 g litters in 68 containers and >500 g litters in 1 container. The species number of the litter falls in a container was 18 in maximum, and was 12 in common (32 containers). Litter falls mass was positively proportional to the sum of the basal area at breast height of parent trees in the plot, and the amount of the litter falls in the containers was related with the locations of the containers, exhibiting an evident spatial heterogeneity in the plot. PMID:21265134

  10. Influences of evergreen gymnosperm and deciduous angiosperm tree species on the functioning of temperate and boreal forests.

    Science.gov (United States)

    Augusto, Laurent; De Schrijver, An; Vesterdal, Lars; Smolander, Aino; Prescott, Cindy; Ranger, Jacques

    2015-05-01

    It has been recognized for a long time that the overstorey composition of a forest partly determines its biological and physical-chemical functioning. Here, we review evidence of the influence of evergreen gymnosperm (EG) tree species and deciduous angiosperm (DA) tree species on the water balance, physical-chemical soil properties and biogeochemical cycling of carbon and nutrients. We used scientific publications based on experimental designs where all species grew on the same parent material and initial soil, and were similar in stage of stand development, former land use and current management. We present the current state of the art, define knowledge gaps, and briefly discuss how selection of tree species can be used to mitigate pollution or enhance accumulation of stable organic carbon in the soil. The presence of EGs generally induces a lower rate of precipitation input into the soil than DAs, resulting in drier soil conditions and lower water discharge. Soil temperature is generally not different, or slightly lower, under an EG canopy compared to a DA canopy. Chemical properties, such as soil pH, can also be significantly modified by taxonomic groups of tree species. Biomass production is usually similar or lower in DA stands than in stands of EGs. Aboveground production of dead organic matter appears to be of the same order of magnitude between tree species groups growing on the same site. Some DAs induce more rapid decomposition of litter than EGs because of the chemical properties of their tissues, higher soil moisture and favourable conditions for earthworms. Forest floors consequently tend to be thicker in EG forests compared to DA forests. Many factors, such as litter lignin content, influence litter decomposition and it is difficult to identify specific litter-quality parameters that distinguish litter decomposition rates of EGs from DAs. Although it has been suggested that DAs can result in higher accumulation of soil carbon stocks, evidence from

  11. Long-term experimental warming, shading and nutrient addition affect the concentration of phenolic compounds in arctic-alpine deciduous and evergreen dwarf shrubs

    DEFF Research Database (Denmark)

    Hansen, Anja Hoff; Jonasson, Sven Evert; Michelsen, Anders;

    2006-01-01

    Environmental changes are likely to alter the chemical composition of plant tissues, including content and concentrations of secondary compounds, and thereby affect the food sources of herbivores. After 10 years of experimental increase of temperature, nutrient levels and light attenuation in a sub......-arctic, alpine ecosystem, we investigated the effects on carbon based secondary compounds (CBSC) and nitrogen in one dominant deciduous dwarf shrub, Salix herbacea × polaris and two dominant evergreen dwarf shrubs, Cassiope tetragona and Vaccinium vitis-idaea throughout one growing season. The main aims were...... to compare the seasonal course and treatment effects on CBSC among the species, life forms and leaf cohorts and to examine whether the responses in different CBSC were consistent across compounds. The changes in leaf chemistry both during the season and in response to the treatments were higher in S...

  12. Vegetation response and landscape dynamics of Indian Summer Monsoon variations during Holocene: an eco-geomorphological appraisal of tropical evergreen forest subfossil logs.

    Directory of Open Access Journals (Sweden)

    Navnith K P Kumaran

    Full Text Available The high rainfall and low sea level during Early Holocene had a significant impact on the development and sustenance of dense forest and swamp-marsh cover along the southwest coast of India. This heavy rainfall flooded the coastal plains, forest flourishing in the abandoned river channels and other low-lying areas in midland.The coastline and other areas in lowland of southwestern India supply sufficient evidence of tree trunks of wet evergreen forests getting buried during the Holocene period under varying thickness of clay, silty-clay and even in sand sequences. This preserved subfossil log assemblage forms an excellent proxy for eco-geomorphological and palaeoclimate appraisal reported hitherto from Indian subcontinent, and complements the available palynological data. The bulk of the subfossil logs and partially carbonized wood remains have yielded age prior to the Holocene transgression of 6.5 k yrs BP, suggesting therein that flooding due to heavy rainfall drowned the forest cover, even extending to parts of the present shelf. These preserved logs represent a unique palaeoenvironmental database as they contain observable cellular structure. Some of them can even be compared to modern analogues. As these woods belong to the Late Pleistocene and Holocene, they form a valuable source of climate data that alleviates the lack of contemporaneous meteorological records. These palaeoforests along with pollen proxies depict the warmer environment in this region, which is consistent with a Mid Holocene Thermal Maximum often referred to as Holocene Climate Optimum. Thus, the subfossil logs of tropical evergreen forests constitute new indices of Asian palaeomonsoon, while their occurrence and preservation are attributed to eco-geomorphology and hydrological regimes associated with the intensified Asian Summer Monsoon, as recorded elsewhere.

  13. Vegetation Response and Landscape Dynamics of Indian Summer Monsoon Variations during Holocene: An Eco-Geomorphological Appraisal of Tropical Evergreen Forest Subfossil Logs

    Science.gov (United States)

    Kumaran, Navnith K. P.; Padmalal, Damodaran; Nair, Madhavan K.; Limaye, Ruta B.; Guleria, Jaswant S.; Srivastava, Rashmi; Shukla, Anumeha

    2014-01-01

    The high rainfall and low sea level during Early Holocene had a significant impact on the development and sustenance of dense forest and swamp-marsh cover along the southwest coast of India. This heavy rainfall flooded the coastal plains, forest flourishing in the abandoned river channels and other low-lying areas in midland.The coastline and other areas in lowland of southwestern India supply sufficient evidence of tree trunks of wet evergreen forests getting buried during the Holocene period under varying thickness of clay, silty-clay and even in sand sequences. This preserved subfossil log assemblage forms an excellent proxy for eco-geomorphological and palaeoclimate appraisal reported hitherto from Indian subcontinent, and complements the available palynological data. The bulk of the subfossil logs and partially carbonized wood remains have yielded age prior to the Holocene transgression of 6.5 k yrs BP, suggesting therein that flooding due to heavy rainfall drowned the forest cover, even extending to parts of the present shelf. These preserved logs represent a unique palaeoenvironmental database as they contain observable cellular structure. Some of them can even be compared to modern analogues. As these woods belong to the Late Pleistocene and Holocene, they form a valuable source of climate data that alleviates the lack of contemporaneous meteorological records. These palaeoforests along with pollen proxies depict the warmer environment in this region, which is consistent with a Mid Holocene Thermal Maximum often referred to as Holocene Climate Optimum. Thus, the subfossil logs of tropical evergreen forests constitute new indices of Asian palaeomonsoon, while their occurrence and preservation are attributed to eco-geomorphology and hydrological regimes associated with the intensified Asian Summer Monsoon, as recorded elsewhere. PMID:24727672

  14. LA DEFORESTACIÓN DEL BOSQUE SIEMPRE VERDE EN SOROA CANDELARIA, ARTEMISA, CUBA THE DEFORESTATION OF THE EVERGREEN FOREST IN SOROA CANDELARIA, ARTEMISA, CUBA

    Directory of Open Access Journals (Sweden)

    Seidel González Díaz

    2011-06-01

    Full Text Available La acción depredadora del hombre ha incidido en la desaparición de especies que identifican al bosque siempre verde. Este artículo demuestra el efecto de la deforestación del bosque en la comunidad de Soroa del municipio Candelaria, Artemisa, Cuba así como las potencialidades existentes en el área para revertir la actual situación, desde una perspectiva económica, social y ambiental. El objetivo es evaluar la incidencia de la proximidad a la comunidad sobre la afectación de las especies del bosque siempre verde en Soroa. Se seleccionaron al azar 20 parcelas en las cuales se contabilizó la abundancia de especies forestales, midiéndose también la distancia hasta la comunidad y el diámetro de árboles y arbustos. Se aplicó la regresión logística binaria para estimar la probabilidad de encontrar una proporción superior al 25% de las especies características de la zona, se calcularon los índices de diversidad y equidad, en los estratos arbóreos y arbustivos que fueron comparados con la aplicación de la prueba de rangos con signos de Wilcoxon. Se formaron así dos grupos, uno en que la distancia desde la comunidad es inferior a 2,5 km y el otro para una distancia mayor o igual a 2,5 km. Se realizó la prueba U de Mann Whitney para comparar los diámetros en los dos grupos, demostrándose con ello que la actividad antrópica es una de las causas que incide en la deforestación del bosque siempre verde del macizo montañoso en Candelaria.The negative man’s action on the forest has impacted in the disappearance of many species that belong to the evergreen forest. The present investigation demonstrate the grade of interference on the forest in the community of Soroa, Candelaria, Artemisa, Cuba and the existent potentialities in the area to revert this situation, from an economic, social and environmental perspective. The objective is to evaluate the influence of the proximity to community in the affectation of species to the

  15. Deepened winter snow increases stem growth and alters stem δ13C and δ15N in evergreen dwarf shrub Cassiope tetragona in high-arctic Svalbard tundra

    International Nuclear Information System (INIS)

    Deeper winter snow is hypothesized to favor shrub growth and may partly explain the shrub expansion observed in many parts of the arctic during the last decades, potentially triggering biophysical feedbacks including regional warming and permafrost thawing. We experimentally tested the effects of winter snow depth on shrub growth and ecophysiology by measuring stem length and stem hydrogen (δ2H), carbon (δ13C), nitrogen (δ15N) and oxygen (δ18O) isotopic composition of the circumarctic evergreen dwarf shrub Cassiope tetragona growing in high-arctic Svalbard, Norway. Measurements were carried out on C. tetragona individuals sampled from three tundra sites, each representing a distinct moisture regime (dry heath, meadow, moist meadow). Individuals were sampled along gradients of experimentally manipulated winter snow depths in a six-year old snow fence experiment: in ambient (c. 20 cm), medium (c. 100 cm), and deep snow (c. 150 cm) plots. The deep-snow treatment consistently and significantly increased C. tetragona growth during the 2008–2011 manipulation period compared to growth in ambient-snow plots. Stem δ15N and stem N concentration values were significantly higher in deep-snow individuals compared to individuals growing in ambient-snow plots during the course of the experiment, suggesting that soil N-availability was increased in deep-snow plots as a result of increased soil winter N mineralization. Although inter-annual growing season-precipitation δ2H and stem δ2H records closely matched, snow depth did not change stem δ2H or δ18O, suggesting that water source usage by C. tetragona was unaltered. Instead, the deep insulating snowpack may have protected C. tetragona shrubs against frost damage, potentially compensating the detrimental effects of a shortened growing season and associated phenological delay on growth. Our findings suggest that an increase in winter precipitation in the High Arctic, as predicted by climate models, has the potential to

  16. Deepened winter snow increases stem growth and alters stem δ13C and δ15N in evergreen dwarf shrub Cassiope tetragona in high-arctic Svalbard tundra

    DEFF Research Database (Denmark)

    Blok, Daan; Weijers, Stef; Welker, Jeffrey M;

    2015-01-01

    ), medium ( c . 100 cm), and deep snow ( c . 150 cm) plots. The deep-snow treatment consistently and significantly increased C. tetragona growth during the 2008–2011 manipulation period compared to growth in ambient-snow plots. Stem δ 15 N and stem N concentration values were significantly higher in deep...... season and associated phenological delay on growth. Our findings suggest that an increase in winter precipitation in the High Arctic, as predicted by climate models, has the potential to alter the growth and ecophysiology of evergreen shrub C. tetragona through changes in plant mineral nutrition and...... winter snow depth on shrub growth and ecophysiology by measuring stem length and stem hydrogen ( δ2H), carbon ( δ13C), nitrogen ( δ15N) and oxygen ( δ18O) isotopic composition of the circumarctic evergreen dwarf shrub Cassiope tetragona growing in high-arctic Svalbard, Norway. Measurements were carried...

  17. Plant functional types are more efficient than climate in predicting spectrums of trait variation in evergreen angiosperm trees of tropical Australia and China

    Science.gov (United States)

    Togashi, H. F.; Prentice, I. C. C.; Atkin, O. K.; Bloomfield, K. J.; Bradford, M.; Weerasinghe, L. K.; Harrison, S. P.; Evans, B. J.; Liddell, M. J.; Wang, H.; Cao, K. F.; Fan, Z.

    2015-12-01

    The representation of Plant Functional Types (PFTs) in current generation of Dynamic Global Vegetation Models (DGVMs) is excessively simplistically. Key ecophysiological properties, such as photosynthesis biochemistry, are most times merely averaged and trade-off with other plant traits is often neglected. Validation of a PFT framework based in photosynthetic process is crucial to improve reliability of DGVMs. We present 431 leaf-biochemical and wood level measurements in evergreen angiosperm trees of tropical forests in Australia and China that were divided in four spectrums of plant trait variation: metabolic, structural, hydraulic and height dimensions. Plant traits divided in each of these dimensions adopt survival strategies reflected more clearly by trade-off within each spectrum, and in some extent across spectrums. Co-ordination theory (that Rubisco- and electron-transport limited rates of photosynthesis are co-limiting) and least-coast theory (that intercellular to ambient CO2 concentration minimizes the combined costs per unit carbon assimilation, regulating maximum height and wood density) expectations matched PFT (which takes in account canopy position and light access, and life spam) variation. Our findings suggest that climate (air moisture, air temperature, light) has lower power representing these dimensions, in comparison to the PFT framework.

  18. Species composition, diversity and stratification in subtropical evergreen broadleaf forests along a latitudinal thermal gradient in the Ryukyu Archipelago, Japan

    Directory of Open Access Journals (Sweden)

    S.M. Feroz

    2015-07-01

    Full Text Available A well-developed evergreen broadleaf forest exists in the northern part of Okinawa and in the central part of the Ishigaki Islands in the Ryukyu Archipelago, Japan. All woody plants were identified to species level and their heights and diameters were measured in a 750m2 plot in Okinawa and a 400m2 plot in the Ishigaki Islands. Species overlap, dominance, diversity, multi-strata structure, and spatial distribution were calculated. The floristic composition in Okinawa was found to be different from that in Ishigaki. The species overlap between strata was higher in Okinawa than in Ishigaki. Species diversity and evenness tended to increase from the top down in Okinawa and the reverse in Ishigaki. Mean tree weight of each stratum decreased and tree density increased from top down in both forests. This trend resembled the mean weight–density trajectory of self-thinning plant populations. The degree of stand stratification, species richness and species diversity for trees with DBH ⩾4.5  cm increased along the latitudinal thermal gradient in the Ryukyu Archipelago. Thus, trees in the lower strata of Okinawa and upper strata of Ishigaki are important for sustainable maintenance of higher woody species diversity in the Ryukyu Archipelago.

  19. Molecular phylogeography and ecological niche modelling of a widespread herbaceous climber, Tetrastigma hemsleyanum (Vitaceae): insights into Plio-Pleistocene range dynamics of evergreen forest in subtropical China.

    Science.gov (United States)

    Wang, Yi-Han; Jiang, Wei-Mei; Comes, Hans Peter; Hu, Feng Sheng; Qiu, Ying-Xiong; Fu, Cheng-Xin

    2015-04-01

    Warm-temperate evergreen (WTE) forest represents the typical vegetation type of subtropical China, but how its component species responded to past environmental change remains largely unknown. Here, we reconstruct the evolutionary history of Tetrastigma hemsleyanum, an herbaceous climber restricted to the WTE forest. Twenty populations were genotyped using chloroplast DNA sequences and nuclear microsatellite loci to assess population structure and diversity, supplemented by phylogenetic dating, ancestral area reconstructions and ecological niche modeling (ENM) of the species distributions during the Last Glacial Maximum (LGM) and at present. Lineages in Southwest vs Central-South-East China diverged through climate/tectonic-induced vicariance of an ancestral southern range during the early Pliocene. Long-term stability in the Southwest contrasts with latitudinal range shifts in the Central-South-East region during the early-to-mid-Pleistocene. Genetic and ENM data strongly suggest refugial persistence in situ at the LGM. Pre-Quaternary environmental changes appear to have had a persistent influence on the population genetic structure of this subtropical WTE forest species. Our findings suggest relative demographic stability of this biome in China over the last glacial-interglacial cycle, in contrast with palaeobiome reconstructions showing that this forest biome retreated to areas of today's tropical South China during the LGM. PMID:25639152

  20. 亚热带常绿阔叶林群落物种多度分布格局对取样尺度的响应%Responses of species-abundance distribution to varying sampling scales in a subtropical broad-leaved forest

    Institute of Scientific and Technical Information of China (English)

    程佳佳; 米湘成; 马克平; 张金屯

    2011-01-01

    We determined the best-fit model for, and explored the mechanisms shaping species-abundance distributions (SADs) by fitting five widely-used SAD distribution models at several scales.We used data collected in 2005 from a 24-ha dynamic plot in an evergreen broad-leaved forest in the Gutianshan National Nature Reserve.We estimated SAD at different sampling scales from the mean value of SADs taken from 100 randomly-selected subplots within the 600 m×400 m Gutianshan plot.We subsequently used the SADs to test the fit of different models, including the broken stick, lognormal distribution, niche preemption, Zipf,Zipf- Mandelbrot, and neutral models.We employed AIC and x2 values to test goodness-of-fit for these models.All computations were conducted using the Vegan package in R 2.7.1.At smaller scales (10 m× 10 m and 20 m×20 m), the broken stick, lognormal distribution, niche preemption, Zipf, and Zipf-Mandelbrot models all fit well to the observed species-abundance distribution.The Zipf-Mandelbrot was the best model at the 20 m×20 m scale.The Lognormal was the best-fit model at the 40 m×40 m scale, and the Zipf-Mandelbrot model was the only suitable one in explaining the observed SAD at scales of 60 m×60 m and 80 m×80 m.None of these models performed well at a scale of 100 m× 100 m, but the neutral model was better at explaining patterns of SADs at larger scales (40 m×40 m to 100 m× 100 m) than smaller scales and it is suitable in explaining patterns of SADs at all scales.Patterns in SAD were scale-dependent, suggesting that SADs at different scales are likely structured by different ecological processes.%为揭示物种多度格局随尺度的变化规律,探讨多度格局形成的机理及生态学过程,作者以古田山亚热带常绿阔叶林24 ha固定监测样地为背景.采用断棍模型(broken stick model)、对数正态模型(Iognormal distribution model)、生态位优先占领模型(preemption model)、Zipf模型(Zipf model

  1. Effect of precipitation condition on photosynthesis and biomass accumulation and referring to splash erosion status in five typical evergreen tree species in humid monsoon climatic region of subtropical hill-land

    Institute of Scientific and Technical Information of China (English)

    余蔚青; 王云琦; 王玉杰; 张会兰; 王彬; 刘勇

    2015-01-01

    Negative effect of precipitation on plant photosynthesis was investigated in this work. Stomatal conductance, transpiration rate and net photosynthetic rate were measured before and after each precipitation event, respectively, and the corresponding precipitation was recorded as well. Moreover, plant dry matter accumulation was counted at the end of our entire experiment. The results show that precipitation fully demonstrates its negative effect on plant photosynthesis under the condition of without water shortage. Although it has not been proved, leaf shape seems to be associated with this effect. Broad-leaved species are less influenced than coniferous and lanceleaf species no matter on the length of variation time or changes in variation values. The different situation among three broad-leaved species seems to illustrate that the effect is also related to the size of single leaf area. The correlation between precipitation and photosynthetic rate variation is analogous to the relationship between precipitation and splash erosion, and in the view of the relationship between plant photosynthetic characteristics and dry mass accumulation, it can be thought that it can reflect the negative impact of precipitation on plant growth by making use of splash erosion. Therefore, a section was added in the traditional plant biomass estimation algorithms by using eco-physiological models, and this was proved to enhance the accuracy of traditional estimation from preliminary verifications.

  2. Sporopollen analysis of Core B10 in the southern Yellow Sea and the reflected characteristics of climate changes

    Institute of Scientific and Technical Information of China (English)

    FUMingzuo; LIZhen; XUXiaowei; SHIXuefa

    2003-01-01

    Eight sporopollen zones have been divided based on the results of high-resolution sporopollen analysis of Core B10 in the southern Yellow Sea. Based on the results along with 14C datings and the subbottom profiling data,climatic and environmental changes since the last stage of late Pleistocene are discussed. The main conclusions are drawn as follows: (1) the vegetation evolved in the process of coniferous forest-grassland containing broad-leaved trees→coniferous and broad-leaved mixed forest→coniferons and broad-leaved mixed forest-grassland prevailed by coniferous trees→coniferous and broad-leaved mixed forest-grassland containing evergreen broad-leaved trees→coniferons and broad-leaved mixed forest-grassland prevailed by broadleaved trees→deciduous broad-leaved forest-meadow containing evergreen broad-leaved trees→coniferous and broadleaved mixed forest-grassland prevailed by broad-leaved trees→coniferous and broad-leaved mixed forest containing evergreen broad-leaved trees; (2) eight stages of climate changes are identified as the cold and dry stage, the temperate and wet stage, the cold and dry stage, the warm and dry stage, the temperate and wet stage, the hot and dry stage, the temperate and dry stage, then the warm and dry stage in turn; (3) the sedimentary environment developed from land,to littoral zone, to land again, then to shore-neritic zone; and (4) the Yellow Sea Warm Current formed during early-Holocene rather than Atlantic stage.

  3. Comparison of cold resistance among nine evergreenIlex cultivars%9个常绿杂交冬青的抗寒能力比较

    Institute of Scientific and Technical Information of China (English)

    曾雯; 金晓玲; 邢文; 胡曼筠

    2016-01-01

    In order to evaluate the cold resistance of nine evergreenIlex cultivars, the physiological mechanism of detached-leaf from nine evergreenIlex cultivars under low temperature stress was studied.Their semi-lethal temperatures were calculated by relative electric conductivity (Rec) and logistic equation. Meanwhile, the con-tents of SOD,MDA,free proline and soluble protein were determined to provide their cold resistance.The re-sults indicated that Rec increased as the droping of temperature, and LT50 was between –14.13°C and –34.91°C. With the temperature decreased, the contents of MDA increased, and the SOD activity and soluble protein con-tents increased ifrstly, then decreased, and the contents of free proline increased or increased ifrstly, then de-creased. Synthetic evaluation of LT50 and the membership function indicated that the ranking of cold tolerance ofIlex cultivars was: ‘Shamrock’>‘Forsteri’ > ‘Schworbel’s Compacta’ > ‘Anna’s Choice’ > ‘Tensaw’ > ‘Blue Maid’ > ‘Bronze Beauty’ > ‘Oscar Gray’ > ‘Savannah’.%以9个常绿杂交冬青品种的离体叶片为供试材料进行低温胁迫处理,用电导法配以Logistic方程计算出半致死温度(LT50),并测定了超氧化物歧化酶(SOD)、丙二醛(MDA)、脯氨酸和可溶性蛋白各项指标,运用隶属函数法进一步分析其抗寒能力。结果表明,杂交冬青的相对电导率(Rec)随着温度的降低而上升, LT50均在–34.91~–14.13°C之间;低温胁迫下,随着温度的降低, MDA含量逐渐上升, SOD活性和可溶性蛋白含量呈先上升后下降的趋势,而脯氨酸含量呈先升后降或上升的变化趋势。综合LT50和各指标隶属函数分析法得出抗寒性强弱顺序为:‘Shamrock’>‘Forsteri’>‘Schworbel’s Compacta’>‘Anna’s Choice’>‘Tensaw’>‘Blue Maid’>‘Bronze Beauty’>‘Oscar Gray’>‘Savannah’。

  4. Tree size and light availability increase photochemical instead of non-photochemical capacities of Nothofagus nitida trees growing in an evergreen temperate rain forest.

    Science.gov (United States)

    Coopman, Rafael E; Briceño, Verónica F; Corcuera, Luis J; Reyes-Díaz, Marjorie; Alvarez, Daniela; Sáez, Katherine; García-Plazaola, José I; Alberdi, Miren; Bravo, León A

    2011-10-01

    Nothofagus nitida (Phil.) Krasser (Nothofagaceae) regenerates under the canopy in microsites protected from high light. Nonetheless, it is common to find older saplings in clear areas and adults as emergent trees of the Chilean evergreen forest. We hypothesized that this shade to sun transition in N. nitida is supported by an increase in photochemical and non-photochemical energy dissipation capacities of both photosystems in parallel with the increase in plant size and light availability. To dissect the relative contribution of light environment and plant developmental stage to these physiological responses, the photosynthetic performance of both photosystems was studied from the morpho-anatomical to the biochemical level in current-year leaves of N. nitida plants of different heights (ranging from 0.1 to 7 m) growing under contrasting light environments (integrated quantum flux (IQF) 5-40 mol m(-2). Tree height (TH) and light environment (IQF) independently increased the saturated electron transport rates of both photosystems, as well as leaf and palisade thickness, but non-photochemical energy flux, photoinhibition susceptibility, state transition capacity, and the contents of D1 and PsbS proteins were not affected by IQF and TH. Spongy mesophyll thickness and palisade cell diameter decreased with IQF and TH. A(max), light compensation and saturation points, Rubisco and nitrogen content (area basis) only increased with light environment (IQF), whereas dark respiration (R(d)) decreased slightly and relative chlorophyll content was higher in taller trees. Overall, the independent effects of more illuminated environment and tree height mainly increased the photochemical instead of the non-photochemical energy flux. Regardless of the photochemical increase with TH, carbon assimilation only significantly improved with higher IQF. Therefore it seems that mainly acclimation to the light environment supports the phenotypic transition of N. nitida from shade to

  5. I. Identification and characterization of dasheen mosaic virus in Chinese evergreen plants (Aglaonema commutatum) in California. II. New approaches for detecting plant viruses

    Energy Technology Data Exchange (ETDEWEB)

    Kositratana, W.

    1985-01-01

    Chinese evergreen plants (Aglaonema commutatum) with symptoms of mild stunting, chlorosis, leaf distortion and mosaic, were observed in Southern California. Flexuous rods (ca. 750 nm) were detected in leaf dip and partially purified preparations. Dasheen mosac virus (DMV) was identified as the causal agent on the basis of host range, morphology and reaction with DMV antiserum in immunodouble diffusion and immunosorbent electron microscopy (ISEM) tests. Tetragonia expansa was found to be a new host of this virus. Surveys indicate that DMV is not widespread in cultivars of A. commutatum in Southern California. The virus was purified from leaves of seedling Philodendron selloum by clarification with CCl/sub 4/, CHCl/sub 3/, and Triton X-100, precipitation with PEG-8000 and centrifugation in either Cs/sub 2/SO/sub 4/-sucrose cushion gradients or Cs/sub 2/SO/sub 4/ equilibrium density gradients. Purified virions formed a single UV-absorbing infectious band with densities of 1.31 and 1.245 g/ml in CsCl/sub 2/ and Cs/sub 2/SO/sub 4/ equilibrium density gradients, respectively, and a sedimentation coefficient of 154 S as determined by a linear-log sucrose density gradient centrifugation. Dasheen mosaic virus has a plus-sense ssRNA with the M.W. of 3.2 x 10/sup 6/ under denaturing conditions. Molecular hybridization analysis using /sup 3/H-complementary DNA specific to DMV-Ca RNA showed that DMV-Ca isolate was more closely related to DMV-Fiji isolate than to DMV-Fla isolate, and was very distantly related to ZYMV, TEV. PeMoC and PVY.

  6. Pleiotropic phenotypes of the salt-tolerant and cytosine hypomethylated leafless inflorescence, evergreen dwarf and irregular leaf lamina mutants of Catharanthus roseus possessing Mendelian inheritance

    Indian Academy of Sciences (India)

    Renu Kumari; Vishakha Sharma; Vinay Sharma; Sushil Kumar

    2013-12-01

    In Catharanthus roseus, three morphological cum salt-tolerant chemically induced mutants ofMendelian inheritance and their wild-type parent cv Nirmal were characterized for overall cytosine methylation at DNA repeats, expression of 119 protein-coding and seven miRNA-coding genes and 50 quantitative traits. The mutants, named after their principal morphological feature(s), were leafless inflorescence (lli), evergreen dwarf (egd) and irregular leaf lamina (ill). The Southern-blot analysis of MspI digested DNAs of mutants probed with centromeric and 5S and 18S rDNA probes indicated that, in comparison to wild type, the mutants were extensively demethylated at cytosine sites. Among the 126 genes investigated for transcriptional expression, 85 were upregulated and 41 were downregulated in mutants. All of the five genes known to be stress responsive had increased expression in mutants. Several miRNA genes showed either increased or decreased expression in mutants. The C. roseus counterparts of CMT3, DRM2 and RDR2 were downregulated in mutants. Among the cell, organ and plant size, photosynthesis and metabolism related traits studied, 28 traits were similarly affected in mutants as compared to wild type. Each of the mutants also expressed some traits distinctively. The egd mutant possessed superior photosynthesis and water retention abilities. Biomass was hyperaccumulated in roots, stems, leaves and seeds of the lli mutant. The ill mutant was richest in the pharmaceutical alkaloids catharanthine, vindoline, vincristine and vinblastine. The nature of mutations, origins of mutant phenotypes and evolutionary importance of these mutants are discussed.

  7. Pleiotropic phenotypes of the salt-tolerant and cytosine hypomethylated leafless inflorescence, evergreen dwarf and irregular leaf lamina mutants of Catharanthus roseus possessing Mendelian inheritance.

    Science.gov (United States)

    Kumari, Renu; Sharma, Vishakha; Sharma, Vinay; Kumar, Sushil

    2013-12-01

    In Catharanthus roseus, three morphological cum salt-tolerant chemically induced mutants of Mendelian inheritance and their wild-type parent cv Nirmal were characterized for overall cytosine methylation at DNA repeats, expression of 119 protein coding and seven miRNA-coding genes and 50 quantitative traits. The mutants, named after their principal morphological feature(s), were leafless inflorescence (lli), evergreen dwarf (egd) and irregular leaf lamina (ill). The Southern-blot analysis of MspI digested DNAs of mutants probed with centromeric and 5S and 18S rDNA probes indicated that, in comparison to wild type, the mutants were extensively demethylated at cytosine sites. Among the 126 genes investigated for transcriptional expression, 85 were upregulated and 41 were downregulated in mutants. All of the five genes known to be stress responsive had increased expression in mutants. Several miRNA genes showed either increased or decreased expression in mutants. The C. roseus counterparts of CMT3, DRM2 and RDR2 were downregulated in mutants. Among the cell, organ and plant size, photosynthesis and metabolism related traits studied, 28 traits were similarly affected in mutants as compared to wild type. Each of the mutants also expressed some traits distinctively. The egd mutant possessed superior photosynthesis and water retention abilities. Biomass was hyperaccumulated in roots, stems, leaves and seeds of the lli mutant. The ill mutant was richest in the pharmaceutical alkaloids catharanthine, vindoline, vincristine and vinblastine. The nature of mutations, origins of mutant phenotypes and evolutionary importance of these mutants are discussed. PMID:24371160

  8. Influence of summer marine fog and low cloud stratus on water relations of evergreen woody shrubs (Arctostaphylos: Ericaceae) in the chaparral of central California.

    Science.gov (United States)

    Vasey, Michael C; Loik, Michael E; Parker, V Thomas

    2012-10-01

    Mediterranean-type climate (MTC) regions around the world are notable for cool, wet winters and hot, dry summers. A dominant vegetation type in all five MTC regions is evergreen, sclerophyllous shrubland, called chaparral in California. The extreme summer dry season in California is moderated by a persistent low-elevation layer of marine fog and cloud cover along the margin of the Pacific coast. We tested whether late dry season water potentials (Ψ(min)) of chaparral shrubs, such as Arctostaphylos species in central California, are influenced by this coast-to-interior climate gradient. Lowland coastal (maritime) shrubs were found to have significantly less negative Ψ(min) than upland interior shrubs (interior), and stable isotope (δ(13)C) values exhibited greater water use efficiency in the interior. Post-fire resprouter shrubs (resprouters) had significantly less negative Ψ(min) than co-occurring obligate seeder shrubs (seeders) in interior and transitional chaparral, possibly because resprouters have deeper root systems with better access to subsurface water than shallow-rooted seeders. Unexpectedly, maritime resprouters and seeders did not differ significantly in their Ψ(min), possibly reflecting more favorable water availability for shrubs influenced by the summer marine layer. Microclimate and soil data also suggest that maritime habitats have more favorable water availability than the interior. While maritime seeders constitute the majority of local Arctostaphylos endemics, they exhibited significantly greater vulnerability to xylem cavitation than interior seeders. Because rare seeders in maritime chaparral are more vulnerable to xylem cavitation than interior seeders, the potential breakdown of the summer marine layer along the coast is of potential conservation concern. PMID:22526938

  9. Insect diversity along a successional gradient in conifer and broad-leaved mixed forests in Changbai Mountain%长白山针阔混交林不同演替阶段的昆虫多样性

    Institute of Scientific and Technical Information of China (English)

    贾玉珍; 赵秀海; 孟庆繁

    2009-01-01

    It has been noted that insect community is a powerful indicator of forest discover and succession. We examined the changes in species diversity and faunal composition of insect along a successional gradient of conifer and broad-leaved mixed forests in Changbai Mountain in this study. Insect community of three habitats, viz. Secondary birch forest (SBF), secondary conifer and broad-leaved mixed forest (SCBF), and original broad-leaved Korean pine forest (OBPF), from the early successional stage to mature forest understory were investigated by using sweeping nets, light traps and pitfall traps. The results showed that a total of 8 183 individuals representing 699 species in 362 orders were recorded. The dominant species were of Lepidoptera and Coleoptera. SCBF had the highest number of individuals and OBPF had the highest number of species, but the number of species and individuals between the successional habitats did not differ significantly. The Fisher' s a index values of SCBF and OBPF were significantly greater than that of SBF, and the diversity at the family level was not significantly different between the three habitats. Insect diversity increased following the herb diversity along the successional habitats. Because of different feeding habits and habitat preference, the diversity of Lepidoptera increased along the successional habitats, while that of Coleoptera decreased, which was similar to that found in previously reported studies.%昆虫多样性变化对生态系统健康有重要的指示作用,为研究昆虫群落变化与生境演替之间的关系,本研究采用网捕、灯诱和诱捕法系统调查了长白山针阔混交林不同演替阶段(次生白桦林、次生针阔混交林、原始阔叶红松林)昆虫群落的组成和多样性,分析了昆虫在森林演替过程中的规律及与植被群落之间的关系.系统调查共采集昆虫标本8 183头,隶属于14个目699种,其中鳞翅目和鞘翅目是主要优势类群.次生针

  10. 小兴安岭天然阔叶混交林生长季CO2通量特征分析%Analysis on CO2 Flux during Growth Season of Natural Broadleaved Mixed Forest in Xiaoxinganling Mountains

    Institute of Scientific and Technical Information of China (English)

    于成龙; 刘丹

    2011-01-01

    The research on CO2 flux in forest system was one of the hot topics in global changes. The CO2 flux during growth season of natural broadleaved mixed forest in Xiaoxinganling mountains was analyzed, based on observed data continuously in 2008 by using open-path eddy covariance system. The results showed that the CO2 flux changed from -0. 46 to 0. 42 mg · M-2·S-1 during the whole growth season. The maximum uptake occurred at 9 o' clock during June and the maximum efflux occurred at 5 o' clock during July. During daytime, the carbon uptake increased with the temperature increasing when it was below 26. 63℃. On the contrary, it decreased with temperature increasing when it was above 26. 631. During nighttime, the maximum efflux occurred 13. 501. In all, it showed that carbon assimilation was 212.32 g · M-2 during the whole growth season of natural broadleaved mixed forest in Xiaoxinganling mountains in 2008.%森林生态系统CO2通量的研究已成为全球变化研究的热点之一.本文采用开路式涡度相关系统对小兴安岭天然阔叶混交林CO2通量进行为期1a的连续观测(2008年),分析了生长季(5-9月)CO2通量的变化特征.结果表明,在生长季,天然阔叶混交林系统的CO2通量变化范围为-0.46~0.42mg·m-2·s-1;最大吸收量出现在6月份的9:00,最大释放量出现在7月份的5:00.白天气温低于26.63℃时,碳吸收量随气温的升高而加大;但气温超过26.63℃后,则呈相反趋势.夜晚气温在13.50℃时的碳释放量最大.2008年整个生长季呈现白天碳吸收,夜晚碳释放的现象,总体表现为碳吸收,吸收总量为212.32g· m-2.

  11. 上阔下竹混交林对竹林土壤养分的影响%Effects of Phyllostachys edulis and broad-leaved mixed forest on soil nutrient content

    Institute of Scientific and Technical Information of China (English)

    杨宽; 王福升; 徐爱珍; 汪玉凤

    2015-01-01

    By taking the different proportions moso bamboo and broad-leaved mixed forests[Ⅰ(28.3%),Ⅱ(22.5%),Ⅲ(20.1%)]and moso bamboo pure forest[Ⅳ(0)]in north of Fujian as test materials,the soil nutritional of the forests in different depths were analyzed.The results showed that the soil pH of type Ⅳ was the lowest,the surface soil organic matter and available N,P,and B content of typeⅠ,Ⅱ and Ⅲ were significantly higher than those in type Ⅳ(P Ⅲ >Ⅱ >Ⅳ,which showed that the upper broad-leaves forests had some improvements on the soil nutritional of the lower moso bamboo for-est.%以闽北地区不同比例的上阔下竹混交林Ⅰ(28.3%)、Ⅱ(22.5%)、Ⅲ(20.1%)和毛竹纯林Ⅳ(0)为研究对象,对竹林土壤养分进行分析。结果表明:相同坡位之间,类型Ⅳ土壤 pH 最低;类型Ⅰ、Ⅱ、Ⅲ竹林表层土壤有机质、水解氮、有效磷和有效硼含量均明显高于类型Ⅳ(P <0.05);土壤有效态养分含量之间也存在极显著相关性,各类型毛竹林土壤综合肥力顺序为Ⅰ>Ⅲ>Ⅱ>Ⅳ,表明上位阔叶林对毛竹林土壤肥力具有一定的改善作用。

  12. 长白山针阔混交林秋季净生态系统水气交换量%Net water vapour exchange over a mixed needle and broad-leaved forest in Changbai Mountain during autumn

    Institute of Scientific and Technical Information of China (English)

    温学发; 于贵瑞; 孙晓敏

    2003-01-01

    Water vapour and CO2 fluxes were measured by the eddy-covariance technique above a mixed needle and broad-leaved forest with affiliated meteorological measurements in Changbai Mountain as part of China's FLUX projects since late August in 2002. Net water vapour exchange and environmental control over the forest were examined from September 1 to October 31 in 2002.To quantify the seasonal dynamics, the transition period was separated into leafed, leaf falling and leafless stages according to the development of leaf area. The results showed that (a) seasonal variation of water vapour exchange was mainly controlled by net radiation (Rn) which could account for 78.5%, 63.4% and 56.6% for leafed, leaf falling and leafless stages, respectively, while other environmental factors' effects varied evidently; (b) magnitude of water vapour flux decreased remarkably during autumn and daily mean of water vapour exchange was 24.2 mgm-2 s-1 (100%),14.8 mgm-2 s-1 (61.2%) and 10.3 mg m-2 s-1 (42.6%) for leafed, leaf falling and leafless stage,respectively; and (c) the budget of water vapour exchange during autumn was estimated to be 87.1 kg H2O m-2, with a mean of 1427.2 g H2O d-1 varying markedly from 3104.0 to 227.5 g H2O m-2d-1.

  13. 亚热带地区阔叶林与杉木林土壤活性有机质比较%Soil active organic matter in broadleaved forest and Chinese fir plantation in subtropical region of China

    Institute of Scientific and Technical Information of China (English)

    王清奎; 范冰; 徐广标

    2009-01-01

    A comparative study was made on the soil active organic matter in a broadleaved forest and two Chinese fir (Cunninghamia lanceolata) plantations in subtropical region of China, aimed to understand the effects of forest conversion and continuous plantation on soil organic C and nutrient status. After the conversion from broadleaved forest to Chinese fir plantation, the contents of soil total organic C, humus C, humic acid, and fulvic acid decreased by 27.8%-52.1%, 32.2%-52.8%, 36.4%-59.0%, and 29.7%-50.0%, respectively. Continuous plantation also resulted in the decrease of soil organic C and humus contents. The contents of soil total organic C, humus C, humic acid, and fulvic acid in second generation of Chinese fir plantation were 9.0%-25.0%, 25.0%-38.0%, 28.6%-39.2% and 23.1%-36.4% lower than those in the first generation of Chinese fir plantation, respectively. More obvious effects were observed on the soil active organic matter. After the conversion from broadleaved forest to Chinese fir plantation, the maximum decrement of soil microbial biomass C and N and dissolved organic C and N was 61.8%, 38.2%, 43.3%, and 69.0%; while comparing with the first generation of Chinese fir plantation, the second generation of Chinese fir plantation had the maximum decrement of soil microbial biomass C and N and dissolved organic C and N being 34.7%, 29.3%, 30.4%, and 18.4%, respectively. Soil nutrient contents also decreased due to forest conversion and continuous plantation. In comparing with broadleaved forests, Chinese fir plantations had a decrease of soil N, P, and K contents being 15.7%-31.2%, 11.5%-49.3%, and 15.1%-33.8%, respectively. There were close relationships between soil nutrients and soil active organic matter fractions except cold water extractable organic N.%通过对亚热带3个地区地带性阔叶林和杉木林土壤活性有机质的比较,分析森林类型变化及杉木连栽对土壤有机碳和养分含量的影响.结果表明:地带性阔叶林

  14. Carbon allocation to biomass production of leaves, fruits and woody organs at seasonal and annual scale in a deciduous- and evergreen temperate forest

    Directory of Open Access Journals (Sweden)

    M. Campioli

    2010-10-01

    of the growing season for pine. Seasonal differences in C allocation are likely due to functional differences between deciduous and evergreen species and temporal variability of the sink strength.

    The similar GPP and autotrophic respiration between stands and the remarkable larger C allocation to wood at the beech stand indicate that at the beech ecosystem C has a longer residence time than at the pine ecosystem. Further research on belowground production and particularly on fine roots and ectomycorrhizal fungi likely represents the most important step to progress our knowledge on C allocation dynamics.

  15. Community ecology and spatial distribution of trees in a tropical wet evergreen forest in Kaptai national park in Chittagong Hill Tracts, Bangladesh

    Institute of Scientific and Technical Information of China (English)

    S.M.Feroz; Md Rabiul Alam; Prokash Das; Abdullah Al Mamun

    2014-01-01

    We investigated the floristic composition, woody species diversity and spatial distribution of trees in a tropical wet evergreen forest in Kaptai national park in Chittagong Hill Tracks, Bangladesh. We recorded 25 families, 37 genera, 40 species and 1771 woody individuals in a 0.09 ha plot. Euphorbiaceae and Moraceae were the most species-rich families, and Castanopsis, Ficus and Terminalia were the most species-rich genera. Bursera serrata Wall. ex Colebr. was the dominant species in terms of highest importance value (13%). Trema orientalis (L.) Bl was typically a light demanding species as it appeared in the top can-opy with only one individual having the seventh highest IV, but had no regeneration. The expected maximum number of species (Smax) was 140, indicating that many species may invade the forest as the Smax is greater than the recorded total number of species. The nature of the disappear-ance and appearance of species in the present forest reflects instability of floristic composition. The values of Shannon’s index H′ and Pielou’s index J′ (evenness) were 3.36 bit and 0.63, respectively. These values show moderately high species diversity as compared to other subtropical forests in the tropics. In addition, a sample area of 200 m2 in this forest would be sufficient for measuring the diversity indices H′ and J′ , whereas the trend of J′may indicate the rate of equality of individuals among the different species decreased with increasing area. The distribu-tion pattern for the total stand was completely random. However, the dominant species showed aggregate distribution for small areas, but random distribution for large areas. The spatial association between species showed that the strongest positive interspecific association oc-curred between Streblus asper Lour. and Castanea indica Roxb. (ω =0.51). As a whole, most species were weakly associated with each other, of which 58%species associations were completely negative. The result of

  16. Factors promoting larch dominance in central Siberia: fire versus growth performance and implications for carbon dynamics at the boundary of evergreen and deciduous conifers

    Directory of Open Access Journals (Sweden)

    E.-D. Schulze

    2012-04-01

    Full Text Available The relative role of fire and of climate in determining canopy species composition and aboveground carbon stocks were investigated. Measurements were made along a transect extending from the dark taiga zone of central Siberia, where Picea and Abies dominate the canopy, into the Larix zone of eastern Siberia. We test the hypotheses that the change in canopy species composition is based (1 on climate-driven performance only, (2 on fire only, or (3 on fire-performance interactions. We show that the evergreen conifers Picea obovata and Abies sibirica are the natural late-successional species both in central and eastern Siberia, provided there has been no fire for an extended period of time. There are no changes in performance of the observed species along the transect. Fire appears to be the main factor explaining the dominance of Larix and of soil carbon. Of lesser influence were longitude as a proxy for climate, local hydrology and active-layer thickness. We can only partially explain fire return frequency, which is not only related to climate and land cover, but also to human behavior.

    Stand-replacing fires decreased from 300 to 50 yrs between the Yenisei Ridge and the upper Tunguska. Repeated non-stand-replacing surface fires eliminated the regeneration of Abies and Picea. With every 100 yrs since the last fire, the percentage of Larix decreased by 20%.

    Biomass of stems of single trees did not show signs of age-related decline. Relative diameter increment was 0.41 ± 0.20% at breast height and stem volume increased linearly over time with a rate of about 0.36 t C ha−1 yr−1 independent of age class and species. Stand biomass reached about 130 t C ha−1(equivalent to about 520 m3 ha−1. Individual trees of Larix were older than 600 yrs. The maximum age and biomass seemed to be limited by fungal rot of

  17. Zeaxanthin-independent energy quenching and alternative electron sinks cause a decoupling of the relationship between the photochemical reflectance index (PRI) and photosynthesis in an evergreen conifer during spring.

    Science.gov (United States)

    Fréchette, Emmanuelle; Wong, Christopher Y S; Junker, Laura Verena; Chang, Christine Yao-Yun; Ensminger, Ingo

    2015-12-01

    In evergreen conifers, the winter down-regulation of photosynthesis and its recovery during spring are the result of a reorganization of the chloroplast and adjustments of energy-quenching mechanisms. These phenological changes may remain undetected by remote sensing, as conifers retain green foliage during periods of photosynthetic down-regulation. The aim was to assess if the timing of the spring recovery of photosynthesis and energy-quenching characteristics are accurately monitored by the photochemical reflectance index (PRI) in the evergreen conifer Pinus strobus. The recovery of photosynthesis was studied using chlorophyll fluorescence, leaf gas exchange, leaf spectral reflectance, and photosynthetic pigment measurements. To assess if climate change might affect the recovery of photosynthesis, seedlings were exposed to cold spring conditions or warm spring conditions with elevated temperature. An early spring decoupling of the relationship between photosynthesis and PRI in both treatments was observed. This was caused by differences between the timing of the recovery of photosynthesis and the timing of carotenoid and chlorophyll pool size adjustments which are the main factors controlling PRI during spring. It was also demonstrated that zeaxanthin-independent NPQ mechanisms undetected by PRI further contributed to the early spring decoupling of the PRI-LUE relationship. An important mechanism undetected by PRI seems to involve increased electron transport around photosystem I, which was a significant energy sink during the entire spring transition, particularly in needles exposed to a combination of high light and cold temperatures. PMID:26386258

  18. Effects of leaf surface characteristics on dust-retaining capability of six highway evergreen plants%6种公路常绿植物叶面特性对滞尘效果的影响研究

    Institute of Scientific and Technical Information of China (English)

    黄宇轩

    2015-01-01

    通过选择6种具有代表性的道路常绿植物,应用接触角测定仪测定了不同树种叶片的接触角,通过扫描电镜观察比较了6种常绿植物的叶表面形态结构,分析其对滞尘能力的影响。试验结果表明常绿植物叶片正面接触角越大,滞尘能力越小;表面叶孔越多,粗糙度越大,滞尘能力越强。研究成果可为城市绿化树种的选择提供基础依据。%Six highway evergreen plants were selected to investigate the effects of leaf surface characteristics on dust-retaining capability. Contact angle of water droplet on leaf surface was measured by goniometer and scanning electron microscopy was used to compare their surface morphology. Results showed that dust-retaining capabilities increased with the decrease of contact angle of the leaf surface. It also indicated that higher stomata density and roughness would result in higher dust-retaining capabilities. The result will provide scientific data for choosing evergreen tree species for urban greening.

  19. Zeaxanthin-independent energy quenching and alternative electron sinks cause a decoupling of the relationship between the photochemical reflectance index (PRI) and photosynthesis in an evergreen conifer during spring.

    Science.gov (United States)

    Fréchette, Emmanuelle; Wong, Christopher Y S; Junker, Laura Verena; Chang, Christine Yao-Yun; Ensminger, Ingo

    2015-12-01

    In evergreen conifers, the winter down-regulation of photosynthesis and its recovery during spring are the result of a reorganization of the chloroplast and adjustments of energy-quenching mechanisms. These phenological changes may remain undetected by remote sensing, as conifers retain green foliage during periods of photosynthetic down-regulation. The aim was to assess if the timing of the spring recovery of photosynthesis and energy-quenching characteristics are accurately monitored by the photochemical reflectance index (PRI) in the evergreen conifer Pinus strobus. The recovery of photosynthesis was studied using chlorophyll fluorescence, leaf gas exchange, leaf spectral reflectance, and photosynthetic pigment measurements. To assess if climate change might affect the recovery of photosynthesis, seedlings were exposed to cold spring conditions or warm spring conditions with elevated temperature. An early spring decoupling of the relationship between photosynthesis and PRI in both treatments was observed. This was caused by differences between the timing of the recovery of photosynthesis and the timing of carotenoid and chlorophyll pool size adjustments which are the main factors controlling PRI during spring. It was also demonstrated that zeaxanthin-independent NPQ mechanisms undetected by PRI further contributed to the early spring decoupling of the PRI-LUE relationship. An important mechanism undetected by PRI seems to involve increased electron transport around photosystem I, which was a significant energy sink during the entire spring transition, particularly in needles exposed to a combination of high light and cold temperatures.

  20. Sporopollen analysis of Core B10 in the southern Yellow Sea and the reflected characteristics of climate changes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Eight sporopollen zones have been divided based on the results of high-resolution sporopollen analysis of Core B10 in the southern Yellow Sea. Based on the results along with 14C datings and the subbottom profiling data, climatic and environmental changes since the last stage of late Pleistocene are discussed. The main conclusions are drawn as follows: (1) the vegetation evolved in the process of coniferous forest-grassland containing broad-leaved trees→coniferous and broad-leaved mixed forest→coniferous and broad-leaved mixed forest-grassland prevailed by coniferous trees→coniferous and broad-leaved mixed forest-grassland containing evergreen broad-leaved trees→coniferous and broad-leaved mixed forest-grassland prevailed by broad- leaved trees→deciduous broad-leaved forest-meadow containing evergreen broad-leaved trees→coniferous and broad- leaved mixed forest-grassland prevailed by broad-leaved trees→coniferous and broad-leaved mixed forest containing evergreen broad-leaved trees;(2) eight stages of climate changes are identified as the cold and dry stage, the temperate and wet stage, the cold and dry stage, the warm and dry stage, the temperate and wet stage, the hot and dry stage, the temperate and dry stage, then the warm and dry stage in turn; (3) the sedimentary environment developed from land, to littoral zone, to land again, then to shore-neritic zone; and (4) the Yellow Sea Warm Current formed during early- Holocene rather than Atlantic stage.

  1. Doses reduzidas de herbicidas no controlo do Juncus Bufonius L. e infestantes dicotiledóneas em trigo de sementeira directa Reduced doses of herbicides to control Juncus Bufonius L. and broad-leaved weeds in no-till wheat

    Directory of Open Access Journals (Sweden)

    José Calado Barros

    2011-01-01

    Full Text Available O estudo foi levado a cabo nos anos de 2007/08 e 2008/09 numa herdade privada no distrito de Évora (Sul de Portugal, onde a cultura do trigo é semeada após o início das chuvas de Outono. O trigo foi estabelecido usando o sistema de sementeira directa, o qual possibilita a aplicação de herbicidas de pós-emergência numa fase mais precoce do desenvolvimento das infestantes. Para controlar o Juncus bufonius L. e diferentes infestantes de folha larga, foi aplicada uma mistura de dois herbicidas quando as infestantes se encontravam no estádio de desenvolvimento de 3-4 pares de folhas. Os herbicidas aplicados foram o mesossulfurão-metilo + iodossulfurão-metilo-sódio + mefenepir-dietilo (H1 e o clortolurão (H2 e utilizaram-se duas doses diferentes dos dois herbicidas. O maior controlo do J. bufonius foi obtido quando na mistura se utilizou a dose mais alta do herbicida H2 (2.0 L ha-1 e para se conseguir um maior controlo das infestantes dicotiledóneas foi também necessário aplicar a dose mais alta do herbicida H1 (0.3 kg ha-1. Apesar das diferenças na produção de grão não terem sido significativas para os diferentes tratamentos, verificou-se a tendência de um aumento na produção de grão com um controlo mais eficaz do Juncus bufonius L.The study was carried out over 2 years (2007/2008 and 2008/2009 on a private farm in the Alentejo region (Évora, in the South of Portugal where rainfed wheat is sown after the beginning of the autumn rainfall season. The wheat crop was established using no-till which permits the post-emergence application of herbicides at an early weed development stage. To control J. bufonius and different broad-leaved weeds, a mixture of two herbicides was used when the weeds were at the 3-4 pair of leaves development stage. The herbicides applied were mesosulfuron-methyl + iodosulfuron- methyl-sodium + mefenpyr-diethyl (H1 and clortoluron (H2 at two different doses. Best J. bufonius control was achieved with

  2. [Correlations between standing trees trunk decay degree and soil physical-chemical properties in Korean pine-broadleaved mixed forest in Xiao Xing'an Mountains of Northeast China].

    Science.gov (United States)

    Sun, Tian-Yong; Wang, Li-Hai; Sun, Mo-Long

    2013-07-01

    Standing trees decay often causes vast loss of timber resources. To investigate the correlations between the standing trees decay and the site conditions is of importance to scientifically and reasonably manage forests and to decrease wood resources loss. By using Resistograph and meter ruler, a measurement was made on the decay degree of the trunk near root and the diameter at breast height (DBH) of 15 mature Korean pine standing trees in a Korean pine-broadleaved mixed forest in Xiao Xing' an Mountains in May, 2011. In the meantime, soil samples were collected from the root zones of standing trees and the upslope and downslope 5 meters away from the trunks, respectively. Five physical-chemical properties including moisture content, bulk density, total porosity, pH value, and organic matter content of the soil samples were tested. The regression equations concerning the trunk decay degree of the standing trees, their DBH, and the 5 soil properties were established. The results showed that the trunk decay degree of the mature Korean pine standing trees had higher correlations with the bulk density, total porosity, pH value, and organic matter content (R = 0.687), and significant positive correlation with the moisture content (R = 0.507) of the soils at the root zones of standing trees, but less correlation with the 5 properties of the soils at both upslope and downslope 5 meters away from the trunks. The trunk decay degree was decreased when the soil moisture content was below 18.4%. No significant correlation was observed between the trunk decay degree of mature Korean pine standing trees and the tree age. PMID:24175511

  3. 小兴安岭红松阔叶混交林土壤动物群落研究%Study on Soil Animals Community of Pinus koraiensis Broad-Leaved Mixed Forest in Xiaoxing' an Mountain

    Institute of Scientific and Technical Information of China (English)

    苗雅杰; 殷秀琴

    2005-01-01

    Soil animal communities of Pinus koraiensis broad-leaved mixed forest were studied. The purpose was to discuss the dynamic characteristic of soil animals and relationship with environmental factors. The ecosystem geography distribution law of soil animals, soil animals' role and function in ecological system were revealed. In June, August, October each year, three plots were selected. In each plot, four layers were sampled( litter layer,0 - 10 cm, 10 - 20 cm & 20 - 30 cm), adding up to 72 soil sample. The area for large-sized soil animals was 50 cm × 50 cm, and the area for middle-small-sized soil animals was 10 cm × 10 cm. Separated soil animals through adopting hand-picking method and Tullgren method respectively. Sampled the soil animals in two continuing years. Shannon-Wiener index was adopted to analyze the diversity of soil animals. Monad liner regression was used to search the relationship between soil animals and environmental factors. The dominant groups were Oribatida, Isotomidae. There were relatively great changes in groups and individual numbers of dominant groups and rare groups when the reason changed. The individual numbers of dominant groups and the groups of rare groups changed. The number of individual and group was the most in August. Obviously it correlated with climatic factors in middle temperate zone. The evenness was low and dominance was high. The diversity index was not most. Among the annual fluctuating there was a increasing trend. The evenness was low and dominance was high. The diversity index was low. It conformed with the law of reason change. The correlation between soil animals and atmospheric temperature, rainfall, ground temperature and sunlight showed the correlation with rainfall and soil temperature was the most significant.

  4. [Correlations between standing trees trunk decay degree and soil physical-chemical properties in Korean pine-broadleaved mixed forest in Xiao Xing'an Mountains of Northeast China].

    Science.gov (United States)

    Sun, Tian-Yong; Wang, Li-Hai; Sun, Mo-Long

    2013-07-01

    Standing trees decay often causes vast loss of timber resources. To investigate the correlations between the standing trees decay and the site conditions is of importance to scientifically and reasonably manage forests and to decrease wood resources loss. By using Resistograph and meter ruler, a measurement was made on the decay degree of the trunk near root and the diameter at breast height (DBH) of 15 mature Korean pine standing trees in a Korean pine-broadleaved mixed forest in Xiao Xing' an Mountains in May, 2011. In the meantime, soil samples were collected from the root zones of standing trees and the upslope and downslope 5 meters away from the trunks, respectively. Five physical-chemical properties including moisture content, bulk density, total porosity, pH value, and organic matter content of the soil samples were tested. The regression equations concerning the trunk decay degree of the standing trees, their DBH, and the 5 soil properties were established. The results showed that the trunk decay degree of the mature Korean pine standing trees had higher correlations with the bulk density, total porosity, pH value, and organic matter content (R = 0.687), and significant positive correlation with the moisture content (R = 0.507) of the soils at the root zones of standing trees, but less correlation with the 5 properties of the soils at both upslope and downslope 5 meters away from the trunks. The trunk decay degree was decreased when the soil moisture content was below 18.4%. No significant correlation was observed between the trunk decay degree of mature Korean pine standing trees and the tree age.

  5. 50%吡氟酰草胺水分散粒剂对春小麦田阔叶杂草的防效%Control Effect of Diflufenican 50%WG on Broad-leaved Weeds in Spring Wheat Field

    Institute of Scientific and Technical Information of China (English)

    程亮

    2015-01-01

    通过田间药效试验明确50%吡氟酰草胺水分散粒剂对春小麦田阔叶杂草的防除效果和田间推荐使用剂量,结果表明,50%吡氟酰草胺水分散粒剂对小麦田杂草密花香薷、野油菜和酸模叶蓼的防除效果稍差,施药后40 d对杂草株数总体防效为53.01%~61.75%,鲜重总体防效为54.30%~58.03%。该药剂对小麦安全,较空白对照增产6.44%~8.52%。建议该药剂于春小麦3叶期前,杂草2叶期前进行茎叶喷雾处理。%Based on the field trials,the efficacy and recommended dosage of diflufenican 50% WG are determined for controlling broad-leaf weeds in spring wheat field. The result shows that diflufenican 50% WG had not good control effect to broad-leaved weeds. The integrated plant and fresh weight control effects are 53.01%~61.75% and 54.30%~58.03% on weeds respectively after 40 days after spaying. Diflufenican 50% WG had no significant effect on spring wheat growth and the yield increasing rate of spring wheat is 6.44%~8.52%after sparing. The proper period of spraying is 2 leaves in weeds(3 leaves in wheat).

  6. Observation and Analysis of Growing Speeds and Heights of 6 Evergreen Lianas%6种常绿藤本植物的生长速度与高度的观测与分析

    Institute of Scientific and Technical Information of China (English)

    许晓岗; 童丽丽

    2012-01-01

    [目的]观测与分析6种常绿藤本植物的生长速度与高度.[方法]通过对南京及周边地区的常绿攀缘植物调查和引种栽培,选出6个具开发应用潜力的常绿种络石、洋常春藤、扶芳藤、南五味子、宁油麻藤、薛荔,并对这6种攀缘植物的生长速度和高度方面作了定性的和定量的观测和分析.[结果]前10年生长速度由快至慢的顺序为:洋常春藤>扶芳藤>宁油麻藤>薜荔>络石>南五味子,前10年中生长高度由高至低的顺序为:洋常春藤>扶芳藤>薜荔>络石>南五味子>宁油麻藤.[结论]藤本植物的攀缘高度与其寄主有关,不同种间攀缘高度差异较大,灰色系统模型并不能描述所有这6种攀缘植物的生长高度.%[Objective] Growing speeds and heights of 6 evergreen lianas were observated and analyzed. [ Method ] By surveying the evergreen liana resources, introductiing and cultivatiing them in Nanjing region, 6 potential evergreen species were screened for ornamental application purposes. Qualitative and quantitative measurements were applied to test their growing speeds and heights. [Result]The growing speeds in the first ten years from fast to slow was: Hedera helix > Euonymus fortunei > Mucuna paohwashanica > Fiats pumila > Trachelospermum jasmi- noides > Kadsura longipedunadata. The growing heights in the first ten years from high to low was; Hedera helix > Euonymus fortunei > Ficus pumila > Trachelospermum jasmirwides > Kadsura longipedunadata > Mucuna paohwashanica. [Conclusion]The climbing heights of lianas were correlated with their hosts. There was a great difference between of climbing height among different species of liana. The gray system can not fit the growing speed and height of all the 6 species of liana.

  7. Evergreen Valley College Matriculation Aide Intervention Evaluation: Success Rates of Fall 1992 Sections Using a Matriculation Aide Compared to Non-Intervention Sections for the Same Semester and Two Previous Semesters, English 321, 322, 330, and Math 12. Research Report #408.

    Science.gov (United States)

    Kangas, Jon

    In fall 1992, a study was performed at Evergreen Valley College, in San Jose, California, to determine whether the presence of full-time instructional aides and part-time matriculation aides in four specific courses (English 321, 322, 330, and Math 12) led to increases in student success. Success was defined as receipt of a grade of "A,""B," or…

  8. [Spatiotempaoral distribution patterns of photosynthetic photon flux density, air temperature, and relative air humidity in forest gap of Pinus koraiensis-dominated broadleaved mixed forest in Xi-ao Xing' an Mountains].

    Science.gov (United States)

    Li, Meng; Duan, Wen-biao; Chen, Li-xin

    2009-12-01

    A continuous measurement of photosynthetic photon flux density (PPFD), air temperature, and relative air humidity was made in the forest gap in primary Pinus koraiensis-dominated broadleaved mixed forest in Xiao Xing' an Mountains to compare the spatiotemporal distribution patterns of the parameters. The diurnal maximum PPFD in the forest gap appeared between 11:00 and 13:00 on sunny and overcast days. On sunny days, the maximum PPFD during various time periods did not locate in fixed locations, the diurnal maximum PPFD occurred in the canopy edge of northern part of the gap; while on overcast days, it always occurred in the center of the gap. The mean monthly PPFD in the gap was the highest in June and the lowest in September, with the largest range observed in July. The maximum air temperature happened between 9:00 and 15:00 on sunny days, between 15:00 and 19:00 on overcast days, the locations were 8 m in the southern part of gap center both on sunny and overcast days. From 5:00 to 9:00, the air temperature at measured positions in the gap was higher on overcast days than on sunny days; but from 9:00 to 19:00, it was opposite. The mean monthly air temperature was the highest in June, and the lowest in September. The maximum relative humidity appeared between 5:00 and 9:00 on sunny and overcast days, and occurred in the canopy border of western part of the gap, with the relative air humidity on overcast days being always higher than that on sunny days. The mean monthly relative humidity was the highest in July, and the lowest in June. The heterogeneity of PPFD was higher on sunny days than on overcast days, but the heterogeneities of air temperature and relative humidity were not obvious. The maximum PPFD, air temperature, and relative humidity were not located in the same positions among different months during growing season. For mean monthly PPFD and air temperature, their variation gradient was higher in and around the center of gap; while for mean monthly

  9. 红松阔叶混交林林隙土壤养分的空间异质性%Spatial Heterogeneity of Soil Nutrition in the Mixed Broad-Leaved Korean Pine Forest Gap

    Institute of Scientific and Technical Information of China (English)

    刘少冲; 段文标

    2011-01-01

    采用经典统计学和地统计学方法分析了小兴安岭阔叶红松混交林林隙表层土壤(0-10 cm)养分空间变异结构及其分布格局.结果表明:土壤pH值(CV=5.28%)和速效钾(CV=7.33%),呈弱变异性,其他土壤化学指标均表现为中等程度变异.土壤pH值、有机质、全氮、全磷、铵态氮、硝态氮、有效磷和速效钾变异函数曲线的理论模型符合球状模型.土壤养分的空间变异主要是由结构性因素引起的,且空间自相关程度均属中等(空间结构比均在25%以上).克里格法插值估计和各养分属性的等值线图表明,林隙表层土壤养分具有块状或连续分布的特点,不同的指标表现出不同的分布规律.%The spatial heterogeneity and distribution pattern in surface soil layer(0-10 cm) in mixed broad-leaved koren pine forest gap ir Xiao Xing'an Mountains were analysed by the methods of the traditional statistics and geostatistics. The results showed that. pH (CV= 5.28 %) and available potassium (CV= 7.33 %) showed weaker variability,other chemical indices exhibited moderate variability. The theoretical models of variation function curve of soil pH, organic matter, total nitrogen, total phosphorous, ammonium nitrogen, nitrate nitrogen, available phosphorous and available potassium were best described by exponential models. The spatial variability of soil nutrient primarily resulted from structural factors,and the spatial heterogeneity degree of these indices was moderate with spatial structural ratio above 25 %. Both Kriging interpolation method and the isoline maps of soil nutrients revealed that the spatial distributions of upper soil nutrients had the characteristic of patchy or continuous distribution, the spatial distribution of different indices were clearly different.

  10. 东灵山4种落叶阔叶次生林的物种组成与群落结构%Species composition and community structure of four deciduous broadleaved secondary forest in Dongling Mountain

    Institute of Scientific and Technical Information of China (English)

    李亮; 刘海丰; 白帆; 祝燕; 李广起; 李文超; 桑卫国

    2011-01-01

    植被的群落构成是决定森林演替方向的重要因素之一.辽东栎林(Quercus wutaishanica forest,QWF)、棘皮桦林(Betula dahurica forest,BDF)、胡桃楸林(Juglans mandshurica forest,JMF)与杂木林(mixed forest,MF)是东灵山地区4种典型的暖温带落叶阔叶次生林.为了更好地了解东灵山地区暖温带落叶阔叶次生林植被动态,我们对该4种林型的物种组成与群落结构进行了综合分析.参照巴拿马(Barro Colorado Island,BCI)50 ha热带雨林样地的技术规范,于2009年在北京东灵山地区以上4个林型中各建立了一块1 ha样地,对样地中所有胸径大于1 cm的木本个体进行了坐标定位和调查.结果表明,QWF样地有22种,属于20科20属;BDF样地共22种,属于16科18属;JMF样地30种,隶属于21科23属;MF样地19种,隶属于14科15属.从物种多度、平均胸径、胸高断面积和重要值等指标来看,各群落具有比较明显的优势种:4个样地所有树种的径级分布均旱倒"J"型,具有良好的更新层;共有树种的径级分布在不同样地有所不同,如辽东栎在QWF样地呈偏态分布,在BDF样地则为倒"J"型分布,而棘皮桦在QWF和BDF样地都呈正态分布,但是径级分布有所差异,表明径级结构与群落类型有密切关系.%The following are typical communities in the secondary deciduous broad-leaved forests in the Dongling Mountain area: Quercus wutaishanica forest (QWF), Betula dahurica forest (BDF), luglans mandshurica forest (JMF) and mixed forest (MF). Comprehensive research on species composition and community structure of these four forest types will contribute to a more thorough knowledge of the successional dynamics and ecological functions in warm temperate deciduous broad-leaved forests. Following the field protocol of the 50-ha plot on Barro Colorado Island in Panama, one l-ha plot was established in each of these forest types in Dongling Mountain in 2009. In these plots, all free-standing trees ≥1

  11. 帽儿山天然次生林主要阔叶树种叶量分布模拟%Simulation of Foliage Distribution for Major Broad-Leaved Species in Secondary Forest in Mao'er Mountain

    Institute of Scientific and Technical Information of China (English)

    卢军; 李凤日; 张会儒; 张守攻

    2011-01-01

    The spatial distribution of foliage is the fundamental composition of crown structure, moreover, it is convenient to understand the mechanism of the energy convert to biomass above-ground through the crown by evaluating the spatial distribution of foliage and researching the relationship between foliage and factors in individual trees and stand. In Mao' er Mountains of Heilongjiang Province, 30 permanent sample plots in secondary forest were established where 3 401 biomass of living branches from 176 stem analysis sample trees with 10 different broad-leaved species were measured, 2007. This study presents 10 individual tree models for the prediction of vertical distribution of living crown. The 3 parameters Chapman-Richards model was used to estimate the distribution of the crown biomasses between the lower and upper limits of the crown. In the models for the relative cumulative living crown, parameters estimate results show that all coefficiens of determination are high more than 0. 91 especially 0. 98 for birch. The highest relative height at which the foliage reached its maximum point was 0. 82 CL( crown length) for manchurian ash and the lowest was 0. 52 CL for cork tree. The peak points for other species were between these two values, e. G. 0. 66 CL for birch and 0. 78 CL for oak. The percentage of foliage for broad-leaved species in secondary forestry at the top crown (above 0. 3 CL)was very small, which in middle crown and below it(0. 4 CL -0. 8 CL)took about 60% -70% of total biomass, especially 72. 22% for birch, 72. 55% for poplar and the minimum was 57. 51% for manchurian ash, however at under-part of the crown for all species occupied about 10% of total foliage. The models can be used for the planning of harvesting operations, for the selection of feasible harvesting methods, and for the estimation of nutrient removals of different harvesting practices.%2007年,在黑龙江省帽儿山林区,设置30块天然次生林固定标准地,获取10

  12. Available Phosphorus in Forest Soil Increases with Soil Nitrogen but Not Total Phosphorus: Evidence from Subtropical Forests and a Pot Experiment

    OpenAIRE

    Xingzhao Liu; Wei Meng; Guohua Liang; Kun Li; Weiqiang Xu; Liujing Huang; Junhua Yan

    2014-01-01

    This paper aims to establish evidence for available phosphorous (AP) binding with total nitrogen (N) in subtropical forest soils. Soil organic carbon (SOC), total N, total phosphorous (P) and AP concentration were measured for three contrasting forest types in southern China: Masson pine forest (MPF), coniferous and broadleaved mixed forest (CBMF) and monsoon evergreen broadleaved forest (MEBF). A pot experiment with N addition was conducted to confirm the dominant factor to affect on soil AP...

  13. Effects of multiple environmental factors on CO2 emission and CH4 uptake from old-growth forest soils

    OpenAIRE

    H. J. Fang; G. R. Yu; Cheng, S. L.; Zhu, T. H.; Wang, Y. S.; Yan, J H; M. Wang; Cao, M; Zhou, M.

    2010-01-01

    To assess contribution of multiple environmental factors to carbon exchanges between the atmosphere and forest soils, four old-growth forests referred to as boreal coniferous forest, temperate needle-broadleaved mixed forest, subtropical evergreen broadleaved forest and tropical monsoon rain forest were selected along eastern China. In each old-growth forest, soil CO2 and CH4 fluxes were measured from 2003 to 2005 applying the static opaque chamber and gas chromatography tec...

  14. Hypoxylon species on beech and other broadleaves

    Directory of Open Access Journals (Sweden)

    Milijašević Tanja

    2004-01-01

    Full Text Available Fungi in the genus Hypoxylon cause wood decay and most of them are saprophytes on dead wood or parasites of weakness. The following species in this genus were identified in this study performed at several localities in Serbia and Montenegro: H. deustum, H. fragiforme, H. nummularium, H. multiforme, H. rubiginosum and H. fuscum. Among them the most significant species is H. deustum, the fungus causing root and butt rot of standing beech trees. It was recorded from all coppice and high forests of beech. This paper presents the morphological characteristics of the recorded fungi their range, plant hosts and significance.

  15. Effects of litter cover on soil evaporation in broadleaved Korean pine forest%枯落物覆盖对阔叶红松林土壤蒸发的影响

    Institute of Scientific and Technical Information of China (English)

    林茂森; 关德新; 金昌杰; 王安志; 牛丽华; 吴家兵; 袁凤辉

    2012-01-01

    通过对枯落物覆盖下森林土壤蒸发的观测,研究了不同干重及类型的枯落物对土壤蒸发的影响,及其与含水率的关系.结果表明:土壤含水率相同,枯落物覆盖量越大,土壤蒸发量越小;不同类型的枯落物对土壤蒸发的抑制作用不同,在相同干重的枯落物覆盖下,未分解、半分解和分解的枯落物对土壤蒸发的抑制能力依次减弱.土壤蒸发量与枯落物质量呈对数关系.随土壤含水率的降低,土壤蒸发量减少,含水率在41% ~38%时,每下降1%,75 g、45 g、15 g枯落物覆盖下的土壤蒸发量依次减少2.38 g、1.43 g、1.30 g,且在土壤含水率下降过程中,覆盖的枯落物分解程度越高,土壤蒸发速率降低越不显著.%By observing the soil evaporation under litter cover in broadleaved Korean pine forest, this paper studied the effects of the litters with different dry weights and at different decomposition stages on the soil evaporation as well as the relations between the soil evaporation and soil moisture content. The results showed that at the same soil moisture contents, the larger the litter cover, the smaller the soil evaporation was. The mitigation effect of the litter cover on the soil respiration differed with the decomposition stage of the litters, being decreased in the order of un-decomposed, semi-decomposed, and decomposed litters. There existed a logarithm relationship between the soil evaporation and the litter mass. With the decrease of soil moisture content, the soil evaporation reduced. When the soil moisture content was within the range of 38% -41% , each 1% decline of the moisture content induced the soil evaporation under the covering of 75 g, 45 g, and 15 g litters decreased by 2. 38 g, 1.43 g, and 1.30 g, respectively, and, during the declining of the moisture content, the higher the decomposition rate of the litters, the lesser the decrement of the soil respiration.

  16. Experiment on Ecological Firebreak of Broadleaved-oriented Transformation of Coniferous Forest%针叶林阔叶化改造的森林生态防火效果初报

    Institute of Scientific and Technical Information of China (English)

    徐高福

    2009-01-01

    结合森林生态防火,引入木荷、苦槠、青冈、石栎、枫香等耐火目的树种对马尾松和杉木林退化系统进行阀叶化改造.在千岛湖区进行杉木间伐补植木荷、枫香,杉木萌芽林补植苦槠、青冈,马尾松林下补植枫香、青冈或苦槠、石栎四种不同阔叶化改造试验,3年后的调查测定结果表明:通过改造,优化了林分结构,马尾松阔叶化改造促进生态恢复的速度更为迅速.改造林分内枯落物比针叶林少,而枯落物含水率高;土壤含水率则因立地条件而异.阔叶化改造后具有明显提高生物多样性和防火效果及一定的涵养水源、保持水土作用.通过针叶林阔叶化改造,调整树种的组成结构、可燃物的空间分布,改善林地环境,以森林的片状控制代替林带控制,全方位有效控制森林火灾,在当前可持续发展和生态环境改善日益重视的社会背景与发展趋势下,具有推广应用前景.%Experiment on transformation of degraded pine and Chinese fir forest was conducted by planting fire-resistant tree species such as Schima superba, Castanopsis sclerophylla, Cyclobalanopsis glauca, Lithocarpus glaber, Liquidambar formosana. Four experiment plots were selected for filling-up of S. superba and L. formasana after intermediate cutting of Cunninghamia lanceolata in Qiandaohu, Zhejiang province, for filling-up of C. sclerophylla and C. glauca under sprout of C. lanceolata, for filling-up of L. formosana and C. glauca or C. sclerophylla and L. glaber under Pinus massoniana forest. Investigation in three years later resulted that transformation of pine forest had faster ecological recovery. Transformed forest had less litter with higher moisture content than coniferous forest. Moisture content in soil of each plot varied in accordance of site conditions. Broadleaved-oriented transformation could evidently increase biodiversity and firebreak effect, as well as water and soil conservation.

  17. 我国东北4种常见阔叶乔木物候对气候变化的响应%Response of 4 Common Broad-Leaved Arbors Phenology to Climate Change in the Northeast China

    Institute of Scientific and Technical Information of China (English)

    裴顺祥; 郭泉水; 辛学兵; 刘玮; 洪明

    2011-01-01

    物候现象是指示气候及自然环境变化的重要指标(Pe(n)uelas et al.,2001;Moresette et al.,2009).自然物候记录可以提供全球环境变化最直接和最有效的证据.已有研究结果表明,受全球气候变化影响,1952-2000年地中海地区(Pe(n)uelas et al.,2001)、1851-1994年匈牙利(Walkovszky,1998)、1936-1998年美国Wisconsin地区(Bradley et al.,1999)和1970-1999年美国华盛顿地区(Abu-Asab et al.,2001)的许多植物花期提前了1个星期左右;中国北纬33°左右地区植物的早春物候每10年提前1.1 ~4.3天,晚春物候提前1.4~5.4天(Zheng et al.,2006).%In order to reveal the response of four broad - leaved arbors to climate change, we studied relationships between interannual variations of air temperature and various phenophases (I.e., seasonal biological events) of broad-leaved arbors species ( Betula platyphylla, Juglans mandshurica, Ulmus pumila and Morus alba ) in the Harbin, based on meteorological data from 1951 -2008 and phenological data from 1963 -2008. Results showed that the air temperature in Harbin had an increasing trend from 1951 to 2008, especially after 1978. The increase of the annual minimum temperature was greater than that of the annual maximum temperature and annual mean temperature. Annual precipitation slightly increased, but not significantly. In the period of 1963 -2008, bud burst, beginning of leaf expansion and first flowering of the 4 species all shifted to 5. 7 d, 10. 2 d and 7. 9 d earlier, respectively, and end of leaf - falling was delayed for 7. 5 d. The pattern of phenological change was consistent with that of air temperature change. The phenophases earlier or later was mainly subjected to air temperature, especially the mean temperature of the same month and previous month when phenophase began. The phenophase had little correlation with the precipitation. When the mean temperature in March rose up by 1 ℃ , Betula platyphylla, Juglans mandshurica, Ulmus pumila

  18. Composition and Spatial Pattern of Tree Seedlings in Korean Pine Broadleaved Forest in Changbai Mountains%长白山阔叶红松林乔木树种幼苗组成与空间分布

    Institute of Scientific and Technical Information of China (English)

    陈贝贝; 赵秀海; 倪瑞强; 黄珍

    2012-01-01

    A study was performed to analyze species composition and spatial distribution of tree seedlings based on a permanent plot in Korean pine broadleaved forest in Changbai Mountains as well as field surveys of seedlings and adult trees in the plot. The relationship between mature trees and seedlings was further assessed. Results showed that a total of 1 802 trees were recorded in this plot, among which there were 9 332 tree seedlings. The numbers of Fraxinus mandshurica, Tilia amurensis, Acer mono, A. Tegmentosum, A. Ukurunduensi, A. Pseudo-sieboldianum, A. Barbinerve, Pinus koraiensis, Quercus mongolica, and Maackia amurensis seedlings were 6 986, 832, 394, 250, 123, 289, 438, 3, 10, and 7, respectively. Seedlings of dominate tree species were characterized by clumped distribution on the scales less than certain critical points. When the scales were enlarged beyond these points, seedlings were randomly dispersed. Analysis of spatial relationship showed an unobvious correlation between seedlings of dominate tree species and their mature trees.%以长白山阔叶红松林永久样地为平台,基于该群落幼苗、大树的调查数据,对乔木树种幼苗组成进行初步分析,并运用点格局分析法,对群落中幼苗及幼苗与大树相关关系进行研究.结果表明:该群落物种组成较丰富,共调查到乔木树种大树1 802株,隶属于20种,幼苗9332株,隶属于10种,这些幼苗也是样地内主要乔木树种的组成成分.在1 hm2样地内,共调查到水曲柳(Fraxinus mandshurica)幼苗6 986株,紫椴(Tilia amurensis)幼苗832株,色木槭(Acer mono)幼苗394株,青楷械(Acer tegmentosum)幼苗250株,花楷械(Acer ukurunduensis)幼苗123株,假色槭(Acer pseudo-sieboldianum)幼苗289株,簇毛槭(Acer barbinerve)幼苗438株,红松(Pinus koraiensis)幼苗3株,蒙古栎(Quercus mongolica)幼苗10株,怀槐(Maackia amurensis)幼苗7株.从幼苗的空间分布格局来看,优势树种幼苗在小尺度上呈现聚集分布,随着尺

  19. Seasonal ozone uptake by a warm-temperate mixed deciduous and evergreen broadleaf forest in western Japan estimated by the Penman–Monteith approach combined with a photosynthesis-dependent stomatal model

    International Nuclear Information System (INIS)

    Canopy-level stomatal conductance over a warm-temperate mixed deciduous and evergreen broadleaf forest in Japan was estimated by the Penman–Monteith approach, as compensated by a semi-empirical photosynthesis-dependent stomatal model, where photosynthesis, relative humidity, and CO2 concentration were assumed to regulate stomatal conductance. This approach, using eddy covariance data and routine meteorological observations at a flux tower site, permits the continuous estimation of canopy-level O3 uptake, even when the Penman–Monteith approach is unavailable (i.e. in case of direct evaporation from soil or wet leaves). Distortion was observed between the AOT40 exposure index and O3 uptake through stomata, as AOT40 peaked in April, but with O3 uptake occurring in July. Thus, leaf pre-maturation in the predominant deciduous broadleaf tree species (Quercus serrata) might suppress O3 uptake in springtime, even when the highest O3 concentrations were observed. -- Highlights: • We estimate canopy-level O3 uptake in a warm-temperate mixed forest in Japan. • The Penman–Monteith approach is compensated by a photosynthesis-dependent model. • Stomatal conductance can be estimated, even in a partly-opened or wet canopy. • The estimated O3 dose peaks in summer though O3 exposure peaks in spring. -- Estimation of seasonal O3 uptake over a mixed-temperate forest compensated by a photosynthesis-dependent stomatal model

  20. 酸铝胁迫下常绿杨根冠超微结构变化%Acid and Aluminum Stress on Root Cap Ultrastructure of Evergreen Poplar Clone

    Institute of Scientific and Technical Information of China (English)

    钱莲文; 吴文杰

    2014-01-01

    The climate of China's subtropical area is warm humid, abundant rainfall, is fast-grown forest base. Forest soil is partial acidic or acidic, rich in aluminum. Which easily cause aluminum poisoning for the plant.A-61/186 (Populus x euramericana CV.) is the semi-evergreen poplar clone cultivated by Australian doctor L.D.Pryor, which female parent is Populus deltoids Marsh from the southern United States, and the male parent is originated Populus nigra CV. of Chile. It is one of three evergreen poplar clones and suitable for tropical and subtropical areas were introduced from Pakistan in 1987 by Mr. Shikai Zheng, who is a researcher of state forestry administration P.R.China. The changs in Ultrastructure of root cap cells were studied under controlled concentration and acting time by evergreen poplar clone A-61/186 (Populus euramericana CV.), using hydroponic experiment acid aluminum stress. Root cap cell ultrastructure were observed and shooting under the transmission electron microscopein in 30 d, 60 d and 90 d. Acid concentration and acted time under aluminum stress on its ultrastructure were explored. Used for revealing changes of poplar root cap cells ultrastructure under aluminum toxicity, then for aluminum toxicity submicroscopic level evaluation of root cap cells. The results showed that cellwall was dissolved and brokend with the increasing of stress concentration, and Al content 3 was obvious . Cell matrix changed from gel state to Scattered debris. Starch grain declined in the number and amyloplasts increased in the number. While the core deviation of starch grain heap were changed from non-clear to clear trend. With the development of acting time, Starch grain were sharply reduced in Al content 2 under 60 d stresse and amyloplasts in Al conten 3 under 90 d stress. The core of starch grain heap was not deviated obviously.%中国的亚热带地区气候温暖湿润、雨量充沛,是中国速生丰产林基地,森林土壤多呈偏酸性和酸性,为

  1. Regeneration and restoration of broad-leaved Korean pine forests in Lesser Xing′an Mountains of Northeast China%中国东北小兴安岭阔叶红松林更新及其恢复研究

    Institute of Scientific and Technical Information of China (English)

    李俊清; 李景文

    2003-01-01

    研究了中国东北小兴安岭地区阔叶红松林的更新和红松的生长及其影响因素.研究结果表明由于成树树冠的遮蔽作用所导致的光照减少是制约幼树生长和存活的关键因素.阔叶红松林是该区最典型和稳定的植被类型,但是在过去的50a中,由于皆伐和更新不良导致了它的分布面积和蓄积量的减少.阔叶红松林是地带性"顶极"植被,并通过具有连续性年龄结构的树种有规律的替代和演替过程中不同阔叶树种组成而处于优势地位.这种林型无疑应作为一种重要的基因库加以保护.次生阔叶林是在阔叶红松林受干扰后出现的,但它的种类组成简单,而且结构也很不稳定.因此,必须对现有的林分结构加以调整以利于林分的长期稳定和高产.同时,提出了红松阔叶林的恢复和重建的经营方式.%This paper studied the regeneration and growth of Korean pine (Pinus koraiensis) and the influencing factors in broad-leaved Korean pine forests in Lesser Xing′an Mountains of Northeast China. Light solar radiation decrement within the forest stand overshadowed by the mature tree canopy was considered as the key factor that limited the seedling growth and survival. Broad-leaved Korean pine forest is the most typical and the most stable vegetation type in the region, but its area and stocking have been decreased in the last 50 years caused by the over-cutting and poor regeneration. Broad-leaved Korean pine forest is the zonal "climax" vegetation type and remains dominant through the regular replacement of succeeding age classes of tree species and the succession between different assemblages of species. This forest type should, undoubtedly, be conserved so as to preserve an important gene pool for future generations. The secondary deciduous forest occurring after disturbance of the broad-leaved Korean pine forest is much simpler in composition and highly unstable in structure. Forest structure must

  2. Hydrological characteristics of litter in different forest succession stages at Liuxihe Watershed, southern China

    Institute of Scientific and Technical Information of China (English)

    Zhuowen ZHANG; Yunfei LEI; Kaijun SU; Guang WANG; Dongyun WANG; Hongyan MA

    2009-01-01

    The hydrological characteristics of litter in four different forest succession stages, i.e., a Pinus massoniana forest, a mixed conifer and broad-leaved forest with conifer being the dominant species, a mixed conifer and broad-leaved forest with deciduous trees as dominant species, and an evergreen broad-leaved forest, have been studied by means of substituting space for time. The results show that while a community is developing to a zonal climax, the amount of litter becomes larger and its decomposition intensity becomes stronger; there is a positive relation between its water-holding capacity and velocity and its community maturity for the halfdecomposed litter layer.

  3. Foliage Respiratory Characteristics of 5 Evergreen Tree Species Native to the Temperate Deciduous Evergreen Mixed Forest of North American%北美地区温带针阔叶混交林5个常绿树种叶片呼吸特性

    Institute of Scientific and Technical Information of China (English)

    李熙萌; 李征珍; 刘海鸥; 石莎; 冯金朝

    2016-01-01

    Obiective]This study aimd to investigate the interspecies variation in leaf respiratory characteristics and its underpinning factors,and quantify the impacts of such variation on the estimation of leaf carbon flux. [Method]Five evergreen species of Chamaecyparis thyoides,Pinus rigida,P. resinosa,P. strobes and Tsuga canadensis,which are common to temperate coniferous-broadleaf forest of Northern America,were chosen in this study. Leaf light photosynthetic response curves,and CO2 response curves and respiration temperature response curve as well as leaf morphological and biochemical traits were measured. Using linear regression, we analyzed the relationship among leaf respiratory characteristics,leaf structural,biochemical and physiological attributes. A coupled stomata-photosynthesis model was adopted to simulate the dynamic of leaf level carbon flux during the experimental period. [Result]Our results showed:(1) Interspecific difference was found in leaf area-based nitrogen content(Narea),but not in mass-based nitrogen content (Nmass). Likewise,there was obvious difference in the area-based respiration rate(Rnarea) was highly regulated by leaf morphological traits; 2 ) Leaf respiration rate could be well explained by its nitrogen content. Moreover,a positive relationship was also found among R,maximum net carbon assimilation rate(A) and specific leaf area(SLA); 3) Light inhibited leaf dark respiration in all species investigated,with the ratio of mitochondrial respiration under daylight to dark respiration rate(RL/Rn) spanning from 0. 39 to 0. 90. The RL/Rn ratio was positively correlated with maximum oxygenation rate( vo1500 ) and carboxylation rate( vc1500 ) of Rubisco. In addition,strong correlation was also found between leaf Rn and RL;4) Q10 of dark respiration ranged from 1. 44 ~2. 24. Activation energy of respiration(E0) varied among species,but the variation was marginal;5) With using fixed Q10 and assuming RL =Rn affected the estimation of leaf carbon

  4. Unexpected Presence of Graminan- and Levan-Type Fructans in the Evergreen Frost-Hardy Eudicot Pachysandra terminalis (Buxaceae): Purification, Cloning, and Functional Analysis of a 6-SST/6-SFT Enzyme1[W

    Science.gov (United States)

    Van den Ende, Wim; Coopman, Marlies; Clerens, Stefan; Vergauwen, Rudy; Le Roy, Katrien; Lammens, Willem; Van Laere, André

    2011-01-01

    About 15% of flowering plants accumulate fructans. Inulin-type fructans with β(2,1) fructosyl linkages typically accumulate in the core eudicot families (e.g. Asteraceae), while levan-type fructans with β(2,6) linkages and branched, graminan-type fructans with mixed linkages predominate in monocot families. Here, we describe the unexpected finding that graminan- and levan-type fructans, as typically occurring in wheat (Triticum aestivum) and barley (Hordeum vulgare), also accumulate in Pachysandra terminalis, an evergreen, frost-hardy basal eudicot species. Part of the complex graminan- and levan-type fructans as accumulating in vivo can be produced in vitro by a sucrose:fructan 6-fructosyltransferase (6-SFT) enzyme with inherent sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan 6-exohydrolase side activities. This enzyme produces a series of cereal-like graminan- and levan-type fructans from sucrose as a single substrate. The 6-SST/6-SFT enzyme was fully purified by classic column chromatography. In-gel trypsin digestion led to reverse transcription-polymerase chain reaction-based cDNA cloning. The functionality of the 6-SST/6-SFT cDNA was demonstrated after heterologous expression in Pichia pastoris. Both the recombinant and native enzymes showed rather similar substrate specificity characteristics, including peculiar temperature-dependent inherent 1-SST and fructan 6-exohydrolase side activities. The finding that cereal-type fructans accumulate in a basal eudicot species further confirms the polyphyletic origin of fructan biosynthesis in nature. Our data suggest that the fructan syndrome in P. terminalis can be considered as a recent evolutionary event. Putative connections between abiotic stress and fructans are discussed. PMID:21037113

  5. Unexpected presence of graminan- and levan-type fructans in the evergreen frost-hardy eudicot Pachysandra terminalis (Buxaceae): purification, cloning, and functional analysis of a 6-SST/6-SFT enzyme.

    Science.gov (United States)

    Van den Ende, Wim; Coopman, Marlies; Clerens, Stefan; Vergauwen, Rudy; Le Roy, Katrien; Lammens, Willem; Van Laere, André

    2011-01-01

    About 15% of flowering plants accumulate fructans. Inulin-type fructans with β(2,1) fructosyl linkages typically accumulate in the core eudicot families (e.g. Asteraceae), while levan-type fructans with β(2,6) linkages and branched, graminan-type fructans with mixed linkages predominate in monocot families. Here, we describe the unexpected finding that graminan- and levan-type fructans, as typically occurring in wheat (Triticum aestivum) and barley (Hordeum vulgare), also accumulate in Pachysandra terminalis, an evergreen, frost-hardy basal eudicot species. Part of the complex graminan- and levan-type fructans as accumulating in vivo can be produced in vitro by a sucrose:fructan 6-fructosyltransferase (6-SFT) enzyme with inherent sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan 6-exohydrolase side activities. This enzyme produces a series of cereal-like graminan- and levan-type fructans from sucrose as a single substrate. The 6-SST/6-SFT enzyme was fully purified by classic column chromatography. In-gel trypsin digestion led to reverse transcription-polymerase chain reaction-based cDNA cloning. The functionality of the 6-SST/6-SFT cDNA was demonstrated after heterologous expression in Pichia pastoris. Both the recombinant and native enzymes showed rather similar substrate specificity characteristics, including peculiar temperature-dependent inherent 1-SST and fructan 6-exohydrolase side activities. The finding that cereal-type fructans accumulate in a basal eudicot species further confirms the polyphyletic origin of fructan biosynthesis in nature. Our data suggest that the fructan syndrome in P. terminalis can be considered as a recent evolutionary event. Putative connections between abiotic stress and fructans are discussed. PMID:21037113

  6. Developing and Applications of a Gap-filling Model for Eddy covariance CO2 Flux: Evaluating the Net Ecosystem Exchange of a Subtropical Evergreen Forest after a Server Environmental Disturbance

    Science.gov (United States)

    Li, M.; CHEN, Y.

    2013-12-01

    Successful eddy covariance (EC) applications often challenged by several difficulties, including non-ideal micrometeorological conditions, instrument failures, measurement limitations, and lacking consistent footprint area. Consequently, the resultant gaps in the time series of EC measurements limit the use of these dataset and cause the uncertainty in a range of 1 to 2 ton C/ha/yr for evaluating net ecosystem exchange (NEE) after different CO2 gap-filling procedures (Saigusa et al., 2013). It is crucial to develop a suitable gap-filling model for EC CO2 flux observations to provide reliable long-term surface fluxes for numerous applications. In this study, a gap-filling model was developed for EC CO2 flux by linking the gap-filled water vapor fluxes estimated by Chen et al. (2012) and the optimal nearest QC/QA passed CO2 fluxes for interpolating CO2 flux gaps. Considering the atmosphere characteristics and controlling mechanisms of CO2 fluxes, measured hydrometerological and flux data at the Lien-Hua-Chih (LHC) experimental watershed were separated into clear sky and cloudy/nighttime conditions. The successful applications of our gap-filling approaches were examined with various sizes of artificial CO2 gaps. Without any significant environmental disturbance in 2012, the annual NEE of this subtropical evergreen forest was estimated around 6.7 ton C/ha/yr as the amount of terrestrial CO2 sequestration. The effect of sever Typhoon Soulik (11-13, July, 2013) invasion on several ecosystem variables, such as changes of intrinsic water use efficiency, leaf area index, and canopy storage capacity, will be investigated to propose indicators for estimating NEE variations in association with environmental disturbances at this forest ecosystem.

  7. 长荣汽贸人力资源管理实践对组织绩效影响研究%Research the Impact of Human Resource Management Practices of Evergreen Group on Organizational Performance

    Institute of Scientific and Technical Information of China (English)

    聂攀科; 田雪莹

    2015-01-01

    In the face of fierce competition, talent management has caused widespread concern in the enterprise. The paper with the evergreen Qimao company data from 2008 to 2013, made an empirical analysis of the influence of human resource management practices on firm performance. The results of the study show that, only part of the practice of performance in human resource management has a significant effect. And different practical impact on the financial performance and non-financial performance is of different degree. The effects of training on organizational performance is maximum. The influence degree of the practice of human resource management system on financial performance is more than the degree of the influence of non financial performance.%面对激烈的外部竞争环境,人才的管理逐渐引起了企业的广泛关注。利用长荣汽贸公司2008—2013年的数据,实证检验了人力资源管理实践对企业绩效的影响。研究结果表明,人力资源管理中只有部分实践对绩效有显著影响,并且不同的实践对财务绩效和非财务绩效的影响程度不同,其中员工培训对组织绩效的影响最大。此外,人力资源管理实践系统对财务绩效的影响程度大于其对非财务绩效的影响程度。

  8. Ultrastructure of minor-vein phloem and assimilate export in summer and winter leaves of the symplasmically loading evergreens Ajuga reptans L., Aucuba japonica Thunb., and Hedera helix L.

    Science.gov (United States)

    Hoffmann-Thoma, G; van Bel, A J; Ehlers, K

    2001-01-01

    Minor-vein ultrastructure and sugar export were studied in mature summer and winter leaves of the three broadleaf-evergreen species Ajuga reptans var. artropurpurescens L., Aucuba japonica Thunb. and Hedera helix L. to assess temperature effects on phloem loading. Leaves of the perennial herb Ajuga exported substantial amounts of assimilates in form of raffinose-family oligosaccharides (RFOs). Its minor-vein companion cells represent typical intermediary cells (ICs), with numerous small vacuoles and abundant plasmodesmal connectivity to the bundle sheath. The woody plants Hedera and Aucuba translocated sucrose as the dominant sugar species, and only traces of RFOs. Their minor-vein phloem possessed a layer of highly vacuolated cells (VCs) intervening between mesophyll and sieve elements. Depending on their location and ontogeny, VCs were classified either as companion or parenchyma cells. Both cell types showed symplasmic continuity to the adjacent mesophyll tissue although at a lower plasmodesmal frequency compared to the Ajuga ICs. p-Chloromercuribenzenesulfonic acid did not reduce leaf sugar export in any of the plants, indicating a symplasmic mode of phloem loading. Winter leaves did not show symptoms of frost injury, and the vacuolar pattern in ICs and VCs was equally prominent in both seasons. Starch accumulation as a result of reduced phloem loading was not observed to be triggered by low temperature. In contrast, high amounts of starch were found in mesophyll and bundle-sheath cells of summer leaves. Physiological data on season-dependent leaf exudation showed the maintenance of sugar export in cold-acclimated winter leaves. PMID:11216844

  9. Composition and Diversity of Ground-dwelling Beetle (Coleoptera) Along a Succession Gradient in Broad-leaved and Korean Pine Mixed Forest in the Changbai Mountains, China%长白山阔叶红松林不同演替阶段地表甲虫组成和多样性

    Institute of Scientific and Technical Information of China (English)

    贾玉珍; 赵秀海; 孟庆繁

    2011-01-01

    鞘翅目昆虫多样性的变化是森林演替过程的综合反映.于2007年6~8月采用陷阱诱捕法对长白山阔叶红松林带不同演替阶段地表甲虫物种组成和数量进行了调查,并分析了该地区不同演替阶段地表甲虫多样性的变化趋势及主要生境因子对地表甲虫群落的影响.结果显示,长白山阔叶红松林内共诱捕地表甲虫23种,共511头,隶属于10个科.其中个体数最多的为埋葬甲科,物种数最多的为步甲科,优势类群为步甲科和埋葬甲科.不同演替阶段中,次生白桦林地表甲虫物种数和个体数高于原始阔叶红松林和次生针阔混交林,3个生境内地表甲虫多样性无显著差别.地表甲虫高峰期为7月份.不同演替阶段的样地中物种统计数量都没有达到渐进线,次生白桦林样地中实际物种只占估计值的67%,其它2个生境实际物种数都在物种估计值的95%区间范围内,略低于平均值.3个生境的地表甲虫种-多度曲线无显著差异,符合对数分布.胸高断面积和土壤湿度对地表甲虫的分布有显著影响,它们可以解释99.2%的物种与环境之间的关系.%Some studies showed a mixed response of ground-dwelling beetle to forest regeneration and succession.In order to prove the change trend of beetle diversity following the gradient of succession and discuss the effect of environment factors on beetle community,a study of ground-dwelling beetle in three habitats along a succession gradient was carried out from June to August 2007 in the broad-leaved and Korean pine mixed forest in the Changbai Mountains,China using pitfall trapping.Total of 511 individuals and 23 species were identified.Carabidae and Silphidae were dominant families with maximum of species and individuals,respectively.The numbers of species and individuals in the secondary birch forest were greater than those in the secondary conifer and broad-leaved mixed forest and original broad-leaved and

  10. Physical and Chemical Characteristics of Soil of Cunninghamia lanceolata Conifer-broadleaved Mixed Forest with Different Age%南亚热带不同林龄杉木针阔混交林土壤理化性质分析

    Institute of Scientific and Technical Information of China (English)

    苏木荣; 张卫强; 冼伟光; 唐洪辉; 殷祚云; 陈伟光; 许雄坚; 盘李军

    2014-01-01

    森林发育对土壤理化性质有着重要的影响。在南亚热带,以杉木皆伐改造林地3个林龄段(3~5 a、7~9 a和10~11 a)的针阔混交林为研究对象,研究了土壤理化性质的变化特征以及不同理化性质指标之间的相关性。结果表明,土壤容重、总孔隙度、毛管孔隙度随林龄的增加呈上升趋势,而非毛管孔隙度和土壤通气度表现为先升高后降低。土壤pH值、有机质、全N、全P、全K、水解N、速效K随林龄的增加呈现出先降低后升高的趋势,而有效P处于下降的趋势。相关分析表明,不同林龄段针阔混交林的土壤容重主要取决于土壤有机质含量,自然含水量主要取决于毛管孔隙度;土壤有机质含量与全N和水解N相关性最高,土壤中绝大部分N素以有机态存在;而土壤有效P含量主要取决于土壤有机质含量,同时受土壤pH值影响也较大。%Forest development has great influence on physical and chemical characteristics of soil.A study was conducted on variation of soil physical and chemical characteristics and correlations between these indicators in conifer-broadleaved mixed plantations in southern subtropical region.These conifer-broadleaved mixed plantations which developed from clearcutting Cunninghamia lanceolata plantation were in different age group (3-5 ,7-9 and 1 0-1 1 years old).The results were as following:soil bulk density,total porosities and capillary porosities in-creased,while non-capillary porosities and soil aeration capacity first increased and then decreased with increasing forest age.The pH of soil,soil organic matter,total N,total P,total K,hydrolysable N,available K first de-creased and then increased,while available P decreased with increasing forest age.The correlation analysis showed that soil bulk density depended on soil organic matter content for conifer-broadleaved mixed forest in southern sub-tropical region,while soil natural water

  11. [Soil physical and chemical characteristics under different vegetation restoration patterns in China south subtropical area].

    Science.gov (United States)

    Kang, Bing; Liu, Shi-rong; Cai, Dao-xiong; Lu, Li-hua; He, Ri-ming; Gao, Yan-xia; Di, Wei-zhi

    2010-10-01

    This paper studied the change of soil physical and chemical properties under eleven vegetation restoration patterns (1 kind of secondary forest, 2 kinds of pure coniferous plantations, 5 kinds of evergreen broad-leaved plantations, 2 kinds of conifer and broad-leaved mixed plantations, and 1 kind of shrub) typical in Daqingshan of Guangxi. Obvious differences were observed in the soil physical and chemical properties under different vegetation restoration patterns. The soil physical properties were better in secondary forest but poorer in pure conifer plantations. Conifer and broad-leaved mixed plantations had lower soil bulk density, and their soil total porosity and water-holding capacity were higher than those in pure plantations. There were no significant differences in the soil porosity among the 5 evergreen broad-leaved plantations. Except that of soil total K, the contents of soil nutrients in secondary forest were higher than those in plantations, and the soil C/N ratio and pH value were relatively lower. Comparing with shrub, the 9 plantations had an obvious change in their soil nutrient contents, e. g. , the increase of soil total N and available K. The 2 pure coniferous plantations had lower soil nutrient contents, but after mixed planted with evergreen broad-leaved trees, their soil nutrient contents increased markedly, and the soil C/N ratio decreased. PMID:21328932

  12. Can native clonal moso bamboo encroach on adjacent natural forest without human intervention?

    Science.gov (United States)

    Bai, Shangbin; Wang, Yixiang; Conant, Richard T.; Zhou, Guomo; Xu, Yong; Wang, Nan; Fang, Feiyan; Chen, Juan

    2016-09-01

    Native species are generally thought not to encroach on adjacent natural forest without human intervention. However, the phenomenon that native moso bamboo may encroach on surrounding natural forests by itself occurred in China. To certificate this encroaching process, we employed the transition front approach to monitor the native moso bamboo population dynamics in native Chinese fir and evergreen broadleaved forest bordering moso bamboo forest in Tianmu Mountain Nature Reserve during the period between 2005 and 2014. The results showed that the bamboo front moved toward the Chinese fir/evergreen broadleaved stand with the new bamboo produced yearly. Moso bamboo encroached at a rate of 1.28 m yr‑1 in Chinese fir forest and 1.04 m yr‑1 in evergreen broadleaved forest, and produced 533/437 new culms hm‑2 yr‑1 in the encroaching natural Chinese fir/evergreen broadleaved forest. Moso bamboo coverage was increasing while adjacent natural forest area decreasing continuously. These results indicate that native moso bamboo was encroaching adjacent natural forest gradually without human intervention. It should be considered to try to create a management regime that humans could selectively remove culms to decrease encroachment.

  13. Vegetation and climate changes in the Changjiang (Yangtze River) Delta, China, during the past 13,000 years inferred from pollen records

    Science.gov (United States)

    Yi, Sangheon; Saito, Yoshiki; Zhao, Quanhong; Wang, Pinxian

    2003-06-01

    A high-resolution pollen record from 2 boreholes from the Changjiang (Yangtze River) delta shows a series of well-defined changes in vegetation and climate over the last 13,000 yr. In latest Pleistocene to early Holocene time (12,900- 10,300 cal yr BP), pollen dominated by the xerophytic herb Artemisia and common conifers indicate coniferous forest and grasslands and a cool, dry climates, possibly represented by the Younger Dryas. From 10,300 to 9000 cal yr BP, a warm, wet climate fostered the development of mixed broadleaved evergreen-deciduous forests to grow on the grasslands and surrounding hills and uplands. From 9000 to 7600 cal yr BP, the dominance of conifers and the reduction in broadleaved evergreen trees pollen suggest cool, dry conditions. The mid-Holocene "hypsithermal" (7600- 4800 cal yr BP) is represented by a large expansion of subtropical evergreen-deciduous broadleaved forests. Between 4800 and 1300 cal yr BP, which corresponds to a Neoglacial period elsewhere, conifers are dominant, along with common herbs, whereas the area with broadleaved evergreen trees shrink under the cool, dry conditions. The first occurrence of Fagopyrum pollen at 4500 cal yr BP suggests human influence. The significant change in arboreal and herbaceous pollen after 1300 cal yr BP reflects widespread intensive human influence.

  14. 不同生境中杉阔混交林物种多样性特征初步研究%Primary study on the characteristics of species diversity in Chinese-fir and broad-leaved mixed forests in different habitats

    Institute of Scientific and Technical Information of China (English)

    黄世国; 林思祖; 曹光球; 吴淑芳; 陈建宇

    2001-01-01

    The categorization of different habitat types was done with principal component analysis and dynamical clustering based on parameters of the habitat. In addition, the quantitative characteristics of tree organization in Chinese fir and broad-leaved forests in different habitat types were analyzed. The results showed that: the characteristics of main parameters of habitat were distinctly different in different habitat and the dominant species and relative importance values were also different. The total number of species, species diversity, and community evenness of tree organization were different. The influence of altitude on the total number of species and on their ecological dominance was highly significant. Slope-exposure influenced the number of unit more significantly in certain degree. Altitude and slope-exposure had no influence on the ecological dominance of trees in different habitats. The protection of diversity in Chinese-fir and broad-leaved mixed forest in different habitats should be emphasized.%根据生境因子应用主分量分析和动态聚类方法进行生境的划分,在此基础上分析不同生境中杉阔混交林群落数量特征。结果表明:不同生境中植物群落的主要优势种组成不一,其重要值也不同。不同生境中植物群落乔木层的物种数目、物种多样性、群落均匀度均有较大差异。海拔对不同生境中植物群落乔木层的物种数目、物种多样性和群落均匀度有很大影响,坡向则对个体总数和种类数量的影响较大。海拔和坡向对不同生境中植物群落乔木层生态优势度则无明显影响。应该重视不同生境中杉阔混交林多样性的保护。

  15. Genetic diversity of Lithocarpus harlandii populations in three forest communities with different succession stages

    Institute of Scientific and Technical Information of China (English)

    Jianhui LI; Zexin JIN; Wenyan LOU; Junmin LI

    2008-01-01

    By using random amplified polymorphic DNA (RAPD) technique,this paper studied the genetic diversity and genetic differentiation of Lithocarpus harlandii populations in three forest communities (con-iferous forest, coniferous and broad-leaved mixed forest, and evergreen broad-leaved forest) with different succes-sion stages in Tiantai Mountain in Zhejiang Province.The results showed that a total of 173 repetitive loci were produced in 60 individuals of L. Harlandii by 12 random primers, among which, 152 loci were polymorphic, and the total percentage of polymorphic loci was 87.86%. The average percentage of polymorphic loci of the popula-tions was 65.32%, and their total genetic diversity estimated by Shannon information index was 0.4529,with an average of 0.3458,while that judged from Nei's index was 0.3004, with an average of 0.2320. The percentage of polymorphic loci, Shannon information index, and Nei's index of the populations were in the sequence of coniferous forest community coniferous and broad-leaved mixed forest community evergreen broad-leaved forest community. Analysis of molecular variance (AMOVA) showed that 72.85% of genetic variance was found within the populations,and 27.15% of genetic variance resided among the populations. The coefficient of gene differentiation was 0.2277, and the gene flow was 1.6949. The genetic structure of L. Harlandii was influenced not only by the biological characteristics of this species, but also by the micro-environment of different communities. The mean of genetic identity among three populations of L. Harlandii was 0.8662, and the mean of their genetic distance was 0.1442. The genetic similarity between coniferous and broad-leaved mixed forest community and evergreen broad-leaved forest community was the highest, while that between evergreen broad-leaved forest community and coniferous forest community was the lowest.The unweighted pair group method with arithmeticmean (UPGMA) cluster analysis based on Nei's genetic

  16. 闽北天然阔叶林径阶材种结构分析及出材率表的编制%Compilation of Output Structure of Diameter Grade Wood Assortments and Volume Ratio Table for Natural Broad-Leaved Forest Tree Species in North Fujian Province

    Institute of Scientific and Technical Information of China (English)

    李晓景; 江希钿; 庄崇洋; 李小铃

    2012-01-01

    应用闽北天然阔叶林现场造材资料,在分析径阶材种结构规律的基础上,选择适合的方程建立材种出材率模型并编制二元材种出材率表.经检验,该表精度较高,在林业生产上有实用价值.为方便生产中应用,还建立了树高曲线模型,由二元材种出材率袁导出了一元材种出材率表.%The volume ratio model of wood assortment was built by choosing the proper equation, and the two dimension merchantable wood assortment volume yielding rate tables were compiled based on structure analyses of diameter grade wood assortments, with on the spot sample timber data collected from the natural broad-leaved forests in the north Fujian Province. The wood assortment volume yielding rate tables were tested to be with high precision and practicable in forestry production. In order to facilitate the production and application, tree height model was established, and the one dimension merchantable wood assortment volume yielding rate tables were derived from the two dimension tables.

  17. Seasonal changes in the photosynthetic performance of two evergreen Nothofagus species in south central Chile Cambios estacionales en el desempeño fotosintético de dos especies siempreverdes de Nothofagus en el centro sur de Chile

    Directory of Open Access Journals (Sweden)

    RAFAEL ZÚÑIGA

    2006-12-01

    Full Text Available The evergreen Nothofagus dombeyi and Nothofagus nitida are important members of the temperate Chilean rainforest. They seldom grow together in nature. Nothofagus nitida is more susceptible to excess light and drought than N. dombeyi. We postulate that the different properties of the photosynthetic apparatus under common garden conditions of these species could explain their contrasting habitat preferences. The two species growing in a common garden in south central Chile were studied. The optimal photochemical efficiency (Fv/Fm of both species remained within normal values (»0.8 with the exception of a decrease in N. dombeyi at midday in summer, suggesting reversible reduction in photochemical efficiency of photosystem II (PSII. During summer the effective photochemical efficiency (F PSII, photochemical quenching (qP, photosynthesis (Amax, stomatal conductance (gs and transpiration rates (E in N. dombeyi were higher than in N. nitida. The highest increments in photoprotective pigments (zeaxanthin + antheraxanthin and lutein contents between predawn and midday were obtained in summer in N. dombeyi. In N. nitida a nocturnal retention of dissipative pigments, without a decrease in Fv/Fm, was found in winter. The results suggest that N. dombeyi showed a better photosynthetic performance than N. nitida under high light, high temperature, and drier conditions. These data support are consistent with the pioneer character of N. dombeyi and the semi-tolerant shade properties and more restricted distribution of N. nitida. These photosynthetic characteristics, along with their freezing and flooding resistance differences, may result from their habitat separationLas siempreverdes, Nothofagus dombeyi y Nothofagus nitida, representantes importantes de los bosques lluviosos templados de Chile, raramente crecen juntos en forma natural. Nothofagus nitida es más sensible al exceso de luz y déficit de agua que N. dombeyi. Se postula que diferentes propiedades

  18. Photosynthetic Characteristics of Dominant Evergreen Broadleaf Trees in Tiantong Mountain and Its Role of Ecological Significance in Community Succession%天童山常绿阔叶林优势树种光合生理特性在其群落演替中的生态意义研究

    Institute of Scientific and Technical Information of China (English)

    李昊民; 李宁云; 喻庆国; 杨宇明

    2011-01-01

    The photosynthetic characteristics of 4 dominant trees, Castanopsis fargesii, Schima superb, Lithocarpus glaber, and Castanopsis sclerophylla, which consisted of sub climax succession in evergreen broadleaf forestry in Tiantong Mount in Zhejiang, were studied.We analyzed the photosynthetic response curve, light compensation point and light saturation point, CO2 compensation point, daily photosynthesis change, transpiration and water utilization rate in the seedlings, saplings and adult trees of aforementioned four types of trees.By analysis and comparison of these indices, we asserted the photosynthetic characteristics of these dominant evergreen broadleaf trees might reflect the important roles these trees played in the succession of community.We found that the tree of Castanopsis fargesii was mostly adopted to the climax community structure among the four types of trees by having lowest C02 compensation point, excellent water utilization ability and perfect self-conservation in light inhibition condition, thus it had become dominant species in the community of evergreen broadleaf forestry in Tiantong Mount.%对浙江天童山常绿阔叶林组成亚顶级群落的4个优势树种:栲树、木荷、石栎、苦槠的光合生理特性进行了研究.对此4个优势树种幼苗、幼树、成年树等生长阶段的光合响应曲线及其光补偿点和光饱和点、CO2补偿点、光合作用日变化曲线、蒸腾作用和水分利用率等进行了测定,对比分析了优势树种光合生理生态特性及其在天童山常绿阔叶林群落演替过程中的重要作用.结果发现栲树具有最低的光和CO2补偿点、优良的水分利用性能,完善的光抑制自我保护机制,幼苗适应弱光环境且代谢旺盛而利于更新,在4个优势树种中最适应于顶级群落的特殊生境,因此成为了天童山常绿阔叶林自然演替顶级群落中重要值最大的优势种.

  19. Comprehensive Evaluation of Different Transformation Models of Low-Quality Broad-Leaved Mixed Forest in Daxing’an Mountains%大兴安岭低质阔叶混交林不同改造模式综合评价

    Institute of Scientific and Technical Information of China (English)

    宋启亮; 董希斌

    2014-01-01

    Strip transformation test zone with different bandwidths and block transformation test zone with different sizes were established in low-quality mixed broad-leaved forest in Daxing’an Mountains,and principal component analysis was applied to comprehensively evaluate the ecological improvement models with the selection of 33 indicators such as biodiversity,water holding characteristics of litter,soil physical properties,soil chemical properties,soil carbon flux and seedling growth status,etc. The results showed that: strip clear-cutting along the hillside transformation model was better than block clear-cutting transformation model,for the strip clear-cutting transformation,the effect of different bandwidths were 10 m bandwidth > 6 m bandwidth > 18 m bandwidth > 14 m bandwidth plots, for the block clear-cutting transformation,the effect of different sizes were 100 m2 >25 m2 >225 m2 >400 m2 >900 m2 >625 m2 ,strip along the hillside transformation with 10 m bandwidth model and block transformation with 100 m2 model were most appropriate to Daxing’an Mountains broad-leaved mixed low-quality forest, and its improvement effect were better than the other transformation models.%在大兴安岭低质阔叶混交林中建立不同宽度的带状改造试验区和不同面积的块状改造试验区,选取生物多样性、枯落物持水特性、土壤物理性质、土壤化学性质、土壤碳通量和更新苗木生长状况等33项指标,运用主成分分析法综合评价不同改造模式的改造效果。结果表明:顺山带状皆伐改造模式优于块状改造模式,对于带状改造样地,不同带宽的改造效果依次为10 m带宽>6 m带宽>18 m 带宽>14 m 带宽,对于块状改造样地,不同面积的改造效果依次为100 m2>25 m2>225 m2>400 m2>900 m2>625 m2,其中10 m 带宽顺山带状改造模式和100 m2块状改造模式最适宜大兴安岭阔叶混交低质林,其改造效果明显优于其他改造模式。

  20. Micro-topographic spatial differentiation pattern and coexistence mechanism of relict deciduous broadleaved trees: A review%孑遗落叶阔叶树种微地形空间分异格局及共存机制研究概述

    Institute of Scientific and Technical Information of China (English)

    商侃侃; 达良俊

    2013-01-01

    漫长历史时期的气候条件对生物多样性的现代分布格局产生了深远影响,分析以孑遗植物为优势种群落的分布格局、种群更新类型与适应策略,可揭示气候变化下孑遗植物的残存机制.本文以孑遗植物的群落生态学研究为视角,在综述孑遗落叶阔叶树种的定义、分布与生境特征、种间关系、种群更新与群落维持、植物性状与生境响应的基础上,提出在区域孑遗植物多样性研究中,应从微地形-植被关系入手,应用微地形单元的分类体系与手法,以微地形单元上斑块状植物群落为对象,分析其生境特征、种群结构、群落动态以及植物性状,揭示微地形梯度孑遗植物群落的分异格局,阐明区域内多种孑遗落叶阔叶树种的共存机制;结合植物群落谱系结构分析,进一步阐明孑遗植物群落的残存机制,有助于丰富我国亚热带山地植物多样性研究及保护生态学理论.%Climatic conditions in a long history have far-reaching effects on the modern distribution pattern of biodiversity,while analyzing the distribution pattern,regeneration type,and adaptation strategy of relict species-dominated populations can reveal their remnant mechanism under climate change.From the perspective of relict species community ecology,this paper reviewed the connotation of relict deciduous broad-leaved tree species,their distribution and habitat characteristics,inter-species relationship,population regeneration and community maintenance,plant traits,and functional response.It was proposed that in the studies on the diversity of regional relict species,it should start with the relationships between micro-landform and vegetation,and then,analyze the habitat characteristics,population structure,community dynamics,and plant traits of relict species communities at micro-topographic scale,reveal the spatial differentiation pattern among micro-landforms and the coexistence mechanism of many

  1. 中国企业品牌国际化升级路径研究--从品牌机制角度探究国际化品牌长青基因%Research on the Upgrading path of Chinese Enterprise Brand Internationalization---Explore the International Brand Evergreen Gene from Brand Mechanism Angle

    Institute of Scientific and Technical Information of China (English)

    杨光玉; 王海忠

    2014-01-01

    基于品牌国际化升级的多案例研究,利用路径依赖理论探究了我国企业品牌经营和国际品牌经营存在巨大差异的形成机制。通过对国际顶端品牌的对比研究,发现我国机遇型企业要摆脱弊端,创建国际化长青品牌,必须从经验主义升级到方法论,通过学习、超越国际上经典和领先的品牌原理及方法论,借助中国经济形态在国际上的独特竞争优势,打造与世界竞争同步的国际化大品牌,这样才能使得品牌成功从偶然性向必然性转变,成就国际化长青品牌。%Based on the brand internationalization upgrade case study ,using the theory of path dependence explores our country enterprise brand management and international brand management mechanism for the formation of huge differ-ences .Through the comparison study of international top brands ,find opportunities for enterprises to get rid of the disad-vantages in our country .To create international evergreen brand ,must from empiricism to upgrade to the methodology , through learning ,beyond classic and leading brand on the international principle and methodology .With the aid of the Chi-nese economy form unique competitive advantage in the world ,create synchronization with the world competition interna-tionalization big brand ,so as to make the brand successful transition from contingency to necessity ,achievement evergreen brand internationalization .

  2. Responses of two températe evergreen Nothofagus species to sudden and gradual waterlogging: relationships with distribution patterns Respuestas de dos especies siempreverdes de Nothofagus al anegamiento gradual y repentino: relaciones con patrones de distribución

    Directory of Open Access Journals (Sweden)

    FRIDA PIPER

    2008-06-01

    Full Text Available The effects of gradual waterlogging on trees have been little studied. The températe evergreens Nothofagus nítida and N. dombeyi are differentially distributed on soil moisture gradients, only the former being common on poorly-drained sites. We compared the relative height growth rate (RGR H and foliage loss of seedlings subjected experimentally to normal drainage (soil at field capacity, sudden waterlogging and gradual waterlogging for two months to determine which waterlogging regime more accurately predicts interspecific differences in tolerance, as evident from natural distributions. RGR H was similar between species but differed between treatments (normal watering > gradual waterlogging = sudden waterlogging. Sudden waterlogging caused massive foliage loss in the two species, but gradual waterlogging caused much greater foliage loss in N. dombeyi than in N. nítida, indicating some degree of acclimation by the latter species. Linear regressions indicated that RGR H was negatively affected by foliage loss in both species, without differences between them. Since no difference in RGR H was found between species in the waterlogging treatments, but yet in foliage loss, other mechanisms may be in volved in the short term growth reduction of N. nítida. Effects of waterlogging on long-term performance in the field were evaluated by reciprocal transplants between a poorly-drained site naturally occupied by N. nítida, and a well drained site naturally occupied by N. dombeyi. After two growing seasons, N. dombeyi had significantly lower specific leaf área (SLA and RGR H, at the poorly drained site than at its original site. At the poorly drained site N. nítida achieved 100 % survival, compared with 73.5 % in N. dombeyi. Reduced growth and survival of N. dombeyi associated with the negative effects on carbón gain of extensive foliage loss and reduced SLA may thus exelude it from the wetter sites. We conclude that tolerance may be better

  3. Management pattern of ecological public welfare forests in South China

    Institute of Scientific and Technical Information of China (English)

    Chong LOU; Anxing LIU; Guomin ZHU

    2008-01-01

    The characteristics and actualities of ecologi-cal public welfare forests in South China are studied in this paper, including common and special management patterns. The restoration and reconstruction pattern of subtropical evergreen broad-leaved forests, zonal vegeta-tion in the key eco-zone, and the transformation pattern of coniferous and broad-leaved mixed forests in the general eco-zone with multi-forms are discussed in detail. The authors also point out, based on ecological transformation and utilization, that ecological public welfare forests should be oriented to multiple benefit utilization to maintain sustainable management.

  4. Plant Species Diversity of Cunninghamia lanceolata Forest Cutover Lands after Improvement by Planting Broadleaved Trees at Yunyong of Foshan,South China%云勇杉木林采伐迹地阔叶树改造后的植物多样性

    Institute of Scientific and Technical Information of China (English)

    冼杆标; 冼伟光; 殷祚云; 张卫强; 唐洪辉; 陈伟光; 盘李军

    2014-01-01

    2002年来广东省佛山市云勇林场陆续对杉木人工林采伐迹地进行了阔叶树混交造林改造。选取3个林龄为10 a的杉木人工林采伐迹地作为样地,包括1个未改造的对照林分和2个已改造的林分,比较其植物多样性差异。无论是物种丰富度、Shannon-Wiener、Simpson物种多样性和均匀性指数,还是秩多度曲线都表明,已改造林分植物多样性远高于未改造林分;人工引入的本地树种藜蒴、阴香能自我更新。采用乡土阔叶树种及其合理混交模式,对针叶人工纯林进行改造,有利于形成稳定的近自然林。%Yunyong Forest Farm of Foshan (Presently Maintenance Center for Yunyong ecological forest of Foshan),South China,has made stand improvement on Cunninghamia lanceolata forest cutover land since 2002. The study selected 3 C.lanceolata forest cutover lands of 10 years old as sampling plots,one not-improved and two improved,and compared their plant species diversities.The species richness,indexes of Shannon-Wiener,Simp-son diversity and evenness,and rank abundance curve all indicated that (1 )the plant species diversity of each of the two improved stands was larger than that of the not-improved stand;and (2)the planted native trees,Castan-opsis fissa and Cinnamomum burmannii,could regenerate by themselves.The stand improvement on C.lanceolata forest cutover lands by introducing and mixing native broadleaved trees was helpful to nurture stable close-to-nature forests.

  5. Litterfall, litter decomposition and nitrogen mineralization in old-growth evergreen and secondary deciduous Nothofagus forests in south-central Chile Aporte, descomposición de hojarasca y mineralización de nitrógeno en bosques siempreverdes de antiguo crecimiento y bosques secundarios deciduos, centro-sur de Chile

    Directory of Open Access Journals (Sweden)

    JEROEN STAELENS

    2011-03-01

    Full Text Available South Chilean forest ecosystems represent one of the largest areas of old-growth temperate rainforests remaining in the Southern hemisphere and have a high ecological value, but suffer from deforestation, invasion by exotic species, fragmentation, and increasing atmospheric nitrogen (N deposition. To support sustainable forest management, more knowledge is required on nutrient cycling of these ecosystems. Therefore, a descriptive study of nutrient dynamics was done in four Valdivian rainforests in the lower Andes range of south Chile: old-growth and altered evergreen stands and unmanaged and managed secondary deciduous stands. Time series were measured for (i mass (four year and nutrient content (N, K, Ca, and Mg; one year of litterfall, (ii decomposition and nutrient dynamics (N, C, K, Ca, Mg, and P; one year of leaf litter and Saxegothaea conspicua bark litter, and (iii in situ topsoil net N mineralization (one year. Litterfall in the four stands ranged from 3.5 to 5.8 ton ha-1 yr-1, was temporarily lower in the managed than in the unmanaged deciduous stand and had a different seasonality in the evergreen stands than in the deciduous stands. Leaf litter decomposed faster (on average 32 % mass loss after one year than bark litter (8 % but without significant differences between leaf litter types. Net N in evergreen leaf litter decreased during decomposition but increased in deciduous leaf litter. Net soil N mineralization was fastest in the pristine evergreen stand, intermediate in the deciduous stands and slowest in the altered evergreen forest. Given the absence of replicated stands, the definite impact of forest type or management regime on the internal nutrient cycling cannot be demonstrated. Nevertheless, the results suggest that management can affect nutrient turnover by altering species composition and forest structure, while recent (five years selective logging in secondary deciduous forest did not affect litter decomposition or N

  6. 长白山阔叶红松林中影响乔木幼苗存活的关键因素%Effects of biotic and abiotic factors on tree seedling survival in a broad-leaved Korean pine (Pinus koraiensis) mixed forest on Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    肖翠; 刘帅; 黄珍; 樊莹; 王均伟; 赵秀海; 唐景毅

    2015-01-01

    应用广义线性混合模型,对长白山阔叶红松林中影响幼苗存活的生物因素和非生物因素进行分析。结果表明:(1)在群落水平上,幼苗存活率和生物因素中同种幼苗邻居显著负相关,说明在阔叶红松林群落中存在负密度制约效应。(2)生物因子和非生物因子对不同年龄阶段的幼苗存活率影响不同。对于1年生的幼苗,幼苗存活率与异种大树邻居呈显著负相关,与同种大树邻居呈显著正相关;对于2—3年生的幼苗,其存活率和同种幼苗邻居、同种大树邻居均呈显著负相关,和非生物因子相关不显著;对于4年生以上的幼苗,其存活率和土壤主成分分析的PC1(低的有机质、速效钾、速效氮等比较贫瘠的土壤)显著负相关。(3)种子的传播方式不同,幼苗存活率的影响因子也不同。对于风传播的物种,存活率与同种幼苗邻居密度显著正相关。对于重力传播的物种,幼苗存活率与土壤PC3(高的全氮和速效氮,含氮较高的土壤)、异种大树邻居、草本密度呈负相关,与林冠开阔度和草本盖度成正相关。(4)对于不同的物种,影响幼苗存活的因素也不同。紫椴的幼苗存活率与土壤PC3、异种大树邻居、草本密度呈显著负相关,与土壤主成分PC2(高的有机质和全氮等养分比较好的土壤)呈显著正相关。%Seedling recruitment plays a key role in determining species composition and diversity. Exploring patterns of seedling dynamics can therefore provide crucial insights into the mechanisms that affect seedling recruitment. The broad-leaved Korean pine ( Pinus koraiensis) mixed forest is a temperate forest typical of northeast China. In 2007, we established a 1 hm2 plot in a broad-leaved Korean pine mixed forest on Changbai Mountain, northeast China. We identified, tagged, and mapped each tree with diameter at breast height ≥1 cm. At the same time, we set up 100

  7. A preliminary study on in-stream large woody debris in broadleaved and Korean pine forest in Changbai Mountain, Northeast China%长白山二道白河溪流大木质物残体的初步研究

    Institute of Scientific and Technical Information of China (English)

    邓红兵; 王青春; 王庆礼

    2002-01-01

    This study was conducted in Erdaobaihe River passing through the broadleaved and Korean pine forest located on the north slope of Changbai Mountain. In-stream large woody debris (LWD) in two segments of the river channel was investigated with base diameter, top diameter, length, and decay class. To study relationship between in-stream LWD and adjacent riparian forest, species of each log of LWD in segment 1 was identified, and the riparian forest was examined by setting a 32m×24 m quadrat consisting of twelve 8m×8m small quadrats. The results showed that, in segment 1, in-stream LWD loading was 1.733 m3/100m or 10.83 m3@hm-2, and in segment 2, it was 1.709m3/100m or 21.36 m3@hm-2. In-stream LWD in decay class III and IV were accounted for a high proportion, which was different from that in the broadleaved and Korean pine forest, and the possible reason might be different decomposing velocities due to different decomposing conditions. Logs of LWD in stream and living trees in riparian forest declined as diameter increased, and it was in a reverse J-shaped distribution except logs of LWD in segment 1 in the first diameter class. Volumes of LWD in stream and living trees in riparian forest increased as diameter increased, and it was in a typical J-shaped distribution. Loading and species component of in-stream LWD were correlative to status of riparian forest to a certain extent, and there also existed difference. Comparing the correlation and difference was helpful to study on dynamic of the riparian forest.%主要对长白山北坡溪流大木质物残体现存量进行了调查和研究,包括两段河道内所有大木质物残体的基径、顶径、长度、腐烂级,并在其中一段对树种尽可能进行了鉴别,以分析河岸带植被与溪流大木质物残体的关系。在调查的红松阔叶林植被带内4500 m长河道内,共发现溪流倒木425株,分属于17个树种;其中III、IV级腐烂占相当大的比重,与林地倒

  8. Effects of biotic and abiotic factors on tree seedling survival in a broad-leaved Korean pine (Pinus koraiensis) mixed forest on Changbai Mountain%长白山阔叶红松林中影响乔木幼苗存活的关键因素

    Institute of Scientific and Technical Information of China (English)

    肖翠; 刘帅; 黄珍; 樊莹; 王均伟; 赵秀海; 唐景毅

    2015-01-01

    Seedling recruitment plays a key role in determining species composition and diversity. Exploring patterns of seedling dynamics can therefore provide crucial insights into the mechanisms that affect seedling recruitment. The broad-leaved Korean pine ( Pinus koraiensis) mixed forest is a temperate forest typical of northeast China. In 2007, we established a 1 hm2 plot in a broad-leaved Korean pine mixed forest on Changbai Mountain, northeast China. We identified, tagged, and mapped each tree with diameter at breast height ≥1 cm. At the same time, we set up 100 seedling quadrats of 1m × 1m which were censused every July. In total, we collected data on 1288 adult trees and 965 seedlings in the 1 hm2 plot between 2012 and 2013, and examined the importance of biotic and abiotic factors on seedling survival using a generalized mixed linear model. Biotic factors included presence of conspecific seedling neighbors and heterospecific seedling neighbors, presence of conspecific adult neighbors and heterospecific adult neighbors, and herb density and herb cover. Abiotic factors included soil organic matter, available soil phosphorus, available soil potassium, available soil nitrogen, total soil nitrogen, and canopy openness. Conspecific neighbors had a significant negative effect on seedling survival at the community level, indicating significant negative density-dependence effects. The effects of biotic and abiotic factors on seedlings differed with seedling age. Conspecific adult neighbors and canopy openness had significant positive effects on survival of, 1-year seedlings while heterospecific adult neighbors had a significant negative effect. In contrast, for 2- to 3-year-old seedlings, conspecific seedling neighbors and conspecific adult neighbors showed a significant negative effect on seedling survival, but abiotic factors had no significant effect. Moreover, for ≥4-year-old seedlings, soil PC axis 1 ( associated with low organic matter available K, available N

  9. 针阔混交林不同演替阶段表层土壤理化性质与优势林木生长的相关性%Correlation between the Growth of Dominant Trees and Surface Soil Physiochemical Properties of Conifer and Broad-Leaved Mixed Forest at Different Succession Stages

    Institute of Scientific and Technical Information of China (English)

    林文树; 穆丹; 王丽平; 邵立郡; 吴金卓

    2016-01-01

    论】毛管孔隙度、速效钾和全磷含量是影响不同演替阶段土壤质量的主要因子;经过不同演替阶段,表层土壤理化性质质量的综合得分表现为中龄林<成熟林<近熟林<老龄林;随着演替进行,针阔混交林的表层土壤理化性质基本呈现质量提高趋势,到老龄林时期达到最佳。本研究得到的不同演替阶段针阔混交林林木生长与表层土壤理化性质特征的相关性为进一步实现该地区森林可持续经营提供了科学依据。%[Objective]This study aims to analyze the relationship between surface soil physiochemical properties and the growth of dominant trees for mixed forest of conifer and broad-leaved species at different succession stages in order to explore the growth patterns of different stands and provide basis for sustainable forest management. [Method]The mixed forest conifers and broad-leaved trees at different succession stages ( middle-aged forest,near-mature forest,mature forest, and old growth forest) in Jiaohe Management Bureau of Forestry Experimental Area,Jilin Province were studied. The methods of comparison and principal component analysis were used to analyze physical and chemical properties of the surface soil,the growth of dominant trees,and the relationship between them.[Result]with the succession of forest,the average diameter at breast height ( DBH) of the dominant tree species increased,the average tree height varied slightly, the regeneration of Pinus koraiensis tended to be stable,and the number of Juglans mandshurica,Ulmus davidiana var. japonica ,and U. macrocarpa gradually decreased in the upper overstory. With respect to the soil physical properties,the soil density was not significantly different among middle-aged forest,near-mature forest and mature forest and it reached the minimum at the stage of old-growth forest. With the succession of forest,the non-capillary porosity gradually decreased and capillary porosity

  10. Construction of Near-natural Forests as Ecological Restoration of Urban Ecosystem in Shanghai

    Institute of Scientific and Technical Information of China (English)

    DALiangjun

    2004-01-01

    A model stand of near-natural forest with an area of 3 000 m2 was established as a case study in Pudong New District, Shanghai City in 2000. Eleven species were planted in model stand. As the dominant species of community, 4 evergreen broad-leaved tree species, namely: Machilus thunbergii, Cyclobalanopsis glauca, C.mylsinafolia and Castanopsis sclerophylla were chosen, accompanying with evergreen broadleaved shrub species like Pittosporum tobira, Ligustrum quihoui and Dis~'lium racemosum, etc. as well as deciduous tree species, Liquidambarformosana, etc. After three-year growth, the community physiognomy had changed to be a shrub stage, and the highest tree reached to 4.6 m. A forest physiognomy would be formed in about 10 years estimated. The method of construction of near-natural forest that had been worldwidely applied would also play a key role in the construction of urban forest in China.

  11. Study on the interception of precipitation of coniferous plantations and natural broad-leaved forests in mountain region of northern Yanshan%燕山北部山地人工针叶林及天然阔叶林植被层的降水截留量研究

    Institute of Scientific and Technical Information of China (English)

    纪晓林; 李强; 许中旗; 陈圆圆

    2013-01-01

    In order to compare regulating effects of the artificial coniferous forests and natural broad-leaved forests on precipitation, method of branch soaking was used to compare interception capacity of larch plantations and natural secondary birch forests in the mountain region of northern Yanshan. Results indicated that, in every period, the canopy interception of larch was higher than the natural secondary birch forest. The canopy interception capabilities of larch young forests, middle-age forests, near-mature forests trees were 0. 44 mm, 0. 74 mm and 0. 69 mm, respectively, and those of birch forests were 0. 25 mm, 0. 33 mm, 0. 49 mm, respectively. However, the interception of larch shrubs was lower than natural secondary birch forests. The total interception amount of larch forest vegetation layers was higher than the natural secondary birch forests. As the age prolonged, the trend of birch forest canopy ability increased gradually and young forests, middle-age forests, near-mature forests trees were 0. 41mm, 0. 38mm and 0. 76mm respectively, while the canopy interception ability of larch forests decreased when they were near-matured.%为了比较人工针叶林及天然阔叶林对降水的调控作用,利用泡枝法对燕山北部山地落叶松人工林及天然次生杨桦林植被层对降水的截留量进行了比较.研究结果表明:在各个年龄阶段,落叶松乔木林冠截留量都高于天然次生杨桦林.落叶松人工林幼龄林、中龄林、近熟林乔木林冠截留量分别为0.44 mm、0.74 mm、0.69 mm,杨桦林则分别为0.25 mm、0.33 mm、0.49 mm;但落叶松人工林灌木的截留量低于天然次生杨桦林;华北落叶松人工林植被层总截留量高于天然次生杨桦林,分别是0.48 mm、0.78 mm、0.74 mm.随着林龄的增加,杨桦林林冠截留量有逐渐增加的趋势,幼龄林、中龄林、近熟林分别为0.41 mm、0.38 mm、0.76 mm;但落叶松林到达近熟林时林冠截留量却有所下降.

  12. 降水变化驱动下红松阔叶林土壤真菌多样性的分布格局%Effects of precipitation variation on the distribution pattern of soil fungal diversity in broad-leaved Korean pine mixed forest

    Institute of Scientific and Technical Information of China (English)

    王楠楠; 杨雪; 李世兰; 隋心; 韩士杰; 冯富娟

    2013-01-01

    红松阔叶林生态系统是中国东北地区地带性顶极植被,具有重要的生态学意义,长白山是研究温带森林对大气降水变化正负反馈的理想地带.本文以长白山原始红松阔叶林为研究对象,基于末端限制性片段长度多态性分析技术,分析了降水控制样地(增、减30%)和对照样地的0 ~5 cm和5~ 10 cm表层土和红松根际土真菌多样性的空间异质性.结果表明:降水的增加和减少均能提高土壤真菌的多样性,但优势种群有所变化.表层土中,片段长度超过500 bp的T-RFs丰度随降水增加而提高,根际土中对降水变化响应的T-RFs分别为380、455和487 bp,且根际土的响应模式较表层土复杂.典范对应分析结果表明,土壤pH、有机碳含量、总氮和有效磷等对真菌群落组成影响显著.%Broad-leaved Korean pine mixed forest is a kind of zonal climax vegetation with ecological significance in Northeast China,whereas Changbai Mountain is an ideal area to study the effects of precipitation variation on temperate forest.Taking the virgin broad-leaved Korean pine mixed forest in Changbai Mountain as the object,and based on T-RFLP method,this paper analyzed the spatial heterogeneity of fungal diversity in 0-5 cm and 5-10 cm soil layers and in rhizosphere soil at three different precipitation plots (30% increase,30% decrease,and the control).Both the increase and the decrease of precipitation increased the diversity of soil fungi,but the dominant population changed.In 0-5 cm and 5-10 cm soil layers,the T-RFs over 500 bp increased with precipitation; in rhizosphere soil,the T-RFs responded to precipitation variation were 380 bp,455 bp,and 487 bp,and the response mode was more complicated than that in surface soil layers.The results of CCA showed that the fungal community composition was significantly affected by soil pH,organic carbon,total nitrogen,and organic phosphorus.

  13. 小兴安岭红松活立木树干腐朽与立地土壤理化特性的关系%Correlations between standing trees trunk decay degree and soil physical-chemical properties in Korean pine-broadleaved mixed forest in Xiao Xing'an Mountains of Northeast China

    Institute of Scientific and Technical Information of China (English)

    孙天用; 王立海; 孙墨珑

    2013-01-01

    Standing trees decay often causes vast loss of timber resources.To investigate the correlations between the standing trees decay and the site conditions is of importance to scientifically and reasonably manage forests and to decrease wood resources loss.By using Resistograph and meter ruler,a measurement was made on the decay degree of the trunk near root and the diameter at breast height (DBH) of 15 mature Korean pine standing trees in a Korean pine-broadleaved mixed forest in Xiao Xing' an Mountains in May,2011.In the meantime,soil samples were collected from the root zones of standing trees and the upslope and downslope 5 meters away from the trunks,respectively.Five physical-chemical properties including moisture content,bulk density,total porosity,pH value,and organic matter content of the soil samples were tested.The regression equations conceming the trunk decay degree of the standing trees,their DBH,and the 5 soil properties were established.The results showed that the trunk decay degree of the mature Korean pine standing trees had higher correlations with the bulk density,total porosity,pH value,and organic matter content (R =0.687),and significant positive correlation with the moisture content (R =0.507) of the soils at the root zones of standing trees,but less correlation with the 5 properties of the soils at both upslope and downslope 5 meters away from the trunks.The trunk decay degree was decreased when the soil moisture content was below 18.4%.No significant correlation was observed between the trunk decay degree of mature Korean pine standing trees and the tree age.%活立木腐朽造成大量木材资源损失.研究活立木腐朽与立地生境之间的关系,对于科学合理地营林管理、减少木材资源损失有着积极的指导意义.2011年5月,使用阻抗仪对小兴安岭林区红松阔叶混交林中15株成熟龄的红松活立木树干根部腐朽状况及胸径进行了检测,同时分别在活立木根部、坡上距根部5

  14. 土壤铅胁迫下4种北方阔叶树种苗木的生长反应及抗性比较%Comparison on characters of lead stress resistance of four northern broadleaved tree species

    Institute of Scientific and Technical Information of China (English)

    李亚藏; 王庆成

    2011-01-01

    In this paper,the gradient of soil Pb concentration (CK, 100,500,1 000,2 000 mg/kg) was established by mixing Pb( CH3COOH)2 with soil and sand. The growth responses and resistance of four northern broadleaved tree species Acer ginnala ,Pyrus ussuriensis ,A. M ono and Malus baccata to soil lead contamination were studied by growing their seedlings in pots in greenhouse. The results indicated that the seedling growth of all test species was enhanced under lower Pb concentrations ( <500 mg/kg) .including seedling height, ground diameter,leaf blade and the amount of new branches. With the increasing of Pb concentration, the growth became declined. Soil lead prevented the root system' s growth of most species. The changes of every index and difference between species were obvious. According to comprehensive analysis of above indices by using membership function, we could arrive at a conclusion that the P. Ussuriensis had the strongest resistance of soil lead contamination,and next was A. Ginnala, M. Baccata, A. Mono. Under the highest Pb concentration(2 000 mg/kg) the root of plant had the strongest enrichment of Pb,and the following was stem,leaf blade. P. Ussuriensis had the stronger enrichment of soil lead than other three species.%以土壤和风化砂混合物作为栽培基质,设计5种土壤铅含量梯度处理(对照、100、500、1 000、2 000 mg/kg),研究了土壤铅胁迫下4种北方阔叶树种(茶条槭、山梨、五角槭和山荆子)1年生盆栽苗的生长反应和抗性.结果表明:低含量铅(含量< 500 mg/kg)刺激了多数树种的苗高、地径、叶片和新枝的生长,随着铅含量的继续增加植物生长量下降;土壤中铅抑制了多数树种的根系生长,根系各指标的变化树种间差异明显.采用隶属函数综合分析得出,4个树种对土壤铅污染的抗性大小顺序为山梨、茶条槭、山荆子、五角槭.2 000 mg/kg铅处理下,植物体对铅的富集能力大小依次为根、茎、叶.4种

  15. Effects of biotic neighbors and habitat heterogeneity on tree seedling survival in a secondary mixed conifer and broad-leaved forest in Changbai Mountain%长白山次生针阔混交林乔木幼苗存活的影响因素分析

    Institute of Scientific and Technical Information of China (English)

    刘帅; 廖嘉星; 肖翠; 范秀华

    2016-01-01

    基于长白山次生针阔混交林样地,以520个1 m ×1 m幼苗样方中胸径小于1 cm的乔木幼苗为研究对象,选取2013年和2014年的幼苗调查数据,运用广义线性混合模型(GLMM)分析了生物邻体和生境异质性对幼苗存活的影响,探讨了次生针阔混交林幼苗存活影响因素及物种共存机制。结果表明:(1)适宜大树生长的局域生境同样也适宜幼苗的存活,幼苗存活率与土壤含水量和有效氮等土壤养分显著正相关。(2)幼苗个体之间存在明显的竞争,较多的幼苗邻体显著降低幼苗的存活率。同种大树邻体和同种幼苗邻体与幼苗存活显著负相关,表明存在负密度制约效应。(3)随着幼苗年龄的增加,生境异质性对幼苗存活的影响逐渐增大。该研究证实了密度制约效应和生境异质性对幼苗存活有着重要影响,其相对重要性随着幼苗年龄级、功能群以及物种种类而变化。%Aims Our study aimed to understand the effects and the relative importance of biotic neighborhood and habitat heterogeneity for tree seedling survival in a secondary mixed conifer and broad-leaved forest in Changbai Moun-tain, north-eastern China. Methods The generalized mixed linear model was used to examine the relative effects of biotic neighborhood and habitat heterogeneity on seedling survival over two years. Important findingsOur results showed that both biotic neighborhood and habitat heterogeneity had significant effects on the seedling survival at community level. The local environment suitable for the adult growth was also suitable for seedling survival. The soil moisture and soil available nitrogen exhibited significant positive effects on seedling survival. On the other hand, seedling density had significant negative effects on seedling survival due to the individual competition. Particularly, we found significant negative density-dependent effects on seedling sur-vival which was caused by

  16. The controlling factors and coupling of soil CO2, CH4 and N2O fluxes in a temperate needle-broadleaved mixed forest%温带针阔混交林土壤碳氮气体通量的主控因子与耦合关系

    Institute of Scientific and Technical Information of China (English)

    党旭升; 李林森; 王磊; 程淑兰; 方华军; 于贵瑞; 韩士杰; 张军辉; 王淼; 王永生; 徐敏杰

    2015-01-01

    Carbon dioxide ( CO2 ) , methane ( CH4 ) and nitrous oxide ( N2 O) are three major greenhouse gases, accounting for 80% of global warming. Forest ecosystems comprise the largest carbon stocks in terrestrial ecosystems, and function as important sinks and sources of atmospheric CO2 , CH4 and N2 O. Complicated interactions occur during the generation and absorption of soil CO2 , CH4 and N2 O, including synergies, tradeoffs, and randomness. High-latitude forests are experiencing the effects of significant global change ( e. g., warming, changed precipitation, and increased nitrogen deposition) , leading to great uncertainty in estimates of soil greenhouse gas fluxes. Furthermore, the factors controlling the coupling of soil CO2 , CH4 and N2 O fluxes remain unclear. This study was conducted in the temperate needle-broadleaved mixed forest of Changbai Mountain, Northeast China. The net exchange fluxes of soil CO2 , CH4 and N2 O, as well as soil temperature and soil moisture, were measured over four years (2005–2009) using static chamber and gas chromatograph techniques. The results showed that temperate needle-broadleaved mixed forest soils behaved as a source of atmospheric CO2 and N2 O but a sink of atmospheric CH4 over the course of the study. The average soil CH4 , CO2 and N2 O fluxes were estimated at -1.30 kg CH4 hm-2 a-1 , 15102.2 kg CO2 hm-2 a-1 , and 6.13 kg N2 O hm-2 a-1 , respectively. In addition, soil CO2 flux exhibited significant seasonality, and was mainly affected by soil temperature, followed by soil moisture. Seasonal variation in soil CH4 flux was less significant than that of soil CO2 and N2 O fluxes; moreover, it was positively correlated with soil moisture. When soil temperatures were within a threshold range, soil moisture determined CH4 production and oxidation in soil profiles by regulating CH4 and O2 diffusion as well as methanotrophic community activity. Similar to soil CO2 flux, soil N2 O flux was significantly correlated with soil

  17. Using the Lund-Potsdam-Jena Model to Understand the Different Responses of Three Woody Plants to Land Use in China

    Institute of Scientific and Technical Information of China (English)

    SUN Guodong; MU Mu

    2013-01-01

    In this study,the approach of conditional nonlinear optimal perturbation related to initial perturbation (CNOP-Ⅰ) was employed to investigate the maximum variations in plant amount for three main woody plants (a temperate broadleaved evergreen,a temperate broadleaved summergreen,and a boreal needleleaved evergreen) in China.The investigation was conducted within a certain range of land use intensity using a state-of-the-art Lund-Potsdam-Jena dynamic global vegetation model (LPJ DGVM).CNOP-Ⅰ represents a class of deforestation and can be considered a type of land use with respect to the initial perturbation.When deforestation denoted by the CNOP-Ⅰ has the same intensity for all three plants,the variation in plant amount of the boreal needleleaved evergreen in northern China is greater than the variation in plant amount of both the temperate broadleaved evergreen and temperate broadleaved summergreen in southern China.As deforestation intensity increases,the plant amount variation in the three woody plant functional types carbon changes,in a nonlinear fashion.The impact of land use on plant functional types is minor because the interaction between climate condition and land use is not considered in the LPJ model.Finally,the different impacts of deforestation on net primary production of the three plant functional types were analyzed by modeling gross primary production and autotrophic respiration.Our results suggest that the CNOP-Ⅰ approach is a useful tool for exploring the nonlinear and different responses of terrestrial ecosystems to land use.

  18. Association of Soil Aggregation with the Distribution and Quality of Organic Carbon in Soil along an Elevation Gradient on Wuyi Mountain in China

    OpenAIRE

    Li, Liguang; Vogel, Jason; He, ZhenLi; Zou, Xiaoming; Ruan, Honghua; Wei HUANG; Wang, Jiashe; Bianchi, Thomas S

    2016-01-01

    Forest soils play a critical role in the sequestration of atmospheric CO2 and subsequent attenuation of global warming. The nature and properties of organic matter in soils have an influence on the sequestration of carbon. In this study, soils were collected from representative forestlands, including a subtropical evergreen broad-leaved forest (EBF), a coniferous forest (CF), a subalpine dwarf forest (DF), and alpine meadow (AM) along an elevation gradient on Wuyi Mountain, which is located i...

  19. The biomass and aboveground net primary productivity of Schima superba-Castanopsis carlesii forests in east China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The biomass and productivity of Schima superba-Castanopsis carlesii forests in Tiantong,Zhejiang Province,were determined using overlapping quadrants and stem analyses.The total community biomass was(225.3±30.1) t hm-2,of which the aboveground parts accounted for 72.0% and the underground parts accounted for 28.0%.About 87.2% of biomass existed in the tree layer.The resprouting biomass was small,of which over 95.0% occurred in the shrub layer.The productivity of the aboveground parts of the community was(386.8±98.9) g m-2a-1,in which more than 96.0% was present at the tree level.The trunk’s contribution to productivity was the greatest,while that of leaves was the smallest.In China,the community biomass of subtropical evergreen broadleaved forests differs significantly with the age of the forest.The community biomass of the 52-year-old S.superba-C.carlesii forests in this study was lower than the average biomass of subtropical evergreen broadleaved forests in China,and was lower than the biomass of other subtropical evergreen broadleaved forests elsewhere in the world.Moreover,its productivity was lower than the model estimate,indicating that without disturbance,this community has great developmental potential in terms of community biomass and productivity.

  20. Evolution of vegetation and climate since the last glacial maximum recorded at Dahu peat site, South China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Sporopollen analysis on a 346 cm peat record at Dahu, Jiangxi, chronologically constrained by 16 AMS 14C datings, provides an opportunity to reconstruct the vegetation evolution stages responding to cli-mate change in South China since the last glacial maximum. The result shows that during 18330-15630 cal a B.P., broad-leaved forest dominated the area, corresponding to mild, cool and fairly humid climate. At the interval of 15630-11600 cal a B.P., several evergreen broad-leaved species appeared within the broad-leaved forest, indicating moderate and humid condition. During early Holocene, broad-leaved evergreen forest community was constructed as Castanopsis/Lithorcarpus principally developed, suggesting a warm and humid scenario until 6000 cal a B. P. Since 6000 cal a B. P., abrupt forest deterioration happened with an contemporary increase of fern and herb communities, repre-senting a turnover to relatively cool and dry condition and as well, possible impact from human activi-ties. Meanwhile, several relatively cool and dry events can be identified in the sporopollen record, they can be correlated to the North Atlantic Heinrich event, YD and Holocene millennial-scale oscillations, implying that the low latitude climate was coupled with high latitude influences. Moreover, the varia-tions of temperature and humidity since LGM at Dahu were much smaller when compared with the re-cords in north monsoonal China.

  1. Seedling density according to structure, dominance and understory cover in old-growth forest stands of the evergreen forest type in the coastal range of Chile Densidad de plántulas de acuerdo a la estructura, dominancia y cobertura del sotobosque en bosques siempreverdes adultos en la cordillera de la Costa de Chile

    Directory of Open Access Journals (Sweden)

    Pablo J. Donoso

    2005-03-01

    Full Text Available Securing timely regeneration is essential in maintaining the long-term ecological or silvicultural functions and values of forests. Its establishment, in turn, depends on many factors, including the structure and composition of the forest itself. Available information shows that seedling density varies greatly across the evergreen forest type in Chile. Yet stand variables that may affect the establishment of advance regeneration have not been studied. To that end, we evaluated seven stands of the coastal range, within the northern part of the evergreen forest type (39°14'-40°16' S. We documented understory cover, tree density and dominance, and stand structure, and used the information to assess their effects over seedling density. Findings indicate that Laurelia philippiana was the dominant canopy and regenerating species in these stands. Also, seedling density was significantly greater in stands at lower elevations where shade-tolerant Aextoxicon punctatum was important. Chusquea spp. and Lophosoria quadripinnata, both understory species, had a significant negative effect on seedling density. Basal area and canopy cover, per se, showed little relationship with seedling density. Vertical structure, evaluated through a crown index, had a significant relationship with seedling density, but the direction depended on the species (e.g., L. philippiana and A. punctatum and the diameter structure within our plots. Fitted models that included these variables were highly significant, and in most cases their significance increased considerably (14 to 26 % when we accounted for the diameter structures of the plotsLa regeneración es esencial para mantener en el largo plazo las funciones y valores ecológicos o silviculturales de los bosques. Su establecimiento depende de varios factores, incluyendo la estructura y composición del bosque. La información disponible indica que existe una gran variabilidad en la densidad de plántulas a través de la

  2. Study on Litterfall, Nutrient Returned by Litterfall and Nutrient Use Efficiency in Scenic Forests of Central Japan%日本中部风景林凋落物量、养分归还量

    Institute of Scientific and Technical Information of China (English)

    薛达; 薛立; 罗山

    2001-01-01

    研究了日本中部的3个风景林——常绿针叶林、常绿阔叶林和常绿落叶阔叶混交林的凋落物,养分归还量和养分利用效率.常绿针叶林、常绿阔叶林和常绿落叶阔叶混交林的年凋落量分别为7562、6023和5565kg/hm2,养分年归还量分别为233.87、125.20和140.23kg/hm2.各养分中N、K和Ca的归还量大于P和Mg.叶的养分归还量占养分年归还量的64.19%~79.29%.常绿针叶林和常绿阔叶林中Mg的利用效率高,表明Mg可能是这2种风景林生长的限制因子.%Litterfall amounts, nutrients returned by litterfall and nutrientuse efficiency in evergreen coniferous forest, evergreen broad-leaved forest, and evergreen and deciduous broad-leaved mixed forest of Central Japan were studied. Annual amounts of litterfall in evergreen coniferous forest, evergreen broad-leaved forest, and mixed forest were 7 562, 6 023 and 5 565 kg/hm2, respectively, which resulted in the amount of nutrient contained in litterfall being 233.87, 125.20 and 140.23 kg/hm2, respectively. Returned amounts of N, K and Ca were greater than P and Mg in all scenic forests, and leaves contributed 64.19%~79.29% of the total. A high Mg use efficiency in evergreen coniferous forest and evergreen broad-leaved forest indicates that Mg may be in a limited supply in the two scenic forests.

  3. Trade-off between leaf size and number in current-year twigs of deciduous broad-leaved woody species at different altitudes on Qingliang Mountain, southeastern China%清凉峰不同海拔木本植物小枝内叶大小-数量权衡关系

    Institute of Scientific and Technical Information of China (English)

    杨冬梅; 占峰; 张宏伟

    2012-01-01

    Aims Trade-offs are fundamental to life-history strategies theory, and the leaf size and number trade-off is an important determinant of leaf-size evolution. It also has been proposed that this trade-off is dependent on habitat, but this is not well tested. Our objectives were to test whether the negative, isometric relationship between leaf size and number is conserved in different habitats and to explore the effects of altitude change on the relationship between the leaf size and number.Methods Leaf area, mass and number and twig mass and stem mass of current-year twigs were measured for 61 deciduous broad-leaved woody species within three altitude-based habitats on Qingliang Mountain, southeastern China. The standardized major axis estimation method and the phylogenetically independent contrast method were used to examine the scaling relationship between leaf size (leaf mass and leaf area) and leafing intensity (twig mass and stem mass) within current-year twigs.Important findings Significantly negative and isometric scaling relationships between leaf size and leafing intensity were found to be consistent in all three altitude-based habitats, regardless of whether leaf/twig size was expressed as area or mass. However, the intercepts of these relationships significantly decreased with increasing altitude, suggesting that habitats constrain the leaf size that can be supported by a given leafing intensity. The middle-attitude species usually had significant upper shifts along the common slopes relative to the high-altitude species. This suggested that the middle altitude is a more suitable habitat with high nutrients and moderate climate conditions for plants, compared to the high altitude with low temperatures and nutrients.%权衡关系是生活史对策理论的基础,叶大小-数量的权衡关系对理解叶大小进化具有重要的意义.该研究以单叶面积和单叶片干重表示叶大小,用小枝干重和小枝茎干重

  4. 红松阔叶混交林林隙大小及光照对草本植物的影响%Effects of forest gap size and light intensity on herbaceous plants in Pinus koraiensis-dominated broadleaved mixed forest

    Institute of Scientific and Technical Information of China (English)

    段文标; 王丽霞; 陈立新; 杜珊; 魏全帅; 赵健慧

    2013-01-01

    1 m×1 m fixed quadrats were parallelly arranged with a space of 2 m in each of six forest gaps in Pinus koraiensis -dominated broadleaved mixed forest, taking the gap center as the starting point and along east-west and south-north directions.In each quadrat, the coverage and abundance of herbaceous plants at different height levels were investigated by estimation method in June and September 2011, and the matrix characteristics within the quadrats were recorded.Canopy analyzer was used to take fish-eye photos in the selected overcast days in each month from June to September, 2011, and the relative light intensity was calculated by using Gap Light Analyzer 2.0 software.The differences in the relative light intensity and herbaceous plants coverage and richness between different gaps as well as the correlations between the coverage of each species and the direct light, diffuse light, and matrix were analyzed.The results showed that in opening areas and under canopy, the relative light intensity in large gaps was higher than that in small gaps, and the variation ranges of diffuse light and direct light from gap center to gap edge were bigger in large gaps than in small gaps.The direct light reaching at the ground both in large gaps and in small gaps was higher in the north than in the south direction.In the Z1, Z2, Z3, and Z4 zones, both the coverage and the richness of herbaceous plants were larger in large gaps than in small gaps, and the differences of species richness between large and small gaps reached significant level.The coverage of the majority of the herbaceous plants had significant correlations with diffuse light and matrix, and only the coverage of a few herbaceous plants was correlated with direct light.%在小兴安岭红松阔叶混交林中选取的6个林隙内,以每个林隙中心为起点,沿东西和南北两个方向,每隔2 m平行布置1个1 m×l m的固定样方.2011年6月和9月利用估测法测定样方内不同高度等级草本植

  5. Species composition and community structure of the Donglingshan forest dynamic plot in a warm temperate deciduous broad-leaved secondary forest, China%东灵山暖温带落叶阔叶次生林动态监测样地:物种组成与群落结构

    Institute of Scientific and Technical Information of China (English)

    刘海丰; 李亮; 桑卫国

    2011-01-01

    Community structure is one of the key features in the process of vegetation succession.Warm temperate mixed deciduous broad-leaved secondary forest is the main forest vegetation type in China's warm temperate zone.In order to better study the mechanisms of succession and species coexistence in this forest type, we established the Donglingshan 20-ha forest plot (DLS plot) in 2009 and 2010 using the same protocol as the well-established plot on Barro Colorado Island in Panama.In the plot, all free-standing woody plants with DBH (diameter at breast height) ≥1 cm were mapped, tagged, and identified to species.Here, we address preliminary results on floristic characteristics, community composition, and size-class, vertical, and spatial structure of the DLS plot.These datasets will serve as baseline information accessible to a wide range of future studies.We tagged a total of 52,136 genotype individuals (103,284 individuals including branches of genotype individuals), belonging to 58 species, 33 genera and 18 families.All of these tree species were deciduous.Floristic characteristics of the community suggested a temperate flora, including some subtropical and tropical elements.There were very obvious dominant species in the plot.Five species comprised 61% of all individuals, and 20 species comprised 92% of all individuals, while the other 38 species comprised only 8% of all individuals.Vertical structure was composed of an overstory layer (19 species), midstory layer (18 species), and a shrub layer (21 species).The DBH size-class structure of all species in the plot generally fitted a "reverse J" distribution, indicating good regeneration across the community.The size-class structure of the main species in the overstory layer showed a bimodal or nearly normal distribution, while the most abundant species in the midstory and shrub layers showed "reverse J" or even "L" distributions.Spatial distribution patterns of the dominant species varied with size-class and

  6. Genetic diversity of Quercus glandulifera var. brevipetiolata populations in three forest communities with different succession stages

    Institute of Scientific and Technical Information of China (English)

    Junmin LI; Zexin JIN; Qiping GU; Wenyan LOU

    2009-01-01

    In order to understand the relationship between population succession and its genetic behavior, random amplified polymorphic DNA (RAPD) technique was used to analyze the genetic diversity of Quercu glandulifera var.brevipetiolata populations in three forest communities with different succession stages (coniferous forest, coniferous and broad-leaved mixed forest, evergreen broad-leaved forest). The results showed that 145 repetitive loci were produced in 60 individuals of Q. glandulifera using 11 primers, among which 120 loci were polymorphic, and the total percentage of polymorphic loci was 82.76% with an average of 64.14%. Estimated by the Shannon information index, the total genetic diversity of the three populations was 0.4747, with an average of 0.3642, while it was 0.3234, with an average of 0.2484, judged from the Nei index. Judged from percentage of polymorphic loci,Shannon inform at ion index and Nei index, the genetic diversity followed a decreasing order: coniferous forest >broad-leaved mixed forest > evergreen broad-leaved for-est. Analysis of molecular variance (AMOVA) showed that 69.73% of the genetic variance existed within populations and 30.27% of the genetic variance existed among popu-lations. The coefficient of gene differentiation (Gst) was 0.2319 and the gene flow (Nm) was 1.6539. The mean of genetic identity among populations of Q. glandulifera was 0.8501 and the mean of genetic distance was 0.1626. The genetic identity between the Q. glandulifera population in the coniferous forest and that in the coniferous and broad-leaved mixed forest was the highest. UPGMA cluster analysis based on Nei's genetic distance showed that the population in the coniferous forest gathered with that in the coniferous and broad-leaved mixed forest firstly, then with that in the evergreen broad-leaved forest. The genetic structure of Q. glandulifera was not only characteristic of the biological characteristics of this species, but was also influenced by the

  7. Brief analysis on canopy interception effect and influencing factors of five forest types in Simian Mountain of Chongqing%重庆四面山5种森林类型林冠截留影响因素浅析

    Institute of Scientific and Technical Information of China (English)

    张焜; 张洪江; 程金花; 张君玉; 孙龙; 马西军

    2011-01-01

    【Objective】 The study was to probe into the primary and secondary relation of factors influencing canopy interception of different forest types in Three Gorge Reservoir Region of Yangtze River.【Method】 Related data of 25 rainfalls from May to September in 2009 were observed.The paper made a grey correlation analysis on the research of factors influencing canopy interception among five forest type in Simian Mountain of Chongqing.【Result】 ①According to the general interception ratios from high to low,the five forest types are arranged as warm needle-leaved forest(42.70%)temperate needle-leaved forest(39.35%)broadleaf-conifer mixed forest(39.05%)evergreen and deciduous broad-leaved mixed forest(36.28%)evergreen broad-leaved forest(27.73%);According to the average interception ratios from high to low,the five types of forests are arranged as warm needle-leaved forest(50.08%)broadleaf-conifer mixed forest(44.91%)temperate needle-leaved forest(44.18%)evergreen and deciduous broad-leaved mixed forest(42.13%)evergreen broad-leaved forest(31.33%).②The influencing priority of meteorological factors for temperate needle-leaved forest is precipitationrainfall intensitywind velocitytemperatureair humidity.For broadleaf-conifer mixed forest,the priority is precipitationwind velocityrainfall intensitytemperature air humidity.For evergreen broad-leaved forest,the priority is precipitation=rainfall intensitywind velocity=temperatureair humidity.For evergreen and deciduous broad-leaved mixed forest,the priority is precipitationrainfall intensitywind velocitytemperatureair humidity.And for warm needle-leaved forest,the priority is precipitationrainfall intensitywind velocitytemperatureair humidity.③Between the canopy interception amount of each forest types and precipitation,a power function is shown.The precipitation of temperate needle-leaved forest,broadleaf-conifer mixed forest,evergreen broad-leaved forest,evergreen and

  8. 基于模型数据融合的长白山阔叶红松林碳循环模拟%CARBON CYCLE MODELING OF A BROAD-LEAVED KOREAN PINE FOREST IN CHANGBAI MOUNTAIN OF CHINA USING THE MODEL-DATA FUSION APPROACH

    Institute of Scientific and Technical Information of China (English)

    张黎; 于贵瑞; LUO Yi-qi; 何洪林; 张雷明

    2009-01-01

    Aims Our objective was to use multiple terrestrial carbon observations to improve existing terrestrial ecosystem models. Methods We conducted a Bayesian probabilistic inversion to estimate the key parameter (i.e., carbon residence time) of a terrestrial ecosystem model (TECO) by using biometric and eddy covariance flux data measured at a temperate broad-leaved Korean pine forest in Changbai Mountain (CBS) of China from 2003 to 2005. We then estimated carbon stocks, carbon fluxes and uncertainties with posterior estimates of parameters. Biometric measurements consisted of foliage biomass, fine root biomass, woody biomass, litterfall, soil organic matter (SOM) and soil respiration. Important findings Residence times of carbon for most pools can be constrained by eddy covariance flux and biometric measurements, except for the passive soil organic matter pool. Estimated residence times of C ranged from 2 to 6 months for litter and microbial biomass pools, 1 to 2 years for foliage and fine root biomass, 8 to 16 years for slow SOM pool and 77-109 and 409-1 879 years for woody biomass and passive SOM pools, respectively. Model results showed that the prediction uncertainties of carbon stocks and accumulated carbon fluxes increased with time. When air temperature increased 10% and 20%, annual gross primary productivity (GPP) increased 6.5% and 9.9%, but annual net ecosystem productivity (NEP) changed with soil temperature. If soil temperature is constant, annual NEP increased 11.4%-21.9% and 17.6%-33.1%, while if soil temperature increased 10% and 20%, annual NEP decreased to a level that was lower than that under ambient temperature. Given the same climate condition and seasonal variation for leaf area index during 2003-2005, annual NEP and soil respiration in 2020 would be 163±12 and 721±14 g C·m~(-2)·a~(-1). Markov Chain Monte Carlo method is an effective way to estimate model parameters and to evaluate model prediction uncertainties. However, more studies are

  9. 透光抚育对长白山"栽针保阔"红松林土壤碳储量影响%Effect of liberation cutting on the soil carbon storage of a Korean pine forest restored by planting conifers and reserving broad-leaved trees in Changbai Mountains of China.

    Institute of Scientific and Technical Information of China (English)

    张晓亮; 牟长城; 张小单; 韩阳瑞; 庄宸; 曹万亮; 程家友; 郑曈

    2015-01-01

    We studied the effect of liberation cutting on the soil carbon storage and the litter carbon storage of a mid-term (33-year-old) Korean pine forest which was restored by planting conifers and reserving broad-leaved trees by using crown thinning control test method in Changbai Mountains of China. Five levels of cutting intensity were applied, namely, non-cutting ( control) , mild liberation cutting (25%) , moderate liberation cutting ( 50%) , heavy liberation cutting ( 75%) , and clear cutting ( 100%) ( cutting intensity refers to volume percentage) . The main research results were as follows. The liberation cutting had certain effects on the soil bulk density ((0. 83 ± 0. 02) -(1. 15 ± 0. 03)g/cm3) and the soil carbon concentration ((43. 36 ± 1. 60) -(70. 26 ± 1. 94) g/kg) of the Korean pine forest. Compared to the control, moderate liberation cutting decreased the soil bulk density by 8. 4% (P<0. 05), but increased the soil carbon concentration by 14. 9% ( P<0. 05 ) . Heavy liberation cutting and clear cutting increased the soil bulk density by 23. 3% and 27. 1% ( P<0. 05 ) , and degraded the soil carbon concentration by 23. 7% and 29. 1%, respectively ( P<0. 05 ) . Mild liberation cutting had no significant effect on the two parameters. The liberation cutting had great effect on the soil carbon storage ((13. 12 ± 1. 57)-(23. 46 ± 2. 03) kg/m2) of the Korean pine forest. Compared to the control, moderate liberation cutting led to the increase of soil carbon storage by 12. 8% ( P<0. 05 ) , while heavy liberation cutting and clear cutting lowered it by 29. 9% and 36. 9%, respectively ( P<0. 05 ) . Mild liberation cutting had no significant effect on it. The liberation cutting had remarkable effect on the litter carbon storage( (2. 13 ± 0. 39) -(2. 82 ± 0. 37) t/ha) of the Korean pine forest. Moderate liberation cutting resulted in the increase of the litter carbon storage by 19. 5% ( P<0. 05 ) compared to the control, while clear cutting reduced it by 9. 8

  10. Holocene environmental and climatic changes at Gorgo Basso, a coastal lake in southern Sicily, Italy

    Science.gov (United States)

    Tinner, Willy; van Leeuwen, Jacqueline F. N.; Colombaroli, Daniele; Vescovi, Elisa; van der Knaap, W. O.; Henne, Paul D.; Pasta, Salvatore; D'Angelo, Stefania; La Mantia, Tommaso

    2009-07-01

    We used a new sedimentary record to reconstruct the Holocene vegetation and fire history of Gorgo Basso, a coastal lake in south-western Sicily (Italy). Pollen and charcoal data suggest a fire-prone open grassland near the site until ca 10,000 cal yr BP (8050 cal BC), when Pistacia shrubland expanded and fire activity declined, probably in response to increased moisture availability. Evergreen Olea europaea woods expanded ca 8400 to decline abruptly at 8200 cal yr BP, when climatic conditions became drier at other sites in the Mediterranean region. Around 7000 cal yr BP evergreen broadleaved forests ( Quercus ilex, Quercus suber and O. europaea) expanded at the cost of open communities. The expansion of evergreen broadleaved forests was associated with a decline of fire and of local Neolithic ( Ficus carica-Cerealia based) agriculture that had initiated ca 500 years earlier. Vegetational, fire and land-use changes ca 7000 cal yr BP were probably caused by increased precipitation that resulted from (insolation-forced) weakening of the monsoon and Hadley circulation ca 8000-6000 cal yr BP. Low fire activity and dense coastal evergreen forests persisted until renewed human activity (probably Greek, respectively Roman colonists) disrupted the forest ca 2700 cal yr BP (750 BC) and 2100 cal yr BP (150 BC) to gain open land for agriculture. The intense use of fire for this purpose induced the expansion of open maquis, garrigue, and grassland-prairie environments (with an increasing abundance of the native palm Chamaerops humilis). Prehistoric land-use phases after the Bronze Age seem synchronous with those at other sites in southern and central Europe, possibly as a result of climatic forcing. Considering the response of vegetation to Holocene climatic variability as well as human impact we conclude that under (semi-)natural conditions evergreen broadleaved Q. ilex- O. europaea (s.l.) forests would still dominate near Gorgo Basso. However, forecasted climate change and

  11. Rainfall interception by an evergreen beech forest, Nelson, New Zealand

    Science.gov (United States)

    Rowe, L. K.

    1983-10-01

    Throughfall under a beech ( Nothofagus) forest canopy at Donald Creek, Nelson, averaged 69% of the rain falling on the canopy, i.e. 1060 mm of 1530 mm in a year of normal rainfall. Using an estimate for stemflow at 2% of gross rainfall, interception loss averaged 29% of the annual rainfall, or 440 mm yr. -1. Seasonal differences in interception loss were significant, ranging from 22% in winter to 35% in summer, and resulted from seasonal variation in evaporation rates from a wet canopy. Seasonal variation in rainfall rate was slight. Four models, storm linear regression, monthly linear regression, sine curve and Gash's analytical model, were tested by comparison of predicted and observed interception. All gave very satisfactory estimates (< 10% error) and tended to slightly underestimate the measured interception loss.

  12. Schiff Bases: A Short Survey on an Evergreen Chemistry Tool

    Directory of Open Access Journals (Sweden)

    Mauro Panunzio

    2013-10-01

    Full Text Available The review reports a short biography of the Italian naturalized chemist Hugo Schiff and an outline on the synthesis and use of his most popular discovery: the imines, very well known and popular as Schiff Bases. Recent developments on their “metallo-imines” variants have been described. The applications of Schiff bases in organic synthesis as partner in Staudinger and hetero Diels-Alder reactions, as “privileged” ligands in the organometallic complexes and as biological active Schiff intermediates/targets have been reported as well.

  13. 海南岛霸王岭热带山地常绿林和热带山顶矮林群落特征%Community characteristics of tropical montane evergreen forest and tropical montane dwarf forest in Bawangling National Nature Reserve on Hainan Island, South China

    Institute of Scientific and Technical Information of China (English)

    龙文兴; 臧润国; 丁易

    2011-01-01

    Both tropical montane evergreen forest (TMEF) and tropical montane dwarf forest (TMDF) are typical tropical cloud forests on Hainan Island. To compare community structure and species diversity between these two forest types, we established eight and ten plots (each with 2,500 m2 in area) in TMEF and TMDF, respectively, in Bawangling National Nature Reserve on Hainan Island, South China. We investigated each individual plant with diameter at breast height (DBH) ≥1 cm including trees, shrubs and lianas, and found that the mean density of saplings (1 cm≤DBH < 5 cm) and small trees (5 cm≤DBH < 10 cm) was lower in TMEF than TMDF, while there were no differences in density of adult trees (DBH≥10 cm) between the two forest types. TMEF had higher mean DBH of small trees and adult trees, but lower mean DBH of saplings than TMDF. Mean height of saplings, small trees and adult trees was higher in TMEF than TMDF. The dominant species differed between these two forest types, but dominant family, dominant genera and overall species compositions were similar, with a Serensen similarity index value of 0.71. Compared with the power and exponential curves, the logistic curve was the optimal model approximating the species-area relation within the two forest types. The observed species richness values, as well as the values predicted by 1st order Jackknife estimator, 2nd order Jackknife estimator and bootstrap estimator, were higher in TMEF than TMDF. Our results highlight the differences in community structure and species diversity between TMEF and TMDF, which likely resulting from differences in mechanisms maintaining the structure and diversity of these two types of forest communities.%热带山地常绿林和热带山顶矮林均属于热带云雾林.为了揭示其群落结构和物种多样性特征,在海南岛霸王岭热带山地常绿林和热带山顶矮林分别设置8个和10个2,500 m2样方,调查所有DBH≥1cm的乔木、灌木和藤本植株.结果显示:(1

  14. Evolution of vegetation and climate since the last glacial maximum recorded at Dahu peat site,South China

    Institute of Scientific and Technical Information of China (English)

    XIAO JiaYi; L(U) HaiBo; ZHOU WeiJian; ZHAO ZhiJun; HAO RuiHui

    2007-01-01

    Sporopollen analysis on a 346 cm peat record at Dahu, Jiangxi, chronologically constrained by 16 AMS 14C datings, provides an opportunity to reconstruct the vegetation evolution stages responding to climate change in South China since the last glacial maximum. The result shows that during 18330-15630 cal a B.P., broad-leaved forest dominated the area, corresponding to mild, cool and fairly humid climate. At the interval of 15630-11600 cal a B.P., several evergreen broad-leaved species appeared within the broad-leaved forest, indicating moderate and humid condition. During early Holocene,broad-leaved evergreen forest community was constructed as Castanopsis/Lithorcarpus principally developed, suggesting a warm and humid scenario until 6000 cal a B. P. Since 6000 cal a B. P., abrupt forest deterioration happened with an contemporary increase of fern and herb communities, representing a turnover to relatively cool and dry condition and as well, possible impact from human activities. Meanwhile, several relatively cool and dry events can be identified in the sporopollen record, they can be correlated to the North Atlantic Heinrich event, YD and Holocene millennial-scale oscillations,implying that the low latitude climate was coupled with high latitude influences. Moreover, the variations of temperature and humidity since LGM at Dahu were much smaller when compared with the records in north monsoonal China.

  15. Spatial-temporal Patterns of Species Diversity in Ecological Forests of Zhejiang%浙江省生态公益林物种多样性时空格局研究

    Institute of Scientific and Technical Information of China (English)

    沈爱华; 袁位高; 张骏; 江波; 朱锦茹; 黄丽霞

    2014-01-01

    通过380个浙江省生态公益林中常绿阔叶林、针阔混交林、松林、杉木林4种主要森林群落的典型样地调查,对不同群落类型物种多样性的时空格局进行研究,结果表明:在空间格局上不同群落类型物种多样性存在较大差异,乔木层多样性指数以针阔混交林和常绿阔叶林为最高;针阔混交林的下木层物种数最高,其次是常绿阔叶林,但下木层各指数在各林型间均无显著差异;杉木林下草本层物种数指数最高,松林草本层各项指数都最低。从时间格局分析,不同群落类型的多样性指数随年龄变化各不相同,常绿阔叶林和针阔混交林乔木层物种数在幼龄-中龄-近熟阶段趋势一致,均为先大幅增加然后略有下降,两种针叶林型的物种数都相对稳定;4种主要群落类型的乔木层Simpson生态优势度指数D,常绿阔叶林和针阔混交林随时间变化趋势一致,均为先增加后略有下降再增加,且显著高于同年龄级的针叶林;常绿阔叶林和针阔混交林乔木层Shannon-Wiener多样性指数H′随时间各异,但都极显著高于同年龄级针叶林的指数。常绿阔叶林和针阔混交林群落物种组成丰富、多样性指数高,是浙江省生态公益林的理想群落与目的群落。%Spatial and temporal patterns of species diversity in evergreen broadleaved forest, coniferous and broadleaved mixed forest, pine forest, Chinese fir forest in Zhejiang Province was investigated by 380 typical sample plots. The results showed that the highest arbor layer diversity in evergreen broadleaved forest and coniferous and broadleaved mixed forest. For species diversity in understory layer, the richest was in coniferous and broadleaved mixed forest, followed by evergreen broadleaved forest. However, the difference of understory diversity indices among various forests was not significant. In herb layer, Chinese fir forest had the

  16. Physiographic and floristic gradients across topography in transitional seasonally dry evergreen forests of southeast Pará, Brazil Gradientes fisiográficos e florísticos ao longo do relevo em florestas perenifólias sazonalmente secas de transição no Sudeste do Pará, Brasil

    Directory of Open Access Journals (Sweden)

    James Grogan

    2006-12-01

    Full Text Available Seasonally dry evergreen forests in southeast Pará, Brazil are transitional between taller closed forests of the interior Amazon Basin and woodland savannas (cerrados of Brazil's south-central plains. We describe abiotic and biotic gradients in this region near the frontier town of Redenção where forest structure and composition grade subtly across barely undulating topography. Annual precipitation averaged 1859 mm between 1995-2001, with nearly zero rainfall during the dry season months of June August. Annual vertical migrations of deep-soil water caused by seasonal rainfall underlie edaphic and floristic differences between high- and low-ground terrain. Low-ground soils are hydromorphic, shaped by perching water tables during the wet season, pale gray, brown, or white in color, with coarse texture, low moisture retention during the dry season, and relatively high macro-nutrient status in the surface horizons. Forest canopies on low ground are highly irregular, especially along seasonal streams, while overstory community composition differs demonstrably from that on high ground. High-ground soils are dystrophic, well-drained through the wet season, brown or red-yellow in color, with finer texture, higher moisture retention, and low macro-nutrient status in the surface horizons compared to low-ground soils. Forest canopies are, on average, taller, more regular, and more closed on high ground. Low-ground areas can be envisioned as energy and nutrient sinks, where, because of hydrologic cycles, canopy disturbance likely occurs more frequently than at high-ground positions if not necessarily at larger scales.As florestas perenifólias sazonalmente secas no sudeste do Pará, Brasil, são áreas de transição entre as florestas fechadas mais altas do interior da Bacia Amazônica e o cerrado das planícies da região Sul-Central do Brasil. Descrevemos os gradientes abióticos e bióticos nessa região próxima da cidade de Redenção, onde a

  17. Forest Litter Containing Moisture and Water Storage and Associated Influencing Factors in Rolling Hill Areas of Southern Jiangsu Province%苏南丘陵森林枯落物含水量及其影响因素分析

    Institute of Scientific and Technical Information of China (English)

    张增信; 闵俊杰; 闫少锋; 姜志林; 张军; 张菲

    2011-01-01

    Forest litter, which has a high water storage and retention capacity, is an extremely important hydrological component for sustaining water conservation function of the forests.The variations of forest litter containing moisture(FLCM) and forest litter water storage(FLWS) were analyzed in Southern Jiangsu Province, associating with influencing factors such as soil water contents and meteorological parameters.The results show that evergreen broad-leaved, deciduous broad-leaved, pine(Pinus taeda L.), and bamboo forests had FLCM values from high to low, respectively, and similarly, deciduous broad-leaved, evergreen broad-leaved, pine, and bamboo forests had high to low FLWS values.Precipitation had an obvious impact on FLWS, as well as evaporation.The increase of FLCM resulted from precipitation normally had a time lag of 1 to 5 days.Evaporation correlated negatively with FLCM, with correlation coefficients of -0.39,-0.38,-0.13 and -0.32 for deciduous broad-leaved, evergreen broad-leaved, pine, and bamboo forests,respectively.FLWSS of deciduous forests(deciduous broad-leaved and bamboo) are affected by soil moisture contents more significantly than those of evergreen forests(pine and evergreen broad-leaved).FLWSS correlated with soil water contents of 10 cm more closely than those of 20 cm.%森林枯落物是保障森林充分发挥涵养水源功能的一个极其重要的水文层次,具有明显的蓄水、保水作用.通过分析苏南丘陵地区的主要森林类型枯落物含水率、蓄水量及其与土壤含水率和气象因子之间的关系,结果发现,苏南丘陵地区枯落物含水率由大到小依次为;常绿阔叶林、落叶阔叶林、火炬松林、毛竹林;蓄水量由大到小则为;落叶阔叶林、常绿阔叶林、火炬松林、毛竹林.降水和蒸发等气象要素对枯落物含水率有重要影响,一次连续降水会显著增加枯落物含水率,但存在1~5 d的滞后;蒸发量与枯落物含水率呈显著负相关,平

  18. Research on Water Conservation Function ol Typical Forests in Jinyun Mountain%重庆缙云山典型林分水源涵养功能研究

    Institute of Scientific and Technical Information of China (English)

    李杨; 王百田; 饶良懿; 王玉杰

    2012-01-01

    [Objective] This study aimed to explore the relationship between different forest types and water conservation function. [Method] Based on field survey and experimental analysis, water conservation function of four typical forest stands in Jinyun Mountain of Chongqing was explored, including conifer-broadleaved mixed for- est, evergreen broad-leaved forest, bamboo forest and shrub forest. [Result] The re- sults showed that the order of saturated water storage capacity of soil in four forest stands was shrub forest (266.48 mm) 〉 conifer-broadleaved mixed forest (190.40 mm) 〉 evergreen broad-leaved forest (186.80 mm) 〉 bamboo forest (174.80 mm); the order of maximum water-holding capacity of litter was shrub forest (8.06 mm) 〉 conifer-broadleaved mixed forest (4.71 mm) 〉 evergreen broad-leaved forest (4.32 mm) 〉 bamboo forest (3.34 mm); the order of canopy interception in various forest stands was conifer-broadleaved mixed forest (16.15%) 〉 evergreen broad-leaved for- est (14.70%) 〉 bamboo forest (12.64%). [Conclusion] The study had great signifi- cance to rational manage forest resources, improve water environment and realize scientific management and use of water resources.%【目的]探讨不同类型林地与涵养水源功能的关系。[方法]通过实地调查与实验分析,对重庆缙云山中针阔混交林、常绿阔叶林、楠竹林和灌木林4种典型林分的水源涵养功能进行了分析。【结果]4种林分的土壤饱和蓄水量顺序为灌木林(266.48mm)〉针阔混交林(190.40mm)〉常绿阔叶林(186.80mm)〉楠竹林(174.80mm);枯落物最大持水量顺序为灌木林(8.06mm)〉针阔混交林(4.71mm)〉常绿阔叶林(4.32mm)〉楠竹林(3.34mm);各种林分的林冠截留率顺序为针阔混交林(16.15%)〉常绿阔叶林(14.70%)〉楠竹林(12.64%)。[结论]该研究对

  19. Research on Water Conservation Function of Typical Forests in Jinyun Mountain%重庆缙云山典型林分水源涵养功能研究

    Institute of Scientific and Technical Information of China (English)

    李杨; 王百田; 饶良懿; 王玉杰; 赵铭军

    2012-01-01

    [Objective] This study aimed to explore the relationship between different forest types and water conservation function. [Method] Based on field survey and experimental analysis, water conservation function of four typical forest stands in Jinyun Mountain of Chongqing was explored, including conifer-broadleaved mixed forest, evergreen broad-leaved forest, bamboo forest and shrub forest. [Result] The results show that the order of saturated water storage capacity of soil in four forest stands was shrub forest (266.48 mm) > conifer-broadleaved mixed forest (190.40 mm) > evergreen broad-leaved forest (186. 80 mm) > bamboo forest (174. 80 mm) ; the order of maximum water-holding capacity of litter was shrub forest (8.06 mm) > conifer-broadleaved mixed forest (4.71 mm) > evergreen broad-leaved forest (4.32 mm) > bamboo forest (3. 34 mm) ; the order of canopy interception in various forest stands was conifer-broadleaved mixed forest (16. 15% ) > evergreen broad-leaved forest (14. 70% ) > bamboo forest (12. 64% ). [Conclusion] The study had great significance to rational manage forest resources, improve water environment and realize scientific management and use of water resources.%[目的]探讨不同类型林地与涵养水源功能的关系.[方法]通过实地调查与实验分析,对重庆缙云山中针阔混交林、常绿阔叶林、楠竹林和灌木林4种典型林分的水源涵养功能进行了分析.[结果]4种林分的土壤饱和蓄水量顺序为灌木林(266.48 mm)>针阔混交林(190.40 mm)>常绿阔叶林(186.80 mm)>楠竹林(174.80 mm);枯落物最大持水量顺序为灌木林(8.06 mm)>针阔混交林(4.71 mm)>常绿阔叶林(4.32 mm)>楠竹林(3.34 mm);各种林分的林冠截留率顺序为针阔混交林(16.15%)>常绿阔叶林(14.70%)>楠竹林(12.64%).[结论]该研究对合理经营森林资源、改善水环境、实现水资源的科学管理和利用具有重要意义.

  20. Response of Termite (Blattodea: Termitoidae) Assemblages to Lower Subtropical Forest Succession: A Case Study in Dinghushan Biosphere Reserve, China.

    Science.gov (United States)

    Li, Zhi-Qiang; Ke, Yun-Ling; Zeng, Wen-Hui; Zhang, Shi-Jun; Wu, Wen-Jing

    2016-02-01

    Termite (Blattodea: Termitoidae) assemblages have important ecological functions and vary in structure between habitats, but have not been studied in lower subtropical forests. To examine whether differences in the richness and relative abundance of termite species and functional groups occur in lower subtropical regions, termite assemblages were sampled in Dinghushan Biosphere Reserve, China, among pine forest, pine and broad-leaved mixed forest (mixed forest), and monsoon evergreen broad-leaved forest (monsoon forest). The dominant functional group was wood-feeding termites (family Termitidae), and the mixed forest hosted the greatest richness and relative abundance. Soil-feeding termites were absent from the lower subtropical system, while humus-feeding termites were sporadically distributed in mixed forest and monsoon forest. The species richness and functional group abundance of termites in our site may be linked to the forest succession. Altitude, soil temperature, air temperature, surface air relative humidity, and litter depth were significant influences on species and functional group diversity. PMID:26577861

  1. Response of Termite (Blattodea: Termitoidae) Assemblages to Lower Subtropical Forest Succession: A Case Study in Dinghushan Biosphere Reserve, China.

    Science.gov (United States)

    Li, Zhi-Qiang; Ke, Yun-Ling; Zeng, Wen-Hui; Zhang, Shi-Jun; Wu, Wen-Jing

    2016-02-01

    Termite (Blattodea: Termitoidae) assemblages have important ecological functions and vary in structure between habitats, but have not been studied in lower subtropical forests. To examine whether differences in the richness and relative abundance of termite species and functional groups occur in lower subtropical regions, termite assemblages were sampled in Dinghushan Biosphere Reserve, China, among pine forest, pine and broad-leaved mixed forest (mixed forest), and monsoon evergreen broad-leaved forest (monsoon forest). The dominant functional group was wood-feeding termites (family Termitidae), and the mixed forest hosted the greatest richness and relative abundance. Soil-feeding termites were absent from the lower subtropical system, while humus-feeding termites were sporadically distributed in mixed forest and monsoon forest. The species richness and functional group abundance of termites in our site may be linked to the forest succession. Altitude, soil temperature, air temperature, surface air relative humidity, and litter depth were significant influences on species and functional group diversity.

  2. Effects of litter manipulation on litter decomposition in a successional gradients of tropical forests in southern China

    DEFF Research Database (Denmark)

    Chen, Hao; Gurmesa, Geshere A.; Liu, Lei;

    2014-01-01

    Global changes such as increasing CO2, rising temperature, and land-use change are likely to drive shifts in litter inputs to forest floors, but the effects of such changes on litter decomposition remain largely unknown. We initiated a litter manipulation experiment to test the response of litter...... decomposition to litter removal/addition in three successional forests in southern China, namely masson pine forest (MPF), mixed coniferous and broadleaved forest (MF) and monsoon evergreen broadleaved forest (MEBF). Results showed that litter removal decreased litter decomposition rates by 27%, 10% and 8......% and litter addition increased litter decomposition rates by 55%, 36% and 14% in MEBF, MF and MPF, respectively. The magnitudes of changes in litter decomposition were more significant in MEBF forest and less significant in MF, but not significant in MPF. Our results suggest that change in litter quantity can...

  3. Analysis on Plant Diversity Quanfu Village Basin of Water-holding Forest in of Yuanyang Terrace%元阳梯田全福庄流域水源涵养林的植物多样性分析

    Institute of Scientific and Technical Information of China (English)

    和弦; 宋维峰; 彭永刚; 王惠生; 崔吉林

    2012-01-01

    元阳梯田已有1200多年的历史,水源涵养林的存在对于梯田的延续具有重要的价值。为得到元阳梯田水源涵养林的植物多样性分布特征,对元阳梯田全福庄流域4种主要植被类型水源涵养林下的植物物种数量特征、物种丰富度、多样性、均匀度等多样性规律进行了标准样地调查。结果表明,研究区共有植物155种,隶属66科,其中,山茶科、禾本科、蓼科植物占有绝对优势,不同植被类型森林群落的优势种不同;物种丰富度大小为:次生常绿阔叶林〉杂木林〉次生落叶阔叶林〉人工水冬瓜林;物种多样性特征表现为,乔木层:次生常绿阔叶林〉次生落叶阔叶林〉杂木林〉人工水冬瓜林;灌木层:次生常绿阔叶林〉杂木林〉次生落叶阔叶林,人工水冬瓜林无灌木层分布;草本层:次生落叶阔叶林〉人工水冬瓜林〉次生常绿阔叶林〉杂木林。植被分布的物种丰富度和均匀度对物种多样性存在交叉影响。%Yuanyang terrace with over 1 200 years of history, the existence of water-holding forest has an important value for development of Yuanyang terrace. In order to investigate the distribution of plant diversity in water-holding forest of Yuanyang terrace this study adopted the method of standard statistical and on-site investigation. The study on the quantitative features, the species richness, diversity and evenness, etc. char- acteristics in 4 types of vegetation regions in Quanfu middle village basin were carried out. The results showed that there were 155 species of plants in this area, belonging to 66 families, and Theaceae, Poaceae and Polygonaceae were 3 dominant families. The different vegetation regions had different dominant species. The species richness index followed the order of secondary evergreen broad-leaved forest〉weed tree forest〉 secondary deciduous broad-leaved forest〉artificial Alder forest. Within

  4. Vertical patterns of the flora of seed plants in Dawei Mountain in Yunnan Province, Southwest China

    Institute of Scientific and Technical Information of China (English)

    Wang Juan; Ma Qin-yan; Du Fan; Yang Yu-ming

    2007-01-01

    Vertical gradients incorporate multiple resources gradients which vary continuously. Therefore, research on mountain floristic patterns along vertical gradients is important to reveal regular patterns of the flora along environmental gradients and to understand the changes in biodiversity along these gradients and their biological fitness. This study was designed to explore the characteristics of the floral compositions and ecological significance of floristic patterns along the vertical gradients of the National Nature Reserve of Dawei Mountain, located in the southeast of Yunnan Province. We analyzed the structural characteristics of the flora and the distribution patterns of its floristic components as a function of elevation on the basis of our field investigations along vertical vegetation transects. We carried out a systematic cluster analysis in order to determine the dividing line of floristic changes by elevation along gradients and studied the effects of mountain climate on the vertical variation of floristic composition. The study shows: 1)that the obvious boundary, which differentiates tropical distribution, is located at an elevation of approximately 1,500 m, which separates the tropical rain forests from the evergreen broad-leaved forests; 2) that humid rain forests are found below 700 m elevation,mountain rain forests between 700 and 1,500 m, monsoon evergreen broad-leaved forests between 1,300 and 1,800 m and mountain mossy evergreen broad-leaved forests above 1,800 m. Non-representative mountain mossy dwarf forests (above 2,100 m) in the area are found on the windward sides and barren lands on mountain slopes; 3) that Hopea mollissima is one of the major component species of mountain rain forests, but it should not be considered as the major indicator species in humid rain forests as is generally accepted.

  5. Soil fractal features of typical forest stands in Jinyun Mountain, Chongqing City, Southwest China

    Institute of Scientific and Technical Information of China (English)

    CHENG Chen; WANG Yujie; WANG Yunqi; PAN Yujuan

    2007-01-01

    In order to explore the forest soil physical property in the Three Gorges Reservoir areas,the fractal theory was adopted to study the soil fractal features of the four typical forest stands(mixed Pinus massoniana-broadleaf forests,evergreen broadleaved forests,Phyllostachyspubescens forests and evergreen broadleaved shrub forests)in Jinyun Mountain,Chongqing City,and they were compared with arable land.It has been proposed that the model can be used for the analysis of the relationship between the fractal dimensions and the properties of forest soil.The impacts of fractal dimensions on the soil properties were analyzed with the elasticity analysis and marginal yield analysis.Results showed that the fractal dimension of particle size distribution(PSD),the micro-aggregate size distribution(ASD)and the soil pore size distribution(SPD)can be used as the indices to evaluate the soil structure.In the typical stands of Jinyun Mountain,the fractal dimension of PSD is 2.7-2.9,the ASD is 2.5-2.8,and the SPD is 2.3-2.8.The soil structure of evergreen broadleaved shrub forests performed best in PSD,ASD and SPD,and the soil of P.pubescens forests is the worst.There were some relationships among the PSD,ASD,SPD and some soil properties in the different forests and farmland.The related coefficients are over 0.5.Based on the elasticity analysis and marginal yield analysis,the effect of PSD was more than those of ASD and SPD.Obviously,the further study on the fractal theory application in soil structure and soil properties has important significance.

  6. Spatial and seasonal variations of leaf area index (LAI) in subtropical secondary forests related to floristic composition and stand characters

    Science.gov (United States)

    Zhu, Wenjuan; Xiang, Wenhua; Pan, Qiong; Zeng, Yelin; Ouyang, Shuai; Lei, Pifeng; Deng, Xiangwen; Fang, Xi; Peng, Changhui

    2016-07-01

    Leaf area index (LAI) is an important parameter related to carbon, water, and energy exchange between canopy and atmosphere and is widely applied in process models that simulate production and hydrological cycles in forest ecosystems. However, fine-scale spatial heterogeneity of LAI and its controlling factors have yet to be fully understood in Chinese subtropical forests. We used hemispherical photography to measure LAI values in three subtropical forests (Pinus massoniana-Lithocarpus glaber coniferous and evergreen broadleaved mixed forests, Choerospondias axillaris deciduous broadleaved forests, and L. glaber-Cyclobalanopsis glauca evergreen broadleaved forests) from April 2014 to January 2015. Spatial heterogeneity of LAI and its controlling factors were analysed using geostatistical methods and the generalised additive models (GAMs) respectively. Our results showed that LAI values differed greatly in the three forests and their seasonal variations were consistent with plant phenology. LAI values exhibited strong spatial autocorrelation for the three forests measured in January and for the L. glaber-C. glauca forest in April, July, and October. Obvious patch distribution pattern of LAI values occurred in three forests during the non-growing period and this pattern gradually dwindled in the growing season. Stem number, crown coverage, proportion of evergreen conifer species on basal area basis, proportion of deciduous species on basal area basis, and forest types affected the spatial variations in LAI values in January, while stem number and proportion of deciduous species on basal area basis affected the spatial variations in LAI values in July. Floristic composition, spatial heterogeneity, and seasonal variations should be considered for sampling strategy in indirect LAI measurement and application of LAI to simulate functional processes in subtropical forests.

  7. Pollination in a degraded tropical landscape: a Hong Kong case study

    OpenAIRE

    Corlett, RT

    2001-01-01

    Although the pollination biology of many individual plant species has been investigated in the Oriental region, there have been very few community-level studies. The two most comprehensive of these were in the primary mixed dipterocarp forest of Lambir Hills National Park, Sarawak (4°20[prime prime or minute]N: Momose et al. 1998, Sakai et al. 1999) and in the warm temperate evergreen broad-leaved forest and cool temperate mixed forest on Yakushima Island (30°N: Yumoto 1987, 1988). Hong Kong ...

  8. Generation of runoff characteristics over three time period for four typical forests in Jinyun Mountain, Chongqing City southwest China

    Institute of Scientific and Technical Information of China (English)

    Xiaoyuan CHU; Yujie WANG; Yiping XIA; Yun WU; Lin CHEN

    2009-01-01

    In order to provide a basis for water conservation in the restoration of vegetation for an urban water resource area, we studied the generation of runoff characteristics in four typical forests over three time periods in Jinyun Mountain, Chongqing City, based on the observation data of rainfall and runoff processes during the period 2002-2005. The results show that: 1) Rainfall was distributed evenly during the years 2002-2005. Annual rainfall variability was 4.46% and coefficient of variation was 0.0618. Average monthly rainfall tended towards a normal distribution N (113.8, 45972). 2) Both precipitation and runoff can be clearly divided into a dry and a wet season. The dry season was from October to March and the wet season from April to September. Most of annual runoff of the four forest stands occurred in the wet season. The surface runoff in the wet season accounted for more than 85% of the annual runoff, and more than 75% of underground runoff. 3) Both peak values of surface runoff and underground runoff occurred in June. The relation between monthly rainfall and surface/underground runoff was fitted by the model W = aP2 + bP + c. The order of annual surface runoff was as follows: Phyllostachys pub-escens forest > shrub forest > mixed Pinus massoniana-broadleaf forest > evergreen broad-leaved forest. The annual underground runoff was evergreen broad-leaved forest > mixed Pinus massoniana-broadleaf forest >Phyl-lostachys pubescens forest > shrub forest. 4) Under similar rainstorms events, the order of the surface runoff coefficient was: evergreen broad-leaved forest mixed Pinus massoniana-broadleaf forest > Phyllostachys pubescens forest > shrub forest. The relation between rainstorms and surface runoff was fitted by the linear relationship: Q = mp-n. Both mixed Pinus massoniana-broadleaf forest and evergreen broad-leaved forest have better flood regulation effects on an annual and monthly basis and per individual rainstorm. The function of Phyllostachys

  9. Comparative studies on phenotypic plasticity of two herbs, Changium smyrnioides and Anthriscus sylvestris

    Institute of Scientific and Technical Information of China (English)

    常杰; 关保华; 葛滢; 陈玉成

    2004-01-01

    The endangered medicinal herb, Changium smyrnioides can only be found in deciduous forest gaps within the middle to northern subtropical broad-leaved evergreen forest zone of China. The considerable plasticity of its shoot and root structure helps it to capture light more effectively in winter and early spring, and to adapt to the soil moisture conditions in its narrow habitat. Another medicinal plant, Anthriscus sylvestris, is of similar economic importance but commonly distributed widely. In contrast to C. smyrnioides, it has low structural plasticity. It is also specialized to adapt to the moist and sunny environment, where habitat, such as the banks of creeks and rivers, is abundant.

  10. Comparative studies on phenotypic plasticity of two herbs,Changium smyrnioides and Anthriscus sylvestris

    Institute of Scientific and Technical Information of China (English)

    常杰; 关保华; 葛滢; 陈玉成

    2004-01-01

    The endangered medicinal herb, Changium smyrnioides can only be found in deciduous forest gaps within the middle to northern subtropical broad-leaved evergreen forest zone of China. The considerable plasticity of its shoot and root structure helps it to capture light more effectively in winter and early spring, and to adapt to the soil moisture conditions in its narrow habitat. Another medicinal plant, Anthriscus sylvestris, is of similar economic importance but commonly distributed widely. In contrast to C. smyrnioides, it has low structural plasticity. It is also specialized to adapt to the moist and sunny environment, where habitat, such as the banks of creeks and rivers, is abundant.

  11. Efectos del fósforo y carbono lábiles en la fijación no simbiótica de N2 en hojarasca de bosques siempreverdes manejados y no manejados de la Isla de Chiloé, Chile Effects of labile phosphorous and carbón on non-symbiotic N2 fixation in logged and unlogged evergreen forests in Chiloé Island, Chile

    Directory of Open Access Journals (Sweden)

    SANDRA E PÉREZ

    2008-06-01

    experimentalmente. El manejo de bosque afectó la composición florística de la hojarasca, pero no hubo diferencias su relación C/N, ni en los contenidos de N o P totales.Nitrogen input to evergreen températe forests of Chiloé Island, Chile occurs predominantly via non-symbiotic fixation (NSF. Because this is a bacterial-mediated process (diazotrophs, in addition to environmental factors (e.g., temperature and moisture, phosphorous availability and energy supply from carbón in the substrate may influence the rates of N fixation. Our hypothesis is that if both phosphorous and carbón are limiting NSF, this limitation would be greater in logged forests, where additions of labile P and C would stimulate microbial activity. Our objectives are to assess the effects of inorganic phosphorus and labile carbón (as glucose additions (0 mmol P/L, 0.645 mmol P/L, 3.23 mmol P/L y 6.45 mmol P/L and 0 mmol P/L, 23.3 mmol C/L, 46.6 mmol C/L y 70 mmol C/L, respectively on the rates of NSF measured in the litter layer of each forest in laboratory assays, under controlled temperature and moisture and using homogeneous litter samples. We studied lowland evergreen rainforests (100-200 m of altitude, located in the Chonchi district, in Chiloé Island. Two forest stands were logged, subjected to industrial and non-industrial selective logging, and the third stand was unlogged (control. The NSF of nitrogen was assessed by the acetylene reduction assay. Two-way ANOVAs showed that phosphorous addition had no effect on acetylene reduction rates (ARR in the litter of logged or unlogged forests, but the addition of labile carbón in the form of glucose negatively affected ARR when applied at the máximum level to the litter of unlogged forest. In all treatments the factor forest accounted for the differences in ARR, which was higher in unlogged forest. These differences were not explained by any of the variables experimentally manipulated in this study. The main difference among forests was floristic

  12. Dead wood quality influences species diversity of rare cryptogams in temperate broadleaved forests

    Directory of Open Access Journals (Sweden)

    Preikša Z

    2016-04-01

    Full Text Available Dead wood is one of the most important indicators of forest naturalness and the most important manageable habitat for biodiversity in forests. Standing and lying dead wood, and especially coarse woody debris, plays an important part in creating habitats for many highly specialized organisms, e.g., insects, fungi, lichens and bacteria. Temperate mixed deciduous forests, rich in species, have been studied only to a small extent from the point of view of the ecology of wood-related cryptogams. Our study aimed at the reduction of the gap in knowledge about the ecological characteristics of dead wood-dependent organisms by focusing on species of cryptogams developing on various dead wood structures typical of temperate non-beech forests. Studies were performed in forests located in Lithuania, Poland, Belarus and Russia. We recorded 48 species of cryptogams: 18 species of bryophytes, 24 species of fungi and 6 species of lichens developing on dead wood. Our study stresses the importance of all types of dead wood as a substrate for the development of rare cryptogam species. Logs were the most important substratum type for cryptogams, followed by snags, dead trees and stumps. The cryptogam species richness on logs was several times higher than on the three other types of substrata. Coarse logs of intermediate decay stages hosted the highest number of cryptogams, followed by freshly fallen logs and, finally, well decayed logs. Assessing the importance of dead wood quality for the studied cryptogams, we found that intermediate decay stages are extremely important for fungi, while bryophytes or lichens do not show a clear preference. The highest number of cryptogams was found on Fraxinus excelsior, Quercus robur and Picea abies, while other tree species had less than half cryptogam species.

  13. Quantifying Rainfall Interception Loss of a Subtropical Broadleaved Forest in Central Taiwan

    Directory of Open Access Journals (Sweden)

    Yi-Ying Chen

    2016-01-01

    Full Text Available The factors controlling seasonal rainfall interception loss are investigated by using a double-mass curve analysis, based on direct measurements of high-temporal resolution gross rainfall, throughfall and stemflow from 43 rainfall events that occurred in central Taiwan from April 2008 to April 2009. The canopy water storage capacity for the wet season was estimated to be 1.86 mm, about twice that for the dry season (0.91 mm, likely due to the large reduction in the leaf area index (LAI from 4.63 to 2.23 (m2·m−2. Changes in seasonal canopy structure and micro-meteorological conditions resulted in temporal variations in the amount of interception components, and rainfall partitioning into stemflow and throughfall. Wet canopy evaporation after rainfall contributed 41.8% of the wet season interception loss, but only 17.1% of the dry season interception loss. Wet canopy evaporation during rainfall accounted for 82.9% of the dry season interception loss, but only 58.2% of the wet season interception loss. Throughfall accounted for over 79.7% of the dry season precipitation and 76.1% of the wet season precipitation, possibly due to the change in gap fraction from 64.2% in the dry season to 50.0% in the wet season. The reduced canopy cover in the dry season also produced less stemflow than that of the wet season. The rainfall stemflow ratio ( P s f / P g was reduced from 12.6% to 8.9%. Despite relatively large changes in canopy structure, seasonal variation of the ratio of rainfall partitioned to interception was quite small. Rainfall interception loss accounted for nearly 12% of gross precipitation for both dry and wet seasons.

  14. Subantarctic forest ecology : case study of a conifer-broadleaved stand in Patagonia, Argentina

    NARCIS (Netherlands)

    Dezzotti, A.

    2000-01-01

    In the temperate rainforests of southern South America, the tree genus Nothofagus (Nothofagaceae) is the dominant in extension and abundance on zonal soils at different latitudes and altitudes, as well as on intrazonal (e.g., wetlands) and azonal soils (e.g., morrenic and fluvioglacial deposits). Al

  15. Effects of Seedbed Density on Seedling Morphological Characteristics of four Broadleaved Species

    Energy Technology Data Exchange (ETDEWEB)

    Yucedag, C.; Gailing, O.

    2012-11-01

    The aim of this study was to investigate the effects of seedling spacing on morphological characteristics of one year-old Amygdalus communis L., Prunus avium L., Pyrus elaeagnifolia Pall. and Eriolobus trilobatus (Poiret) Roemer seedlings under nursery conditions. Seedlings were grown in completely randomized blocks with four replications. Seedbeds were 1.2 m wide with 5 rows each 20 cm apart. Within-row spacings were chosen as 4, 8 and 12 cm to analyze the effect of seedlings density on growth performance. Seedling spacing significantly affected root collar diameter, shoot height, tap root length and number of fine roots in A. communis and P. avium, but not in P. elaeagnifolia and E. tribolatus. Additionally wider seedling spacings resulted in larger seedlings in A. communis and P. avium. In conclusion, it would be beneficial to use wider seedling spacing in order to obtain better seedling growth in A. communis and P. avium. Larger seedlings could also provide significant advantages because of reduced cultural activities and an expected higher growth and survival rate. (Author) 27 refs.

  16. Management of broadleaved weeds in small-scale in an on-farm perspective

    International Nuclear Information System (INIS)

    An on-farm trial was conducted at eight different sites in Rongai and Njoro areas of Nakuru district and only six of the sites were finally harvested. The study was mainly to evaluate different weed control methods to offer a variety of recommendations for small scale wheat farmers. Of the treatments tested Buctril Mc out performed all the treatments except for Ariane. Cultural methods of control seemed to be inferior to almost all the chemical control. (author)

  17. Assessment of Light Environment Variability in Broadleaved Forest Canopies Using Terrestrial Laser Scanning

    Directory of Open Access Journals (Sweden)

    Dimitry Van der Zande

    2010-06-01

    Full Text Available Light availability inside a forest canopy is of key importance to many ecosystem processes, such as photosynthesis and transpiration. Assessment of light availability and within-canopy light variability enables a more detailed understanding of these biophysical processes. The changing light-vegetation interaction in a homogeneous oak (Quercus robur L. stand was studied at different moments during the growth season using terrestrial laser scanning datasets and ray tracing technology. Three field campaigns were organized at regular time intervals (24 April 2008; 07 May 2008; 23 May 2008 to monitor the increase of foliage material. The laser scanning data was used to generate 3D representations of the forest stands, enabling structure feature extraction and light interception modeling, using the Voxel-Based Light Interception Model (VLIM. The VLIM is capable of estimating the relative light intensity or Percentage of Above Canopy Light (PACL at any arbitrary point in the modeled crown space. This resulted in a detailed description of the dynamic light environments inside the canopy. Mean vertical light extinction profiles were calculated for the three time frames, showing significant differences in light attenuation by the canopy between April 24 on the one hand, and May 7 and May 23 on the other hand. The proposed methodology created the opportunity to link these within-canopy light distributions to the increasing amount of photosynthetically active leaf material and its distribution in the considered 3D space.

  18. Leaf trait-environment relationships in a subtropical broadleaved forest in South-East China.

    Directory of Open Access Journals (Sweden)

    Wenzel Kröber

    Full Text Available Although trait analyses have become more important in community ecology, trait-environment correlations have rarely been studied along successional gradients. We asked which environmental variables had the strongest impact on intraspecific and interspecific trait variation in the community and which traits were most responsive to the environment. We established a series of plots in a secondary forest in the Chinese subtropics, stratified by successional stages that were defined by the time elapsed since the last logging activities. On a total of 27 plots all woody plants were recorded and a set of individuals of every species was analysed for leaf traits, resulting in a trait matrix of 26 leaf traits for 122 species. A Fourth Corner Analysis revealed that the mean values of many leaf traits were tightly related to the successional gradient. Most shifts in traits followed the leaf economics spectrum with decreasing specific leaf area and leaf nutrient contents with successional time. Beside succession, few additional environmental variables resulted in significant trait relationships, such as soil moisture and soil C and N content as well as topographical variables. Not all traits were related to the leaf economics spectrum, and thus, to the successional gradient, such as stomata size and density. By comparing different permutation models in the Fourth Corner Analysis, we found that the trait-environment link was based more on the association of species with the environment than of the communities with species traits. The strong species-environment association was brought about by a clear gradient in species composition along the succession series, while communities were not well differentiated in mean trait composition. In contrast, intraspecific trait variation did not show close environmental relationships. The study confirmed the role of environmental trait filtering in subtropical forests, with traits associated with the leaf economics spectrum being the most responsive ones.

  19. Leaf trait-environment relationships in a subtropical broadleaved forest in South-East China.

    Science.gov (United States)

    Kröber, Wenzel; Böhnke, Martin; Welk, Erik; Wirth, Christian; Bruelheide, Helge

    2012-01-01

    Although trait analyses have become more important in community ecology, trait-environment correlations have rarely been studied along successional gradients. We asked which environmental variables had the strongest impact on intraspecific and interspecific trait variation in the community and which traits were most responsive to the environment. We established a series of plots in a secondary forest in the Chinese subtropics, stratified by successional stages that were defined by the time elapsed since the last logging activities. On a total of 27 plots all woody plants were recorded and a set of individuals of every species was analysed for leaf traits, resulting in a trait matrix of 26 leaf traits for 122 species. A Fourth Corner Analysis revealed that the mean values of many leaf traits were tightly related to the successional gradient. Most shifts in traits followed the leaf economics spectrum with decreasing specific leaf area and leaf nutrient contents with successional time. Beside succession, few additional environmental variables resulted in significant trait relationships, such as soil moisture and soil C and N content as well as topographical variables. Not all traits were related to the leaf economics spectrum, and thus, to the successional gradient, such as stomata size and density. By comparing different permutation models in the Fourth Corner Analysis, we found that the trait-environment link was based more on the association of species with the environment than of the communities with species traits. The strong species-environment association was brought about by a clear gradient in species composition along the succession series, while communities were not well differentiated in mean trait composition. In contrast, intraspecific trait variation did not show close environmental relationships. The study confirmed the role of environmental trait filtering in subtropical forests, with traits associated with the leaf economics spectrum being the most responsive ones. PMID:22539999

  20. Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

    Science.gov (United States)

    Madrigal-González, Jaime; Ruiz-Benito, Paloma; Ratcliffe, Sophia; Calatayud, Joaquín; Kändler, Gerald; Lehtonen, Aleksi; Dahlgren, Jonas; Wirth, Christian; Zavala, Miguel A.

    2016-01-01

    Neglecting tree size and stand structure dynamics might bias the interpretation of the diversity-productivity relationship in forests. Here we show evidence that complementarity is contingent on tree size across large-scale climatic gradients in Europe. We compiled growth data of the 14 most dominant tree species in 32,628 permanent plots covering boreal, temperate and Mediterranean forest biomes. Niche complementarity is expected to result in significant growth increments of trees surrounded by a larger proportion of functionally dissimilar neighbours. Functional dissimilarity at the tree level was assessed using four functional types: i.e. broad-leaved deciduous, broad-leaved evergreen, needle-leaved deciduous and needle-leaved evergreen. Using Linear Mixed Models we show that, complementarity effects depend on tree size along an energy availability gradient across Europe. Specifically: (i) complementarity effects at low and intermediate positions of the gradient (coldest-temperate areas) were stronger for small than for large trees; (ii) in contrast, at the upper end of the gradient (warmer regions), complementarity is more widespread in larger than smaller trees, which in turn showed negative growth responses to increased functional dissimilarity. Our findings suggest that the outcome of species mixing on stand productivity might critically depend on individual size distribution structure along gradients of environmental variation. PMID:27571971

  1. Composition and Characteristics of Natural Secondary Forests in Shenzhen,South China

    Institute of Scientific and Technical Information of China (English)

    Wang Dianpei; Ji Shuyi; Chen Feipeng; Peng Shaolin

    2004-01-01

    The composition and structure of five natural secondary forests in Shenzhen were studied based on data of plots and were compared with Hong Kong zonal forest, so as to detect their succession stage and species diversity level. According to succession process of subtropical forest and ecological characteristics of dominant species, the authors speculate that five communities are at different stages. Sinosideroxylon community dominated by heliophilous evergreen broad-leaved tree (Sinosideroxylon wightianum) and conifer tree (Pinus massoniana) is at the third stage. Itea + Acronychia community dominated by two evergreen broad-leaved heliophytes (Itea chinensis and Acronychia pedunculata) is at the fourth stage. The others, I.e., Schefflera, Sterculia and Cleistocalyx + Sterculia community are at the fifth stage where some mesophytes are dominant but heliophytes have a weighed percentage of importance value. Due to succession stage and different forest management and conservation models, the species diversity of five communities is significantly lower than that of Endospermum community in Hong Kong. The values of Shannon-Wiener index and Pielous evenness index of five communities are 2.04-2.953 and 64.2%-74% respectively, but those of the Endospermum community are 4.74 and 79% respectively. The current situation of these communities suggests that the necessary measures should be taken to protect and restore the communities.

  2. Fitness analysis of seed and vegetative reproduction of clonal tree Symplocos laurina

    Institute of Scientific and Technical Information of China (English)

    Zhang Yunchun; Du Xiaojun; Zhang Qiaoying; Gao Xianming; Su Zhixian

    2006-01-01

    There are two ways for Symplocos laurina to propagate: clonal reproduction and sexual reproduction.S.laurina adopted different ways to propagate and occupy space in different environments: under conditions with abundant water,nutrient resources,and lower light such as in an evergreen broad-leaved or a bamboo forest;survival rates and the ability of both clonal and sexual seedlings to occupy space,were relatively high.But clonal ramets took advantage both in terms of number and space.Therefore,clonal propagation predominated in such an environment.However,in habitats lacking sufficient nutrition and with higher light intensity,survival rates and space-occupying ability of two kinds of seedlings (sexual and asexual produced) were low and the space would be preempted by grown-up plantlets.A bottleneck in sexual "propagation appeared at the stage from seed to seedling,while in clonal propagation it appeared during the period from an asexual plantlet to a ramet.The way S.laurina invaded space was like that of a plantlet settled in a place and then occupied the space rapidly by clonal growth under conditions of abundant water and nutrient resources and lower light such as in an evergreen broad-leaved forest or a bamboo forest.Clonal seedlings showed a great advantage in the initial stages,but this advantage disappeared after 15 years.

  3. Seed plant phylogenetic diversity and species richness in conservation planning within a global biodiversity hotspot in eastern Asia.

    Science.gov (United States)

    Li, Rong; Kraft, Nathan J B; Yu, Haiying; Li, Heng

    2015-12-01

    One of the main goals of conservation biology is to understand the factors shaping variation in biodiversity across the planet. This understanding is critical for conservation planners to be able to develop effective conservation strategies. Although many studies have focused on species richness and the protection of rare and endemic species, less attention has been paid to the protection of the phylogenetic dimension of biodiversity. We explored how phylogenetic diversity, species richness, and phylogenetic community structure vary in seed plant communities along an elevational gradient in a relatively understudied high mountain region, the Dulong Valley, in southeastern Tibet, China. As expected, phylogenetic diversity was well correlated with species richness among the elevational bands and among communities. At the community level, evergreen broad-leaved forests had the highest levels of species richness and phylogenetic diversity. Using null model analyses, we found evidence of nonrandom phylogenetic structure across the region. Evergreen broad-leaved forests were phylogenetically overdispersed, whereas other vegetation types tended to be phylogenetically clustered. We suggest that communities with high species richness or overdispersed phylogenetic structure should be a focus for biodiversity conservation within the Dulong Valley because these areas may help maximize the potential of this flora to respond to future global change. In biodiversity hotspots worldwide, we suggest that the phylogenetic structure of a community may serve as a useful measure of phylogenetic diversity in the context of conservation planning.

  4. Community dynamics of a montane Fagus engleriana–Cyclobalanopsis multiervis mixed forest in Shennongjia, Hubei, China

    Directory of Open Access Journals (Sweden)

    Jielin Ge

    2012-11-01

    Full Text Available Montane evergreen and deciduous broad-leaved mixed forests are some of the main vegetation types in China. Specifically, the Fagus–Cyclobalanopsis mixed forest is a dominant forest community in themountainous region of Shennongjia. Using three datasets (2001, 2006, and 2010 from a permanent 120 m ×80 m plot in the montane evergreen and deciduous broad-leaved mixed forest in Shengnongjia, we analyzedthe dynamics of tree species composition and community structure for individual trees (DBH ≥ 4 cm. We found that total species number increased from 81 in 2001 to 84 in 2006, and then decreased to 83 in 2010. Dominant species remained constant throughout the study period, including Cyclobalanopsis multiervis, Fagus engleriana, Rhododendron hypoglaucum and Lithocarpus henryi. Stem number and basal area followed the same trend with an initial increase, followed by a decline. The mortality and recruitment of this survey plot changed substantially over the nine-year study period. Although an ice storm in 2008 had some impact on the community, the species richness and community structure did not alter significantly and the community appeared to be in a state of dynamic equilibrium with strong resilience to external disturbances.

  5. Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

    Science.gov (United States)

    Madrigal-González, Jaime; Ruiz-Benito, Paloma; Ratcliffe, Sophia; Calatayud, Joaquín; Kändler, Gerald; Lehtonen, Aleksi; Dahlgren, Jonas; Wirth, Christian; Zavala, Miguel A.

    2016-08-01

    Neglecting tree size and stand structure dynamics might bias the interpretation of the diversity-productivity relationship in forests. Here we show evidence that complementarity is contingent on tree size across large-scale climatic gradients in Europe. We compiled growth data of the 14 most dominant tree species in 32,628 permanent plots covering boreal, temperate and Mediterranean forest biomes. Niche complementarity is expected to result in significant growth increments of trees surrounded by a larger proportion of functionally dissimilar neighbours. Functional dissimilarity at the tree level was assessed using four functional types: i.e. broad-leaved deciduous, broad-leaved evergreen, needle-leaved deciduous and needle-leaved evergreen. Using Linear Mixed Models we show that, complementarity effects depend on tree size along an energy availability gradient across Europe. Specifically: (i) complementarity effects at low and intermediate positions of the gradient (coldest-temperate areas) were stronger for small than for large trees; (ii) in contrast, at the upper end of the gradient (warmer regions), complementarity is more widespread in larger than smaller trees, which in turn showed negative growth responses to increased functional dissimilarity. Our findings suggest that the outcome of species mixing on stand productivity might critically depend on individual size distribution structure along gradients of environmental variation.

  6. 广东南岭国家级自然保护森林景观格局分析%Analysis of Forest Landscape Pattern in Nanling National Nature Reserve, Guangdong

    Institute of Scientific and Technical Information of China (English)

    廖芳均; 何嘉

    2013-01-01

    [Objective] The study was to analyze the forest landscape in Nanling Na-tional Nature Reserve to provide information for the protection of local forest ecosys-tems. [Method] With the documents of 1∶10 000 topographic maps, updated Forest Resource Inventory Data, based on the GIS platform and Fragstats software, the paper analyzed the patterns and heterogeneity of forest landscapes by adopting the landscape ecological theory and the method of landscape index. [Result] The forest landscape types, in terms of area occupation from large to smal , are in the order of evergreen broad-leaved forest, coniferous mixed forest, evergreen and deciduous broad-leaved mixed forest, shrubs, mixed needle leaf forest, suitable land for forest deciduous broad-leaved forest and non-forest. [Conclusion] Overal , the Reserve had maintained sufficient forest landscape diversity with a low level fragmentation. The distribution of various types of forest landscape was extremely uneven, dominated by several types such as evergreen broad-leaved forest, coniferous forest, etc.%[目的]分析南岭国家级自然保护区森林景观格局,为该保护区的森林生态系统的保护提供支持。[方法]以1∶10000地形图、森林资源二类调查数据和实地补充调查数据为基础资料,基于GIS平台和 Fragstats软件,运用景观生态学原理和景观指数分析方法,对研究区内森林景观的格局和异质性进行分析。[结果]森林景观类型面积大小依次为常绿阔叶林、针叶林、针阔混交林、阔叶混交林、灌丛、针叶混交林、宜林地、落叶阔叶林和非林地。[结论]研究区域森林景观格局分析表明,保护区景观异质性较高,连通性较好,破碎化程度不明显,各景观组分的面积和比例分布极不均衡,常绿阔叶林和针叶林等少数几种组分在景观中占绝对优势。

  7. Natural succession of vegetation in Tiantong National Forest Park, Zhejiang Province of East China: A simulation study.%浙江天童国家森林公园植被自然演替动态模拟

    Institute of Scientific and Technical Information of China (English)

    吕娜; 倪健

    2013-01-01

    By using spatially explicit landscape model (LANDIS 6.0 PRO), and parameterized this model with the long-term research and observation data of Tiantong National Station of Forest Eco-system Observation and Research, this paper simulated the natural succession of evergreen broad-leaved forest in Tiantong National Forest park, Zhejiang Province in the future 500 years, analyzed the spatial distribution and age structure of dominant species and major landscapes, and explored the succession pattern of the evergreen broad-leaved forest. In the park, the species alternation mostly occurred before the stage of evergreen broad-leaved forest. Pinus massoniana, Quercus fab-ric, and Liquidambar formosana occupied a large proportion during the early succession, but gradu-ally disappeared with the succession process. Schima superba and Castanopsis fargesii took the main advantage in late succession, and developed to the climax community. Under the conditions without disturbances, the community was mainly composed of young forests in the early succession, and of mature or over-mature forests in the late succession, implying the insufficient regeneration ability of the community. LANDIS model could be used for simulating the landscape dynamics of evergreen broad-leaved forest in eastern China. In the future research, both the model structure and the model parameters should be improved, according to the complexity and diversity of subtropical evergreen broad-leaved forest.%应用空间明晰景观模型LANDIS 6.0 PRO,以浙江天童国家森林公园常绿阔叶林为研究对象,根据天童国家野外观测站的长期研究和观测数据对LANDIS模型进行参数化,模拟无干扰情况下常绿阔叶林在未来500年间的演替动态,分析优势种和主要景观类型的空间分布以及年龄结构组成,揭示了常绿阔叶林演替的规律.结果表明:研究区物种的交替多发生在常绿阔叶林阶段之前,马尾松、白栎和枫香等先锋物种在

  8. 重庆地区主要森林类型的空气负离子水平及其评价1)%Air Anions Content and Its Evaluation for Main Forest Types in Chongqing

    Institute of Scientific and Technical Information of China (English)

    王轶浩; 刘访兵; 周小舟; 刘茜; 李彬

    2014-01-01

    With AIC1000 portable air anions tester, the air anion concentration of six main forest types had been measured in 41 monitoring plots of Chongqing in 2012.All forest types significantly can improve air anion content (Pdeciduous broad-leaved forest>evergreen broad-leaved forest>coniferous forest>bamboo forest>mixed conifer-broadleaved forest>CK(Jiefangbei Business District).For evergreen broad-leaved forest and mixed conifer forest, the air anions content in sunny day is higher than that in cloudy day and rain day (P0.05).Air anions of every forest types presents an obviously seasonal variation (P<0.01).The air anions content is the most in spring for mixed conifer-broadleaved forest, evergreen broad-leaved forest and mixed conifer forest, but it is the most in autumn for deciduous broad-leaved forest.Except bamboo forest and mixed conifer forest, air anions of other forest types are the least in winter.The air anions content mainly located in the grade of V level ( 400-1 000 air anions/cm-3 ) in the monitoring spots, and the air quality of Simian Mountains Nature Reserve is the best in all monitoring spots.%利用便携式空气负离子测定仪( AIC1000),对重庆地区6种主要森林类型的41个监测点进行为期1 a的空气负离子监测和研究。结果表明:各森林类型均能显著提高空气负离子水平(P<0.01),从大到小依次为针叶混交林、落叶阔叶林、常绿阔叶林、针叶纯林、竹林、针阔混交林、对照(解放碑商务区);常绿阔叶林和针叶混交林在晴天时的空气负离子水平显著高于阴天和雨天的(P<0.01),而落叶阔叶林却相反;天气阴晴对其它森林类型的空气负离子影响则不显著(P>0.05)。各森林类型的空气负离子呈明显的季节变化(P<0.01),针阔混交林、常绿阔叶林和针叶混交林均以春季最大,落叶阔叶林则以秋季最大;除竹林和针叶混交林外,其它森

  9. Plant Functional Types and Biomes of China at a Regional Scale%区域尺度的中国植物功能型与生物群区

    Institute of Scientific and Technical Information of China (English)

    倪健

    2001-01-01

    Thirty-nine dominant plant functional types (PFTs) of China wereidentified based on the present Chinese vegetation types and their distributional pattern using the “eco-physiognomy" principle. They are alpine evergreen conifer, boreal evergreen conifer, boreal summergreen conifer, cool temperate evergreen conifer, temperate evergreen conifer, warm temperate evergreen conifer, tropical evergreen conifer, boreal summergreen broadleaf, cool temperate summergreen broadleaf, temperate summergreen broadleaf, cold warm-temperate evergreen broadleaf, intermediate warm-temperate evergreen broadleaf, southern warm-temperate evergreen broadleaf, warm-temperate schlerophyllous broadleaf, warm temperate summergreen broadleaf, tropical evergreen broadleaf, tropical raingreen broadleaf, tropical deciduous broadleaf, warm temperate bamboo, alpine/subalpine shrub, temperate steppe shrub, temperate desert shrub, cool temperate shrub, temperate shrub, warm temperate shrub, tropical shrub, xeric shrub, alpine forb, desert forb, temperate steppe grass, temperate grass, sedge, mangrove, boreal crop, cool temperate crop, temperate crop, warm temperate crop, tropical crop, and bare land. Twenty-one potential biomes were then assigned on the basis of dominant PFTs. They are boreal deciduous forest, boreal evergreen forest, cold temperate mixed coniferous-broadleaf forest, temperate deciduous broad-leaved forest, warm temperate mixed deciduous-evergreen broadleaf forest, warm temperate broad-leaved evergreen forest, warm temperate broad-leaved evergreen monsoon forest, tropical rain forest, tropical seasonal forest, tropical deciduous forest, mangrove forest, xeric woodland/savannas, temperate meadow/savannas, temperate steppe, temperate semi-steppe, temperate desert, temperate semi-desert, alpine/subalpine coniferous forest, alpine/subalpine shrub/meadow, alpine/subalpine steppe, and alpine/subalpine desert. If the agricultural vegetation was taken into account, twenty-five actual biomes

  10. First identification of the pathogen causing tumor malformations in evergreen oaks in Spain

    Directory of Open Access Journals (Sweden)

    María Martín-Santafé

    2014-08-01

    Full Text Available Aim of study: In recent years an increase in pests and diseases associated with truffle plantations has been detected in Spain. The appearance of tumor malformations in trunks and branches of Quercus ilex L. must be highlighted. These bumps have expanded dramatically since the increase in the number and density of truffle plantations. This pathology is not only found in plantations, but also in forests, and in trees of all ages.Area of study: the eastern mountains and the truffle plantations of the Iberian Peninsula.Material and methods: Positive results were obtained by using two types of PCR: Real-Time PCR and nested-PCR. They were carried out with primers that amplified 16S ribosomal gene sequences that are common to all known phytoplasmas.Main result: The disease manifests itself as an irregular thickening in branches of any age and in the trunk that results in the woody tissue cracking open, forming wounds. The affected branches usually undergo necrosis and in case of affecting the trunk, the tree will eventually die. After an extensive literature review and several failed attempts to isolate fungal and bacterial species from these tumors and wounds, the disease-causing organism has been identified as a Candidatus Phytoplasma.Research highlights: The appearance of this disease may endanger the profitability of an a priori profitable crop. Due to the intrinsic characteristics of the organism, and knowing that no phytosanitary treatment is able to control phytoplasmas, future works should be directed towards identifying the transmitter in order to control the disease.Key words: Candidatus Phytoplasma; PCR; Quercus ilex; black truffle; Tuber melanosporum.

  11. A Study of the Puente Project: 1983-1986. Evergreen Valley College.

    Science.gov (United States)

    Atondo, Angelo; And Others

    Puente Projects are currently operating at 10 community colleges in California to increase retention, general education requirements completion, and transfer among Hispanic community college students. Puente integrates the skills of an English teacher, a Hispanic counselor, and Hispanic professionals acting as mentors to promote academic…

  12. Event-scale soil moisture dynamics in open evergreen woodlands of southwest Spain

    Science.gov (United States)

    Lozano-Parra, F. J.; Schnabel, S.; Gómez-Gutiérrez, Á.

    2012-04-01

    Rangelands with a disperse tree cover occupy large areas in the southwestern part of the Iberian Pensinsula and are also found in other parts of the Mediterranean. In these grazed, savannah-like ecosystems water constitutes an important limiting factor for vegetation growth because of the strong summer dry period, being annual potential evapotranspiration nearly twice the annual rainfall amount. Previous studies by other authors have found lower values of soil water content below the tree canopy as compared to the open spaces, covered only by herbaceous vegetation. The differences of soil moisture between tree covered and open areas vary along the year, commonly being highest during autumn, low when water content is close to saturation and the inverse during summer. Our studies indicate that the spatial variation of soil moisture is more complex. The main objective of this study is to analyze soil moisture dynamics at the event scale below tree canopies (Quercus ilex) and in the open spaces. Because soils are commonly very shallow (Cambisols) and a high concentration of grass roots is found in the upper five centimetres, soil moisture measurements were carried out at 5, 10, 15 and 30 cm depth. The study area is located in Extremadura. Soil moisture is measured continuously with a time resolution of 30 minutes using capacitive sensors and rainfall is registered in 5-minute intervals. Data from the hydrological year 2010-11 are presented here. The main factors which produced variations in soil moisture in the upper 5 cm were amount and duration of the rainfall event. Rainfall intensity was also significantly related with an increase of the water content. At greater depth (30 cm) soil moisture was more related with antecedent rainfall, as for example the amount of precipitation registered 30 and 45 days prior to the event. Maximum increases produced by a rainstorm were approximately 0.20 m3m-3 in grasslands and 0.17 m3m-3 below tree canopy. However, in the uppermost soil layer and with rainfall amounts of less than 5 mm, below the tree canopy only few events (15%) produced a notable response in soil moisture, as opposed to the grasslands (42%), which points to the role of rainfall interception by the tree. Furthermore, at greater soil depth low rainfall events only produced an increase of water content in few occasions. This fact is important because more than 50% of the events registered less than 5 mm of rainfall. Soil moisture dynamics were directly related with the wetting process, which varied according to soil cover and its antecedent water content, the characteristics of the rainfall event and the soil depth considered. In the uppermost soil layer of the grassland 86% of the maximum soil moisture values were registered during the event, whereas below the tree canopy the increase was slower and maximum values were registered at the end or after the rainfall event. At depth water dynamics were fairly similar with respect to vegetation cover, depending closely on the antecedent rainfall amounts. Furthermore, abrupt increases of soil moisture were observed during some events, presumably related with preferential flow through macropores.

  13. Reproductive biology of Cinnamomum sulphuratum Nees. from wet evergreen forest of Western Ghats in Karnataka

    Directory of Open Access Journals (Sweden)

    D. Shivaprasad

    2015-03-01

    Full Text Available In Cinnamomum sulphuratum the initiation of the buds occurred after the leaf initiation during October and initiation of buds started during November last week. Inflorescence is an axillary panicle with 62.48±7.01 floral buds that took 13±1.41 days to bloom. Flower offer both pollen and nectar as a floral reward to the pollinators. Foragers include honeybees, butterflies, wasps, flies and ants. The flowers are self-compatible, pollinate both by self and cross pollination. In Allogamy (Hand cross pollination, highest mean percentage of fruit set was observed as 71 and 75% respectively for the period 2012-13 and 2013-14.

  14. No evidence for enemy release during range expansion of an evergreen tree in northern Europe

    DEFF Research Database (Denmark)

    Skou, Anne-Marie Thonning; Markussen, Bo; Sigsgaard, Lene;

    2011-01-01

    aquifolium L. in both the historical and the expanding range in Denmark to study possible effects of geographical position, small-scale distance, and plant types on presence and performance of the monophagous insect leaf-miner Phytomyza ilicis Curtis. 3. The leaf miner was present in the entire range of I....... aquifolium in Denmark, and there were no differences in emergence success depending on geographical position. Small-scale distance to existing adult plants inßuenced the activity of the insect on the transplants, and oviposition density was negatively correlated with distance to adult plants. 4. Plant type...

  15. Using microbial community interactions within plant microbiomes to advance an evergreen agricultural revolution

    Science.gov (United States)

    Innovative plant breeding and technology transfer fostered the Green Revolution, which transformed agriculture worldwide by increasing grain yields in developing countries. The Green Revolution temporarily alleviated world hunger, but also reduced biodiversity, nutrient cycling, and carbon sequestr...

  16. Comparing growth phenology of co-occurring deciduous and evergreen conifers exposed to drought

    Science.gov (United States)

    Swidrak, Irene; Schuster, Roman; Oberhuber, Walter

    2013-01-01

    Plant phenological events are influenced by climate factors such as temperature and rainfall. To evaluate phenological responses to water availability in a Spring Heath-Pine wood (Erico-Pinetum typicum), the focus of this study was to determine intra-annual dynamics of apical and lateral growth of co-occurring early successional Larix decidua and Pinus sylvestris and late successional Picea abies exposed to drought. The effect of reduced plant water availability on growth phenology was investigated by conducting a rainfall exclusion experiment. Timing of key phenological dates (onset, maximum rate, end, duration) of growth processes were compared among species at the rain-sheltered and control plot during 2011 and 2012. Shoot and needle elongation were monitored on lateral branches in the canopy at c. 16 m height and radial growth was recorded by automatic dendrometers at c. 1.3 m height of > 120 yr old trees. Different sequences in aboveground growth phenology were detected among the three species under the same growing conditions. While onset of radial growth in April through early May was considerably preceded by onset of needle growth in Larix decidua (5 - 6 weeks) and shoot growth in Pinus sylvestris (c. 3 weeks), it occurred quite simultaneously with onset of shoot growth in Picea abies. Low water availability had a minor impact on onset of aboveground growth, which is related to utilization of stored water, but caused premature cessation of aboveground growth. At the control plot mean growing season length was 130 days in Pinus sylvestris, 95 days in Larix decidua and 73 days in Picea abies supporting the hypothesis that early successional species are resource expenders, while late successional species are more efficient in utilizing resources and develop safer life strategies. High synchronicity found in culmination of radial growth in late spring (mid-May through early June) prior to occurrence of more favourable environmental conditions in summer might indicate sink competition for carbohydrates to belowground organs. This is supported by completion of apical growth in mid June in all species, except for needle growth of Pinus sylvestris, which lasted until early August. Phenological observations of conifers exposed to drought revealed that tree water status early during the growing season determines total annual aboveground growth and besides temperature, species-specific endogenous and/or environmental factors (most likely photoperiod and/or different threshold temperatures) are involved in controlling apical and lateral growth resumption after winter dormancy. PMID:24273375

  17. Study of the radiocaesium cycle in forest ecosystems (evergreen and deciduous trees)

    International Nuclear Information System (INIS)

    Determinations made after the Chernobyl accident on rain water collected under spruces and oaks show that there is a good correlation between the deposition fluxes of both radiocesium and stable potassium, at least under spruces, suggesting that potassium could be used as an indicator of the behaviour of 137Cs in contaminated trees. Four years after the accident it seems that a short-term (1-3 yr) equilibrium has been realized in the contaminated trees and that radiocesium is now transferred by trees to the soil mainly via throughfall. Estimation of the global contamination of the different compartments of the forest is given. (author)

  18. Dispersal limitation at the expanding range margin of an evergreen tree in urban habitats?

    DEFF Research Database (Denmark)

    Møller, Linda Agerbo; Skou, Anne-Marie Thonning; Kollmann, Johannes Christian

    2012-01-01

    experiment with fruits of Ilex aquifolium, a species that is currently expanding its range margin in northern Europe in response to climate change. The species is also a popular ornamental tree and naturalization has been observed in many parts of its range. Fruits of native I. aquifolium and of three...... cultivars were offered to birds at the expanding range margin in urban habitats in eastern Denmark. The four fruit types were removed at different rates and red fruits were preferred over a yellow cultivar. Small fruit diameter was positively related to fruit removal, and removal was faster under tree...... canopies compared with open habitats. The preference for red cultivars compared with native I. aquifolium may contribute to naturalization and potential invasion of garden escapes. Preferential foraging under closed canopies indicates trees and shrubs as recruitment foci for fleshy-fruited plants in urban...

  19. Reproductive biology of Cinnamomum sulphuratum Nees. from wet evergreen forest of Western Ghats in Karnataka

    OpenAIRE

    D. Shivaprasad; C. N. Prasannakumar; R. K. Somashekar, et al.

    2015-01-01

    In Cinnamomum sulphuratum the initiation of the buds occurred after the leaf initiation during October and initiation of buds started during November last week. Inflorescence is an axillary panicle with 62.48±7.01 floral buds that took 13±1.41 days to bloom. Flower offer both pollen and nectar as a floral reward to the pollinators. Foragers include honeybees, butterflies, wasps, flies and ants. The flowers are self-compatible, pollinate both by self and cross pollination. In Allogamy (Hand cr...

  20. Relative growth rate variation of evergreen and deciduous savanna tree species is driven by different traits

    NARCIS (Netherlands)

    Tomlinson, K.W.; Poorter, L.; Bongers, F.; Borghetti, F.; Jacobs, L.; Langevelde, van F.

    2014-01-01

    Background and Aims Plant relative growth rate (RGR) depends on biomass allocation to leaves (leaf mass fraction, LMF), efficient construction of leaf surface area (specific leaf area, SLA) and biomass growth per unit leaf area (net assimilation rate, NAR). Functional groups of species may differ in

  1. Evaporation of intercepted rainfall from isolated evergreen oak trees: do the crowns behave as wet bulbs ?

    OpenAIRE

    Pereira, F. L.; Gash, J.H.C.; David, J. S.; Valente, F.

    2009-01-01

    A new approach is suggested for estimating evaporation of intercepted rainfall from single trees in sparse forests. It is shown that, theoretically, the surface temperature of a wet tree crown will depend on the available energy and windspeed. But for a fully saturated canopy under rainy conditions, surface temperature will approach the wet bulb temperature when available energy tends to zero. This was confirmed experimentally from measurements of the radiation balance, aerodyn...

  2. Faunal diversity in a semi-evergreen forest of Bornadi-Khalingduar Complex of Assam, India

    Directory of Open Access Journals (Sweden)

    Pallabi Chakraborty

    2015-09-01

    Full Text Available The Bornadi-Khalingduar Complex under the Manas Tiger Reserve, Assam is known to be an important area for wildlife movement to and from India and Bhutan. The contiguous landscape encompassing the two neighbouring countries provides a good habitat for diversity of wildlife and also as an important corridor area.  We carried out an opportunistic camera-trapping exercise to document the faunal diversity in the area. A month-long exercise photo-captured a total of 19 species belonging to 12 families, including the Leopard, Wild Dog, Leopard Cat, Binturong, Elephant, Sambar, Barking Deer and various birds. These findings of the study reveal the importance, threats and potential of the area and recommendations have been made to secure this corridor for continuous animal movement. Anthropogenic disturbance is a major deterrent to undisturbed animal movement in this area with resultant forest fragmentation and degradation. This indicates the need for effective conservation strategies in order to maintain the remnants of this corridor complex.  

  3. EBBR Observation and fluctuation of evapotranspiration in a Cambodian evergreen forest

    Science.gov (United States)

    Shimizu, A.; Tanaka, K.; Nobuhiro, T.; Kabeya, N.; Tamai, K.; Chann, S.; Keth, N.

    2006-12-01

    In the Mekong River basin, the increase in farming associated with a rapidly growing population has lead to a dramatic reduction in forest area. The incidence of illegal logging and wood collection is also increasing throughout the entire Asian Monsoon area, including Cambodia. According to Cambodian government statistics, the proportion of forested area in Cambodia has declined from 74% in the 1970s to 58% in 1993. Despite this reduction, the area covered by forests in Cambodia remains high compared to that in adjacent countries. We measured several meteorological elements associated with evapotranspiration, runoff, and precipitation in the broadleaf forest watersheds in Kampong Thom Province of central Cambodia. The topography of the watershed studied was relatively gentle. Meteorological factors were observed with a 60-m-high meteorological observation tower to determine the amount of evapotranspiration. The Energy Balance Bowen Ratio (EBBR) system was used to calculate the energy budget above the forest canopy for estimating evapotranspiration. Moreover, an automatic rain gauge was placed at the top of the observation tower and an interception plot was established for calculating the rainfall interception ratio by forest coverage near the tower. The main vegetation species at the research site were Vatica odorata and Myristica iners. The mean tree height in the upper crown layer at the research site was 27 m, and the maximum tree height was 45 m. Meteorological data for estimation of evapotranspiration were collected from October 2003 to September 2004. The SPAC model, used for analyzing characteristics of evapotranspiration variation, is a multilayer model considering factors such as Reynolds stress, temperature and H2O exchanges of leaves and ground surface, radiation transfer within the canopy, atmospheric diffusion within and above the canopy, energy balance for leaves and ground surface, interception of rainfall, and water budget for leaves. Several parameters were identified from the observation data set. The simulations reproduced the variation in evapotranspiration.

  4. Allometric equations for aboveground and belowground biomass estimations in an evergreen forest in Vietnam

    NARCIS (Netherlands)

    Nam, Vu Thanh; Kuijk, Van Marijke; Anten, Niels P.R.

    2016-01-01

    Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations fo

  5. Ozone uptake by an evergreen forest canopy - temporal variation and possible mechanisms

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.; Pilegaard, K.;

    2000-01-01

    similar diel nu(d) patterns. Daytime F(c) was correlated with CO(2) and water vapour fluxes, while no correlation between [O(3)] in the range 10-70 ppb (nl l(-1)) and F(c)was seen in this study. F(c) was primarily driven by stomatal conductance, reactions with surfaces, particles and gases, and not by [O...

  6. Effects of topography, neighboring plants and size-dependence of Machillus thunbergii on sapling growth and survivorship

    Directory of Open Access Journals (Sweden)

    Yuewei Tong

    2013-05-01

    and evergreen broadleaved species, followed by evergreen broadleaved species and lastly by evergreen needle leaved species; Machilus sapling growth was positively size-dependent, i.e., larger saplings grew faster. We conclude that, modelling tree growth should simultaneously incorporate topographical factors, species-specific neighborhood interaction and size of individuals, thereby providing a more accurate prediction of forest productivity and development, as well as information that will aid the conservation of endangered species.

  7. Aesthetic Evaluation of Typical Plant Communities in Green Belt around Shanghai%上海环城林带植物群落景观美学评价

    Institute of Scientific and Technical Information of China (English)

    张凯旋; 凌焕然; 达良俊

    2012-01-01

    The landscape evaluation of different plant communities in the green belt around Shanghai was conducted in spring, summer, autumn and winter. The in-forest and outer-forest landscapes were evaluated with the scenic beauty estimation (SBE) method. The results showed that average SBE values of in-forest and outer-forest landscapes were both the highest in summer, and the lowest in winter. The in-forest SBE values of deciduous coniferous forests were the highest in all four seasons among different vegetation types, and SBE values of bamboo forest were the lowest. Among the coniferous forests, the SBE values of evergreen coniferous forest were lower than deciduous coniferous forest in all four seasons. Among the broad - leaved forests, the SBE values of deciduous broad-leaved forest were higher than evergreen deciduous forest in spring and summer, but reversely in autumn and winter. Among mixed forests, except for autumn, the SBE values of broad-leaved and coniferous mixed forest were higher than evergreen and deciduous broad-leaved mixed forest.%以上海环城林带为对象,采用美景度评判法进行不同植被类型的景观评价,评价分为林内景观和林外景观2个空间层次,分别在春、夏、秋、冬4个季节进行。结果表明,林内景观平均值和林外景观的美景度都表现为夏季最高,冬季最低。在不同植被类型的林内景观中,落叶针叶林在不同季节均表现出最高的美景度,竹林的美景度最低;针叶林中,常绿针叶林的美景度四季均低于落叶针叶林;阔叶林中,落叶阔叶林的美景度在春季和夏季高于常绿落叶林,常绿阔叶林在秋季和冬季高于落叶阔叶林;混交林中,除秋季外,针阔混交林的美景度均高于常绿落叶阔叶混交林。

  8. Altitudinal patterns of the flora of seed plants of Dawei Mountain in Yunnan Province,south China

    Institute of Scientific and Technical Information of China (English)

    WANG Juan; MA Qinyan; DU Fan; YANG Yuming

    2007-01-01

    Altitudinal gradient incorporates multiple resource gradients,which vary continuously in different fashions.It is important to study the mountain floristic patterns along altitudinal gradients which reveal the regular pattern of the flora along the environmental gradients,the changing trend of biodiversity patterns along the altitudinal gradient,and relevance of biological fitness.To explore the compositional characteristics and ecological significance of floristic patterns along altitudinal gradient in China National Nature Reserve of Dawei Mountain in the southeast of Yunnan Province,field investigations have been made to the flora along the two routes of the southwest slope and the northeast slope of the said reserve,including a vertical vegetation transect.Meanwhile,further investigations have also been made to the flora of Dawei Mountain,which has been accounted for in the literature,as Flora Yunnan,The Seed Plant in Yunnan,and so on.The structural characteristics of the flora and the altitudinal distribution pattern of its floristic components were analyzed.By applying systematic cluster analysis,the altitudinal position of the dividing line of floristic changes along altitudinal gradient was detected,and the effects of the montane climate on the vertical variation of floristic composition were studied.Conclusions were put forward.This paper can be summarized as follows:(1) The obvious boundary that differentiates tropical floristic elements is located at the altitude of approximately 1,500 m;it is reasonable to stipulate the boundary line between tropical rain forests and the evergreen broad-leaved forests.(2) The vertical vegetation spectrum made by cluster analysis shows that humid rain forests are below 700 m a.s.1,montane rain forests are between 700 and 1,500 m,monsoon evergreen broad-leaved forests are between 1,300 and 1,800 m,and montane mossy evergreen broad-leaved forests are above 1,800 m a.s.1.Nonrepresentative montane mossy dwarf forests (above

  9. Vegetation in karst terrain of southwestern China allocates more biomass to roots

    Directory of Open Access Journals (Sweden)

    J. Ni

    2015-03-01

    Full Text Available In mountainous areas of southwestern China, especially Guizhou Province, continuous, broadly distributed karst landscapes with harsh and fragile habitats often lead to land degradation. Research indicates that vegetation located in karst terrains has low aboveground biomass, and land degradation reduces vegetation biomass, but belowground biomass measurements are rarely reported. Using the soil pit method, we investigated the root biomass of karst vegetation in five degraded (successional stages: grassland, grass-scrub tussock, thorn-scrub shrubland, scrub-tree forest, and mixed evergreen and deciduous forest in Maolan, southern Guizhou Province, growing in two different soil-rich and rock-dominated habitats. The results show that roots in karst vegetation, especially the coarse roots, and roots in rocky habitats, are mostly distributed in the topsoil layers (89% on the surface up to 20 cm depth. The total root biomass in all habitats of all vegetation degradation periods is 18.77 Mg ha−1, in which roots in rocky habitat have higher biomass than in earthy habitat, and coarse root biomass is larger than medium and fine root biomass. The root biomass of mixed evergreen and deciduous forest in karst habitat (35.83 Mg ha−1 is not greater than that of most typical, non-karst evergreen broad-leaved forests in subtropical regions of China, but the ratio of root to aboveground biomass in karst forest (0.37 is significantly greater than the mean ratio (0.26±0.07 of subtropical evergreen forests. Vegetation restoration in degraded karst terrain will significantly increase the belowground carbon stock, forming a potential regional carbon sink.

  10. 大别山自然保护区天然次生林分类及其生态位特征%Classification and ecological niche of natural secondary forest in the Nature Reserve of Dabie Mountain

    Institute of Scientific and Technical Information of China (English)

    张卓文; 王永健; 唐亚坤; ULRICH Apel; 王艳; 肖宋高; 李振

    2012-01-01

    Based on data with important values for classification and niche measuring,the classification, niche breadth and overlap of dominant woody species of natural secondary forest in Dabie Mountain Reserve were studied by means of sampling, two-way indicator species analysis (TWINSPAN) ,detrend-ed correspondence analysis (DCA) and niche analysis. The results showed that communities of natural secondary forest in Dabie Mountain Reserve were divided into six community types (coniferous forest I and II 籧oniferous broad-leaved mixed forest I and IJ , deciduous broad-leaved forest E and evergreen deciduous broad-leaved mixed forest F) based on TWINSPAN and DCA. DCA ordination figures also reflected the pattern of communities changing from the coniferous forest I and H to coniferous broad-leaved mixed forest I and JJ ,then to deciduous and evergreen deciduous mixed forest. Pinus massoni-ana and Pinus hivangshanensis had a large niche breadth in coniferous forest I and JJ . Pinus and Quer-cus both had larger niche in coniferous broad-leaved mixed forest I and TJ . Many woody species had larger niche in deciduous and evergreen deciduous mixed forest. The niche breadth and overlap of main dominant species in different communities might change according to the succession trend. It was feasible for using niche overlap index and species characteristic as the main evaluation criterion in terms of majority species relationships in different community succession.%通过样方调查、TWINSPAN分类与DCA排序及生态位分析,以物种重要值为分类排序与生态位计测的数据指标,研究湖北省大别山自然保护区天然次生林分类及优势木本生态位宽度与重叠.结果表明:应用TWINSPAN分类并结合DCA排序,可将植被划分为6个群落类型(针叶林Ⅰ、Ⅱ,针阔混交林Ⅰ、Ⅱ,E落叶阔叶林和F常绿落叶阔叶混交林).同时DCA排序图中反映了植被由针叶林Ⅰ、Ⅱ——针阔混交林Ⅰ、Ⅱ——落叶阔叶林与

  11. 青石冈林场木荷杉木混交林更新演替研究%Study on regeneration and succession of mixed forest of Schima superb and Cunninghamia lanceolata in Qingshigang Forest Farm

    Institute of Scientific and Technical Information of China (English)

    曾思齐; 张敏; 肖化顺; 黄炎俊; 甘静静; 彭其龙

    2013-01-01

    In order to know the state of regeneration and succession of the Schima superb and Cunninghamia lanceolata mixed forest in Qingshigang Forest Farm, layered frequency method was used to analyze the trend of regeneration and succession of four kinds of S. superb and C. lanceolata mixed forest in Qingshigang Forest Farm in Yanling county, Hunan province, to provide a reasonable basis for the management of the forest so that proper human intervention and guidance could be given to avoid the forest reverse regressive succession. The results show that the forest stand No. 1 developed into a evergreen broad-leaved forest dominated by S. superb, Castanopsis everi and Cyclobalanopsis gracilis; The forest stand No.2 evolved to the needle and broad-leaved mixed evergreen forest dominated by C. eyeri, Quercus fabri, S. superb and C. lanceolata; The forest stand No.3 still was a needle and broad-leaved mixed evergreen forest dominated by S. superb and C. lanceolata; The forest stand No.4 developed into a evergreen and deciduous, needle and broad-leaved mixed forest dominated by Dalbergia hupeana, C. lanceolata and S. superb. The states of regeneration of stand No.l and No.2 were good, that of No. 3 was medium while No.4 was bad.%为了解青石冈林场4类木荷杉木混交林更新演替情况,为森林合理经营提供依据,以便对林分加以适当的人工干预及引导,避免森林逆向演替,利用分层频度法对湖南省炎陵县青石冈林场4种木荷杉木混交林进行更新演替趋势分析.结果表明:林分5杉4木1甜+马+尖-红-山将演替为木荷、甜槠和细叶青冈占优势的常绿硬阔混交林群落;林分5杉3木1甜1细-合-椆-马-山-雷-白将演替为甜槠、白栎、木荷、杉木占优势的常绿针阔混交林群落;林分6木3杉1茅-细在一定时期内仍为木荷、杉木占优势的常绿针阔混交林群落;林分5木5杉-檫-樱将演替为黄檀、杉木和木荷占优势的常绿落叶针阔混交林群落

  12. Age-Structure and Dynamic of Dominant Population of Castanopsis carlesii Community in Dujiangyan City,Sichuan, China

    Institute of Scientific and Technical Information of China (English)

    CAI Xiao-hu; ZHONG Xiang-hao; WANG Jin-xi; HE Fei; LIU Xing-liang

    2005-01-01

    It analyses the Castanopsis carlesii, Camellia oleifera and Symplocos laurina populations' status and role in the Castanopsis carlesii community basing on the study on the dominant population size structure, survival curve and dynamic. It reveals the Castanopsis carlesi population acts as a main role in the community which maintains the stabilization and renovation of the community. The populations of Camellia oleifera and Symplocos laurina act as a secondary position. The development and succession dynamics of dominant populations is also discussed. The management method is preliminary drawn out which offers a theoretical basis for the evergreen broad-leaved forest restoration and reconstruction in the lower hilly of the west edge of the Sichuan basin.

  13. Discovery and Significance of the Grain of Wild Rice in Ancient-Woods Layer in Zhujiajian Island of Zhejiang Province, China

    Institute of Scientific and Technical Information of China (English)

    SHENXian-sheng; LIShu-mei; YANGJie-pin; SUNHao

    2004-01-01

    A large number of plant remains were discovered in the ancient-woods layer of Zhujiajian Island, Zhejiang Province.There were some thick trunks, complete laminas, fruit, seeds and so on. According to radiocarbon tests conducted for plant remains, the ancient-woods layer has been dated back to about 8750 - 6200 years, and the vegetation was a subtropical evergreen and deciduous broad-leaved mixed forests on the island in the past. In the middle of the ancient-woods layer, two grains of wild rice were explored accidentally, which are Oryza rufipogon, along with the fruit and seeds of some water plants, such as Ceratophyllum dcmcrsum, C.oryzetoum, Euryale fetox, Trapa incisa var. quadricaudata , Scirpus yagara and so on. There might be marshy soil and a pond in ancient forest vegetation from where the grains of wild rice and hydrophytic fruit were found. It is of tremendous importance to study the origin of wild rice in China.

  14. Discovery and Significance of the Grain of Wild Rice in Ancient-Woods Layer in Zhujiajian Island of Zhejiang Province, China

    Institute of Scientific and Technical Information of China (English)

    SHEN Xian-sheng; LI Shu-mei; YANG Jie-pin; SUN Hao

    2004-01-01

    A large number of plant remains were discovered in the ancient-woods layer of Zhujiajian Island, Zhejiang Province.There were some thick trunks, complete laminas, fruit, seeds and so on. According to radiocarbon tests conducted for plant remains, the ancient-woods layer has been dated back to about 8750 - 6200 years, and the vegetation was a subtropical evergreen and deciduous broad-leaved mixed forests on the island in the past. In the middle of the ancient-woods layer, two grains of wild rice were explored accidentally, which are Oryza rufipogon, along with the fruit and seeds of some water plants, such as Ceratophyllum demersum, C. oryzetorum, Euryale ferox, Trapa incisa var. quadricaudata , Scirpus yagara and so on. There might be marshy soil and a pond in ancient forest vegetation from where the grains of wild rice and hydrophytic fruit were found. It is of tremendous importance to study the origin of wild rice in China.

  15. Inferring genetic diversity and differentiation of the endangered chinese endemic plant sauvagesia rhodoleuca (ochnaceae) using microsatelite markers

    International Nuclear Information System (INIS)

    Sauvagesia rhodoleuca is one of the most endangered species in China. It has a narrow distribution in the evergreen broadleaved forest of southern China. Up to now, only six populations remained in two provinces. In this study, eight microsatellite loci were used to examine genetic diversity in these populations. We found very low levels of genetic diversity within populations of S. rhodoleuca with average observed and expected heterozygosity (HO and HE) of 0.069 and 0.186, respectively. Estimated inbreeding coefficients (FIS) within populations were high suggests the probable selfing in the species.Combination of the UPGMA dendrogram and the INSTRUCT analysis show that six extant populations could be classified into three distinct genetic groups and no pattern of isolation by distance was detected among populations. The low genetic variation within populations and high genetic differentiation among populations indicate that the management for the conservation of genetic diversity in S. rhodoleuca should aim to preserve every population. (author)

  16. Dynamics of soil inorganic nitrogen and their responses to nitrogen additions in three subtropical forests, south China

    DEFF Research Database (Denmark)

    Fang, Yun-ting; Zhu, Wei-xing; Mo, Jiang-ming;

    2006-01-01

    Three forests with different historical land-use, forest age, and species assemblages in subtropical China were selected to evaluate current soil N status and investigate the responses of soil inorganic N dynamics to monthly ammonium nitrate additions. Results showed that the mature monsoon...... evergreen broadleaved forest that has been protected for more than 400 years exhibited an advanced soil N status than the pine (Pinus massoniana) and pine-broadleaf mixed forests, both originated from the 1930's clear-cut and pine plantation. Mature forests had greater extractable inorganic N pool, lower N...... retention capacity, higher inorganic N leaching, and higher soil C/N ratios. Mineral soil extractable NH4+-N and NO3--N concentrations were significantly increased by experimental N additions on several sampling dates, but repeated ANOVA showed that the effect was not significant over the whole year except...

  17. Photosynthetic response to variation in CO2 concentrations and temperature of four broad-leaved trees in Beijing region

    Institute of Scientific and Technical Information of China (English)

    Zhibo MA; Shengqing SHI; Qinyan MA; Yutao WANG; Xingliang LIU

    2008-01-01

    Responses of the photosynthetic characteris-tics to variation in CO2 concentration and temperature of Ginkgo biloba, Eucornmia ulmoides, Magnolia denudata and Tiliajaponica were measured during the peak growing season. The results show that the ambient CO2 concentra-tion could not meet the requirements for photosynthesis of these four species. The optimal temperatures for pho-tosynthesis were lower than the average daytime air tem-perature. Hence, the photosynthesis of these four species was restricted by the low CO2 concentration and high daytime air temperature at the time of measurement. Marked enhancements in the net photosynthetic rate were found in all four species when the CO2 concentration was doubled. When the dependency on CO2 and temperature were examined simultaneously, it was seen that for increased CO2 concentrations there was a shift in the optimum temperature for M. denudata and T. japonica towards higher temperatures. Due to their independence on CO2 concentrations, this trend could not be found in the G. biloba and E. ulmoides data sets. The stomatal con-ductance (Gs) was sensitive to a vapor pressure deficit (VPD) which in turn was sensitive to temperature. An increase in temperature would cause the VPD to increase and plants might be assumed to react by reducing their stomatal apertures. The effect on stomatal resistance would be most significant at high temperatures. The restriction to stomatal conductance for these four species would increase if CO2 concentrations were elevated at the same temperature.

  18. Milestone – a selective herbicide for the control of important grasses and broadleaved weeds in winter oilseed rape

    Directory of Open Access Journals (Sweden)

    Zotz, Agnes

    2016-02-01

    Full Text Available MilestoneTM herbicide contains the active substance propyzamide (500 g/L and aminopyralid (5.3 g a.e./L and is formulated as a suspension concentrate (SC. Registration for Milestone for the use in winter oilseed rape was granted in Germany in July 2014. The active substance propyzamide is well known from the product KerbTM FLO (containing 500 g/L propyzamide, suspension concentrate, SC which is widely used in winter oilseed rape (WITTROCK et al., 2008. Aminopyralid is formulated in the commercial product Runway (clopyralid + picloram + aminopyralid. Milestone is applied with a use rate of 1.5 L/ha as a post-emergence herbicide from growth stage BBCH 14 of the crop at the beginning of November until February. Kerb FLO is applied with a use rate of 1.875 L/ha at the same timing. The efficacy of Milestone and Kerb FLO was tested in randomised and replicated plot trials in Germany, France and the United Kingdom. Milestone and Kerb FLO showed comparable and very high control levels against monocotyledonous species such as Alopecurus myosuroides, Apera spica-venti, Bromus species and volunteer cereals. Milestone shows a broader spectrum of activity vs. Kerb FLO against dicotyledonous weeds such as Matricaria chamomilla, Papaver rhoeas and Centaurea cyanus. The use of Milestone in dense crops (as the situation was in autumn 2014 for many areas in Germany shows very high efficacy levels as well. The comparison of various application timings between end of October until beginning of December confirms the application date early November for best results. Milestone controls herbicide-resistant weed populations and can be considered an important part of a resistance management program not only in winter oilseed rape but as a component of an integrated weed management strategy in cropping systems.

  19. Similar biodiversity of ectomycorrhizal fungi in set-aside plantations and ancient old-growth broadleaved forests

    OpenAIRE

    Spake, Rebecca; van der Linde, Sietse; Newton, Adrian C.; Suz, Laura M.; Bidartondo, Martin I.; Doncaster, C. Patrick

    2016-01-01

    Setting aside overmature planted forests is currently seen as an option for preserving species associated with old-growth forests, such as those with dispersal limitation. Few data exist, however, on the utility of set-aside plantations for this purpose, or the value of this habitat type for biodiversity relative to old-growth semi-natural ecosystems. Here, we evaluate the contribution of forest type relative to habitat characteristics in determining species richness and composition in seven ...

  20. Photosynthetic characteristics of dominant tree species and canopy in the broadleaved Korean pine forest of Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>Based on the light-photosynthesis response measurement at leaf level, combined with over- and under-canopy eddy covariance measurements, research on photosynthetic characteristics of single trees and forest canopy was conducted. The relationship between light intensity and photo-synthetic rates for leaves and canopy can be well fitted by a non-rectangular hyperbola model. Mongolian oak presented a high light compensation point, Lcp (28μmol·m-2·s-1), a light saturation point Lsp (>1800μmol·m-2·s-1), and a maximal net photosynthetic rate Pmax (9.96μmol·m-2·s-1), which suggest that it is a typical heliophilous plant. Mono maple presented the highest apparent quantum efficiencyα(0.066) but the lowest, Lcp (16μmol·m-2·s-1), Lsp (=800μmol·m-2·s-1), and Pmax (4.51μmol·m-2·s-1), which suggest that it is heliophilous plant. Korean pine showed the lowestαvalue but a higher Pmax, which suggest that it is a semi-heliophilous plant. At the canopy level, the values of both or and Pmax approached the upper limit of reported values in temperate forests, while Lcp was within the lower limit. Canopy photosynthetic characteristics were well consistent with those of leaves. Both showed a high ability to photosynthesize. However, environmental stresses, especially high vapor pressure deficits, could significantly reduce the photosynthetic ability of leaves and canopy.

  1. Species composition and minimum sampling area of a riparian mixed broadleaved-Korean pine forest in Changbai Mountain Nature Reserve

    Institute of Scientific and Technical Information of China (English)

    DAI Fang-zhou; XU Dong; DENG Hong-bing

    2011-01-01

    Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changhai Mountain were investi- gated by using field data collected from eight sampling transects perpen- dicular to the Erdaobai River channel. Two kinds of species-area satura- tion curves were used to examine the relationship between species num- ber and minimum sampling area. The results showed that riparian gym- nosperms accounted for a high proportion of all gymnosperms in the Changbai Mountain Nature Reserve while riparian ferns and angiosperms accounted for a relatively low proportion. The average minimum sam- pling areas of riparian forest that included 60%, 80%, and 90% of the community species pool were about 85, 185, and 328 m, respectively; while those for nonriparian forest were about 275, 390, and 514 m, correspondingly.

  2. Environmental Correlates of Distribution of the 25 Broad-leaved Tree Species Indigenous to Guangdong Province, China

    Institute of Scientific and Technical Information of China (English)

    Su Zhiyao; Chen Beiguang; Chang Yong; Yang Jiazhi

    2004-01-01

    Twenty-five tree species indigenous to Guangdong Province were chosen in this study to portray their distribution patterns in relation to environmental factors. Both data of species distribution and environmental factors were tabulated based on a digitized map of Guangdong Province gridded at 0.5° latitude × 0.5° longitude. Grid-based diversity was mapped using DMAP, a distribution mapping program, and horizontal patterns were assessed using Kruskal-Wallis tests. The diversity center of the indigenous tree species under study is located north of 23° N. These tree species exhibit significant latitudinal variation (P = 0.007 4), but no significant longitudinal difference (P = 0.052 2). Non-metric Multidimensional Scaling (NMS) identified five different ecological species groups, while Canonical Correspondence Analysis (CCA) showed the distribution of tree species along each of the five environmental gradients. An understanding of the environmental correlates of distribution patterns has great implication for the introduction of the indigenous tree species for afforestation.

  3. Eddy flux corrections for CO2 exchange in broad-leaved Korean pine mixed forest of Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    WU; Jiabing; GUAN; Dexin; SUN; Xiaomin; YU; Guirui; ZHAO; X

    2005-01-01

    Based on analysis of mechanisms causing energy no-closure and nocturnal low fluxes issues for CO2 exchange studies by eddy covariance method, corrections were done with the raw data sets obtained from Changbai Mountains forest flux site, to evaluate the impacts of sonic anemometer tilt, frequency response limitations and advection on estimation of CO2 exchange, respectively. The results show that the planar fit coordinate transforming method is superior to the streamline coordinate transforming method in tilt correction. The latter could cause a systematical underestimation of eddy fluxes relating with the angle of sensor and terrain tilt. The underestimation of CO2 and energy fluxes for frequency response limitations average 3.0% and 2.0% during daytime, respectively, which increase by 9.0% and 5.5% during nighttime, respectively. The corrections of frequency response limitations are closely related to atmospheric stability. The advection loss of CO2 fluxes is dominated by nocturnal vertical advection, which is at least 18% when the horizontal advection is neglected. It is suggested that more work be done to understand the characteristics of horizontal advection and turbulent eddies under a complexcircumstance.

  4. Using Remote Sensing Products for Environmental Analysis in South America

    Directory of Open Access Journals (Sweden)

    Fabrício Brito Silva

    2011-09-01

    Full Text Available Land cover plays a major role in many biogeochemical models that represent processes and connections with terrestrial systems; hence, it is a key component for public decisions in ecosystems management. The advance of remote sensing technology, combined with the emergence of new operational products, offers alternatives to improve the accuracy of environmental monitoring and analysis. This work uses the GLOBCOVER, the Vegetation Continuous Field (VCF, MODIS Fire Radiative Power (FRP and the Tropical Rainfall Measuring Mission (TRMM remotely sensed databases to analyze the biomass burning distribution, the land use and land cover characteristics and the percent of tree cover in South America during the years 2000 to 2005. Initially, GLOBCOVER was assessed based on VCF product, and subsequently used for quantitative analysis of the spatial distribution of the South America fires with the fire radiative power (FRP. The results show that GLOBCOVER has a tendency to overestimate forest classes and to underestimate urban and mangroves areas. The fire quantification based on GLOBCOVER product shows that the highest incidence of fires can be observed in the arc of deforestation, located in the Amazon forest border, with vegetation cover composed mainly of broadleaved evergreen or semi-deciduous forest. A time series analysis of FRP database indicates that biomass burning occurs mainly in areas of broadleaved evergreen or semi-deciduous forest and in Brazilian Cerrado associated with grassland management, agricultural land clearing and with the deforestation of Amazon tropical rainforest. Also, variations in FRP intensity and spread can be attributed to rainfall anomalies, such as in 2004, when South America had a positive anomaly rainfall.

  5. Environmental and Archaeological Implications of a Late Quaternary Palynological Sequence, Poyang Lake, Southern China

    Science.gov (United States)

    Jiang, Qinhua; Piperno, Dolores R.

    1999-09-01

    Paleoecological data from Poyang Lake, southern China, indicate that significant natural and human-induced vegetational changes have occurred during the Late Quaternary in the Middle Yangtze River valley, the likely location of rice (Oryza sativa L.) domestication. During the late Pleistocene (from ca. 12,830 to ca. 10,500 yr B.P.), the climate was cooler and drier than today's. The subtropical, mixed deciduous-evergreen broad-leaved forest which constitutes the modern, potential vegetation was reduced and herbaceous vegetative cover expanded. A hiatus in sedimentation occurred in Poyang Lake, beginning sometime after ca. 10,500 yr B.P. and lasting until the middle Holocene (ca. 4000 yr B.P.). At ca. 4000 yr B.P., the regional vegetation was a diverse, broad-leaved forest dominated by many of the same arboreal elements (e.g., Quercus, Castanopsis, Liquidambar) that grow in the area today. A significant reduction of arboreal pollen and an increase of herbaceous pollen at ca. 2000 yr B.P. probably reflect human influence on the vegetation and the expansion of intensive rice agriculture into the dryland forests near the river valleys.

  6. [Soil infiltration characteristics under main vegetation types in Anji County of Zhejiang Province].

    Science.gov (United States)

    Liu, Dao-Ping; Chen, San-Xiong; Zhang, Jin-Chi; Xie, Li; Jiang, Jiang

    2007-03-01

    The study on the soil infiltration under different main vegetation types in Anji County of Zhejiang Province showed that the characteristics of soil infiltration differed significantly with land use type, and the test eight vegetation types could be classified into four groups, based on soil infiltration capability. The first group, deciduous broadleaved forest, had the strongest soil infiltration capability, and the second group with a stronger soil infiltration capability was composed of grass, pine forest, shrub community and tea bush. Bamboo and evergreen broadleaved forest were classified into the third group with a relatively strong soil infiltration capability, while bare land belonged to the fourth group because of the bad soil structure and poorest soil infiltration capability. The comprehensive parameters of soil infiltration (alpha) and root (beta) were obtained by principal component analysis, and the regression model of alpha and beta could be described as alpha = 0. 1708ebeta -0. 3122. Soil infiltration capability was greatly affected by soil physical and chemical characteristics and root system. Fine roots (soil physical and chemical properties, and the increase of soil infiltration capability was closely related to the amount of the fine roots. PMID:17552181

  7. Seasonal dynamics of water use efficiency of typical forest and grassland ecosystems in China

    CERN Document Server

    Zhu, Xianjin; Wang, Qiufeng; Hu, Zhongmin; Han, Shijie; Yan, Junhua; Wang, Yanfen; Zhao, Liang

    2014-01-01

    We selected four sites of ChinaFLUX representing four major ecosystem types in China-Changbaishan temperate broad-leaved Korean pine mixed forest (CBS), Dinghushan subtropical evergreen broadleaved forest (DHS), Inner Mongolia temperate steppe (NM), and Haibei alpine shrub-meadow (HBGC)-to study the seasonal dynamics of ecosystem water use efficiency (WUE = GPP/ET, where GPP is gross primary productivity and ET is evapotranspiration) and factors affecting it. Our seasonal dynamics results indicated single-peak variation of WUE in CBS, NM, and HBGC, which were affected by air temperature (Ta) and leaf area index (LAI), through their effects on the partitioning of evapotranspiration (ET) into transpiration (T) (i.e., T/ET). In DHS, WUE was higher at the beginning and the end of the year, and minimum in summer. Ta and soil water content affected the seasonal dynamics of WUE through their effects on GPP/T. Our results indicate that seasonal dynamics of WUE were different because factors affecting the seasonal dyn...

  8. Effect of Continuous Plantation of Chinese Fir on Soil Fertility

    Institute of Scientific and Technical Information of China (English)

    DINGYING-XIANG; CHENJIN-LIN

    1995-01-01

    The changes in soil fertility under continuous plantation of Chinese fir were studied by comparing soil samples from different forest stands:the first and second plantations of Chinese fir,evergreen broad-leaved forests,and clear-cut and burnt Chinese fir land located at Xihou Village,Nanping of Fujian Province.The soils were humic red soil originated from weathered coarse granite of the Presinian system.Soil pH,CEC,base saturation ,exchangeable Ca2+,exchangeable Mg2+ and A1-P declined after continuous plantation of Chinese fir.The same trends were also found in the soils under broad-leaved stands and slash burnt lands.The explantation was that not merely the biological nature of the Chinese fir itself but the natural leaching of nutrients,soil erosion and nutrient losses due to clear cutting and slash burning of the preceduing plantation caused the soil deterioration .Only some of main soil nutrients decreased after continuous plantation of Chinese fir,depending on specific silvicultural system,which was different from the conclusions in some other reports which showed that all main nutrients,such as OM,total N,available P and available K decreased,Some neccessary step to make up for the lost base,to apply P fertilizer and to avoid buring on clear cut lands could be taken to prevent soil degradation and yield decline in the system of continuous plantation of Chinese fir.

  9. Roots of pioneer trees in the lower sub-tropical area of Dinghushan, Guangdong, China

    Institute of Scientific and Technical Information of China (English)

    HAO Yan-ru; PENG Shao-lin; MO Jiang-ming; LIU Xin-wei; CHEN Zhuo-quan; ZHOU Kai; WU Jin-rong

    2006-01-01

    Representative pioneer tree root systems in the subtropical area of South China were examined with regard to their structure, underground stratification and biomass distribution. Excavation of skeleton roots and observation of fine roots of seven species including the Euphorbiaceae, Theaceae, Melastomataceae, Lauraceae and Fagaceae families was carried out. The results showed that: (1) Pioneer tree roots in the first stage of natural succession were of two types, one characterized by taproot system with bulky plagiotropic branches; the other characterized by flat root system with several tabular roots. The late mesophilous tree roots were characterized by one obvious taproot and tactic braches roots up and down. Shrub species roots were characterized by heart fibrous root type featured both by horizontally and transversally growing branches. Root shapes varied in different dominant species at different stages of succession. (2) Roots of the different species varied in the external features-color, periderm and structure of freshly cut slash. (3) In a set of successional stages the biomass of tree roots increased linearly with the age of growth. During monsoon, the total root biomass amounted to 115.70 t/ha in the evergreen broad-leaved forest; 50.61t/ha in needle and broad-leaved mixed forest dominated by coniferous forest; and 64.20 t/ha in broad-and needle-leaved mixed forest dominated by broad-leaved heliophytes, and are comparable to the underground biomass observed in similar tropical forests. Thisis the first report about roots characteristics of forest in the lower sub-tropical area of Dinghushan, Guangdong, China.

  10. Study on Biological Diversity of Several Different Forest Community Types in Northern Subtropical Region%北亚热带不同森林群落类型的生物多样性研究

    Institute of Scientific and Technical Information of China (English)

    丁增发; 张瑶; 刘俊龙; 马永春; 吴中能

    2011-01-01

    北亚热带地区的人工针叶纯林可以通过抚育间伐或者封山育林等措施大大加快其向着该地区的顶级群落方向演替。该地区几种典型群落的乔木层生物多样性指数大小依次为:针阔混交林〉〉常绿阔叶纯林〉马尾松纯林(郁0.5)〉马尾松纯林(CK组)〉杉木纯林(修枝)〉杉木纯林(间伐10%);灌木层生物多样性指数大小排序为:马尾松纯林(CK组)〉杉木纯林(间伐10%)〉杉木纯林(修枝)〉常绿阔叶纯林〉马尾松纯林(郁0.5)〉针阔混交林。%The succession process from artificial pure coniferous forests to climax communities could be accelerated greatly by tending thinning or mountain closure for forest recovery in the northern subtropical region.The sequence of the tree layer diversity indexes of several typical forest communities is: Mixed coniferous and broadleaved forest Evergreen broadleaved pure forest Masson pine pure forest(crown density 0.5) Masson pine pure forest(CK group) Chinese fir pure forest(pruned) Chinese fir pure forest(thinned by 10%).The sequence of shrub layer diversity indexes is: Masson pine pure forest(CK group) Chinese fir pure forest(thinned by 10%) Chinese fir pure forest(pruned) Evergreen broadleaved pure forest Masson pine pure forest(crown density 0.5) Mixed coniferous and broad leaved forest.