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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. Comparison of Characteristic of Water Balance between Evergreen Coniferous and Deciduous Broad-leaved Forests

    Science.gov (United States)

    Hisada, Shigeta; Senge, Masateru; Ito, Kengo; Maruyama, Toshisuke

    Hydrological observation was carried out at two basins occupied mainly by evergreen coniferous forest of Chamaecyparis obtusa and deciduous broad-leaved forest of Quercus crispula in order to clarify the influences of different forest type on water balance. The analysis of short-time period water-budget method showed that the evapotranspiration of coniferous forest was more than broad-leaved one. By calculating transpiration from Priestley-Taylor equation, intercepted evaporation was separated from evapotranspiration. The result of comparison of intercepted evaporation between two basin was that intercepted evaporation of coniferous basin was more than that of broad-leaved basin. From separating total runoff into direct and base flow components; it was shown that there was no difference in direct runoff of two basins, so the differences of total runoff of two basins were caused due to the difference of base flow. From the above analysis of water balance components, it is clarified that the different forest type influences the amount of intercepted evaporation and base flow.

  6. Spatial heterogeneity and its causes in evergreen broad-leaved forests in the Ailao Mountains, Yunnan Province

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    Yuanjie Xu

    2017-01-01

    Full Text Available Understanding the variation of species richness over spatial scales, and elucidating the response of plant community composition to habitat heterogeneity has been one of the major topics in the study of community ecology. Niche differentiation related to habitat heterogeneity plays an important role in shaping diversity levels and species distribution patterns of plant communities. Based on a survey of 42 plots of four types of evergreen broad-leaved forests in the Ailao Mountains of Yunnan Province, this paper explored how community distribution and tree species richness of such forests changed along topographic and edaphic gradients. We found significant differences in community composition among the four types of evergreen broad-leaved forests. Tree species richness of monsoon evergreen broad-leaved forests was significantly higher than that of the other forest types. Tree species richness of mid-montane moist evergreen broad-leaved forests was significantly higher than that of semi-humid evergreen broad-leaved forests, whereas no significant difference was observed among the other forest types. Non-metric multidimensional scaling (NMDS revealed that nine environmental gradients, including elevation, slope, soil water content, soil organic matter, were the determinants of forest community composition and tree distribution patterns. As the best predictors of tree species richness, soil available boron, elevation, soil total potassium and convexity together explained 63.2% of the variance of tree species richness. The combination of topographic and edaphic factors explained most of the variance of community composition and tree species richness of the evergreen broad leaved forests in the Ailao Mountains.

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

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    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. [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.

  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

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    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.

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    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. 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

  13. 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).

  14. 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

  15. Accessing the impacts of bamboo expansion on NPP and N cycling in evergreen broadleaved forest in subtropical China

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    Song, Qing-Ni; Lu, Hui; Liu, Jun; Yang, Jun; Yang, Guang-Yao; Yang, Qing-Pei

    2017-01-01

    Bamboo (Phyllostachys pubescens) expansion into adjacent forests is a widespread phenomenon in subtropical regions, and it has greatly changed the dominance hierarchy from trees to bamboos. This process may be accompanied by changes in productivity, nutrients accumulation and biogeochemical cycles. We compared the net primary production (NPP) and major pools and fluxes of nitrogen (N) in bamboo-dominant forest (BDF) and neighboring secondary evergreen broadleaved forest (EBF) in South China using the space-for-time substitution method. We found that the mean NPP of the BDF was 30.0 t ha‑1 yr‑1, which was 51.5% greater than that of the EBF (19.8 t ha‑1 yr‑1). The plant N pool for the BDF was 37.5% larger than that of the EBF, whereas the soil inorganic N pool significantly decreased by 31.2% with conversion of the EBF to BDF. Additionally, the ratio of N return to N uptake was 0.69 in the BDF and 0.88 in the EBF because of the lower litter N return of the BDF compared with that of the EBF. These results indicated that the expansion of P. pubescens significantly increased the NPP and plant N accumulation but reduced the soil N available pool and slowed the N cycling rate, which could lead to soil degradation.

  16. 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.

  17. Accessing the impacts of bamboo expansion on NPP and N cycling in evergreen broadleaved forest in subtropical China

    Science.gov (United States)

    Song, Qing-ni; Lu, Hui; Liu, Jun; Yang, Jun; Yang, Guang-yao; Yang, Qing-pei

    2017-01-01

    Bamboo (Phyllostachys pubescens) expansion into adjacent forests is a widespread phenomenon in subtropical regions, and it has greatly changed the dominance hierarchy from trees to bamboos. This process may be accompanied by changes in productivity, nutrients accumulation and biogeochemical cycles. We compared the net primary production (NPP) and major pools and fluxes of nitrogen (N) in bamboo-dominant forest (BDF) and neighboring secondary evergreen broadleaved forest (EBF) in South China using the space-for-time substitution method. We found that the mean NPP of the BDF was 30.0 t ha−1 yr−1, which was 51.5% greater than that of the EBF (19.8 t ha−1 yr−1). The plant N pool for the BDF was 37.5% larger than that of the EBF, whereas the soil inorganic N pool significantly decreased by 31.2% with conversion of the EBF to BDF. Additionally, the ratio of N return to N uptake was 0.69 in the BDF and 0.88 in the EBF because of the lower litter N return of the BDF compared with that of the EBF. These results indicated that the expansion of P. pubescens significantly increased the NPP and plant N accumulation but reduced the soil N available pool and slowed the N cycling rate, which could lead to soil degradation. PMID:28067336

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

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

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    Lin, Dunmei; Lai, Jiangshan; Muller-Landau, Helene C; Mi, Xiangcheng; Ma, Keping

    2012-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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. Soil Drought Anomalies in MODIS GPP of a Mediterranean Broadleaved Evergreen Forest

    Directory of Open Access Journals (Sweden)

    Jia Liu

    2015-01-01

    Full Text Available The Moderate Resolution Imaging Spectroradiometer (MODIS yields global operational estimates of terrestrial gross primary production (GPP. In this study, we compared MOD17A2 GPP with tower eddy flux-based estimates of GPP from 2001 to 2010 over an evergreen broad-leaf Mediterranean forest in Southern France with a significant summer drought period. The MOD17A2 GPP shows seasonal variations that are inconsistent with the tower GPP, with close-to-accurate winter estimates and significant discrepancies for summer estimates which are the least accurate. The analysis indicated that the MOD17A2 GPP has high bias relative to tower GPP during severe summer drought which we hypothesized caused by soil water limitation. Our investigation showed that there was a significant correlation (R2 = 0.77, p < 0.0001 between the relative soil water content and the relative error of MOD17A2 GPP. Therefore, the relationship between the error and the measured relative soil water content could explain anomalies in MOD17A2 GPP. The results of this study indicate that careful consideration of the water conditions input to the MOD17A2 GPP algorithm on remote sensing is required in order to provide accurate predictions of GPP. Still, continued efforts are necessary to ascertain the most appropriate index, which characterizes soil water limitation in water-limited environments using remote sensing.

  2. 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.

  3. 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.

  4. [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.

  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. Biomass of Secondary Evergreen and Deciduous Broadleaved Mixed Forest in Plateau-type Karst Terrain of Guizhou Province, SW China

    Science.gov (United States)

    Liu, L.

    2014-12-01

    Using allometric functions, harvest and soil column methods, we investigated the biomass of a secondary evergreen and deciduous broadleaved mixed forest in Tianlongshan permanent monitoring plot (a horizontally-projected area of 2 hectares) of Puding Karst Ecosystem Research Station, Guizhou Province, southwestern China. Results showed that the total biomass of the forest is 165.4 Mg·hm-2. The aboveground biomass and root biomass are 137.7 Mg·hm-2 and 27.7 Mg·hm-2, respectively. Among the aboveground biomass, the tree layer accounts for 97.76%, which is obviously greater than the shrub layer and herb layer. Larger trees (the diameter at breast height, DBH is between 5 cm and 20 cm) occupies 76.85% of the aboveground biomass, especially the five dominant species(Lithocarpus confinis, Platycarya longipes, Itea yunnanensis, Machilus cavaleriei and Carpinus pubescens). Shrubs and lianas (DBH = 1 cm) account for more than 30% of total shrub and liana biomass, although their individuals are less than 2% of total shrub individuals and 1% of total liana individuals, respectively. The root biomass differs in root diameters, i.e. coarse root > medium root > fine root. Root biomass decreases with the increase of soil depth. Within soil depth of 20 cm, the root biomass is 20.1 Mg·hm-2, which is more than 70% of total root biomass. Within soil depth of 50 cm, the root biomass is 26.7 Mg·hm-2, which is 96.39% of total root biomass. Compared with non-karst forests in the same climate zone, karst forest has lower biomass and carbon stock, but it further has greater potential of carbon sink.

  7. Changes in sapwood permeability and anatomy with tree age and height in the broad-leaved evergreen species Eucalyptus regnans.

    Science.gov (United States)

    England, Jacqueline R; Attiwill, Peter M

    2007-08-01

    Increases in plant size and structural complexity with increasing age have important implications for water flow through trees. Water supply to the crown is influenced by both the cross-sectional area and the permeability of sapwood. It has been hypothesized that hydraulic conductivity within sapwood increases with age. We investigated changes in sapwood permeability (k) and anatomy with tree age and height in the broad-leaved evergreen species Eucalyptus regnans F. Muell. Sapwood was sampled at breast height from trees ranging from 8 to 240 years old, and at three height positions on the main stem of 8-year-old trees. Variation in k was not significant among sampling height positions in young trees. However, k at breast height increased with tree age. This was related to increases in both vessel frequency and vessel diameter, resulting in a greater proportion of sapwood being occupied by vessel lumina. Sapwood hydraulic conductivity (the product of k and sapwood area) also increased with increasing tree age. However, at the stand level, there was a decrease in forest sapwood hydraulic conductivity with increasing stand age, because of a decrease in the number of trees per hectare. Across all ages, there were significant relationships between k and anatomy, with individual anatomical characteristics explaining 33-62% of the variation in k. There was also strong agreement between measured k and permeability predicted by the Hagen-Poiseuille equation. The results support the hypothesis of an increase in sapwood permeability at breast height with age. Further measurements are required to confirm this result at other height positions in older trees. The significance of tree-level changes in sapwood permeability for stand-level water relations is discussed.

  8. 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.

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

    Science.gov (United States)

    Aoki, Kyoko; Ueno, Saneyoshi; Kamijo, Takashi; Setoguchi, Hiroaki; Murakami, Noriaki; Kato, Makoto; Tsumura, Yoshihiko

    2014-01-01

    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 imply the

  10. 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.

  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. Effects of selection cutting on the forest structure and species diversity of evergreen broad-leaved forest in northern Fujian, southern China

    Institute of Scientific and Technical Information of China (English)

    Qiu Ren-hui; Chen Han; Zhuo Li-xin

    2006-01-01

    The short-term effects of selection cutting of different intensities on the forest structure and species diversity of evergreen broad-leaved forest in northern Fujian Province were investigated and analyzed. The results showed that selection cutting of low and medium intensities caused little variation in the forest structure. After cutting, the dominant species retained their leading status in the community. However, the community structure changed significantly following selection cutting of high and extra-high intensities;the status of the dominant species of the community declined dramatically. Some tree species began to disappear from the sampling plots. Except for extra-high intensity cutting, the diversity of tree species did not change significantly for the other three cutting intensities. However, the evenness of the stands was very different among the four kinds of cutting plots. For low and medium intensity selection cutting, the evenness declined slightly. For extra-high intensity selection cutting, the evenness increased to some extent,which might be due to a more even distribution of tree species after cutting. Cutting operations resulted in some adverse reactions to development of arborous species diversity of evergreen broad-leaved forest, particularly serious damage to the forest canopy. But the rational selection cuttings, which may benefit the restoration and maintenance of species diversity over a long period and may come about from the variations in environmental factors such as sunlight, temperature and humidity.

  13. 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.

  14. 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

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Azita Ahmad Zawawi

    2015-04-01

    Full Text Available 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. Dominant tree canopy layers were estimated using multi-scale filtering and local maxima detection. The LiDAR estimation results were then compared to the ground inventory data and a high resolution orthophoto image for accuracy assessment. Main results: A Wilcoxon matched pair test suggests that LiDAR data is highly capable of estimating tree height in a subtropical forest (z = 4.0, p = 0.345, but has limitation to detect small understory trees and a single tree delineation. The results show that there is a statistically significant different type of crown detection from LiDAR data over forest inventory (z = 0, p = 0.043. We also found that LiDAR computation results underestimated the stand density and overestimated the crown size. Research highlights: Most studies involving crown detection and tree height estimation have focused on the analysis of plantations, boreal forests and temperate forests, and less was conducted on tropical and/or subtropical forests. Our study tested the capability of LiDAR as an effective application for analyzing a highly dense forest

  17. 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.

  18. Studies on Material Cycling in Evergreen Broad-Leaved Forest Ecosystem in Hangzhou:Ⅳ.Uptake,Storage and Return of S by Vegetation

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    The work was carried out to study the uptake,storage and return of S in the evergreen broad-leaved forest ecosystem of Hangzhou in Zhejiang Province,based on the annuam increments of plants and Scontents per unit weight plant organs as well as the measured data about the biological return and decomposition.Results showed that the vegetation layer had an annual S uptake of 55.02kg ha-1,which accounted for 15.8% of the total S storage in the vegetation layer,The S uptake was the highest in the arbor layer but the lowest in the shrub layer,the biological return of S was 50% higher than the biological uptake,indicating the relatively high cycling effciency of S.Nevertheless,S had a relatively low rate opf biological release,so that S trended to accumulate in the litter layer,S taken up by plants each year came mostly from precipitation and the reserve of soil.

  19. 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.

  20. 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.

  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. Phylogenetic Structure of Tree Species across Different Life Stages from Seedlings to Canopy Trees in a Subtropical Evergreen Broad-Leaved Forest.

    Science.gov (United States)

    Jin, Yi; Qian, Hong; Yu, Mingjian

    2015-01-01

    Investigating patterns of phylogenetic structure across different life stages of tree species in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of tree species across life stages from seedlings to canopy trees, as well as forest gap influence on the phylogenetic structure of forest regeneration in a forest of the subtropical region in China. We investigate changes in phylogenetic relatedness (measured as NRI) of tree species from seedlings, saplings, treelets to canopy trees; we compare the phylogenetic turnover (measured as βNRI) between canopy trees and seedlings in forest understory with that between canopy trees and seedlings in forest gaps. We found that phylogenetic relatedness generally increases from seedlings through saplings and treelets up to canopy trees, and that phylogenetic relatedness does not differ between seedlings in forest understory and those in forest gaps, but phylogenetic turnover between canopy trees and seedlings in forest understory is lower than that between canopy trees and seedlings in forest gaps. We conclude that tree species tend to be more closely related from seedling to canopy layers, and that forest gaps alter the seedling phylogenetic turnover of the studied forest. It is likely that the increasing trend of phylogenetic clustering as tree stem size increases observed in this subtropical forest is primarily driven by abiotic filtering processes, which select a set of closely related evergreen broad-leaved tree species whose regeneration has adapted to the closed canopy environments of the subtropical forest developed under the regional monsoon climate.

  3. 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.

  4. 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

  5. 北京引种7种常绿阔叶植物的抗寒适应性研究%The Cold Resistance of Seven Introduced Evergreen Broad-leaved Plants in Beijing

    Institute of Scientific and Technical Information of China (English)

    金花; 王斌; 戴思兰; 杨秀珍

    2011-01-01

    The morphological, biochemical and physiological index of seven introduced evergreen broad-leaved plants in the over-wintering period in Beijing were studied from Nov. 2007 to Mar. 2008. The cold resistance of each introduced evergreen broad-leaved plant was evaluated, and the effect of each determination index in the evaluation was analyzed. The study showed that: the overall changes of water saturation deficit value, electrical conductivity, ration of bound water and free water, SOD activity, APX activity and soluble sugar content showed a trend of firstly rise and then decline, while chlorophyll content showed a trend of firstly decline and then rise, so they can be considered as the physiological index to evaluate cold resistance of evergreen broad-leaved plant; the changes of POD activity and MDA content were not significant, so they can hardly be the evaluation index for cold resistance of evergreen broad-leaved plant. Comprehensive analysis of each index found that the cold resistance of seven plants ordered as Cotoneaster suecicus Coral Beauty>Ilex meserveae Blue Princess and C. oleifera>Euonymus fortunei Emerald -'n' Gold and E. fortunei Emerald Gaiety >C. japonica and C. japon.ica April Rose. Consequently we suggested that when evaluate the cold resistance of the introduced evergreen broad-leaved plant should use comprehensive analysis method that using multiphysiological index, and combined with growing index.%2007年11月到2008年3月,对引种到北京的7种常绿阔叶植物越冬期间的形态指标和生理生化指标进行分析,评价各种引种材料的抗寒性,分析各测定指标在评价中的作用.研究发现:7种植物的水分饱和亏缺值、电导率、束缚水和自由水比值、SOD活性、APX活性以及可溶性糖含量总体呈现先上升后下降的趋势,叶绿素含量的变化则相反.呈现先下降后上升的变化,可以作为评价抗寒性的生理指标;而POD活性和MDA含量变化不明显,不宜

  6. 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

  7. 万木林自然保护区不同群落优势种高度结构研究%Height structures of dominant species of different subtropical evergreen broadleaved forest communities in Wanmulin Natural Reserve

    Institute of Scientific and Technical Information of China (English)

    毕晓丽; 洪伟; 吴承祯; 闫淑君; 封磊; 王新功

    2003-01-01

    Based on the data of four subtropical evergreen broadleaved forest communities in Wanmulin Natural Reserve, whose dominant species were Tsoongiodendron odorum Chun, Cinnamomum micranthum Hayata, Castanopsis fabri Hance and Pinus massoniana, respectively, the height class and diameter class structures and the dynamics of height structure were analyzed. The results showed that the relationships between tree species, tree density, basal area at D. B. H, and height class (or diameter class) could be simulated by different equations. There was a significant positive correlation between tree species and tree density for different height class or different D. B. H. class. The structure dynamic analysis showed that the community of Tsoongiodendron odorum Chun was very unstable, and the species sharing degree in four communities was fairly lower, indicating that the dominant species were very obvious. The results could give a useful clue for the studies on endangered mechanism of rare species.

  8. Spatial Patterns and Associations of Dominant Tree Spe-cies in Subtropical Evergreen Broadleaved Forest in Southern China%中国亚热带常绿阔叶林优势种的空间格局与关联

    Institute of Scientific and Technical Information of China (English)

    覃林; 温远光; 梁宏温; 朱宏光

    2014-01-01

    Objective]It is well known that the spatial pattern in plant communities plays an im-portant role in community assembly and dynamic.[Methods]We analyzed the population struc-ture of eight dominant tree species at a 3.2hm2 subtropical evergreen broadleaved forest plot in Damingshan Nature Reserve in southern China.Based on the O-ring statistic,a technique of spatial point pattern analysis,we analyzed small-scale intraspecific spatial distribution patterns and intra-or inter-specific spatial association patterns among eight dominant species.[Results]The results showed that significant aggregated for intraspecific,and for smaller trees within species at small scales.Large trees of Huodendron biaristatum and Diospyros morrisiana showed significant positive association with their smaller trees at small scales,while large tree of Acer fabric showed significant negative association with its smaller trees at all scales of 0~40m.Only 2 of 58 species pairs among these species showed significant small-scale positive as-sociation.[Conclusion]These results revealed that seed dispersal limitation and microhabitat heterogeneity might contribute to the coexistence of these dominant species at subtropical ever-green broadleaved forest in Damingshan.However,the ecological assembly rules in subtropical evergreen broadleaved forest are required to further explore in southern China.%【目的】种群空间格局对阐明植物群落构建与动态具有重要意义。【方法】在广西大明山国家级自然保护区建立了一个面积3.2hm2的常绿阔叶林固定样地。运用O-ring空间点格局分析方法对样地8个优势种的空间格局以及种群大小关联和种间关联进行了研究。【结果】8个优势树种及其小径级个体在小尺度上均为聚集分布;云贵山茉莉和毛狗骨柴的大径级与其小径级个体在小尺度上呈正相关,而罗浮槭的大径级与小径级在0~40m上为负相关;58个种对中有2个种对在小尺度

  9. Habitat associations of woody plant species in Baishanzu subtropical broad-leaved evergreen forest%百山祖常绿阔叶林木本植物的生境相关性分析

    Institute of Scientific and Technical Information of China (English)

    王伟; 骆争荣; 周荣飞; 许大明; 哀建国; 丁炳扬

    2011-01-01

    Both unified neutral theory and niche theory have played an important role in understanding the mechanisms of species coexistence in tropical rain forests. Using Toms-translation tests, we examined the relationships between microtopography (elevation, convexity, and slope) and the distribution of 89 wood species with >5 individuals and diameter at breast height (DBH) > 1.0 cm in a 5-ha permanent plot in a subtropical broad-leaved evergreen forest in Baishanzu, Zhejiang Province. We classified plants into three growth stages (sapling, juvenile and mature stages) based on their diameter-classes, and compared relationships between microtopography and the distribution of plants in different growth stages for each species.Species with less than 40 individuals always showed few associations with their habitats, while most common species in the 89 studied showed significant associations with their habitats. The majority of species exhibited shifts in habitat preference among growth stages; the exceptions were Rhododendron latoucheae,Cyclobalanopsis stewardiana and Cleyera pachyphylla, whose associations with habitats were similar at all stages. Our study suggests that topographical differentiation is important for maintaining species diversity in this subtropical broad-leaved evergreen forest, and that habitat associations of species change ontogenetically.%中性理论和生态位理论在解释热带雨林中物种共存机制上发挥了重要作用.本文通过Torus-translation榆测方法对百山祖常绿阔叶林5 ha样地中DBH≥1 cm、个体数大于5的89种木本植物与4个根据地形和物种组成划分的小生境进行了关联性分析.同时按植物的胸径径级大小将其分为幼树期、生长期、成熟期3个生长阶段,并分别分析了植物在这3个生长阶段与生境的关联性.结果表明:89个木本植物中,没有表现出显著的生境相关件的物种多是稀有种或是个体数较少的物种,而大部分的常见

  10. 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.

  11. Mycorrhizae respond to plant diversity in monsoon evergreen broadleaved forest succession choronsequence%季风常绿阔叶林演替系列菌根资源及其与群落多样性的关系

    Institute of Scientific and Technical Information of China (English)

    郑克举; 唐旭利; 张静; 韩天丰

    2013-01-01

    Plant species diversity, community structure, productivity and edaphic factors varied significantly with forest succession, these variations may influence the diversity of mycorrhizae. To understand how forest structure and function impact on mycorrhizae at ecosystem level, three subtropical forests were chosen along a forest succession series in South China to investigate mycorrhizae, ectomycorrhizae ( ECM ), arbuscular mycorrhizae ( AM ), and mycorrhizal fungal spores in the top soil ( 0-20 cm depth ). Potential influences of forest structure on mycorrhizae were analyzed based on field census together with plant diversity and soil nutrients. The results showed that nearly 70% of fine roots less than 2 mm diameter in the top soil of each forest were colonized by mycorrhizal fungi, but dominate mycorrhizae types varied significantly in the three successional forests. AM accounted for 78% of total mycor-rhizae in the pine forest at early successional stage, ECM contributed to 75% of mycorrhizae in the mixed forest at middle succes-sional stage, and AM and ECM contributed equivalently to total mycorrhizae in the monsoon evergreen broadleaved forest at late succession stage. Mycorrhizal fungal spore density was highest in the pine forest (2 925 spores per 20 g dry soil), which was 2.5 and 2 times of those in the mixed forest and monsoon evergreen broadleaved forest, respectively. We found that the difference of mycor-rhizae composition was associated with plant diversity, community structure and soil nutrient condition in successional forests. Spe-cies-rich and individual high density of grass plants and poor soil nutrient level in the pine forest may result in relatively high propor-tion of AM in the pine forest. Mycorrhizae were dominated by ECM resulting from the dominance of ECM plant in the mixed forest. Abundant plant species and complex community structure in the monsoon evergreen broadleaved forest contributed AM and ECM to equal distribution in the forest

  12. 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...

  13. 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

  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. Effects of N and P addition on soil nitrogen mineralization in a subtropical evergreen broadleaved forest%氮磷添加对亚热带常绿阔叶林土壤氮素矿化的影响

    Institute of Scientific and Technical Information of China (English)

    赵阳; 张驰; 赵竑绯; 徐小牛

    2013-01-01

    Three treatments (no nutrient addition,CK; N addition,100 kg N hm-2 a-1 and N+P addition,100 kg N · hm-2 · a-1 + 50 kg P · hm-2 · a-1) were installed in an evergreen broadleaved forest in northern subtropics to study the effects of nutrient addition on the soil nitrogen dynamics and mineralization in the forest.The annual mean inorganic N concentrations (NH4+-N + NO3--N) in 0-10 cm and 10-20 cm soil layers for the treatments CK,N addition,and N+P addition were 7.27 and 6.80 mg · kg-1,13.94 and 8.92 mg · kg-1,and 11.20 and 7.13 mg · kg-1,respectively,among which,the percentages of NH4 +-N to total inorganic N were 90.66% and 91.15%,65.78% and 72.85%,and 84.64% and 85.08%,respectively.The net ammonification,nitrification,and N mineralization rates in the 0-10 cm and 10-20 cm soil layers of the three treatments showed the similar seasonal patterns,with the maximum in summer and the minimum in winter.There were no significant differences for the net rates of N transformation in spring and autumn.Nutrient addition (N and N+P) decreased the annual average net rates of nitrogen mineralization.N addition decreased the net nitrification rate but increased the net ammonification rate,whereas N+P addition increased the net nitrification rate but decreased the net ammonification rate.Due to the long-term dynamic processes of forest ecosystems in response to nutrient addition,it would be necessary to conduct a long-term observation on the nitrogen dynamics in forest ecosystems under scenario of increasing N deposition.%设计了2种处理(即氮添加,100 kg N·hm-2·a-1;氮磷添加,100 kgN·hm-2·a-1+50kgP·hm-2·a-1),研究了氮磷添加对亚热带北部常绿阔叶林土壤无机氮和氮素矿化的影响.结果表明,不同处理0 ~ 10 cm和10 ~ 20 cm土层无机氮(铵态氮+硝态氮)含量年平均值分别为:对照7.27和6.80 mg·kg-1、氮添加13.94和8.92 mg·kg-1、氮磷添加11.20和7.13 mg·kg-1,其中铵态氮分别占90.66%和91

  16. 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

  17. Effects of snow damage on the leaf litter' s nutrient content and return amount of constructive species in evergreen broadleaved forest in Gutianshan National Natural Reserve,East China%雪灾对古田山常绿阔叶林建群种养分含量及归还量的影响

    Institute of Scientific and Technical Information of China (English)

    晏丽蓉; 刘会; 李铭红; 张磊; 于明坚

    2013-01-01

    在古田山国家级自然保护区24 hm2长期监测样地设置凋落物收集框,对常绿阔叶林的养分归还量进行动态监测.2008年初南方发生特大雪灾,为研究雪灾对建群种甜槠和木荷凋落叶中主要养分含量、归还量的影响提供了契机.结果表明:(1)虽然建群种凋落叶中碳含量受雪灾影响不显著,但雪灾导致其凋落量明显下降,因此碳的归还量在灾后明显减少.(2)建群种凋落叶氮含量在雪灾前后有显著差异,表现为灾前<灾后;但因受凋落量的影响,其归还量仍表现为灾前>灾后.(3)建群种凋落叶磷含量在雪灾前后存在极显著差异(P<0.01),表现为灾前<灾后,导致其归还量也表现为灾前<灾后.%A 24-hm2 plot was installed in the Gutianshan National Natural Reserve, East China to dynamically monitor the leaf litter' s nutrient content and return amount of evergreen broad-leaved forest. In 2008, a serious snow damage event happened in southern China, which gave us an opportunity to study the effects of snow damage on the leaf litter' s nutrient content and return amount of two constructive species (Castanopsis eyrei and Schima superba) in the evergreen broadleaved forest. No obvious difference was observed in the leaf litter' s C content of the constructive species before and after the snow damage, but the leaf litter' s production after the snow damage showed an obvious decrease, and thus, the leaf litter' s C return amount after the snow damage also showed an obvious decrease. As compared with that before the snow damage, the leaf litter' s N content of the constructive species after the snow damage was significantly larger, but the litter' s N return amount was smaller, due to the decrease of the litter' s production after the snow damage. Same as the leaf litter' s N content, the leaf litter' s P content of the constructive species after the snow damage was significantly larger than that before the snow damage ( P< 0

  18. 1996-2012天目山常绿落叶阔叶混交林乔木层群落动态%Community Dynamics of Arbor Layer in the Mixed Evergreen and Deciduous Broad-Leaved Forests during 1996 -2012 in Tianmu Mountain

    Institute of Scientific and Technical Information of China (English)

    游诗雪; 张超; 库伟鹏; 朱弘; 赵明水; 余树全

    2016-01-01

    要原因;中小径级个体间竞争剧烈,死亡率高。%Objective]Using long-term exploration of community dynamics ( ranging from 1996 to 2012 ) ,this study was aimed to provide scientific support for forest protection,management and operation in Tianmu Mountain.[Method]In 1996,a field site with the size of 1hm2 locating in evergreen and deciduous broad-leaved mixed forest of Tianmu Mountain,a national nature reserve in Zhejiang province was built,and then each tree in the site was numbered,labeled and recorded it’s species name,height,diameter at breast height (DBH),location and other information. In 2012,the above data was determined again to compare the community dynamics of the trees with the DBH more than 10 cm during the past 16 years.[Result]The results showed that in 1996,the evergreen broad-leaved trees and deciduous broad-leaved trees accounted for 54. 97% and 45. 03% of the total number of trees,respectively,while in 2012,the ratios changed to 62. 81% and 37. 19% respectively. The community structure changed from 40 species,34 genera and 24 families in 1996 to 48 species,40 genera and 29 families in 2012. During the 16 years,there were 14 species emerged which are belonging to 11 genera and 8 families and 6 species disappeared which are belonging to 5 genera and 3 families. Among them, 66. 67% of the disappeared species were accidental species ( defined as the total number of individuals varying from 1 to 3 ) ,while in new emergent species,92. 86% of which were accidental species. . The total number of trees increased from 553 in 1996 to 597 in 2012,of which the dead was 191 and the regeneration was 235. The richness index,Simpson diversity index,Shannon-Wiener index and Pielou evenness index were changed from 40,0. 72,3. 98,and 1. 03 in 1996, respectively to 48,0. 88,3. 88,and 1. 05 in 2012,respectively. The small DBH class ( DBH 60 cm) trees were 2. 53% and 2. 01%,respectively and the mortality ratio was 7. 69%; In general,the DBH class

  19. Diversity and Distribution of Vascular Epiphytes in Different Restoration Stages of Monsoonal Broad-leaved Evergreen Forest Communities%季风常绿阔叶林不同恢复阶段附生维管植物多样性及分布

    Institute of Scientific and Technical Information of China (English)

    李帅锋; 苏建荣; 刘万德; 张志钧; 刘庆云; 李忠文

    2011-01-01

    Vascular epiphytes are important components of species richness in monsoonal broad-leaved evergreen forest.Field data collection on vascular epiphytes was based on 0.81 hm2 plot ( including 9 subplots) in different restoration stages (community of 15 years restoration (15 a), community of 30 years restoration (30 a) ) and primary monsoonal broadleaved evergreen forest distribute in Caiyanghe Nature Reserve, Yixiang Township and Xinfang reservoir, Pu' er city, Yunnan, China. On the basis of analyzing vascular epiphytes species richness, abundance, distribution, similarity coefficient,the relationship between epiphytes and phorophytes was discussed. The results showed that: ( 1 ) 3 116 vascular epiphytes,belonging to 22 species in 20 genera and 9 families were recorded in all plots. (2) The diversity of vascular epiphytes was low in restoration stages ( 15 a, 5 spp. and 30 a, 7 spp. ) compared to primary forest (17 spp. ). (3) The composition of epiphytic species in primary forests and the stand in restoration stages differed markedly: 15a harboured no orchid species but more fern species and primary forest hold more orchid species. Probably the families occurring only in primary forest sites which the authors studied may be used as bioindicators to determine the degree of restoration in monsoonal broadleaved evergreen forest. (4) The epiphyte abundance was also lower in restoration stages. The declines in species number and abundance as well as the differences in species composition were mainly due to the less diversified phorophyte structure and less differentiated microclimate in the disturbed and secondary vegetation compared to the primary forest. Sφrensen coefficient between 15 a and primary forest was higher than that between 30a and primary forest. (5) The vascular epiphytes were clumped horizontally iu 3 eommunity types. Vertically, vascular epiphytes of 15a were mainly distributed at 0 ~ 5 m and that of primary forest was up to 20 m. (6) Both the

  20. 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

  1. Effects of Stand Vegetation Factors and Soil Nitrogen on Fine Root Biomass in Evergreen Broad-leaved Secondary Forests in Lower Subtropical China%植被因子和土壤氮对南亚热带常绿阔叶次生林细根生物量的影响

    Institute of Scientific and Technical Information of China (English)

    徐伟强; 周璋; 李意德; 李健容; 张霞; 徐大平

    2016-01-01

    The relationship between fine root biomass and tree basal area at breast height, and how fine roots would respond to soil nitrogen (N) in the forests with high atmospheric N deposition both are still not clear. Therefore, a study on the relationships of fine root biomass with total tree basal area at breast height, the ratio of basal area for big trees (diameter at breast height, DBH≥30 cm) to total trees, tree density, understory biomass, soil nitrogen concentration, and soil N/C ratio was conducted in lower subtropical evergreen broad-leaved secondary forests in Guangzhou. Forty-eight forest plots with mostly 1 200 m2 area were set up and investigated. These forests, called ecological forests, were protected from commercial use and human disturbance for about 40 years. This study was aim to estimate the effects of the stand vegetation factors and soil N on fine root biomass. Our results showed that:(1) Both of fine root biomass in 0~20 cm (topsoil) and 20~40 cm soil layers (subsoil) were not correlated to total tree basal area at breast height, but were negatively correlated to the ratio of basal area for big trees to total trees. (2) The correlation between fine root biomass and understory biomass was not significant in topsoil, but was negatively significant in subsoil. (3) The correlations between fine root biomass in each soil layers and the according soil N concentration or N concentration per unit carbon concentration (N/C ratio) were negatively significant, except that for fine root biomass in topsoil and soil N concentration. These results indicated that the ratio of basal area for big trees (DBH≥30 cm) to total trees rather than the total tree basal area affect fine root biomass in these secondary forests with large different tree DBH composition. The negative correlations between fine root biomass and soil N concentration indicate that forest plants still respond to soil N even in these evergreen broad-leaved forests in lower subtropical China with

  2. 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

  3. 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

  4. 模拟降水分配季节变化对南亚热带常绿阔叶林凋落物的影响%Effects of Seasonal Precipitation Variation on Litter-fall in Lower Subtropical Evergreen Broad-leaved Forest

    Institute of Scientific and Technical Information of China (English)

    焦敏; 申卫军

    2014-01-01

    为探讨降水季节分配的变化对南亚热带常绿阔叶林凋落物的影响,在广东省鹤山国家野外生态观测站模拟干季更干(DD)和延长干季(ED)的野外降水控制实验,对森林生态系统中凋落物变化进行了分析研究。结果表明,该试验林年凋落物总量为9.24 t hm–2,在不同时期均以叶凋落物为主,约占50.7%~69.3%。DD处理显著减少了干季(10–3月)叶凋落物量(P<0.01)。虽然DD处理下全年总凋落物量比对照降低了10.3%,但差异不显著。ED处理也减少了春季(4–5月)的叶和花果及总凋落物量,全年总凋落物量则比对照增加了11.3%,但ED处理对春季和全年凋落物量的影响均差异不显著。两种干旱处理对凋落物叶质量总体上影响不明显,但DD处理显著减小了火力楠(Michelia macclurei)凋落叶的木质素含量。因此,降水格局的变化可能会影响南亚热带森林土壤的碳汇能力。%In order to understand the effects of precipitation pattern on litter-fall in lower subtropical evergreen broad-leaved forest, a field precipitation manipulation experiment at Heshan National Forest Research Station (Guangdong Province, China) was designed to simulate decreasing dry-season (October–March) and spring (April–May) rainfall and the litter-fall respones in the forest was studied. The results showed that annual litter-fall of the experimental forest was 9.24 t hm–2, of which leaf litter was the main composition at different stages, accounting for 50.7%–69.3% of the total. The decreasing dry-season rainfall (DD) treatment significantly reduced leaf litter production (P<0.01). The whole-year litter production was also reduced by 10.3% under the DD treatment compared to the control, but not statistically significant. Decreasing spring rainfall (ED) also reduced flower-, fruit-, and leaf-litter as well as the total during the spring time, but the whole-year litter production was increased by 11

  5. 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

  6. Allocation of Carbon Storage in the Arbor Layer of Young and Old-growth Evergreen Broad-leaved Forests in Wanmulin%万木林青年和老龄常绿阔叶林乔木层碳贮量分配特征

    Institute of Scientific and Technical Information of China (English)

    黄蓉; 王超; 杨智杰; 陈光水

    2011-01-01

    In order to investigate the influence of forest biomass carbon on forest carbon storage,carbon sink measurement and management,as well as biodiversity conservation,this paper analyses the evergreen broad-leaved forests,including the young forest(about 47 a)and old-growth forest(about 120 a)in the Wanmulin Nature Reserve in Fujian.According to the results of biodiversity investigation and Biomass Different Speed Equation,we figure out the carbon storage in tree layer and its distribution features in different heights,diameter classes and tree species.The results are shown as follows:1)The carbon storage of young forest is 115.03 t·hm-2,while that of the old-growth forest is 224.43 t·hm-2.2)In young forest,the maximum carbon storage is 23.17 t·hm-2 in height class Ⅶ(15~17 m),in old-growth forest,it(62.96 t·hm-2)happens in height class Ⅷ(17~19 m).3)In young forest,the maximum carbon storage which amounts to 34.25 t·hm-2,lies in DBH class Ⅵ(15 cm≤DBH17 cm);in old-growth forest,the maximum carbon storage lies in class XIX(DBH≥41 cm)which amounts to 60.03 t·hm-2,taking up 26.78% of total carbon storage.4)Most carbon is stored in a small minority of trees,in other words,most tree species contribute only a tiny part to the total carbon storage.%了解森林生物量碳分配特征,对于森林碳贮量和碳汇估算、森林碳汇经营和生物多样性保护有重要意义.本课题选择福建省万木林自然保护区青年(约47 a生)和老龄(约120 a生)常绿阔叶林为研究对象,根据生物多样性调查结果和生物量异速方程,计算乔木层生物量碳贮量,并分析其高度级、径级和树种间的分配特征.结果表明:1)青年林碳贮量为115.03 t.hm-2,老龄林碳贮量为224.43 t.hm-2;2)青年林最大碳贮量出现在高度级Ⅶ级(15~17 m),为23.17 t.hm-2,而老年林最大碳贮量出现在高度级Ⅷ级

  7. Temporal and spatial variation of seedfall in a broad-leaved evergreen forest in Gutianshan Nature Reserve of Zhejiang Province, China%浙江古田山自然保护区常绿阔叶林种子雨的时空变异

    Institute of Scientific and Technical Information of China (English)

    杜彦君; 马克平

    2012-01-01

    木本植物种子产量的时间和空间变化格局对植物更新以及群落组成和结构有着重要影响,是种子雨研究的一个重要方面.2006年6月在古田山亚热带常绿阔叶林24 hm2样地布置了130个面积为0.5 m2的种子雨收集器,每周收集一次.利用4年的种子雨数据,研究了种子雨的时间和空间变异.主要结果如下:(1)共收集到124 227粒成熟种子,属于29科51属63种,每月降水量与平均每月种子数、物种数均呈显著负相关;(2)种子产量在每年干季(秋季)有明显的高峰,有10个物种在湿季扩散种子,不同物种结实物候起始和终止时间有差异;(3)基于4年的种子雨数据,几乎所有物种的种子雨均存在很大的年际变异,收集到的所有物种的种子产量年际变异系数的中位数为1.72;(4)种子雨在不同收集器之间有很大的变异,变异系数的中位数为8.06;几乎所有物种的空间变异都远远大于时间变异,这可能是由于母树的稀有性、种子传播距离的差异,以及地形等因素造成.通过与巴拿马Barro Colorado Island 50 hm2样地108个物种种子产量的年际变异系数相比较,古田山种子雨数据支持了高纬度地区种子产量变异高于低纬度地区的假说.%Aims Seedfall of woody plants often fluctuates considerably from year to year and from site to site. These variations may have strong effects not only on the recruitment of the plant populations themselves, but also on the community composition and structure. Our objective was to elucidate seasonal, annual and spatial variations of seedfall in broad-leaved evergreen forest in Gutianshan Nature Reserve of Zhejiang Province over four years. Methods Seed rain was censused weekly since June 2006, using 130 seed traps set along 2.3 km of trails within the Gutianshan 24 hm2 subtropical evergreen forest plot. Each seed trap consisted of a square, 0.5 m2 Poly Vinyl Chloride (PVC) frame supporting a shallow, open

  8. Structural Characteristics and Diversity of the Tree Species in the mid-montane Humid Ever-green Broad-leaved Forest in the Gaoligong Mountains, Yunnan%高黎贡山中山湿性常绿阔叶林树种结构及多样性特征

    Institute of Scientific and Technical Information of China (English)

    柴勇; 孟广涛; 李贵祥; 袁春明; 李品荣

    2015-01-01

    Structural characteristics and diversity of the tree species in the mid-montane humid ever-green broad-leaved forest in the Gaoligong Mountains in Yunnan Province were studied .The results showed that the forest is characterized by evergreen mesophanerophytes with simple and leathery and entire mesophylls , having a few decid-uous trees in the canopy layer and an unconspicuous seasonal aspect .In the plot , the species richness and the a-bundance are most among trees with height <5 m or with 1 cm≤DBH<5 cm, and decreased with the increase of the height or DBH class, respectively, which can be fitted very well with linear function or negative exponential function.The basal area are largest among trees with 11 m≤H<14 m or with 20 cm≤DBH<25 cm.In the plot, there were 10 546 individuals in 95 species, and ite Shannon-Weiner indes is 1.716, its Simpson index is 0.014, and its evenness index is 0.867 , indicating a higher level of species diversity in the whole .The species richness , the abundance and the Shannon-Weiner index were decreased gradually with the increase of the height and DBH class, but the Simpson index and the evenness index showed the opposite trend .Compared with other domestic plots, the species richness , density, basal area per ha of Gaoligongshan plot were at the middle level , but the maximum importance value was the lowest , and the proportion of the rare species was only higher than one plot , showing a higher diversity among these plots .%对高黎贡山中山湿性常绿阔叶林树种结构及多样性特征进行了研究。结果表明,高黎贡山中山湿性常绿阔叶林动态监测样地中树种以单叶、革质、全缘、中型叶为主,群落外貌以常绿的中高位芽植物为主,落叶树种较少,群落季相变化不明显。群落中树种数、树木个体数分别在H<5 m高度级及1 cm≤DBH<5 cm胸径级最多,并随高度或胸径的增加而不断减少,这种变化趋势可用直线函数或

  9. FIFTEEN-YEAR CHANGES OF TREE POPULATIONS IN THE SECONDARY SUBTROPICAL EVERGREEN BROAD-LEAVED FORESTS IN SOUTHWESTERN CHINA%亚热带次生常绿阔叶林主要乔木种群自然恢复15年来的变化

    Institute of Scientific and Technical Information of China (English)

    包维楷; 刘照光; 刘朝禄; 袁亚夫; 刘仁东

    2001-01-01

    The present study was conducted in the secondary su btrop ical evergreen broad-leaved forests at altitude 1650~1670m in Mt.Wawusha n National Forest Park,southwestern China.In order to understand stand restoratio n dynamics,the stand structure in three permanent 0.04hm2 plots for 3~4t imes were recorded from 1982 to 1997 and expounded the changes in 15 years about tree composition,important value index,several diversity indices,structure and volume productivity of both communities and populations.The results were followe d:11 tree species disappeared and about another 10 species entered into tree lay er in the stand,keeping tree layer dynamic equilibrium and developing tree speci es diversity.The dominant species,Castanopsis platyacantha,assumed the super ior status,but its important value(Ⅳ)was decreased.The position of secondary do minant species,Schima sinense and Lithocarpus hancei, are gradually enha nced with gradually increased Ⅳ.The changes of densities,DBH and height dis tribution of tree populations displayed that the secondary evergreen forest was developed from past single or double dominant tree species to double or three do minant trees,from single tree layer to multiple levels in vertical structure.And the resulting community becomes more complicated and more stable.The growth rat es of average height and DBH of all main trees were 24~48cm.a-1 an d 0 .34~1.10cm.a-1,respectively.According to the differentiation of grow th,the main trees could be divided into three growth groups of species:fast-gro wing group including species of Schima sinense and Acanthopanax evodiaefoliu s var.gracills,slow-growing group of Machilus pingii and Lithocarpu s hancei, and the group in between of Castanopsis platyacantha and Cycl ob alanopsis myrsinaefolia. Volume productivity of the dominant population increa s ed firstly and then decreased,but the secondary tree population increased quickl y all the time.Volume productivity of all tree population in

  10. 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

  11. 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

  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. 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

  14. Regeneration dynamics of major tree species during 2002-2007 in a subtropical evergreen broad-leaved forest in Gutianshan National Nature Reserve in East China%古田山常绿阔叶林主要树种2002-2007年间更新动态

    Institute of Scientific and Technical Information of China (English)

    汪殷华; 米湘成; 陈声文; 李铭红; 于明坚

    2011-01-01

    To explore the regeneration dynamics of major tree species in an evergreen broad-leaved forest in Gutianshan National Nature Reserve, a 5-ha dynamic plot was established in 2002. All woody plants with DBH (diameter at breast height) ≥1 cm were tagged, mapped, measured and identified to species. Based on data from one census each in 2002 and 2007, we analyzed the characteristics of dead and recruited individuals to estimate mortality and recruitment rates, and population change for 43 tree species. The results showed the following: (1) A total of 4,758 stems were recruited and 1,384 died during the five years, and the stem increment ratio was consequently 26.05%. (2) The amounts of recruits within three growth forms (tree, subtree or shrub, and sub-shrub) all declined as DBH size class increased; a pattern different from that observed in dead individuals. (3) The average annual mortality and recruitment rate of these 43 tree species was 2.26%and 5.90%, respectively. (4) Comparing mortality and recruitment rates in each DBH class, we found that 19 subtree or shrub species consistently had higher recruitment than mortality rates in small DBH class, and almost no difference in both middle and large DBH classes. (5) 31 out of 43 species showed population growth, while 12 species' populations declined slightly. Populations of 10 species increased or decreased at an annual rate of >5%, indicating that they were experiencing fast turnover. Among these, Chimonanthus salicifolius (45.13%) and Itea oblonga (16.35%) had the highest increment rate in population size, whereas Loropetalum chinense (-3.10%) and Quercus serrata var. brevipetiolata (-1.86%) had the highest rate of decline. In conclusion, both recruitment and mortality rates varied among species and among DBH size classes,pointing to the unique regeneration dynamics of the 43 tree species. These differences might be associated with patterns of density dependence in addition to habitat fluctuations

  15. 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)

  16. 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

  17. 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

  18. 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

  19. Experiment at Evergreen.

    Science.gov (United States)

    Jones, Richard M.

    The philosophy and structure of programs of coordinated study at Evergreen State College from 1970 to 1980 are discussed, and comparisons are made to the experiment at the University of California, Berkeley, promoted by Joseph Tussman. Both programs are based on ideas suggested by Alexander Meiklejohn and his Experimental College at the University…

  20. 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.

  1. 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

  2. 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

  3. 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

    2016-08-16

    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.

  4. 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

  5. Relationships between established seedling survival and growth in evergreen broad-leaved forest in Tiantong

    Directory of Open Access Journals (Sweden)

    Heming Liu

    2017-01-01

    Full Text Available Community seedling regeneration is a crucial process for maintaining species coexistence. The stage from which an established seedling becomes a new reproductive individual is one of the most important components of community regeneration, and influences the community recruitment pattern. However, the short-term mortality of established seedlings is lower than newly germinated seedlings, and previous studies have not been able to analyze the effect of biotic neighborhoods and abiotic micro-habitat factors on established seedling survival perfectly. Therefore, we suggest that the growth status of established seedlings could predict established seedling survival during development, and analyze the effects of these biotic and abiotic factors on established seedling growth, in order to indirectly estimate their effects on established seedling survival. To test this hypothesis, we selected established seedlings in the 20 ha forest dynamics plot in Tiantong as samples. Then, we used generalized linear mixed models to assess the effects of relative growth rate, biotic neighborhood factors (conspecific/heterospecific adult neighborhood indices, density of conspecific/heterospecific seedling neighbors, the amount of conspecific/heterospecific leaf litter from neighbors and abiotic micro-habitat factors (canopy openness, herbaceous coverage, elevation, slope, aspect, pH value, total nitrogen and total phosphorus in the soil on short-term established seedling survival rates. We used linear mixed models to assess the effects of biotic neighborhood factors and abiotic micro-habitat factors on relative growth rates of established seedlings. Results showed that relative growth rates have a significant, positive effect on established seedling survival, and this factor is the most important factor among potential influencing factors. In addition, canopy openness, as only one significant influencing factor, has a positive effect on relative growth rates of established seedlings. These results suggest that the growth status of seedlings could predict established seedling survival during development. Meanwhile, established seedlings prefer to grow in habitat with better light. Therefore, the established seedling survival rate would be higher in the habitat with better light through higher relative growth rates.

  6. Establishment of the evergreen broad-leaved tree species Castanopsis cuspidata in an abandoned secondary forest in western Japan.

    Science.gov (United States)

    Hirayama, Kimiko; Kawamura, Shota; Nishimura, Tatsuya; Takahara, Hikaru

    2010-09-01

    Recently, populations of Castanopsis cuspidata have often expanded into secondary forests in western Japan. To determine the establishment processes of this species, we analyzed its spatial distribution in a secondary forest dominated by Quercus variabilis and Quercus serrata that is located adjacent to a stand dominated by C. cuspidata. Saplings, defined as >or=30 cm stem length (SL) and DBH), were abundant and their size distribution was inversely J-shaped, indicating continuous recruitment. Although seedlings (SL trees of this species, some were found >or=40 m from the nearest adults, suggesting that there is animal-aided dispersal of acorns. The distribution of larger-sized individuals (>or=100 cm SL) of C. cuspidata was unrelated to distance from the nearest flowering C. cuspidata or dominant Quercus species (>or=5 cm DBH), but was associated with dead Pinus densiflora trees, which were abundant at the site. Thus, the establishment of C. cuspidata in this forest is controlled mainly by two factors, viz. patterns of acorn dispersal by animals, and forest disturbance regime (i.e., deaths of pine trees).

  7. Water use efficiency in a primary subtropical evergreen forest in Southwest China

    Science.gov (United States)

    Song, Qing-Hai; Fei, Xue-Hai; Zhang, Yi-Ping; Sha, Li-Qing; Liu, Yun-Tong; Zhou, Wen-Jun; Wu, Chuan-Sheng; Lu, Zhi-Yun; Luo, Kang; Gao, Jin-Bo; Liu, Yu-Hong

    2017-02-01

    We calculated water use efficiency (WUE) using measures of gross primary production (GPP) and evapotranspiration (ET) from five years of continuous eddy covariance measurements (2009–2013) obtained over a primary subtropical evergreen broadleaved forest in southwestern China. Annual mean WUE exhibited a decreasing trend from 2009 to 2013, varying from ~2.28 to 2.68 g C kg H2O‑1. The multiyear average WUE was 2.48 ± 0.17 (mean ± standard deviation) g C kg H2O‑1. WUE increased greatly in the driest year (2009), due to a larger decline in ET than in GPP. At the diurnal scale, WUE in the wet season reached 5.1 g C kg H2O‑1 in the early morning and 4.6 g C kg H2O‑1 in the evening. WUE in the dry season reached 3.1 g C kg H2O‑1 in the early morning and 2.7 g C kg H2O‑1 in the evening. During the leaf emergence stage, the variation of WUE could be suitably explained by water-related variables (relative humidity (RH), soil water content at 100 cm (SWC_100)), solar radiation and the green index (Sgreen). These results revealed large variation in WUE at different time scales, highlighting the importance of individual site characteristics.

  8. 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 ...

  9. 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…

  10. 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).

  11. Contrasting ozone sensitivity in related evergreen and deciduous shrubs.

    Science.gov (United States)

    Calatayud, Vicent; Marco, Francisco; Cerveró, Júlia; Sánchez-Peña, Gerardo; Sanz, María José

    2010-12-01

    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(2) assimilation and stomatal conductance (g(s)), impaired Rubisco efficiency and regeneration capacity (V(c,max,)J(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.

  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. 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...

  14. March Madness! A Look at Evergreen Parenting Topics

    Science.gov (United States)

    Parenting for High Potential, 2014

    2014-01-01

    Many topics in the world of gifted are evergreen. Whether it be 1964 or 2014, they're still relevant. In this issue, "Parenting for High Potential" takes a peek into the archives to look at topics that have run in various March issues of PHP through the years. No matter where you are on the gifted journey, there's something here for…

  15. 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…

  16. 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,…

  17. 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.

  18. 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

  19. 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

    2016-01-12

    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.

  20. 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.

  1. 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.

  2. 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.

  3. Evergreen Brick Works: An Innovation and Sustainability Case Study

    Directory of Open Access Journals (Sweden)

    Seana Irvine

    2012-07-01

    Full Text Available Technology is rapidly being deployed to advance social innovation that creates lasting change. This case study of Evergreen Brick Works explores how Evergreen is leveraging the power of its unique new campus as a showcase for advancing sustainability-related behavioural change along with new and emerging state-of-the-art technologies to advance its mission. The ultimate success of these technologies will be in their ability to engage larger numbers and greater diversity among participants, and in their ability to translate new insights into on-the-ground change in their communities. The article also identifies that the need for an organizational network mindset is as important as the technologies to achieve these changes.

  4. 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. simaruba...

  5. Comparison of seed rain and seed limitation between community understory and gaps in a subtropical evergreen forest

    Science.gov (United States)

    Du, Yanjun; Mi, Xiangcheng; Ma, Keping

    2012-10-01

    Treefall gaps have been identified as important sites for plant recruitment. In this study, we compared seed rain between forest gaps and forest interior using 150 seed traps in the understory and 19 traps in gaps in a 24 ha permanent plot of subtropical evergreen broad-leaved forest in East China. We asked how total seed abundance and seed species richness, the relative representation of different dispersal modes, and seed limitation and its components differed between canopy gaps and the understory. Results showed that most of the species found in both the understory and in gaps were animal-dispersal, but most of the seed rain was comprised of wind-dispersed species in both habitats. No significant differences in either density or diversity of seeds between gaps and non-gap sites were found. Contrary to expectations, wind-dispersed seeds did not occur significantly more in treefall gaps than in the forest understory. There were also no significant differences in seed limitation and its components (source limitation, dispersal limitation) between the understory and gaps. Seed limitation was strong for all but a few of the best-dispersed species in both gap and understory seed traps. Source and dispersal limitation showed large inter-specific variation in both the understory and in gaps. Overall, our results indicate that: (i) gaps may play a neutral role in maintaining seed diversity in this subtropical forest; (ii) under strong seed limitation both in gaps and in the understory, population and community dynamics slows and ecological drift in species composition may become a more important determinant of community structure.

  6. 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

  7. 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...

  8. 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.

  9. Long-term growth of temperate broadleaved forests no longer benefits soil C accumulation

    Science.gov (United States)

    Ji, Yu-he; Guo, Ke; Fang, Shi-bo; Xu, Xiao-niu; Wang, Zhi-gao; Wang, Shu-dong

    2017-01-01

    It is widely recognized that the long-term growth of forests benefits biomass carbon (C) sequestration, but it is not known whether the long-term growth of forests would also benefit soil C sequestration. We selected 79 representative soil profiles and investigated the influence of the forest stand age on the soil C dynamics of three soil layers (0–10, 10–20 and 20–30 cm) in temperate broadleaved forests in East China. The results suggest that the soil C density in temperature broadleaved forests significantly changes with the stand age, following a convex parabolic curve. At an early stand age, the soil C density usually increases, reaching its peak value at a pre-mature stand age (approximately 50 years old). At later stand ages, the soil C density usually decreases. Therefore, our results reveal a turning point in the soil C density at a pre-mature stand age. The long-term growth of temperate broadleaved forests after pre-mature stand age no longer benefits soil C accumulation, probably promotes topsoil C loss. In addition, we found that the soil C density in the upper soil layer usually changes with the forest stand development more significantly than that in deeper soil layers. PMID:28176873

  10. Long-term growth of temperate broadleaved forests no longer benefits soil C accumulation

    Science.gov (United States)

    Ji, Yu-He; Guo, Ke; Fang, Shi-Bo; Xu, Xiao-Niu; Wang, Zhi-Gao; Wang, Shu-Dong

    2017-02-01

    It is widely recognized that the long-term growth of forests benefits biomass carbon (C) sequestration, but it is not known whether the long-term growth of forests would also benefit soil C sequestration. We selected 79 representative soil profiles and investigated the influence of the forest stand age on the soil C dynamics of three soil layers (0–10, 10–20 and 20–30 cm) in temperate broadleaved forests in East China. The results suggest that the soil C density in temperature broadleaved forests significantly changes with the stand age, following a convex parabolic curve. At an early stand age, the soil C density usually increases, reaching its peak value at a pre-mature stand age (approximately 50 years old). At later stand ages, the soil C density usually decreases. Therefore, our results reveal a turning point in the soil C density at a pre-mature stand age. The long-term growth of temperate broadleaved forests after pre-mature stand age no longer benefits soil C accumulation, probably promotes topsoil C loss. In addition, we found that the soil C density in the upper soil layer usually changes with the forest stand development more significantly than that in deeper soil layers.

  11. 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.

  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. Development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen forest in eastern China

    Science.gov (United States)

    Jing, Jun; Xia, Lingdan; Li, Kai

    2016-09-01

    The aim of this work was to understand the development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen broad-leaved forest in China. We measured the main developmental parameters of three typical defoliating insects (i.e., Ourapteryx ebuleata szechuana, Biston marginata, and Euproctis angulata) and their preferences for five host plants at temperatures from 16°C to 31°C at 3°C intervals in the Tiantong National Forest Research station in eastern China. The results showed the following. 1) An appropriate rise in temperature increases the survival rate with an increase in the number of offspring. The developmental durations for these three insects were shortened, and pupal weight increased with an increase in temperature. 2) A shift in the preference for host plants for these three insects was observedat elevated temperatures. They all preferred to feed on Schima superba and Castanopsis sclerophylla at elevated temperatures, showing an opposite response to the other three plants. The daily leaf consumption of the three insects was positively correlated with their feeding preference, with more leaves being consumed from the plants they preferred. 3) For O. ebuleata szechuana larvae, daily leaf consumption initially increased and then decreased with increasing temperatures. In contrast, Biston marginata and Euproctis angulata larvae consumed more leaves at elevated temperatures. The feeding preferences of O. ebuleata szechuana and Biston marginata were more sensitive to changing temperatures than that of Euproctis angulata laevae. We concluded that increased numbers of offspring and generations, pupal weights, and a shift in preference to two plants for these three defoliating insects might lead to severe damage to these two plants which would enhance the fragmentation and decrease the stability of the forest communities under changing temperatures. Meanwhile, the variations in the responses of

  14. 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.

  15. 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.

  16. Variations of Soil Microbial Community Structures Beneath Broadleaved Forest Trees in Temperate and Subtropical Climate Zones.

    Science.gov (United States)

    Yang, Sihang; Zhang, Yuguang; Cong, Jing; Wang, Mengmeng; Zhao, Mengxin; Lu, Hui; Xie, Changyi; Yang, Caiyun; Yuan, Tong; Li, Diqiang; Zhou, Jizhong; Gu, Baohua; Yang, Yunfeng

    2017-01-01

    Global warming has shifted climate zones poleward or upward. However, understanding the responses and mechanism of microbial community structure and functions relevant to natural climate zone succession is challenged by the high complexity of microbial communities. Here, we examined soil microbial community in three broadleaved forests located in the Wulu Mountain (WLM, temperate climate), Funiu Mountain (FNM, at the border of temperate and subtropical climate zones), or Shennongjia Mountain (SNJ, subtropical climate). Although plant species richness decreased with latitudes, the microbial taxonomic α-diversity increased with latitudes, concomitant with increases in soil total and available nitrogen and phosphorus contents. Phylogenetic NRI (Net Relatedness Index) values increased from -0.718 in temperate zone (WLM) to 1.042 in subtropical zone (SNJ), showing a shift from over dispersion to clustering likely caused by environmental filtering such as low pH and nutrients. Similarly, taxonomy-based association networks of subtropical forest samples were larger and tighter, suggesting clustering. In contrast, functional α-diversity was similar among three forests, but functional gene networks of the FNM forest significantly (P < 0.050) differed from the others. A significant correlation (R = 0.616, P < 0.001) between taxonomic and functional β-diversity was observed only in the FNM forest, suggesting low functional redundancy at the border of climate zones. Using a strategy of space-for-time substitution, we predict that poleward climate range shift will lead to decreased microbial taxonomic α-diversities in broadleaved forest.

  17. 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.

  18. [Effects of simulated nitrogen deposition on soil respiration in northern subtropical deciduous broad-leaved forest].

    Science.gov (United States)

    Hu, Zheng-hua; Li, Han-mao; Yang, Yan-ping; Chen, Shu-tao; Li, Cen-zi; Shen, Shuang-he

    2010-08-01

    To investigate the effects of elevated nitrogen deposition on forest soil respiration, a simulated nitrogen deposition field experiment was conducted in northern subtropical deciduous broad-leave forest from April 2008 to April 2009. Nitrogen treatments included the control (no N addition, CK), low-N [50 kg x (hm2 x a)(-1), T(L)], medium-N [100 kg x (hm2 x a)(-1), T(M)], and high-N [150 kg x (hm2 x a)(-1), T(H)]. The respiration rates were measured by a static chamber-gas chromatograph method. Results showed that nitrogen deposition did not change the seasonal and daily variation patterns of soil respiration. Compared to the control, T(L), T(M) and T(H) treatments reduced soil annual average respiration rates by 8.51%, 9.74% and 11.24%, respectively. Meanwhile, T(L), T(M) and T(H) treatments decreased daily average soil respiration rates by 4.42%, 11.09% and 12.17%, respectively. Significant relationship was found between soil respiration rate and soil temperature. The Q10 (temperature sensitivity coefficients) for soil respiration of CK, T(L), T(M), and T(H) treatments were 2.53, 3.22, 2.64 and 2.92, respectively. Our findings suggested that nitrogen deposition reduced soil respiration, and increased soil respiration temperature sensitivity in northern subtropical deciduous broad-leave forest.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. 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.

  7. 76 FR 69222 - Radio Broadcasting Services; Evergreen, AL, and Shalimar, FL

    Science.gov (United States)

    2011-11-08

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Evergreen, AL, and Shalimar, FL AGENCY: Federal Communications Commission. ACTION: Dismissal. ] SUMMARY: The Audio Division, at the request of Qantum 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. 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

    ABSTRACT 1. Plant distributions are dynamic but the role of plantÐinsect interactions in controlling range dynamics is not well understood. Enemy release, for example could facilitate plant range expansion under climate change. 2. We conducted a transplant experiment with the evergreen tree Ilex ...

  10. Seasonal acclimation to light and temperature in an evergreen understory shrub

    NARCIS (Netherlands)

    Muller, Onno

    2005-01-01

    Evergreens in temperate regions often maintain leaves longer than one year. These leaves are exposed to large changes in temperature with the seasons. If plants are growing in the understory of a deciduous forest the light intensity also changes strongly over the year. In summer the plants in the u

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. Hyper-temporal remote sensing helps in relating epiphyllous liverworts and evergreen forests

    NARCIS (Netherlands)

    Jiang, Y.; Bie, de C.A.J.M.; Wang, T.; Skidmore, A.K.; Liu, X.; Song, S.; Shao, X.

    2013-01-01

    Is there, at the macro-habitat scale, a relationship between the fraction of evergreen forests and the presence probability of epiphyllous liverworts? Can these two parameters be estimated and mapped using an NDVI-based indicator that is derived from time-series of SPOT-VGT imagery?

  16. 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.

  17. 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

  18. Carbon dioxide fluxes over an ancient broadleaved deciduous woodland in southern England

    Directory of Open Access Journals (Sweden)

    M. V. Thomas

    2010-05-01

    Full Text Available We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled Net Ecosystem Exchange (NEE data were partitioned into Gross Primary Productivity (GPP and ecosystem respiration (Re and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated at 21.1 Mg C ha−1 yr−1 and Re at 19.8 Mg C ha−1 yr−1; Net Ecosystem Productivity (NEP was 1.2 Mg C ha−1 yr−1. These estimates are very consistent with independent bottom-up estimates derived from Net Primary Productivity (NPP and flux chamber measurements in 2008 (GPP=20.3±1.0 Mg C ha−1 yr−1, Re=18.9±1.7 Mg C ha−1 yr−1, biomass increment =~1.4 Mg C ha−1 yr−1. Interannual variability of seasonal NEP was predominantly driven by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daytime CO2 fluxes (R2=0.53 for the summer months, interannual variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods supports the protection and management of temperate deciduous woodlands (including those

  19. Carbon dioxide fluxes over an ancient broadleaved deciduous woodland in southern England

    Directory of Open Access Journals (Sweden)

    M. V. Thomas

    2011-06-01

    Full Text Available We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled net ecosystem exchange (NEE data were partitioned into gross primary productivity (GPP and ecosystem respiration (Re and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated to be 21.1 Mg C ha−1 yr−1 and Re to be 19.8 Mg C ha−1 yr−1; net ecosystem productivity (NEP was 1.2 Mg C ha−1 yr−1. These estimates were compared with independent bottom-up estimates derived from net primary productivity (NPP and flux chamber measurements recorded at a plot within the flux footprint in 2008 (GPP = 26.5 ± 6.8 Mg C ha−1 yr−1, Re = 24.8 ± 6.8 Mg C ha−1 yr−1, biomass increment = ~1.7 Mg C ha−1 yr−1. Over the two years the difference in seasonal NEP was predominantly caused by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daily values of CO2 fluxes (R2 = 0.53 for the summer months for a linear regression, variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods

  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. [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.

  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. [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.

  5. Effects of Drought and Rewetting on Growth and Gas Exchange of Minor European Broadleaved Tree Species

    Directory of Open Access Journals (Sweden)

    Jörg Kunz

    2016-10-01

    Full Text Available Widespread and economically important European tree species such as Norway spruce, Scots pine, and European beech are projected to be negatively affected by the increasing intensity and frequency of dry and hot conditions in a future climate. Hence, there is an increasing need to investigate the suitability of presumably more drought tolerant species to ensure future ecological stability, biodiversity, and productivity of forests. Based on their distribution patterns and climatic envelopes, the rare, minor broadleaved tree species Sorbus torminalis ((L. CRANTZ, S. domestica (L., Acer campestre (L., and A. platanoides (L. are assumed to be drought tolerant, however, there is only limited experimental basis to support that notion. This study aimed at quantifying growth and gas exchange of seedlings of these species during drought conditions, and their capacity to recover following drought. For that purpose, they were compared to the common companion species Quercus petraea ((MATTUSCHKA LIEBL. and Fagus sylvatica (L.. Here, potted seedlings of these species were exposed to water limitation followed by rewetting cycles in a greenhouse experiment. Photosynthesis and transpiration rates, stomatal conductance as well as root and shoot growth rates indicated a high drought resistance of A. campestre and A. platanoides. Sorbus domestica showed a marked ability to recover after drought stress. Therefore, we conclude that these minor tree species have the potential to enrich forests on drought-prone sites. Results from this pot experiment need to be complemented by field studies, in which the drought response of the species is not influenced by restrictions to root development.

  6. 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.

  7. 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.

  8. 浙江六十田常绿阔叶林主要乔木种生态位研究%Niche of Dominant Species in Evergreen Broadleaved Forest in Liushitian Mini Nature Reserve of Zhejiang Province

    Institute of Scientific and Technical Information of China (English)

    陈子林; 张志祥; 刘鹏; 康华靖; 陈煜

    2007-01-01

    应用Shannon-Wiener生态位宽度指数、生态位相似性比例系数及生态位重叠指数,对浙江省六十田省级自然保护小区常绿阔叶林群落中主要乔木树种的生态位特征进行了研究.结果表明:红楠Machilus thunbergii,华东楠Machilus leptophylla,青冈Cyclobalanopsis glauca、紫楠Phoebe sheareri、木荷Schima superba、东南石栎Lithocarpus harlandii具有较大的生态位宽度,分别为0.969、0.951、0.898、0.867、0.819和0.773,而香槐Cladrastis wilsonii、树参Dendropanax dentiger、枫香Liquidambar formosana的生态位较小,仅为0.345、0.245和0.245;生态位宽度大的树种间一般有较高的生态位相似性比例;香槐、树参和枫香的生态位宽度较小,但与其它树种的相似性却很高,表明这些树种对资源有较明显的共享趋势;从生态位重叠值来看,整体上表现为生态位宽度较大的树种间都有较高的生态位重叠,生态位宽度较小的树种与其它树种的生态位重叠较小.898、0.86、0.819和0.773,而香槐Cladrastis wilsonii、树参Dendropanax dentiger、枫香Liquidambar formosana的生态位较小,仅为0.345、0.245和0.245;生态位宽度大的树种间一般有较高的生态位相似性比例;香槐、树参和枫香的生态位宽度较小,但与其它树种的相似性却很高,表明这些树种对资源有较明显的共享趋势;从生态位重叠值来看,整体上表现为生态位宽度较大的树种间都有较高的生态位重叠,生态位宽度较小的树种与其它树种的生态位重叠较小.

  9. Studies on Soil Microbiological Characteristics of Evergreen Broad-leaved Forest in Northern Fujian Province%闽北常绿阔叶林土壤微生物学特性的研究

    Institute of Scientific and Technical Information of China (English)

    宋漳; 朱锦懋; 杨玉盛

    2000-01-01

    选择闽北地区较有代表性的建瓯万木林自然保护区长期受保护的 (近600 a) 的中亚热带森林(conserved forest,CF)和顺昌县元坑镇近期(50年代以来)受人为干扰破坏的退化森林(degraded forest,DF)作为研究对象,比较了CF和DF群落的土壤微生物及其主要几种生理类群的数量分布和土壤主要化学性质的差异.研究结果表明:DF群落由于受人为的干扰破坏,土壤主要养分含量呈明显下降.对土壤微生物区系研究表明:CF群落的土壤微生物总数、细菌数量以及主要几种微生物生理类群的数量均明显高于DF群落.而真菌和放线菌的数量分布则以DF群落中数量较多,且占土壤微生物总量的比值也较大.DF群落根际和非根际土壤中3大类微生物及生理类群数量分布发生的变化,指示了土壤性质恶化的动态变化.研究结果为揭示森林生态系统土壤性质退化机理、找出防治的技术途径,恢复生物物种的多样性,提供科学依据.

  10. Structural Characteristics of Evergreen Broad-leaved Forest in Jiulianshan Mountain of Subtropical China%江西九连山自然保护区常绿阔叶林的结构特征

    Institute of Scientific and Technical Information of China (English)

    简敏菲; 刘琪璟

    2008-01-01

    基于线路和样方调查的基础上分析了九连山国家级自然保护区常绿阔叶林的结构特征.优势科主要为壳斗科(Fagaceae)、樟科(Lauraceae)、山茶科(Theaceae)、安息香科(Styracaceae)、杜鹃花科(Ericaceae)、木兰科(Magnolicceae)、槭树科(Aceraceae)、枫香科(Altingiaceae)、冬青科(Aquifoliaceae)、厚皮香科(Ternstroemiaceae)、柿树科(Ebenaceae)、桃金娘科(Myrtaceae)、杜英科(Elaeocarpaceae)等科,优势树种也以相应的优势科属树种为主.调查中,胸径DBH≥3 cm的乔木个体密度1 808株/hm2;优势层相对较高大,平均高度达到11.5 m;乔木垂直分化较明显,树种水平分布不均.九连山现状植被是天然原生植被、次生植被和人工植被的混合体,并常见有阳性落叶树如枫香(Liquidambar formosana)、拟赤杨(Alniphyllum fortunei)、光皮桦(Betula luminifera)等侵入林窗,形成常绿与落叶阔叶树的混交林.

  11. Responses of Soil Respiration to Simulated Nitrogen Deposition in an Evergreen Broad-Leaved Forest in Jinyun Mountain%缙云山常绿阔叶林土壤呼吸对模拟氮沉降的响应

    Institute of Scientific and Technical Information of China (English)

    孙素琪; 王玉杰; 王云琦; 张会兰; 李云霞; 于雷; 胡波; 刘婕

    2014-01-01

    通过原位喷施,设置对照(CK,0 kgN.hm-2a-1)、低氮(T50,50 kgN· hm-2a-1)、中氮(T100,100 kgN.hm-2a-1)和高氮(T150,150 kgN·hm-2a-1)4个氮沉降处理,研究重庆缙云山常绿阔叶林土壤呼吸对模拟氮沉降的响应.结果表明:CK,T50,T100和T150氮沉降处理的土壤呼吸速率分别为(4.31±1.14),(3.42±0.74),(2.81±0.38)和(2.49±0.32) μmol·m-2s-1,相对于CK处理,氮沉降处理使土壤呼吸速率显著降低(P<0.05);土壤呼吸速率与5和10 cm深处土壤温度间均存在显著指数正相关关系(P<0.01);4个处理5 cm深处的土壤呼吸温度敏感系数Q10值分别为2.07,1.81,1.62和1.54,10 cm深处的Q10值分别为2.11,1.83,1.63和1.55,氮沉降处理抑制了土壤呼吸温度敏感性;土壤呼吸速率与土壤含水量之间相关性较弱.

  12. 川西南常绿阔叶林土壤呼吸及其对氮沉降的响应%Soil Respiration and Its Response to Simulated Nitrogen Deposition in Evergreen Broad-Leaved Forest, Southwest Sichuan

    Institute of Scientific and Technical Information of China (English)

    宋学贵; 胡庭兴; 鲜骏仁; 肖春莲; 刘文婷

    2007-01-01

    通过原位进行低氮(LN,50 kg N/hm2·a)、中氮(MN,100 kg N/hm2·a)和高氮(HN,150 kg N/hm2·a)处理,研究了川西南天然常绿阔叶林土壤呼吸及其对模拟N沉降的响应.结果表明:(1)该森林土壤呼吸速率最大值612.21±77.82 mg CO2/m2·h出现在7月份,最小值108.95±17.01 mg CO2/m2·h出现在2月,年均土壤呼吸速率为348.00±157.83 mg CO2/m2·h,年均土壤呼吸通量为8.31±3.77 t C/hm2·a.采用双因素关系模型(Rs=aebTWc),土壤温度和土壤湿度共同解释了该常绿阔叶林2005年10月~2006年7月土壤呼吸速率季节变化的68.6%~73.9%,其拟合结果优于以土壤湿度或温度为参数的单因素关系模型.影响土壤呼吸速率的主导因子是温度,其地表温度变化响应的敏感程度Q10值为2.12,以土壤5 cm深处的温度为参数时,Q10值为2.51.(2)N沉降处理3个月后,该森林中HN和MN处理的土壤呼吸速率(309.43±17.24 mg CO2/m2·h,303.82±11.50 mgCO2/m2·h)均显著高于CK(269.28±13.78 mg CO2/m2·h)(P<0.05);处理4个月后,HN的土壤呼吸速率(272.42±13.25 mg CO2/m2·h)均显著高于MN(239.65±10.33 mg CO2/m2·h)、LN(229.10±9.90 mg CO2/m2·h)和CK(234.51±12.77 mg CO2/m2·h)(P<0.05);但处理7~10个月时,各处理之间无显著差异.研究表明,N沉降初期明显促进了常绿阔叶林土壤呼吸,后期无明显影响.

  13. 百山祖常绿阔叶林木本植物的克隆繁殖特性%Clonal propagation characteristics of woody species in Baishanzu broad-leaved evergreen forest

    Institute of Scientific and Technical Information of China (English)

    陈娇; 王伟; 叶珍林; 陈晓慧; 蒋清玲; 丁炳扬

    2012-01-01

    Clonal plants, which are generated through both sexual reproduction and vegetative propagation (clonal growth) in nature, can affect species distribution patterns and dynamics, as well as the species composition and diversity of communities. Clonal plants with ability to adapt to the harsh environment have strong competence for survival, and thus play an important role in regeneration and revegetation of the forest dynamics. Based on the investigation of the root-sprouting situation of shrubs and woody vines with DBH (diameter at breast height) ≥ 1 cm or height ≥ 2 m and trees in Baishanzu permanent plot, the objective of this study was to research the sprouting ability of different species with different growth forms, the relationship between root-sprouting rate and DBH of parent-ramet and the association between sprouting rate and habitats. A 5-hm2 plot in Baishanzu Mountain was divided into 2 000 quadrats (5 m ×5 m) to survey species identity, DBH, root-sprouting number and root-sprouting DBH / basal diameter for shrubs and woody vines with DBH ≥ 1 cm and all trees. Species in the plot were classified into canopy trees, sub-canopy trees, understory trees, shrubs and vines to survey the differences of their root-sprouting capacity. The relationship between root-sprouting rate and DBH of parent-ramet was analyzed based on six common species with the number of mother plant ≥ 400 and root-sprouting rate ≥ 1.0. According to the differences of slope, convexity and elevation among quadrates, the plot was divided into four habitats, including ridge, less-steep slope, steep slope and gully to analyze the association between sprouting rate and habitats. The results showed that: 1) The total parent-ramet and sprout in the plot were 36 769 and 34 786 respectively, thus the sprouting rate of the species in the plot was 0.94 (Table 1); 2) the sprouting rates of species with different growth forms were different with the descending order of canopy species, sub-canopy species, understory species, shrubs and vines (Table 1); 3) twelve species according with the mother plant numbers ≥ 200 and root-sprouting rate ≥ 0.50 belonged to the dominant species from canopy, sub-canopy, understory and shrub species (Table 2); 4) the sprouting rates were positively related to the DBH of the parent-ramet for all species together or six main species, respectively. At the same time, the maximum values of the sprouting rate were responded to the DBH values which were slightly larger than the intermediate values of DBH for all species (Fig. 2, 3); 5) the sprouting rates and sprout density in four habitats in the plot were different, and the sprouting rates and parent-ramet density were both descended with the order of ridge, less-steep slope, steep slope, gully (Table 3). In conclusion, the relatively high sprouting rate in the plot indicates that the clonal reproduction is an important reproduction strategy for woody plants in the communities; the generally high sprouting rate of the dominant species from canopy trees, sub-canopy trees, understory trees and shrubs indicates that the clonal reproduction plays an important role in the formation of forest community structure; the positive relationship between the parent-ramet DBH and root-sprouting rate reflects that the growth and ecesis of root-sprouting depend on resource supplement from the parent-ramet; meanwhile, the relationship between sprouting rates and habitat is consistent with the risk-sharing principle of the clonal plant genets.%通过调查百山祖自然保护区动态样地内所有乔木和胸径≥1cm或高度≥2 m灌木的母株产生根蘖的情况,分析不同生活型层次和不同物种的根蘖能力差异、根蘖率与母株胸径的关系以及根蘖率与生境的相关性.结果表明:样地母株总数36769株,根蘖总数34786株,整个样地的根蘖率为0.94;该样地5种生活型物种的根蘖率存在差异,呈现冠层乔木>亚层乔木>小乔木>灌木>藤本;全部物种整体根蘖率和6个主要物种的根蘖率都随母株胸径增大呈先增加后下降的趋势,最大峰值均出现在略大于母株胸径区间的中间值处;样地沟谷、陡坡、缓坡、山脊4种生境的根蘖数、母株数、母株密度、根蘖密度、根蘖率存在差异,其中母株密度和根蘖率均呈现山脊>缓坡>陡坡>沟谷.此结果反映出样地总体根蘖率较高,克隆繁殖是该群落木本植物的重要繁殖方式;冠层乔木、亚层乔木和小乔木的优势种、亚优势种的根蘖率普遍较高,表明克隆繁殖在群落结构形成中发挥着重要作用;物种在母株胸径与根蘖率方面呈现的一致性反映出根蘖的生长和定居在一定程度上依赖于母株的资源供给;根蘖率与生境的关系符合克隆植物基株的风险分摊原理.

  14. The Next Generation Library Catalog: A Comparative Study of the OPACs of Koha, Evergreen, and Voyager

    Directory of Open Access Journals (Sweden)

    Sharon Q. Yang

    2010-09-01

    Full Text Available Open source has been the center of attention in the library world for the past several years. Koha and Evergreen are the two major open-source integrated library systems (ILSs, and they continue to grow in maturity and popularity. The question remains as to how much we have achieved in open-source development toward the next-generation catalog compared to commercial systems. Little has been written in the library literature to answer this question. This paper intends to answer this question by comparing  the next-generation features of the OPACs of two open-source ILSs (Koha and Evergreen and one proprietary ILS (Voyager’s WebVoyage.

  15. Education and advice contribute to increased density of broadleaved conservation trees, but not saplings, in young forest in Sweden.

    Science.gov (United States)

    Götmark, Frank; Fridman, Jonas; Kempe, Göran

    2009-02-01

    The effectiveness of different conservation policies is debated, but the policies are rarely evaluated quantitatively. A voluntary or 'soft' policy based mainly on education provides information about ecosystems and effects of land use, to encourage conservation action. Swedish forestry relies mainly on soft policy, with substantial resources for education and advice to more than 200,000 forest owners, while legal regulation is weak. Increased retention of broadleaved trees at clear-cutting, with environmental benefits in the conifer-dominated forestry, is important in the policy. We used the Swedish National Forest Inventory to analyse this policy for young forests in southern Sweden. Between 1983-1987 and 1998-2002 the policy had no positive effect on saplings (1.3m tall to 4.9 cm dbh) of birch, oak, beech and other species that mostly decreased in density, due to planting of conifers and browsing by ungulates. However, broadleaved conservation trees (>or=15 cm dbh) increased in density, e.g. to about one oak and six birches per ha in young coniferous forest in 1998-2002. The relative increase in density was higher for large (>or=20 cm dbh) than for small trees (15-20 cm dbh). The density of conservation trees was higher on forestland of high than of low productivity. Thus, the soft conservation policy did not influence regeneration of saplings in this type of forestry system, but large broadleaved trees were increasingly saved at 'clear-cuttings'. Advice and educational programmes probably contributed to this result. A continued increase in conservation trees at harvest may require economical support to forest owners.

  16. Intraspecific sequence variation of chloroplast DNA among the component species of deciduous broad-leaved forests in Japan.

    Science.gov (United States)

    Iwasaki, Takaya; Aoki, Kyoko; Seo, Akihiro; Murakami, Noriaki

    2006-09-01

    To select appropriate plant materials for a phylogeography of deciduous broad-leaved forests in Japan, we surveyed intraspecific chloroplast DNA variation in 34 species found in these forests. A relatively large number of intraspecific cpDNA variations were detected in ten species: Carpinus japonica (nucleotide diversity pi=0.00083), C. laxiflora (pi=0.00221), Magnolia obovata (pi=0.00134), Lindera triloba (pi=0.00255), L. obtusiloba (pi=0.00289), Pourthiaea villosa var. leavis (pi=0.00263), Acer japonicum (pi=0.00170), A. micranthum (pi=0.00237), Euonymus oxyphyllus (pi=0.00322) and Styrax obassia (pi=0.00100).

  17. 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.

  18. 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

  19. 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.

  20. Photosynthesis and photosynthetic electron flow in the alpine evergreen species Quercus guyavifolia in winter

    Directory of Open Access Journals (Sweden)

    Wei Huang

    2016-10-01

    Full Text Available Alpine evergreen broadleaf tree species must regularly cope with low night temperatures in winter. However, the effects of low night temperatures on photosynthesis in alpine evergreen broadleaf tree species are unclear. We measured the diurnal photosynthetic parameters before and after cold snap for leaves of Quercus guyavifolia growing in its native habitat at 3290 m. On 11 and 12 December 2013 (before cold snap, stomatal and mesophyll conductances (gs and gm, CO2 assimilation rate (An, and total electron flow through PSII (JPSII at daytime were maintained at high levels. The major action of alternative electron flow was to provide extra ATP for primary metabolisms. On 20 December 2013 (after cold snap, the diurnal values of gs, gm, An and JPSII at daytime largely decreased, mainly due to the large decrease in night air temperature. Meanwhile, the ratio of photorespiration and alternative electron flow to JPSII largely increased on 20 December. Furthermore, the high levels of alternative electron flow were accompanied with low rates of extra ATP production. A quantitative limitation analysis reveals that the gm limitation increased on 20 December with decreased night air temperature. Therefore, the night air temperature was an important determinant of stomatal/mesophyll conductance and photosynthesis. When photosynthesis is inhibited following freezing night temperatures, photorespiration and alternative electron flow are important electron sinks, which support the role of photorespiration and alternative electron flow in photoportection for alpine plants under low temperatures.

  1. Photosynthesis and Photosynthetic Electron Flow in the Alpine Evergreen Species Quercus guyavifolia in Winter

    Science.gov (United States)

    Huang, Wei; Hu, Hong; Zhang, Shi-Bao

    2016-01-01

    Alpine evergreen broadleaf tree species must regularly cope with low night temperatures in winter. However, the effects of low night temperatures on photosynthesis in alpine evergreen broadleaf tree species are unclear. We measured the diurnal photosynthetic parameters before and after cold snap for leaves of Quercus guyavifolia growing in its native habitat at 3290 m. On 11 and 12 December 2013 (before cold snap), stomatal and mesophyll conductances (gs and gm), CO2 assimilation rate (An), and total electron flow through PSII (JPSII) at daytime were maintained at high levels. The major action of alternative electron flow was to provide extra ATP for primary metabolisms. On 20 December 2013 (after cold snap), the diurnal values of gs, gm, An, and JPSII at daytime largely decreased, mainly due to the large decrease in night air temperature. Meanwhile, the ratio of photorespiration and alternative electron flow to JPSII largely increased on 20 December. Furthermore, the high levels of alternative electron flow were accompanied with low rates of extra ATP production. A quantitative limitation analysis reveals that the gm limitation increased on 20 December with decreased night air temperature. Therefore, the night air temperature was an important determinant of stomatal/mesophyll conductance and photosynthesis. When photosynthesis is inhibited following freezing night temperatures, photorespiration and alternative electron flow are important electron sinks, which support the role of photorespiration and alternative electron flow in photoportection for alpine plants under low temperatures. PMID:27812359

  2. Three causes of variation in the photochemical reflectance index (PRI) in evergreen conifers.

    Science.gov (United States)

    Wong, Christopher Y S; Gamon, John A

    2015-04-01

    The photochemical reflectance index (PRI) reflects diurnal xanthophyll cycle activity and is also influenced by seasonally changing carotenoid : Chl pigment ratios. Both changing pigment pools and xanthophyll cycle activity contribute to photoprotection in evergreen conifers exposed to boreal winters, but they operate over different timescales, and their relative contribution to the PRI signal has often been unclear. To clarify these responses and their contribution to the PRI signal, leaf PRI, pigment composition, temperature and irradiance were monitored over 2 yr for two evergreen conifers (Pinus contorta and Pinus ponderosa) in a boreal climate. PRI was affected by three distinct processes operating over different timescales and exhibiting contrasting spectral responses. Over the 2 yr study period, the greatest change in PRI resulted from seasonally changing carotenoid : Chl pigment ratios, followed by a previously unreported shifting leaf albedo during periods of deep cold. Remarkably, the smallest change was attributable to the xanthophyll cycle. To properly distinguish these three effects, interpretation of PRI must consider temporal context, physiological responses to evolving environmental conditions, and spectral response. Consideration of the separate mechanisms affecting PRI over different timescales could greatly improve efforts to monitor changing photosynthetic activity using optical remote sensing.

  3. Change of evapotranspiration components due to the succession from Japanese red pine to evergreen oak

    Science.gov (United States)

    Iida, Shin'ichi; Tanaka, Tadashi; Sugita, Michiaki

    2006-07-01

    Extensive measurements of water balance components in a forest under the succession from Japanese red pine ( Pinus densiflora) to evergreen oak ( Quercus myrsinaefolia) were carried out. Significant decreases of transpiration from the red pines and forest interception loss were found based on the observational results in 1984/1985 and 2001/2002. The former was the pre-succession period and the latter was the middle succession period in the study forest. Although the forest had a main canopy of the red pines in 1984/1985, the multi-layered canopies were observed in 2001/2002, which were consisted of the upper canopy layer of the red pines and of the lower canopy layer of the evergreen oaks. On the other hand, no significant difference in the amount of total evapotranspiration between the two periods was observed, because the decrease of transpiration from the red pines was compensated by the increase of transpiration from the lower canopy layer, which was about three times larger than that of the red pines. Three factors were identified to produce the large amount of transpiration from the lower canopy layer: (i) increased net radiation over the lower canopy due to the increased gaps in the canopy of red pine, (ii) a relatively small difference of total sapwood area between the red pine and the lower canopies and (iii) larger sap flux densities of main species in the lower canopy which were around two times larger than that of the red pine canopy.

  4. 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

    We report on a full-Holocene pollen, charcoal and macrofossil record from a small forest hollow in Gribskov, eastern Denmark. The Fagus sylvatica pollen record suggests the establishment of a small Fagus population at Gribskov in the early Holocene together with early establishment of other...... 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...... two periods of the early Holocene and from c. 3000 cal. BP to present. The early-Holocene part of the record indicates a highly disturbed forest ecosystem with frequent fires and abundant macrofossils of particularly Betula sp. and Populus sp. The sediment stratigraphy and age–depth relationships give...

  5. 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.

  6. 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.

  7. 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

  8. 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...

  9. 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…

  10. Insight into the photosynthetic apparatus in evergreen and deciduous European oaks during autumn senescence using OJIP fluorescence transient analysis.

    Science.gov (United States)

    Holland, V; Koller, S; Brüggemann, W

    2014-07-01

    Climate change is one of the major issues nowadays, and Mediterranean broadleaf species have been suggested to fill possible future gaps created by climate change in Central European forests. To provide a scientific-based foundation for such practical strategies, it is important to obtain a general idea about differences and similarities in the physiology of Central European and Mediterranean species. In the present study, we evaluated the onset of leaf senescence of a broad spectrum of oak species under the Central European climate in a common garden experiment. Degradation of the photosynthetic apparatus of evergreen (Quercus ilex, Q. suber), semi-evergreen (Q.×turneri, Q.×hispanica) and deciduous oaks (Q. robur, Q. cerris, Q. frainetto, Q. pubescens) was monitored as chlorophyll content and analysed chlorophyll fluorescence induction transients. In the deciduous species, a significant decline in chlorophyll content was observed during autumn/winter, with Q. pubescens showing the slowest decline. Analysis of fluorescence induction transients revealed a significant decline in quantum efficiency of the primary photochemistry and reaction centre density and later, a decrease in quantum efficiency of end acceptor reduction. Alterations in fluorescence parameters were compared to the decline in chlorophyll content, which occurred much more slowly than expected from the fluorescence data. The evergreen species showed no decline in chlorophyll content, nor different chlorophyll a fluorescence induction behaviour despite temperature falling below 0 °C. The hybrids showed intermediate behaviour between their parental evergreen and deciduous taxa.

  11. Leaf adaptations of evergreen and deciduous trees of semi-arid and humid savannas on three continents

    NARCIS (Netherlands)

    Tomlinson, K.W.; Poorter, L.; Sterck, F.J.; Borghetti, M.; Ward, D.; Bie, de S.; Langevelde, van F.

    2013-01-01

    1. Drought stress selects for a suite of plant traits at root, stem and leaf level. Two strategies are proposed for trees growing in seasonally water-stressed environments: drought tolerance and drought avoidance. These are respectively associated with evergreen phenology, where plants retain their

  12. 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…

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Leafing patterns and leaf traits of four evergreen shrubs in the Patagonian Monte, Argentina

    Science.gov (United States)

    Campanella, María Victoria; Bertiller, Mónica B.

    2009-11-01

    We assessed leafing patterns (rate, timing, and duration of leafing) and leaf traits (leaf longevity, leaf mass per area and leaf-chemistry) in four co-occurring evergreen shrubs of the genus Larrea and Chuquiraga (each having two species) in the arid Patagonian Monte of Argentina. We asked whether species with leaves well-defended against water shortage (high LMA, leaf longevity, and lignin concentration, and low N concentration) have lower leaf production, duration of the leafing period, and inter-annual variation of leafing than species with the opposite traits. We observed two distinctive leafing patterns each related to one genus. Chuquiraga species produced new leaves concentrated in a massive short leafing event (5-48 days) while new leaves of Larrea species emerged gradually (128-258 days). Observed leafing patterns were consistent with simultaneous and successive leafing types previously described for woody plants. The peak of leaf production occurred earlier in Chuquiraga species (mid September) than in Larrea species (mid October-late November). Moreover, Chuquiraga species displayed leaves with the longest leaf lifespan, while leaves of Larrea species had the lowest LMA and the highest N and soluble phenolics concentrations. We also observed that only the leaf production of Larrea species increased in humid years. We concluded that co-occurring evergreen species in the Patagonian Monte displayed different leafing patterns, which were associated with some relevant leaf traits acting as plant defenses against water stress and herbivores. Differences in leafing patterns could provide evidence of ecological differentiation among coexisting species of the same life form.

  18. Change of interception process due to the succession from Japanese red pine to evergreen oak

    Science.gov (United States)

    Iida, Shin'ichi; Tanaka, Tadashi; Sugita, Michiaki

    2005-12-01

    Extensive measurements of rainfall, throughfall and stemflow in a forest during succession from Japanese red pine ( Pinus densiflora Sieb. et Zucc.) to a combination of red pine and lower canopy trees—evergreen oak ( Quercus myrsinaefolia Blume) and evergreen theaceous tree ( Eurya japonica Thunb.) allowed the effect of this succession on the interception of rainfall to be evaluated. The measurements were conducted on two occasions: 1984/1985, and 2001/2002 when the lower canopy trees had become dominant. During this period, 75% of the red pines had been removed, and there was a substantial increase in stemflow ( p<0.01), essentially no change in throughfall ( p<0.01), and a substantial decrease in interception ( p<0.01). The increase in stemflow was attributed to the increase in lower canopy trees; trees that have steeply angled branches, smooth bark surfaces and water repellent leaves; all of which enhance stemflow. The decrease in interception was due to the decrease in canopy water storage (2.6-1.1 mm/event) and an increase in evaporation during rainfall event (0.7-1.1 mm/event). The decrease in storage partly resulted from the removal of red pines, the bark of which is thick, flaky, and therefore, very absorptive. It was responsible for 88% of the actual rainfall storage at the beginning of the experiment. During the 17 year-period, the size of the lower canopy trees increased more rapidly than that of red pines. The increase in evaporation was due to the increase in canopy gaps by the removal of 75% of the red pines during the succession, and was a minor factor in affecting interception loss.

  19. 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.

  20. 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

    . herbacea × polaris than in the corresponding current year's leaf cohort of the evergreen C. tetragona. The changes were also much higher than in the 1-year-old leaves of the two evergreens probably due to differences in dilution and turnover of CBSC in growing and mature leaves paired with different rates......-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...

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. [Effects of light intensity heterogeneity in gaps of broadleaved Korean pine forest in Changbai Mountains on Pinus koraiensis seedings growth].

    Science.gov (United States)

    Wang, Zhuo; Fan, Xiu-Hua

    2009-05-01

    By using a Li-6400 portable photosynthesis system, this paper studied the heterogeneity of light intensity in four different size gaps of a broadleaved Korean pine forest in Changbai Mountains, and analyzed the diurnal change of the photosynthesis of Pinus koraiensis saplings in the gaps. In the nine orientations within the gaps, the peak value of the photosynthetically active radiation (PAR) varied in the sequence of west of actual gap, north of extended gap, gap center > south of actual gap, south of extended gap, east of extended gap, east of actual gap > west of extended gap, north of actual gap. Light distribution was dissymmetry in the orientations of east-west and south-north, with the variation in west and north being more significant than that in other orientations. There was no significant difference in the average PAR among the positions within specific orientations. The average PAR of the four gaps from I to IV was 21.85, 45.57, 66.02, and 23.48 micromol x m(-2) x s(-1), respectively, and the difference was statistically significant (P < 0.05). PAR had a significant positive correlation with net photosynthetic rate (P(n)), and the correlation coefficient increased with increasing PAR. With the increase of gap size, both the PAR and the P(n) of P. koraiensis saplings increased first and decreased then, with the maximum values appeared at 267 m2 of gap size.

  11. Similar biodiversity of ectomycorrhizal fungi in set-aside plantations and ancient old-growth broadleaved forests

    Science.gov (United States)

    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 forest blocks, each containing an ancient old-growth stand (> 1000 yrs) paired with a set-aside even-aged planted stand (ca. 180 yrs). We investigated the functionally important yet relatively neglected ectomycorrhizal fungi (EMF), a group for which the importance of forest age has not been assessed in broadleaved forests. We found that forest type was not an important determinant of EMF species richness or composition, demonstrating that set-aside can be an effective option for conserving ancient EMF communities. Species richness of above-ground EMF fruiting bodies was principally related to the basal area of the stand (a correlate of canopy cover) and tree species diversity, whilst richness of below-ground ectomycorrhizae was driven only by tree diversity. Our results suggest that overmature planted forest stands, particularly those that are mixed-woods with high basal area, are an effective means to connect and expand ecological networks of ancient old-growth forests in historically deforested and fragmented landscapes for ectomycorrhizal fungi. PMID:26917858

  12. 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.

  13. [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.

  14. Pollination ecology of Chengam Scyphiphora hydrophyllacea C.F. Gaertn. (Magnoliopsida: Rubiales: Rubiaceae, a non-viviparous evergreen tree species

    Directory of Open Access Journals (Sweden)

    A.J. Solomon Raju

    2014-12-01

    Full Text Available Scyphiphora hydrophyllacea C.F. Gaertn. or Chengam is a non-viviparous evergreen tree species. The flowers are bisexual, self-compatible, self-pollinating, temporally dioecious and exhibit a mixed breeding system.  The plant is both melittophilous and anemophilous at the study area.  Natural fruit set is 100% but seeds are non-viable which might be due to a genetic disorder. 

  15. Patterns of leaf morphology and leaf N content in relation to winter temperatures in three evergreen tree species

    Science.gov (United States)

    Mediavilla, Sonia; Gallardo-López, Victoria; González-Zurdo, Patricia; Escudero, Alfonso

    2012-09-01

    The competitive equilibrium between deciduous and perennial species in a new scenario of climate change may depend closely on the productivity of leaves along the different seasons of the year and on the morphological and chemical adaptations required for leaf survival during the different seasons. The aim of the present work was to analyze such adaptations in the leaves of three evergreen species ( Quercus ilex, Q. suber and Pinus pinaster) and their responses to between-site differences in the intensity of winter harshness. We explore the hypothesis that the harshness of winter would contribute to enhancing the leaf traits that allow them to persist under conditions of stress. The results revealed that as winter harshness increases a decrease in leaf size occurs in all three species, together with an increase in the content of nitrogen per unit leaf area and a greater leaf mass per unit area, which seems to be achieved only through increased thickness, with no associated changes in density. P. pinaster was the species with the most intense response to the harshening of winter conditions, undergoing a more marked thickening of its needles than the two Quercus species. Our findings thus suggest that lower winter temperatures involve an increase in the cost of leaf production of evergreen species, which must be taken into account in the estimation of the final cost and benefit balance of evergreens. Such cost increases would be more pronounced for those species that, like P. pinaster, show a stronger response to the winter cold.

  16. Light-driven growth in Amazon evergreen forests explained by seasonal variations of vertical canopy structure.

    Science.gov (United States)

    Tang, Hao; Dubayah, Ralph

    2017-03-07

    Light-regime variability is an important limiting factor constraining tree growth in tropical forests. However, there is considerable debate about whether radiation-induced green-up during the dry season is real, or an apparent artifact of the remote-sensing techniques used to infer seasonal changes in canopy leaf area. Direct and widespread observations of vertical canopy structures that drive radiation regimes have been largely absent. Here we analyze seasonal dynamic patterns between the canopy and understory layers in Amazon evergreen forests using observations of vertical canopy structure from a spaceborne lidar. We discovered that net leaf flushing of the canopy layer mainly occurs in early dry season, and is followed by net abscission in late dry season that coincides with increasing leaf area of the understory layer. Our observations of understory development from lidar either weakly respond to or are not correlated to seasonal variations in precipitation or insolation, but are strongly related to the seasonal structural dynamics of the canopy layer. We hypothesize that understory growth is driven by increased light gaps caused by seasonal variations of the canopy. This light-regime variability that exists in both spatial and temporal domains can better reveal the drought-induced green-up phenomenon, which appears less obvious when treating the Amazon forests as a whole.

  17. Evergreen or deciduous trees for capturing PAHs from ambient air? A case study.

    Science.gov (United States)

    De Nicola, Flavia; Concha Graña, Estefanía; López Mahía, Purificación; Muniategui Lorenzo, Soledad; Prada Rodríguez, Darío; Retuerto, Rubén; Carballeira, Alejo; Aboal, Jesús R; Fernández, J Ángel

    2017-02-01

    Tree canopies play a key role in the cycling of polycyclic aromatic hydrocarbons (PAHs) in terrestrial ecosystems, as leaves can capture PAHs from the air. In this study, accumulation of PAHs was compared in an evergreen species, P. pinaster, and in a deciduous species, Q. robur, in relation to some physio-morphological characteristics. For this purpose, pine needles and oak leaves collected from different sites across Galicia (NW Spain) were analysed to determine PAH contents, specific leaf area, stomatal density and conductance. Leaves and needles contained similar total amounts of PAHs. The major contribution of particle-bound PAHs in oak (the concentrations of 4- and 5-ring PAHs were two times higher, and those of 6-ring PAHs five times higher in oak than in pine) may be related to the higher specific leaf area (13 and 4 cm(2) g(-1) dry mass in respectively oak and pine). However, the major contribution of vapor-phase PAHs in pines may be affected by the stomatal conductance (two times higher in pine than in oak). Moreover, an increase in the diameter at breast height of trees led to an increase in accumulation of PAHs, with pine capturing higher amounts of low and medium molecular weight PAHs. The study findings underline the potential role of trees in improving air quality, taking into account the canopy biomass and life cycle.

  18. Changes to intellectual property policy in South Africa: putting a stop to evergreening?

    Science.gov (United States)

    Hill, Julia E

    2014-08-01

    South Africa is a middle-income country with the world's largest HIV patient cohort and a growing burden of communicable and non-communicable diseases - a prime location for pharmaceutical companies looking to expand their markets. Yet, 20 years after the country's first democratic elections, poor health indicators and an over-burdened public health system belie persistently stark levels of socioeconomic inequality. As the South African government revises national intellectual property (IP) policies, the pharmaceutical industry and global access to medicines movement are watching, aware of ramifications South Africa's actions will have on patent laws and the availability of generic medicines in other middle-income countries and across Africa. South Africa's draft IP policy is meeting fierce resistance from industry, although proposed reforms are compliant with the Agreement on trade related aspects of intellectual property (TRIPS) and in line with on-going policies and actions of both developing and developed countries. Could the establishment of a patent examination system and new patentability criteria rein in evergreening and lead to lower medicine prices? What will be the potential impact of reform on medical innovation? And why is it both necessary and urgent that the South African government seek a fairer balance between private and public interests?

  19. Bioindication of heavy metals in the town Wrocław (Poland) with evergreen plants

    Science.gov (United States)

    Samecka-Cymerman, A.; Kempers, A. J.

    In this paper the results are reported of a study on the concentration of macroelements (N, P, K, Ca, Mg, S and Fe) and heavy metals (Ni, Cr, Co, V, Zn, Mn, Pb, Cd, Cu, Hg, Ba and Sr) in soil and in three species of the evergreen plants Ilex aquifolium, Mahonia aquifolium and Rhododendron catawbiense. These plants are collected in the Botanical Garden of the Polish town Wrocław (which is exposed to atmospheric exhausts of heavy traffic, chemical factories, metal smelters and a heat and power plant partly alimented with lignite and coals) and in two presumed unpolluted reference (background) sites, one in Poland (the Dendrological Garden in Wojslawice near Niemcza, south from Wrocław) and the other in The Netherlands (the Botanical Garden of the University of Nijmegen). Analyses of both soil and plant samples point to the pollution of the Wrocław Botanical Garden by Ni, Cr, Co, Cd via the atmosphere and pollution by Zn, Pb and Hg probably via atmosphere and soil. Especially pollution with Hg via soil is supported by a significant positive correlation between Hg content in soil and in all the examined species of which Ilex aquifolium seemed to be the best monitor of soil pollution with this element.

  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.

  1. Water-use strategies in two co-occurring Mediterranean evergreen oaks: surviving the summer drought.

    Science.gov (United States)

    David, T S; Henriques, M O; Kurz-Besson, C; Nunes, J; Valente, F; Vaz, M; Pereira, J S; Siegwolf, R; Chaves, M M; Gazarini, L C; David, J S

    2007-06-01

    In the Mediterranean evergreen oak woodlands of southern Portugal, the main tree species are Quercus ilex ssp. rotundifolia Lam. (holm oak) and Quercus suber L. (cork oak). We studied a savannah-type woodland where these species coexist, with the aim of better understanding the mechanisms of tree adaptation to seasonal drought. In both species, seasonal variations in transpiration and predawn leaf water potential showed a maximum in spring followed by a decline through the rainless summer and a recovery with autumn rainfall. Although the observed decrease in predawn leaf water potential in summer indicates soil water depletion, trees maintained transpiration rates above 0.7 mm day(-1) during the summer drought. By that time, more than 70% of the transpired water was being taken from groundwater sources. The daily fluctuations in soil water content suggest that some root uptake of groundwater was mediated through the upper soil layers by hydraulic lift. During the dry season, Q. ilex maintained higher predawn leaf water potentials, canopy conductances and transpiration rates than Q. suber. The higher water status of Q. ilex was likely associated with their deeper root systems compared with Q. suber. Whole-tree hydraulic conductance and minimum midday leaf water potential were lower in Q. ilex, indicating that Q. ilex was more tolerant to drought than Q. suber. Overall, Q. ilex seemed to have more effective drought avoidance and drought tolerance mechanisms than Q. suber.

  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. Changes in understory species occurrence of a secondary broadleaved forest after mass mortality of oak trees under deer foraging pressure

    Directory of Open Access Journals (Sweden)

    Hiroki Itô

    2016-12-01

    Full Text Available The epidemic of mass mortality of oak trees by Japanese oak wilt has affected secondary deciduous broadleaved forests that have been used as coppices in Japan. The dieback of oak trees formed gaps in the crown that would be expected to enhance the regeneration of shade-intolerant pioneer species. However, foraging by sika deer Cervus nippon has also affected forest vegetation, and the compound effects of both on forest regeneration should be considered when they simultaneously occur. A field study was conducted in Kyôto City, Japan to investigate how these compound effects affected the vegetation of the understory layer of these forests. The presence/absence of seedlings and saplings was observed for 200 quadrats sized 5 m ×5 m for each species in 1992, before the mass mortality and deer encroachment, and in 2014 after these effects. A hierarchical Bayesian model was constructed to explain the occurrence, survival, and colonization of each species with their responses to the gaps that were created, expanded, or affected by the mass mortality of Quercus serrata trees. The species that occurred most frequently in 1992, Eurya japonica, Quercus glauca, and Cleyera japonica, also had the highest survival probabilities. Deer-unpalatable species such as Symplocos prunifolia and Triadica sebifera had higher colonization rates in the gaps, while the deer-palatable species Aucuba japonica had the smallest survival probability. The gaps thus promoted the colonization of deer-unpalatable plant species such as Symplocos prunifolia and Triadica sebifera. In the future, such deer-unpalatable species may dominate gaps that were created, expanded, or affected by the mass mortality of oak trees.

  5. [Dynamics of total organic carbon (TOC) in hydrological processes in coniferous and broad-leaved mixed forest of Dinghushan].

    Science.gov (United States)

    Yin, Guangcai; Zhou, Guoyi; Zhang, Deqiang; Wang, Xu; Chu, Guowei; Liu, Yan

    2005-09-01

    The total flux and concentration of total organic carbon (TOC) in hydrological processes in coniferous and broad-leaved mixed forest of Dinghushan were measured from July 2002 to July 2003. The results showed that the TOC input by precipitation was 41.80 kg x hm(-2) x yr(-1), while its output by surface runoff and groundwater (soil solution at 50 cm depth) was 17.54 and 1.80 kg x hm(-2) x yr(-1), respectively. The difference between input and output was 22.46 kg x hm(-2) x yr(-1), indicating that the ecosystem TOC was in positive balance. The monthly variation of TOC flux in hydrological processes was very similar to that in precipitation. The mean TOC concentration in precipitation was 3.64 mg x L(-1), while that in throughfall and stemflow increased 6.10 and 7.39 times after rain passed through the tree canopies and barks. The mean TOC concentration in surface runoff and in soil solution at 25 and 50 cm depths was 12.72, 7.905 and 3.06 mg x L(-1), respectively. The monthly TOC concentration in throughfall and stemflow had a similar changing tendency, showing an increase at the beginning of growth season (March), a decrease after September, and a little increase in December. The TOC concentration in runoff was much higher during high precipitation months. No obvious monthly variation was observed in soil solution TOC concentration (25 and 50 cm below the surface). Stemflow TOC concentration differed greatly between different tree species. The TOC concentration in precipitation, throughfall, and soil solution (25 and 50 cm depths) decreased with increasing precipitation, and no significant relationship existed between the TOC concentrations in stemflow, surface runoff and precipitation. The TOC concentrations in the hydrological processes fluctuated with precipitation intensity, except for that in stemflow and soil solutions.

  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. [Effects of forest gap size and light intensity on herbaceous plants in Pinus koraiensis-dominated broadleaved mixed forest].

    Science.gov (United States)

    Duan, Wen-Biao; Wang, Li-Xia; Chen, Li-Xin; Du, Shan; Wei, Quan-Shuai; Zhao, Jian-Hui

    2013-03-01

    1 m x 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Fragmentation patterns of evergreen oak woodlands in Southwestern Iberia: identifying key spatial indicators.

    Science.gov (United States)

    Costa, Augusta; Madeira, Manuel; Lima Santos, José; Plieninger, Tobias; Seixas, Júlia

    2014-01-15

    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 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 and 2007, for two consecutive periods (1958-1995 and 1995-2007), we calculated a set of landscape metrics to compare woodland fragmentation over time. Our results indicated a continuous woodland fragmentation characterized by their edge dynamics. From 1958 to 2007, the replacement of open farmland 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 that characterize woodland spatial configuration. The edge contrast length with open farmland showed a strong correlation with F1 (correlations ranging between 0.55 and 0.98) and may be used as a proxy for oak woodland mixedness in landscape matrix. The edge dynamics of oak woodlands may result in different patterns of oak recruitment and therefore, its study may be helpful in highlighting future baselines for the sustainable management of oak woodlands.

  13. Calcium and potassium dynamics and biopurification in two populations of the subalpine evergreen shrub Rhododendron ferrugineum

    Directory of Open Access Journals (Sweden)

    Charles Marty

    2014-06-01

    Full Text Available Calcium (Ca and potassium (K are important acidity neutralizers in soils and essential elements for plants. These two elements are known to undergo a biopurification within the plant (i.e., discrimination against strontium (Sr and barium (Ba for Ca, and rubidium (Rb for K. However variations in the magnitude of this process between plant populations have rarely been reported, especially in high altitude, nutrient-depleted habitats. Concentrations of Ca, Sr, Ba, K and Rb were measured in roots, stems and in the different leaf cohorts in two populations of the evergreen shrub R. ferrugineum located at a granitic high elevation site. Calcium and K concentrations in leaves were respectively ~5 and 3 times higher than in roots and stems. Ca concentration increased while K concentration decreased with leaf age. The ratios Ca/Sr, Ca/Ba and K/Rb increased from roots to leaves, revealing a significant biopurification especially between stems and leaves. This phenomenon was higher for Ca than for K, with Ca/Sr and Ca/Ba ratios more than twice and 4 times higher in leaves than in roots, respectively, while K/Rb ratio in leaves was only 50% higher than in roots. Ca/Sr ratio decreased whereas K/Rb increased with leaf age. While the first could result from a "chromatographic effect" of the vascular column, the latter suggests the existence of biopurification mechanisms during influx/efflux of K from the leaf. Surprisingly, the magnitude of Ca biopurification varied between populations on a small geographical scale suggesting that Ca/Sr ratio should be used cautiously for plant Ca source identification.

  14. Tree growth rates in an Amazonian evergreen forest: seasonal patterns and correlations with leaf phenology

    Science.gov (United States)

    Wu, J.; Silva Campos, K.; Prohaska, N.; Ferreira, M. L.; Nelson, B. W.; Saleska, S. R.; da Silva, R.

    2014-12-01

    Metabolism and phenology of tropical forests significantly influence global dynamics of climate, carbon and water. However, there is still lack of mechanistic understanding of the controls on tropical forest metabolism, particularly at individual tree level. In this study, we are interested in investigating (1) what is the seasonal pattern of woody growth for tropical trees and (2) what is the mechanistic controls onwoody growth at individual level?To explore the above questions,we use two data sources from an evergreen tropical forest KM67 site (near Santarem, Brazil). They are: (1) image time series from a tower mounted RGB imaging system, with images recordedin10 minutes interval since October 2013.Images near local noon homogeneous diffuse lighting were selectedfor leaf phenologymonitoring; (2) ground based bi-weekly biometry survey (via dendrometry band technique) for 25 trees from random sampling since September 2013. 12 among 25 trees are within the tower mounted camera image view. Our preliminary resultsdemonstrate that 20 trees among 25 trees surveyed significantly increase woody growth (or "green up") in dry season. Our results also find thatamong those 20 trees, 12 trees reaches the maximum woody increment rate in late dry season with a mean DBH (Diameter at Breast Height) around 30 cm,while 8 trees reaching the maximum in the middle of wet season, with a mean DBH around 90 cm. This study,though limited in the sample size, mightprovide another line of evidence that Amazon rainforests "green up" in dry season. As for mechanistic controls on tropical tree woody control, we hypothesize both climate and leaf phenology control individual woody growth. We would like to link both camera based leaf phenology and climate data in the next to explorethe reason as to the pattern found in this study that bigger trees might have different seasonal growth pattern as smaller trees.

  15. 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.

  16. 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

  17. 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 .

  18. 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

  19. Spatio-temporal patterns of recurrent slope instabilities affecting undercut slopes in flysch: A dendrogeomorphic approach using broad-leaved trees

    Science.gov (United States)

    Šilhán, Karel; Pánek, Tomáš; Turský, Ondřej; Brázdil, Rudolf; Klimeš, Jan; Kašičková, Lucie

    2014-05-01

    The undercut slope of the Skalická Strážnice/Vrchy hill situated in the piedmont of the Carpathian Mountains (Czech Republic) is a regional landslide "hotspot", notorious for its repeated recent and historical sliding reactivations. We performed tree-ring analysis of a large number (n = 274) of broad-leaved trees to reconstruct the spatio-temporal patterns of landslide reactivation for a period spanning more than one hundred years (1884-2011). Although tree rings of broad-leaved trees are less-reliable archives of landslide activity than those of conifers, the application of a methodology based on the weighting of disturbance signals within eccentricity series generated a usable dataset of sliding activity affecting anisotropic flysch bedrock. Although some known landslide years could not be found (or were expressed by only weak signals) in the reconstructed dataset, the majority of landslide events reconstructed from the tree-ring series coincide with hydrometeorological data, revealing a correlation with heavy summer rainfalls lasting from two to ten days. The spatial distribution of landslide recurrence derived from the tree-ring records together with electrical resistivity tomography and a kinematic analysis of slope failures suggest a close link between the concentration of landslide activity and the presence of faulted or fractured flysch bedrock.

  20. 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.

  1. A unique Middle Pleistocene beech (Fagus)-rich deciduous broad-leaved forest in the Yangtze Delta Plain, East China: Its climatic and stratigraphic implication

    Science.gov (United States)

    Shu, Jun-wu; Wang, Wei-ming

    2012-08-01

    Pollen analysis of Middle Pleistocene sediments from the Yangtze Delta Plain provides a paleoecological reconstruction and has implications for stratigraphic correlation in East China. The pollen assemblage is characterized by high values of Fagus (16.8% on average), which is unusual because Fagus is generally present only sporadically in other lowland Quaternary pollen records from the region. In addition to Fagus, the assemblage has a rich diversity of broad-leaved deciduous trees, including Quercus, Ulmus, Carpinus/Ostrya, Juglans, Betula, and Liquidambar, as well as conifers, including Pinus, Picea, Abies, Larix, and Tsuga. Thus, the pollen flora suggests a broad-leaved deciduous forest mixed with abundant conifers, which developed under cooler and more humid conditions than present. The stable pollen sequence throughout the studied section suggests a stable environment. Beech forests also characterize the Middle Pleistocene of Taiwan and Japan, and thus may be a stratigraphic indicator of the Middle Pleistocene in East Asia. The Yangtze Delta Plain may have been an important refugium for the last survival of Fagus in the lowlands.

  2. Transmission of Phytophthora ramorum in Mixed-Evergreen Forest in California.

    Science.gov (United States)

    Davidson, Jennifer M; Wickland, Allison C; Patterson, Heather A; Falk, Kristen R; Rizzo, David M

    2005-05-01

    ABSTRACT During 2001 to 2003, the transmission biology of Phytophthora ramorum, the causal agent of sudden oak death, was studied in mixedevergreen forest, a common forest type in northern, coastal California. Investigation of the sources of spore production focused on coast live oak (Quercus agrifolia) and bay laurel (Umbellularia californica), dominant hosts that comprised 39.7 and 46.2% of the individuals at the study site, respectively. All tests for inoculum production from the surface of infected coast live oak bark or exudates from cankers were negative. In contrast, sporangia and chlamydospores were produced on the surface of infected bay laurel leaves. Mean number of zoospores produced from infected bay laurel leaves under natural field conditions during rainstorms was 1,173.0 +/- SE 301.48, and ranged as high as 5,200 spores/leaf. P. ramorum was recovered from rainwater, soil, litter, and streamwater during the mid- to late rainy season in all 3 years of the study. P. ramorum was not recovered from sporadic summer rains or soil and litter during the hot, dry summer months. Concentrations of inoculum in rainwater varied significantly from year to year and increased as the rainy season progressed for the two complete seasons that were studied. Potential dispersal distances were investigated for rainwater, soil, and streamwater. In rainwater, inoculum moved 5 and 10 m from the inoculum source. For soil, transmission of inoculum was demonstrated from infested soil to bay laurel green leaf litter, and from bay laurel green leaf litter to aerial leaves of bay laurel seedlings. One-third to one-half of the hikers tested at the study site during the rainy season also were carrying infested soil on their shoes. In streamwater, P. ramorum was recovered from an unforested site in pasture 1 km downstream of forest with inoculum sources. In total, these studies provide details on the production and spread of P. ramorum inoculum in mixed-evergreen forest to aid

  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. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 顺昌县不同径阶阔叶树保留木资源调查与分析%Resources of Residual Trees for Broadleaved-Trees at Different Diameter Grades in Shunchang County

    Institute of Scientific and Technical Information of China (English)

    张平

    2016-01-01

    通过2012—2013年顺昌县大历镇阔叶树保留木资源调查分析,结果表明:不同径阶阔叶树保留木的株数分布整体上呈“L”形,每个径阶阔叶树保留木达200株以上的主要分布于径阶为6~14 cm 之间,共有1499株,占总数的73.37%;径阶16 cm以上保留的株数仅占总数的26.63%。阔叶树保留木中间层中径木,共有1978株,占总数的96.82%;上层大树仅65株,仅占总数的3.18%。不同径阶的阔叶树保留木蓄积量分布基本上呈正态分布,径阶5~14 cm阔叶树保留木蓄积量为63.82 m3,占总保留木阔叶树蓄积量187.29 m3的34.08%;径阶16 cm 以上的阔叶树保留木蓄积量为123.47 m3,占总保留木阔叶树蓄积量的65.92%,是径阶5~14 cm 阔叶树保留木蓄积量1.93倍。阔叶树中间层中径木蓄积量为146.08 m3,占总蓄积量的78%;上层大树蓄积量为41.21 m3,蓄积量占总数的22%。阔叶树保留木胸径5~14.9 cm共需补偿3191元,胸径15 cm 以上需补偿12347.00元,大历镇阔叶树保留木共需补偿15538.00元。阔叶树保留株数平均值为138.6株 hm-2,阔叶树蓄积量保留平均值为12.75 m3 hm-2,阔叶树保留木不炼山造林成本从造林至郁闭前需投资27000元 hm-2。%Resources of residual trees for broadleaved-trees at different diameter grades in Dali Town of Shunchang County were analyzed from 2012 to 2013.Result shows that:distribution for number of trees of residual trees for broadleaved-trees at different diameter grades appears an“L”type.Residual trees (above 200 trees)of broadleaved-trees at each diameter class mainly distributed 6-14 cm,a total of 1 499 trees,constitute 73.37% of the total;the number of reserved trees only constitute 26.63% of the total above 16 cm;middle diameter wood in middle layer of broadleaved-trees,there are 1 978 trees,constitute 96.82% of the total;there are only 65 trees in the upper layer which constitute 3.18%.Distribution of stock volume of residual trees for

  11. 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

  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. 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......, 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......, 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...

  14. Detecting Inter-Annual Variations in the Phenology of Evergreen Conifers Using Long-Term MODIS Vegetation Index Time Series

    Directory of Open Access Journals (Sweden)

    Laura Ulsig

    2017-01-01

    Full Text Available Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalized Difference Vegetation Index (NDVI. This study investigates the potential of a Photochemical Reflectance Index (PRI, which has been linked to vegetation light use efficiency, to improve the accuracy of MODIS-based estimates of phenology in an evergreen conifer forest. Timings of the start and end of the growing season (SGS and EGS were derived from a 13-year-long time series of PRI and NDVI based on a MAIAC (multi-angle implementation of atmospheric correction processed MODIS dataset and standard MODIS NDVI product data. The derived dates were validated with phenology estimates from ground-based flux tower measurements of ecosystem productivity. Significant correlations were found between the MAIAC time series and ground-estimated SGS (R2 = 0.36–0.8, which is remarkable since previous studies have found it difficult to observe inter-annual phenological variations in evergreen vegetation from satellite data. The considerably noisier NDVI product could not accurately predict SGS, and EGS could not be derived successfully from any of the time series. While the strongest relationship overall was found between SGS derived from the ground data and PRI, MAIAC NDVI exhibited high correlations with SGS more consistently (R2 > 0.6 in all cases. The results suggest that PRI can serve as an effective indicator of spring seasonal transitions, however, additional work is necessary to confirm the relationships observed and to further explore the usefulness of MODIS PRI for detecting phenology.

  15. 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

  16. 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.

  17. 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.

  18. Terrestrial Macrofungal Diversity from the Tropical Dry Evergreen Biome of Southern India and Its Potential Role in Aerobiology

    Science.gov (United States)

    Priyamvada, Hema; Akila, M.; Singh, Raj Kamal; Ravikrishna, R.; Verma, R. S.; Philip, Ligy; Marathe, R. R.; Sahu, L. K.; Sudheer, K. P.; Gunthe, S. S.

    2017-01-01

    Macrofungi have long been investigated for various scientific purposes including their food and medicinal characteristics. Their role in aerobiology as a fraction of the primary biological aerosol particles (PBAPs), however, has been poorly studied. In this study, we present a source of macrofungi with two different but interdependent objectives: (i) to characterize the macrofungi from a tropical dry evergreen biome in southern India using advanced molecular techniques to enrich the database from this region, and (ii) to assess whether identified species of macrofungi are a potential source of atmospheric PBAPs. From the DNA analysis, we report the diversity of the terrestrial macrofungi from a tropical dry evergreen biome robustly supported by the statistical analyses for diversity conclusions. A total of 113 macrofungal species belonging to 54 genera and 23 families were recorded, with Basidiomycota and Ascomycota constituting 96% and 4% of the species, respectively. The highest species richness was found in the family Agaricaceae (25.3%) followed by Polyporaceae (15.3%) and Marasmiaceae (10.8%). The difference in the distribution of commonly observed macrofungal families over this location was compared with other locations in India (Karnataka, Kerala, Maharashtra, and West Bengal) using two statistical tests. The distributions of the terrestrial macrofungi were distinctly different in each ecosystem. We further attempted to demonstrate the potential role of terrestrial macrofungi as a source of PBAPs in ambient air. In our opinion, the findings from this ecosystem of India will enhance our understanding of the distribution, diversity, ecology, and biological prospects of terrestrial macrofungi as well as their potential to contribute to airborne fungal aerosols. PMID:28072853

  19. 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.

  20. 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.

  1. 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

  2. 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...

  3. Temperature profiles from XBT casts from the EVERGREEN as part of the Marine Resources Monitoring, Assessment and Prediction (MARMAP) project from 1977-04-02 to 1977-04-30 (NCEI Accession 7700355)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profiles were collected from XBT casts from the EVERGREEN from 02 April 1977 to 30 April 1977. Data were collected by the National Marine Fisheries...

  4. 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.

  5. 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

  6. 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 an...

  7. Community characteristics of tropical montane evergreen forest and tropical montane dwarf forest in Bawangling National Nature Reserve on Hainan Island, South China

    OpenAIRE

    Wenxing Long; Runguo Zang; Yi Ding

    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 be-tween 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 a...

  8. 武夷山米槠、甜槠常绿阔叶林的物种组成及多样性分析%Species composition and diversity of evergreen broad-leaved forest of Castanopsis carlesii and C. eyrei in Wuyishan National Nature Reserve, Fujian, China

    Institute of Scientific and Technical Information of China (English)

    方燕鸿

    2005-01-01

    选择武夷山自然保护区最具代表性的米槠(Castanopsis carlesii)、甜槠(C.eyrei)常绿阔叶林设置4800 m2的样方,研究了植物群落生长特征及其物种多样性.共记录到植物物种67科138属311种,其中乔木物种(含更新层或小乔木)160种,灌木89种,藤本25种,草本37种.主要优势种有:米槠、甜槠、黄瑞木(Adinandra mille-ttii)、树参(Dendropanax dentiger)、罗浮栲(C.fabri)、少叶黄杞(Engelhardtia fenzelii)、丝栗栲(C.fargesii)、青冈(Cyclobalanopsis glauca)等,其中米槠和甜槠两个物种的相对胸高断面积(RBA)占44.1%.武夷山常绿阔叶林主要由壳斗科(RBA=60.1%)和山茶科(12.2%)的物种组成;最重要属为栲属(Castanopsis)(RBA=52.0%)、青冈属(Cyclobalanopsis)(6.4%)和黄瑞木属(Adinandra)(4.5%)等.多样性分析结果表明,乔木层Shannon-Wie-ner指数(H')为3.0左右;随着取样面积的增加,H'值和均匀度指数(E)逐渐增加;1500 m2时H'趋于平稳,1000m2时E趋于平稳.从种-面积曲线可知,武夷山常绿阔叶林在取样面积大于4500 m2后物种数量趋于稳定.武夷山常绿阔叶林小径级的乔木(DBH≤10 cm)数量占76.3%,而DBH≥45 cm的个体数量仅占2.3%.该植物群落常绿树种占绝对优势,但落叶物种种类仍然比较丰富.

  9. 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.

  10. 不同梯度氮沉降对亚热带甜槠林凋落物及养分的影响%Effects of Nitrogen Deposition on Litterfall and Its Nutrient in Subtropical Evergreen Broad-leaved Castanopsis Ey rei Forest

    Institute of Scientific and Technical Information of China (English)

    徐俊; 李茂; 刘露; 田地; 徐小牛

    2016-01-01

    Objective] This essay provided data reference and theoretical basis for nitrogen deposition in sub‐tropical regions by analyzing effects of nitrogen deposition on litterfall and its nutrient in a subtropical ever‐green broad‐leaved Castanopsis eyrei forest .[Methods] Different gradient nitrogen control experiments were set up in Xianyu mountain area of Anhui Province to monitor C .eyrei forest litterfall and nutrient response status for a long time .[Results] The order of the annual litterfall were as follows :high nitrogen and phos‐phorus(HN+P)>low nitrogen(LN)> high nitrogen(HN)> control check(CK) .There was no significant difference among the treatments .There was significant difference in foliar litter between LN and CK treat‐ments(p=0 .023) .The total litterfall showed a bimodal type with the peaks appeared in April and Novem‐ber .The order of the proportion of the different litter components for the four treatments ranked as leaf >fruit>branch>miscellaneous>flower>bark .HN+ P and HN treatments changed the fruit percentage to a certain degrees :HN+P(27% )> HN(25% )>CK= LN (23% ) .The annual amount of total nutrient‐returns of the six macro‐elements(C ,N ,P ,K ,Ca ,Mg) was as follows :HN+P 4.62 t/(hm2 · a)>CK 4 .44 t/(hm2 · a)> HN 4 .17 t/(hm2 · a)>LN 3 .96 t/(hm2 · a) .The similar patterns appeared for C ,N ,P ,Mg ,Ca returns in the four treatments .There was significant differences in annual returns of N and P between HN + P and CK treatments(p= 0 .047;p= 0 .023) . The nutrient return from foliar litter covered 52% ~58% of the annual total .[Conclusion] We simulated different gradient of nitrogen settlement and found that it changed the C . eyrei forest total litter amount and composition proportion in a certain extent and affected the absorption of other nutrients and return amount .%[目的]分析不同梯度氮沉降作用下亚热带常绿阔叶甜槠(Castanopsis eyrei)林凋落物量及养分变化规律,从而为亚热带地区氮沉降研究提供数据参考与理论依据。[方法]对安徽省仙寓山地区设置不同梯度施氮对照试验,长期实地监测甜槠林凋落物量及其养分的响应状况。[结果]凋落物量大小顺序为:高氮加磷(HN+ P)>低氮(LN)>高氮(HN)>对照CK ,不同处理间的差异未达到显著水平;但是落叶量LN与CK之间差异显著(p=0.023)。各处理凋落物量的月变化模式均呈双峰型,分别在4和11月达到峰值;凋落物中各组分所占比例从大到小均为:叶>果>枝>碎屑>花>皮;施肥处理不同程度上改变了落果量的比重:HN+ P(27%)> HN(25%)> CK= LN(23%)。甜槠林C ,N ,P ,K ,Ca ,Mg 这6种大量元素的养分年归还量共计:HN+ P 4.62 t/(hm2· a)> CK 4.44 t/(hm2· a)> HN 4.17 t/(hm2· a)>LN 3.96 t/(hm2· a);不同处理各养分(K除外)归还量均表现为上述关系,且 HN+ P与CK之间的N ,P的养分归还量差异显著( p=0.047;0.023)。对于各组分而言,落叶的养分归还量占年养分归还量的52%~58%。[结论]模拟不同梯度的氮沉降处理在一定程度上改变了甜槠林凋落物总量的大小及其组成比例,且影响到其他养分的吸收及归还量。

  11. Effects of simulated nitrogen deposition and precipitation changes on soil respiration in an evergreen broad-leaved forest in the Rainy Area of Western China%模拟氮沉降和降雨对华西雨屏区常绿阔叶林土壤呼吸的影响

    Institute of Scientific and Technical Information of China (English)

    向元彬; 黄从德; 胡庭兴; 涂利华; 周世兴; 肖永翔; 高保丹

    2016-01-01

    从2013年12月至2014年11月,通过野外原位试验,对华西雨屏区常绿阔叶林进行了模拟氮沉降和降雨试验,采用LI-8100土壤碳通量分析系统(LI-COR Inc.,USA)测定了对照(CK)、氮沉降(N)、减雨(R)、增雨(W)、氮沉降+减雨(NR)、氮沉降+增雨(NW)6个处理水平的土壤呼吸速率,并通过回归方程分析了温度和湿度与土壤呼吸速率间的关系.结果表明:(1)氮沉降和增雨抑制了常绿阔叶林土壤呼吸速率,减雨促进了常绿阔叶林土壤呼吸速率.(2)减雨使华西雨屏区常绿阔叶林土壤呼吸年通量增加了258 g/m2,而模拟氮沉降和增雨使华西雨屏区常绿阔叶林土壤呼吸年通量分别减少了321g/m2和406g/m2.(3)减雨增加了土壤呼吸的温度敏感性,模拟氮沉降和增雨降低了土壤呼吸的温度敏感性.(4)模拟温度和湿度与土壤呼吸速率间回归方程分析表明,土壤水分对土壤呼吸速率的影响较小.(5)模拟氮沉降和增雨处理减少土壤微生物生物量碳、氮的含量,减雨处理增加了土壤微生物生物量碳、氮的含量.(6)模拟氮沉降和降雨对华西雨屏区土壤CO2释放的影响未表现出明显的交互作用.

  12. 川南天然常绿阔叶林土壤酶活性特征及其对模拟N沉降的响应%Soil enzyme activities and its response to simulated nitrogen deposition in an evergreen broad-leaved forest, southern Sichuan

    Institute of Scientific and Technical Information of China (English)

    宋学贵; 胡庭兴; 鲜骏仁; 肖春莲

    2009-01-01

    通过原位进行低氮(LN,50 kg N·hm-2·a-1)、中氮(MN,100 kg N·hm-2·a-1)和高氮(HN,150 kg N·hm-2·a-1)处理,研究了川南天然常绿阔叶林土壤酶活性特征及其对模拟N沉降的响应.结果表明,森林土壤过氧化氢酶、脲酶、纤维素酶和蔗糖酶的活性在垂直分布上均表现为0~10 cm土层高于10~20 cm土层;各种土壤酶活性的季节变化明显,但土壤酶活性还因取样时间和土层不同而异.其中,0~10 cm和10~20 cm土层中过氧化氢酶活性高峰均出现在秋季(92 d);0~10 cm土层中脲酶活性高峰出现在秋季,而10~20 cm土层中脲酶活性高峰出现在冬季(183 d);0~10 cm和10~20 cm土层中土壤纤维素酶活性高峰则出现在翌年春季(274 d);0~10 cm土层中蔗糖酶活性有两个高峰,分别出现在秋季和翌年春季;而10~20 cm土层中蔗糖酶活性只有一个高峰,出现在翌年春季.总体上,常绿阔叶林中不同土壤酶活性对N沉降的响应有所差异.其中,N沉降降低了常绿阔叶林土壤纤维素酶和过氧化氢酶活性,增加了土壤脲酶和蔗糖酶活性.不同浓度N处理间酶活性表现出了不同程度的差异性,但其变化的规律还不明显.

  13. 梵净山山地常绿落叶阔叶林种子雨及种子库%Preliminary Study on the Seed Rain and Seed Bank of the MixedEvergreen and Deciduous Broad-Leaved Forest on Fanjing Mountain

    Institute of Scientific and Technical Information of China (English)

    刘济明

    1999-01-01

    梵净山山地常绿落叶阔叶混交林--亮叶水青冈(Fagus lucida)*厚皮香八角(Illicium ternstroemioides)群落种子雨量达18种260粒/m2, 其中成熟有效种子80粒/m2 .在天然萌发开始时种子库中有活力种子33种2 076粒/m2, 其中现存植物种子18种204粒/m2 ,演替前期各阶段植物种子15种1 872粒/m2;木本植物种子20种,草本植物种子13种.种子库的枯枝落叶层中全为现存植物种子.土壤层中随深度增加, 活力种子种类和数量均逐渐减少.天然萌发开始时种子库中现存植物的活力种子种类及数量丰富, 群落更新潜力好.

  14. 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.

  15. 模拟酸沉降对鼎湖山季风常绿阔叶林地表径流水化学特征的影响%Effect of simulated acid deposition on chemistry of surface runoff in monsoon evergreen broad-leaved forest in Dinghushan

    Institute of Scientific and Technical Information of China (English)

    丘清燕; 陈小梅; 梁国华; 周国逸; 张德强

    2013-01-01

    通过模拟酸沉降实验,研究了旱季期间(10-3月份)鼎湖山季风常绿阔叶林在4种不同pH模拟酸雨处理(对照、pH 4.0、pH 3.5、pH 3.0)下地表径流水化学输出特征.结果显示:(1)地表径流pH随酸处理强度增强呈“U”型变化模式,酸沉降对地表径流pH的影响不显著(P>0.05),表明模拟酸沉降尚未引起地表水的酸化.(2)地表径流中NO3-、SO24-浓度随酸处理强度增强略有增加;HCO3-浓度的变化模式与地表径流pH类似.酸根离子浓度与地表径流pH相关性分析表明,SO24-、HCO3-有助于提高地表水抗酸化能力而NO3-则有助于促进地表水酸化.(3)地表径流中盐基离子对酸沉降的响应不尽相同.pH 3.0处理显著提高地表径流中Ca2+、Na+浓度;Mg2+浓度具有随酸处理梯度增强而增加的趋势;K+受模拟酸度的影响小.表明强酸(pH3.0)处理将导致土壤Na+、Ca2+、Mg2+盐基离子流失.(4)酸沉降具有诱发土壤可溶性有机碳(DOC)流失的倾向,增加地表水受有机污染的风险.

  16. 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.

  17. 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.

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

    Science.gov (United States)

    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.

  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. [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.

  1. [Effects of forest gap on tree species regeneration and diversity of mixed broadleaved Korean pine forest in Xiaoxing'an Mountains].

    Science.gov (United States)

    Liu, Shao-Chong; Duan, Wen-Biao; Feng, Jing; Han, Sheng-Zhong

    2011-06-01

    This paper studied the quantitative characteristics of main tree species along a forest gap gradient (gap center-near gap center-gap border) of mixed broadleaved Korean pine forest in Xiaoxing'an Mountains, as well as the effects of forest gap size on the regeneration of the tree species. In forest gap, the density of shrub species was obviously larger than that in non-gap, and the density ratio of the same shrub species in forest gap to in non-gap ranged from 1.08 to 18.15. With the increase of gap size, the regeneration density of tree seedlings increased, and that of sapling I (H > or = 1 m, DBH or = 1 m, 2 cm tree seedlings and sapling I. The mean height, mean basal diameter, species density, and individual density of trees in different locations of forest gaps were all different. From gap center to non-gap, the importance value of tree species seedlings in regeneration layer was ranked in gap center > near gap center > gap border > non-gap, the tree species evenness presented a variation of high-low-high, and the species diversity decreased in the order of early phase gap > mid phase gap > late phase gap.

  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. 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.

  4. 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.

  5. Species identity and neighbor size surpass the impact of tree species diversity on productivity in experimental broad-leaved tree sapling assemblages under dry and moist conditions.

    Science.gov (United States)

    Lübbe, Torben; Schuldt, Bernhard; Leuschner, Christoph

    2015-01-01

    Species diversity may increase the productivity of tree communities through complementarity (CE) and/or selection effects (SE), but it is not well known how this relationship changes under water limitation. We tested the stress-gradient hypothesis, which predicts that resource use complementarity and facilitation are more important under water-limited conditions. We conducted a growth experiment with saplings of five temperate broad-leaved tree species that were grown in assemblages of variable diversity (1, 3, or 5 species) and species composition under ample and limited water supply to examine effects of species richness and species identity on stand- and tree-level productivity. Special attention was paid to effects of neighbor identity on the growth of target trees in mixture as compared to growth in monoculture. Stand productivity was strongly influenced by species identity while a net biodiversity effect (NE) was significant in the moist treatment (mostly assignable to CE) but of minor importance. The growth performance of some of the species in the mixtures was affected by tree neighborhood characteristics with neighbor size likely being more important than neighbor species identity. Diversity and neighbor identity effects visible in the moist treatment mostly disappeared in the dry treatment, disproving the stress-gradient hypothesis. The mixtures were similarly sensitive to drought-induced growth reduction as the monocultures, which may relate to the decreased CE on growth upon drought in the mixtures.

  6. Species identity and neighbor size surpass the impact of tree species diversity on productivity in experimental broad-leaved tree sapling assemblages under dry and moist conditions

    Directory of Open Access Journals (Sweden)

    Torben eLübbe

    2015-10-01

    Full Text Available Species diversity may increase the productivity of tree communities through complementarity and/or selection effects, but it is not well known how this relationship changes under water limitation. We tested the stress-gradient hypothesis, which predicts that resource use complementarity and facilitation are more important under water-limited conditions. We conducted a growth experiment with saplings of five temperate broad-leaved tree species that were grown in assemblages of variable diversity (1, 3 or 5 species and species composition under ample and limited water supply to examine effects of species richness and species identity on stand and tree-level productivity. Special attention was paid to effects of neighbor identity on the growth of target trees in mixture as compared to growth in monoculture. Stand productivity was strongly influenced by species identity while a net biodiversity effect was significant in the moist treatment (mostly assignable to a complementarity effect but of minor importance. The growth performance of some of the species in the mixtures was affected by tree neighborhood characteristics with neighbor size likely being more important than neighbor species identity. Diversity and neighbor identity effects visible in the moist treatment mostly disappeared in the dry treatment, disproving the stress-gradient hypothesis. The mixtures were similarly sensitive to drought-induced growth reduction as the monocultures, which may relate to the decreased complementarity effect on growth upon drought in the mixtures.

  7. 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.

  8. Enhanced accumulation and storage of mercury on subtropical evergreen forest floor: Implications on mercury budget in global forest ecosystems

    Science.gov (United States)

    Wang, Xun; Lin, Che-Jen; Lu, Zhiyun; Zhang, Hui; Zhang, Yiping; Feng, Xinbin

    2016-08-01

    Forest ecosystems play an important role in the global cycling of mercury (Hg). In this study, we characterized the Hg cycling at a remote evergreen broadleaf (EB) forest site in southwest China (Mount Ailao). The annual Hg input via litterfall is estimated to be 75.0 ± 24.2 µg m-2 yr-1 at Mount Ailao. Such a quantity is up to 1 order of magnitude greater than those observed at remote temperate/boreal (T/B) forest sites. Production of litter biomass is found to be the most influential factor causing the high Hg input to the EB forest. Given their large areal coverage, Hg deposition through litterfall in EB forests is appropriately 9 ± 5 Mg yr-1 in China and 1086 ± 775 Mg yr-1 globally. The observed wet Hg deposition at Mount Ailao is 4.9 ± 4.5 µg m-2 yr-1, falling in the lower range of those observed at 49 T/B forest sites in North America and Europe. Given the data, the Hg deposition flux through litterfall is approximately 15 times higher than the wet Hg deposition at Mount Ailao. Steady Hg accumulation in decomposing litter biomass and Hg uptake from the environment were observed during 25 months of litter decomposition. The size of the Hg pool in the organic horizon of EB forest floors is estimated to be up to 2-10 times the typical pool size in T/B forests. This study highlights the importance of EB forest ecosystems in global Hg cycling, which requires further assessment when more data become available in tropical forests.

  9. Implication of Intrastorm Rainfall-Canopy Interaction on Interception Performance of Broadleaf Evergreen Shrubs in an Ultra-Urban Setting

    Science.gov (United States)

    Yerk, W.; Montalto, F. A.

    2015-12-01

    Because of its ability to intercept a portion of rainfall, vegetated canopies can play substantial role in modulating the urban hydrological cycle. However, canopy interception research has historically been focused to forest canopies. The goal of our research is to quantify rainfall partitioning by isolated evergreen shrub canopies in an ultra-urban setting. The three year field experiment involved three exemplars of cherry laurel (Prunus laurocerasus 'Otto Luyken'.) Ten rain gauges positioned under each plant were used to measure throughfall with a sampling frequency of five seconds. A number of specific techniques were implemented to minimize error associated with the gauges, e.g., splash-in, splash-out and excessive wetting. The cumulative throughfall deficit (i.e., gross precipitation minus throughfall within the canopy projected area and minus stemflow) for the periods of August-December 2013, April-December 2014 and April-July 2015 was 39%. Spatial variability of throughfall was large (coefficient of variation up to 1.5.) Stable areas of preferential throughfall flux were observed. Stemflow showed a high variability (1.4 - 24%) between rain events. The relationship between throughfall and precipitation intensity was strongly linear (adjusted coefficient of determination R2 0.79) throughout the entire range of observed rainfall intensities. The overall ratio of throughfall to precipitation intensity was 0.48:1. The observations suggest that reduction of throughfall intensity by the canopy during a rainstorm determines the aggregate interception depth. In contrast, the amount of water stored on the canopy and evaporated between and after rain events contributes minimally to interception loss. Penman-Monteith estimates of wet canopy evaporation cannot account for the throughfall deficit. Lateral displacement of microdrops beyond the canopy projected area is another phenomenon that will be discussed and most recent observations of an extended gauge network will

  10. 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.

  11. 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.

  12. 7种阔叶植物群落降噪的临界达标宽度%Critical Width of Seven Broad-leaved Plant Communities for Noise Reduction to Standard

    Institute of Scientific and Technical Information of China (English)

    祝遵凌; 杜丹; 韩笑

    2012-01-01

    There were 7 kinds of broad-leaved plant communities of some main roads in Nanjing, and they were chosen as the research object. The noise reduction effect from the plant was measured along the longitudinal road by every 5 m and moving uncertain distance. The result showed that all the average equivalent continuous A-weighted sound pressure levels of the road edge in the measuring time were beyond the limits of the corresponding provisions in GB3096-2008, out of which the highest was beyond 6 dB, the lowest beyond 1.3 dB. As the distance from the road edge increasing, the noise reduction effect of the same broad-leaved plant community was more obvious. The noise reduction effect of different broad-leaved plant communities at the same distance from the sound source were different, that closely related with the composition and the internal structure of those plant communities. Not all the noise reduction effect of plant communities had the linear relationship with the belt width. For the 7 kinds of broad-leaved plant communities, the critical width, at which the noise level reached the ambient noise limits of acoustic environmental functional area, focused on the range of 5 - 15 m. The broad-leaved plant communities in a certain width can basically meet the requirement of the noise reduction, so the broad-leaved plant communities can be widely used in the urban main roads.%选取南京市部分主干路道路绿地的7种阔叶植物群落,通过沿道路纵向每间隔5m以及不定距移动测量,结果表明:测量时间段内路缘处噪声的等效连续A声级平均值都超出GB3096—2008中相应规定的限制,其中最高的超出6dB,最低的超出1.3dB;同一阔叶植物群落,随着离开路缘的距离增加,降噪效果更加明显;不同的阔叶植物群落在同一距离处的降噪效果不同,这与植物群落的组成和内部结构特征有密切关系;植物群落的降噪效果与林带宽

  13. 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.

  14. Effect of Severe Winter Cold on the Photosynthetic Potentials of Three Co-occurring Evergreen Woody Species in a Mediterranean Forest, Catalonia (Spain)

    Science.gov (United States)

    Sperlich, Dominik; Gracia, Carlos; Peñuelas, Josep; Sabaté, Santi

    2013-04-01

    Evergreen tree species in the Mediterranean region have to cope with a wide range of environmental stress conditions from summer drought to winter cold. The winter period can lead to photoinhibition due to a combination of high solar irradiances and chilling temperatures which can reduce the light saturation point. However, Mediterranean winter mildness can lead periodically to favourable environmental conditions above the threshold for positive carbon balance benefitting evergreen woody species in contrast to winter deciduous species. The advantage of being able to photosynthesis all year round with a significant fraction in the winter month is compensating for the lower photosynthetic potentials during spring and summer in comparison to deciduous species. In this work, we investigated the physiological behaviour of three evergreen tree species (Quercus ilex, Pinus halepensis, Arbutus undeo) co-occurring in a natural and mature Mediterranean forest after a period of mild winter conditions and their response to a sudden period of intense cold weather. Therefore, we examined in each period the photosynthetic potentials by estimating the maximum carboxylation rate (Vcmax) and the maximum electron transport rate (Jmax) through gas exchange measurements. The results indicate that all species exhibited extraordinary high photosynthetic potentials during the first period of measurement as a response to the mild conditions. However, the sudden cold period affected negatively the photosynthetic potentials of Quercus ilex and A. unedo with reduction ranging between 37 to 45 %, whereas they were observed to be only insignificantly reduced in Pinus halepensis. Our results can be explained by previous classifications into photoinhibition-avoiding (P. halpensis) and photoinhibition-tolerant (Q. ilex, A. undeo) species on the basis of their susceptibility to dynamic photoinhibition (Martinez Ferri 2000). Photoinhibition tolerant species are characterised with a more dynamic

  15. Rainfall Reduction Increases Soil Methane Uptake in Broadleaf Evergreen Eucalypt Forest - a Negative Feedback to Climate Change

    Science.gov (United States)

    Fest, B. J.; Hinko-Najera, N.; Livesley, S. J.; Arndt, S. K.

    2013-12-01

    Well-drained aerated soils are important sinks for atmospheric methane (CH4), a process driven by CH4 oxidation through methanotrophic bacteria. Soils in temperate forest ecosystems represent the greatest terrestrial CH4 sink and soil moisture is one of the key regulators of soil CH4 flux in these systems. Most climate change models predict a decrease in average rainfall, an increase in extreme rainfall events and an increase in temperatures for mid-latitude and sub-arid regions. However, most studies of soil CH4 flux under altered rainfall scenarios have been conducted in mid-latitude forest and grassland systems of the northern hemisphere or in tropical forest systems and have often investigated extended drought rather than an reduction in long-term average rainfall. We measured soil CH4 flux for 18 months (October 2010 - April 2012) after installing a passive rainfall reduction system to intercept approximately 40% of canopy throughfall (as compared to control plots) in a temperate broadleaf evergreen eucalypt forest in south-eastern Australia. Throughfall reduction caused an average reduction of 15.1 × 6.4 (SE) % in soil volumetric water content, a reduction of 19.8 × 6.9 (SE) % in soil water filled pore space (WFPS) and a 20.1 × 6.8 (SE) % increase in soil air filled porosity (AFP). In response to these changes, soil CH4 uptake increased by 54.7 × 19.8 (SE) %. Relative changes in CH4 uptake related better to relative changes in AFP than to relative changes in WFPS, indicating a close relationship between AFP and soil gas diffusivity. Our data indicated that soil moisture was the dominant regulating factor of seasonality in soil CH4 uptake explaining up to 80% of the seasonal variability and accounting for the observed throughfall reduction treatment effect. This was confirmed by additional soil diffusivity measurements and passive soil warming treatments. We investigated non-linear functions to describe the relationship between soil moisture and soil CH4

  16. Growing season variability of net ecosystem CO2 exchange and evapotranspiration of a sphagnum mire in the broad-leaved forest zone of European Russia

    Science.gov (United States)

    Olchev, A.; Volkova, E.; Karataeva, T.; Novenko, E.

    2013-09-01

    The spatial and temporal variability of net ecosystem exchange (NEE) of CO2 and evapotranspiration (ET) of a karst-hole sphagnum peat mire situated at the boundary between broad-leaved and forest-steppe zones in the central part of European Russia in the Tula region was described using results from field measurements. NEE and ET were measured using a portable measuring system consisting of a transparent ventilated chamber combined with an infrared CO2/H2O analyzer, LI-840A (Li-Cor, USA) along a transect from the southern peripheral part of the mire to its center under sunny clear-sky weather conditions in the period from May to September of 2012 and in May 2013. The results of the field measurements showed significant spatial and temporal variability of NEE and ET that was mainly influenced by incoming solar radiation and ground water level. The seasonal patterns of NEE and ET within the mire were quite different. During the entire growing season the central part of the mire was a sink of CO2 for the atmosphere. NEE reached maximal values in June-July (-6.8 ± 4.2 μmol m-2 s-1). The southern peripheral part of the mire, due to strong shading by the surrounding forest, was a sink of CO2 for the atmosphere in June-July only. ET reached maximal values in the well-lighted central parts of the mire in May (0.34 ± 0.20 mm h-1) mainly because of high air and surface temperatures and the very wet upper peat horizon and sphagnum moss. Herbaceous species made the maximum contribution to the total gross primary production (GPP) in both the central and the peripheral parts of the mire. The contribution of sphagnum to the total GPP of these plant communities was relatively small and ranged on sunny days of July-August from -1.1 ± 1.1 mgC g-1 of dry weight (DW) per hour in the peripheral zone of the mire to -0.6 ± 0.2 mgC g-1 DW h-1 at the mire center. The sphagnum layer made the maximum contribution to total ET at the mire center (0.25 ± 0.10 mm h-1) and the herbaceous

  17. 上阔下竹复合经营模式对毛竹生长的影响%Effects of Phyllostachys edulis and broad-leaved mixed forest on bamboo growth

    Institute of Scientific and Technical Information of China (English)

    孟勇; 艾文胜; 杨明; 胡伟; 李美群; 涂佳

    2016-01-01

    为给科学、合理、可持续经营毛竹林提供参考数据,以上阔下竹复合经营模式和毛竹纯林经营模式的竹林为研究对象,对两种经营模式下毛竹的竿形生长和地上各部分生物量等指标进行了测定,研究了上位阔叶林对下位毛竹林生长的影响情况。结果表明:同在上坡位的毛竹,上阔下竹复合经营模式的毛竹其胸径、竿高、壁厚、竹竿质量、竹叶质量等指标均显著大于或高于毛竹纯林经营模式的,毛竹的相对竿径随竿高而变化的趋势也较纯林模式的平缓,而毛竹的相对壁厚随相对竿高的变化趋势较纯林模式的陡峭。两种经营模式的毛竹其胸径、竿高、壁厚、竹竿质量、竹叶质量等指标在中坡位和下坡位的竹林间均无显著差异。%To provide some reference data for scientifically, reasonably and sustainably managing bamboo forest, using compound management mode of Phyllostachys edulis and broad-leaved mixed forest and pure P. edulis forest as study objects, some indexes of culm growth and aboveground biomass in P. edulis were determined under the two kinds of management modes, and the influences of upper broad-leaved forest on growth of bamboo forest were studied. The results indicated that, the indexes of in P. edulis at uphill position under the compound management mode of broad-leaved and P. edulis mixed forest were significantly better than those under the management mode of pure P. edulis forest, include diameter at breast height, culm height, culm-wall thickness, culm mass and leaf mass. The variation trend of relative culm diameter with culm height in P. edulis and broad-leaved mixed forest was smoother than that in pure P. edulis forest. The variation trend of relative culm-wall thickness with relative culm height in P. edulis and broad-leaved mixed forest was steeper than that in pure P. edulis forest. The diameter at breast height, culm height, culm-wall thickness

  18. 大兴安岭南段阔叶次生林空间格局及种间关系%Spatial Distribution Pattern and Interspecific Relationship of Broadleaved Secondary Forest in Southern Daxing’ an Mountains

    Institute of Scientific and Technical Information of China (English)

    曾楠; 周梅; 赵鹏武; 魏江生; 陈翔; 舒洋

    2014-01-01

    In Saihanwula Forest Ecosystem Research Station of southern Daxing ’ an Mountains we used the CTFS ( Center for tropical forest science ) sample area construction standards to build 6 hm2 fixed sample plot of broadleaved secondary forest . By using point pattern analysis , we studied the community within the main population spatial distribution pattern and inter-specificrelationship.Incommunity,thereweresevenspecies,atotalof13906trees,thepopulationdensityof2317hm2. The dominant population of broadleaved secondary forest in southern Daxing ’ an Mountains are aggregation distribution , and the intensity of population aggregation change is more obvious .Intensity aggregation value L( t) is Quercusmongolica>Betuladahurica>Betulaplaty phylla>Populus davidiana Dode.The interspecific relationship of broadleaved secondary forest in southern Daxing ’ an Mountains is positive correlation with less competition and replacement of tree species within the community , and the community composition and structure are in a stable state .The main cause of the high proportion of dry wood in community is not the competition between species .%在大兴安岭南段的赛罕乌拉森林生态系统定位研究站,采用CTFS样地建设标准,设置面积为6 hm2的阔叶次生林固定样地。采用点格局分析方法,对群落内主要种群的空间格局及种间关系进行了研究。结果表明:群落内乔木层共出现7个种群,树木共计13906株,群落密度2317株/hm2;大兴安岭南段阔叶次生林优势种群均呈现聚集分布,种群的聚集强度随尺度变化较明显;聚集强度L( t)值:蒙古栎>黑桦>白桦>山杨;大兴安岭南段阔叶次生林群落种间关系以正相关为主,群落内树种之间的竞争以及物种更替现象并不激烈,群落组成和结构正处于稳定状态,群落内较高比例枯立木的产生并非是种群竞争所致。

  19. 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.

  20. Radiocarbon as a biomarker of urban pollution in leaves of evergreen species sampled in Rome and in rural areas (Lazio—Central Italy)

    Science.gov (United States)

    Alessio, M.; Anselmi, S.; Conforto, L.; Improta, S.; Manes, F.; Manfra, L.

    The aim of the present study is the use of 14C, sampled in leaves of evergreen species, as a natural geochemical marker to estimate the contribution of artificial sources (heating plants, vehicles, etc.) to the complex of atmospheric gases in an urban environment. Leaves were chosen due to sampling easiness and their reliability: in particular the evergreen species, being exposed all the year round to pollutants are especially indicated for bioindication and biomonitoring studies. The response to atmospheric pollutants has been studied of two plant species ( Quercus ilex L., Pinus pinea L.) measuring isotopic ( 14r, δ13C), chemical (Pb concentration) and ecophysiological (gaseous exchange and leaf fluorescence of chlorophyll a) parameters. Leaves of holm-oaks and stone pine needles collected over a 3-year time span in an urban park in Rome (Villa Ada) and in reference localities outside the city on the Tyrrhenian coast and in the pre-Appennine area have been analysed. In Villa Ada measurements were carried out along a transect from the road bordering the park towards the interior; all the parameters, together in agreement, showed a decreasing pollution gradient towards the inner park. It was possible to estimate a 5.5±0.3% contribution of CO 2 from fossil fuels close to the road, decreasing to 1.7±0.3% at <300 m from it towards the inner park. The isotopic analyses conducted on stone pines and holm-oaks show that 14C provides indications on the degree of pollution from fossil fuels, while δ13C appears to be conditioned mainly by the interspecific difference, and also by many other environmental factors that affect the plant functionality. Results confirmed that radiocarbon is a useful tool in environmental studies, allowing to quantify the contributions of CO 2 of anthropic origin: this parameter, together with appropriate isotopic, chemical and ecophysiological analyses, could provide a good indication of the "air quality" in urban and rural contexts.

  1. NATURAL VEGETATION AND ECOSYSTEM SERVICES RELATED TO AIR QUALITY IMPROVEMENT: TROPOSPHERIC OZONE REMOVAL BY EVERGREEN AND DECIDUOUS FORESTS IN LATIUM (ITALY

    Directory of Open Access Journals (Sweden)

    F. Manes

    2012-06-01

    Full Text Available The background concentrations of tropospheric ozone (O3 are increasing in both industrialized and developing countries, thus posing a concrete risk to human health, natural vegetation and crops. Several papers have reported that the total O3 flux from the atmosphere to canopy surfaces can have positive effects on air quality, and consequently to human health and wellbeing. In this work, we have estimated the role of the main natural woody vegetation classes of the CORINE Land cover Classification System in the Latium Region (Central Italy in removing O3 during the growing season of the year 2005. Cumulated O3 fluxes data allowed to estimate the externality value of this ecosystem service provided by deciduous and evergreen forests in the Latium region to be around a total value of 85025821.  In the Apennine chain Province, this value should be around 57248431 $ while  in the Tyrrhenian Borderland Province 2286567 $, 22376136 $ and 3114686 $ for deciduous and evergreen forests, respectively. This corresponds, for the growing season 2005, to a total value of 85025821 $ attributable to the ecosystem service of tropospheric O3 removal provided by the natural forests of the Latium region. Although we acknowledge the uncertainty in producing such estimate, we think our effort  as a useful first contribution addressed to the monetization of one of the ecosystem services of Italian forests at a regional level, and more in general, to open the discussion in a field that would be very useful in forest management and environmental policy-making. 

  2. 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

  3. 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

  4. Radiocarbon as a bio marker of urban pollution in leaves of evergreen species sampled in Rome and in rural areas (Lazio-Central Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Alessio, M.; Improta, S. [La Sapienza University, Rome (Italy). Department of Physics; Anselmi, S. [University of Molise, Isernia (Italy). Department of Sciences and Technologies for the Environment; Conforto, L.; Manfra, L. [La Sapienza University, Rome (Italy). Department of Earth Sciences; Manes, F. [La Sapienza University, Rome (Italy). Department of Plant Biology

    2002-11-01

    The aim of the present study is the use of {sup 14}C, sampled in leaves of evergreen species, as a natural geochemical marker to estimate the contribution of artificial sources (heating plants, vehicles, etc.) to the complex of atmospheric gases in an urban environment. Leaves were chosen due to sampling easiness and their reliability: in particular the evergreen species, being exposed all the year round to pollutants are especially indicated for bioindication and biomonitoring studies. The response to atmospheric pollutants has been studied of two plant species (Quercus ilex L., Pinus pinea L.) measuring isotopic ({sup 14}r, {delta}{sup 13}C), chemical (Pb concentration) and ecophysiological (gaseous exchange and leaf fluorescence of chlorophyll a) parameters. Leaves of holm-oaks and stone pine needles collected over a 3-year time span in an urban park in Rome (Villa Ada) and in reference localities outside the city on the Tyrrhenian coast and in the pre-Appennine area have been analysed. In Villa Ada measurements were carried out along a transect from the road bordering the park towards the interior; all the parameters, together in agreement, showed a decreasing pollution gradient towards the inner park. It was possible to estimate a 5.5{+-}0.3% contribution of CO{sub 2} from fossil fuels close to the road, decreasing to 1.7{+-}0.3% at <300 m from it towards the inner park. The isotopic analyses conducted on stone pines and holm-oaks show that {sup 14}C provides indications on the degree of pollution from fossil fuels, while {delta}{sup 13}C appears to be conditioned mainly by the interspecific difference, and also by many other environmental factors that affect the plant functionality. Results confirmed that radiocarbon is a useful tool in environmental studies, allowing to quantify the contributions of CO{sub 2} of anthropic origin: this parameter, together with appropriate isotopic, chemical and ecophysiological analyses, could provide a good indication of the

  5. 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.

  6. Comparison of Litter Decomposition of Six Species of Coniferous and Broad-leaved Trees in Subtropical China%亚热带6种针叶和阔叶树种凋落叶分解比较

    Institute of Scientific and Technical Information of China (English)

    郭培培; 江洪; 余树全; 马元丹; 窦荣鹏; 宋新章

    2009-01-01

    针叶和阔叶树种分别代表了不同的生活型,其凋落叶片具有不同的分解速率.应用分解网袋法,在中国亚热带地区,选取了具有代表性的3种针叶树种(马尾松Pinus massoniana、水杉Metasequoia glyptostroboides和杉木Cunninghamia lanceolata)和3种阔叶树种(木荷Schima superb、乐昌含笑Michelis chapensis和青冈Cyclobalanopsisgtauca)的凋落叶,放置于样地杭州千岛湖的林地中,经过1 a的分解实验,分析不同类型树种凋落叶的分解特征.6种树种凋落叶质量损失过程基本符合Olson指数模型,其中,3种针叶树种(马尾松、水杉和杉木)凋落叶的分解系数k值(分别为0.51、0.30和0.44),明显小于3种阔叶树种(木荷、乐昌含笑和青冈)凋落叶的分解系数k值(分别为0.55、1.12和0.66);同时,针叶树种(马尾松、水杉和杉木)凋落叶分解50%和95%所需时间(分别为1.36、2.31、1.78 a和5.87、9.99、7.68 a),大于阔叶树种(木荷、乐昌含笑和青冈)凋落叶的分解时间(分别为1.26、0.62、1.05 a和5.45、2.68、4.54a).多元回归分析表明,凋落物分解系数与初始钾元素含量显著相关(P<0.05).一元线性回归分析表明,凋落物的分解系数与初始钾元素和初始木质素含量均具有显著性差异(P<0.05).亚热带地区针、阔叶树种凋落叶分解的差异与自身质量密切相关,其中初始木质素与钾元素含量是控制凋落物分解的主要因素.图2表2参23%Coniferous and broad-leaved trees represent different life types, and their litters differ in decomposition rates. Six species (Pinus massoniana, Metasequoia glyptostroboides, Cunninghamia lanceolata, Schima superb, Michelis chapensis, Cyclobalanopsis glauca) representing typical coniferous and broad-leaved trees were sampled as experimental material for studying leaf litter decomposition in the subtropical region of china. The collected leaf litters were put in litter bags and placed in the forests of the Qiandao

  7. Soil C and N Pools in Chinese Fir and Evergreen Broadleaf Forests and their Changes with Slash Burning in Mid-Subtropical China

    Institute of Scientific and Technical Information of China (English)

    GUO Jian-Fen; YANG Yu-Sheng; CHEN Guang-Shui; XIE Jin-Sheng; LIN Peng

    2006-01-01

    Soil organic carbon (C) and total nitrogen (N) pools of a Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.)(CF) forest, and an evergreen broadleaf (EB) forest located in mid-subtropical, southeastern China, were compared before clearcutting, with the effect of slash burning on organic C and total N in the top 10 cm of soil before and after burning also being evaluated. Prior to clearcutting CF forest had significantly lower (P < 0.05) organic C and total N in the soil(0-100 cm) compared to EB forest with approximately 60% of the C and N at the two forest sites stored at the 0 to 40 cm soil. In post-burn samples of the 0-10 cm depth at 5 days, 1 year, and 5 years for CF and EB forests, significantly lower levels (P < 0.05) of organic C and total N than those in the pre-burn samples were observed. Compared to the pre-burn levels, at post-burn year 5, surface soil organic C storage was only 85% in CF forest and 72% in EB forest, while total N storage was 77% for CF forest and 73% for EB forest. Slash burning caused marked long-term changes in surface soil C and N in the two forest types.

  8. Carbon dioxide exchange in a cool-temperate evergreen coniferous forest over complex topography in Japan during two years with contrasting climates.

    Science.gov (United States)

    Saitoh, Taku M; Tamagawa, Ichiro; Muraoka, Hiroyuki; Lee, Na-Yeon M; Yashiro, Yuichiro; Koizumi, Hiroshi

    2010-07-01

    We investigated carbon dioxide (CO(2)) exchange and its environmental response during two years with contrasting climate (2006 and 2007) in a cool-temperate mixed evergreen coniferous forest dominated by Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa). The study, which was conducted in a mountainous region of central Japan, used the eddy-covariance technique. Our results (crosschecked using the common u (*) approach and van Gorsel's alternative approach) showed that annual gross primary production (GPP) and ecosystem respiration (RE) were at least 6% higher in the dry year than in the wet year, whereas net ecosystem exchange (NEE) was similar in both years. Without soil water stress, strong light stress or seasonality of plant area index during most of the study period, the forest had high metabolic activity. GPP and RE differed greatly between the two years, especially in spring (April-May) and summer (July-September), respectively. The spring GPP difference (>20%) was influenced by different winter air temperatures and snow melt timing, which controlled photosynthetic capacity in spring, and by different spring light intensities. The annual NEE differed depending on the evaluation method used, but the mean 2-year NEE estimated by the u (*) threshold approach [-3.39 +/- 0.11 (SD) MgC ha(-1) year(-1)] appears more reasonable in comparison with results from other forests.

  9. Seasonal variation of leaf wax n-alkane production and δ(2)H values from the evergreen oak tree, Quercus agrifolia.

    Science.gov (United States)

    Sachse, Dirk; Dawson, Todd E; Kahmen, Ansgar

    2015-01-01

    In order to understand the timing of leaf wax synthesis in higher plants, we analysed the variability in leaf wax n-alkane concentration, composition (expressed as average chain length (ACL)), and δ(2)Hwax values as well as plant source water δ(2)H values (xylem and leaf water) in the evergreen tree Quercus agrifolia over a period of 9 months, beginning with leaf flush. We identified three distinct periods of leaf development with the first month following leaf flush being characterized by de novo synthesis and possibly removal of n-alkanes. During the following 3 months, n-alkane concentrations increased sevenfold and δ(2)Hwax and ACL values increased, suggesting this period was the major leaf wax n-alkane formation period. During the remaining 4 months of the experiment, stable values suggest cessation of leaf wax n-alkane formation. We find that n-alkane synthesis in Q. agrifolia takes place over 4 months, substantially longer than that observed for deciduous trees.

  10. 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.

  11. 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.

  12. 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.

  13. 10个常绿树种对砷汞铅镉铬的富积能力研究%Heavy Metal Accumulation Capability of Ten Broadleaved Tree Species to As, Hg, Pb, Cd and Cr

    Institute of Scientific and Technical Information of China (English)

    毕波; 刘云彩; 陈强; 周筑; 张学星; 孙宏

    2012-01-01

    The contents of As, Hg, Pb, Cd and Cr in leaves of ten broadleaved tree species growing in the pollution area of Kunming Steel Company were determined to compare and analyze the heavy metal accumulation capabilities of the tested tree species. The results showed that the same species had different accumulation to different elements , simultaneously different species showed quite different accumulation to the same element. As, Pb, Cd and Cr were the main heavy pollution elements in the study area, and the all the elements were correlated with each other. Considering accumulation capability totally, the heavy metal element accumulation capabilities of these ten broadleaved tree species could be ranked as Viburnum punctatum > Delavaya yunnanensis > Meliosma yunnanensis > Euonymus yunnanensis > Stranvaesia davidiana > Acer oblongum > Decaspermum fruticosum > Cyclobalanopsis glau-coides > Craibiodendron yunnanense > Olea yunnanensis.%通过对10个常绿树种在昆钢污染区和对照叶片中砷、汞、铅、镉、铬5种重金属元素含量的试验测定,分析了各个树种对重金属的富积能力.结果表明,同一树种对不同类型重金属元素的富积能力不同,不同的树种对同一类型重金属的富积能力也有很大差异;参试的10个树种均对重金属元素表现出较好的抗性和富积能力,其中对砷、汞、铅、镉、铬的富积能力最强的树种分别是鳞斑荚蒾、红果树、鳞斑荚蒾、金叶子和云南泡花树.污染物中砷、铅、铬和镉的含量占了较大比重,各重金属元素在污染时存在相互关联.按综合富积能力排序,依次是鳞斑荚蒾>茶条木>云南泡花树>云南卫矛>红果树>飞蛾槭>子楝树>滇青冈>金叶子>云南木樨榄.

  14. Growth Characteristics and Leaf Ultrastructures of Evergreen Poplar Clone Under Aluminum Stress%铝胁迫对常绿杨生长及叶肉细胞超微结构的影响

    Institute of Scientific and Technical Information of China (English)

    钱莲文; 吴文杰; 孙境蔚; 冯莹

    2016-01-01

    【目的】对酸性条件下铝在常绿杨‘A-61/186’体内积累和分布的规律以及铝胁迫下叶片超微结构与生长生理指标的响应变化进行初步研究,以揭示常绿杨对酸性土壤铝胁迫的响应机制,从而对常绿杨在亚热带地区的推广提供理论依据。【方法】以常绿杨‘A-61/186’为试验材料,在水培溶液中进行铝胁迫试验,对铝胁迫下‘A-61/186’杨的生长量及生物量、植株各组织中的铝含量、叶片叶绿素荧光指标进行测定,并利用透射电镜对叶肉细胞超微结构做系统研究。【结果】酸铝胁迫对常绿杨‘A-61/186’生长状况产生影响,根、茎、叶各组织生长量及生物量均显著下降,生物量分配结构上表现出铝对‘A-61/186’地下部分的影响大于地上;铝胁迫下‘A-61/186’根系较茎、叶组织积累更大量的铝。铝胁迫下‘A-61/186’叶绿素荧光参数显示出叶片通过非光化学的途径将过多的光能进行耗散,因而可降低植物的光合效率,影响生长量和生物量,叶肉细胞超微结构损伤程度的变化与生长量及叶绿素荧光参数的变化相一致,说明铝胁迫下‘A-61/186’生长量和生物量的降低与铝对光合系统的直接损伤有关。【结论】从常绿杨‘A-61/186’体内铝含量及初始生长受抑制的铝浓度来看,相比喜酸性树种茶树、龙眼、桉树等,‘A-61/186’对铝胁迫更为敏感,在酸性富铝化土壤上种植要采用一定的铝毒害防治措施。%Objective]Poplar are a sort of plants that are usually for planting in neutral to partially alkaline soil, however the fast development of new varieties for cultivation has expanded its planting range. A-61/186 ( Populus × euramericana cv. A-61/186) is a evergreen poplar clone that is suitable for low-latitude tropical and subtropical areas,and it has been introduced to Fujian Province of China and presents evergreen

  15. 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.

  16. 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

  17. 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.

  18. Changes in soil carbon and nutrients following 6 years of litter removal and addition in a tropical semi-evergreen rain forest

    Science.gov (United States)

    Tanner, Edmund Vincent John; Sheldrake, Merlin W. A.; Turner, Benjamin L.

    2016-11-01

    Increasing atmospheric CO2 and temperature may increase forest productivity, including litterfall, but the consequences for soil organic matter remain poorly understood. To address this, we measured soil carbon and nutrient concentrations at nine depths to 2 m after 6 years of continuous litter removal and litter addition in a semi-evergreen rain forest in Panama. Soils in litter addition plots, compared to litter removal plots, had higher pH and contained greater concentrations of KCl-extractable nitrate (both to 30 cm); Mehlich-III extractable phosphorus and total carbon (both to 20 cm); total nitrogen (to 15 cm); Mehlich-III calcium (to 10 cm); and Mehlich-III magnesium and lower bulk density (both to 5 cm). In contrast, litter manipulation did not affect ammonium, manganese, potassium or zinc, and soils deeper than 30 cm did not differ for any nutrient. Comparison with previous analyses in the experiment indicates that the effect of litter manipulation on nutrient concentrations and the depth to which the effects are significant are increasing with time. To allow for changes in bulk density in calculation of changes in carbon stocks, we standardized total carbon and nitrogen on the basis of a constant mineral mass. For 200 kg m-2 of mineral soil (approximately the upper 20 cm of the profile) about 0.5 kg C m-2 was "missing" from the litter removal plots, with a similar amount accumulated in the litter addition plots. There was an additional 0.4 kg C m-2 extra in the litter standing crop of the litter addition plots compared to the control. This increase in carbon in surface soil and the litter standing crop can be interpreted as a potential partial mitigation of the effects of increasing CO2 concentrations in the atmosphere.

  19. 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.

  20. Indian Patent Law Deterring Evergreening of Patent or Damaging the Incremental Innovation%印度专利法阻却药品专利常青同时损害增量创新

    Institute of Scientific and Technical Information of China (English)

    赵歆; 刘晓海

    2014-01-01

    Objective To find more proper measures to cope with the evergreening of patent in advance and to promote the development of China�s pharmaceutical industry.Methods This paper analyzes the content,legislative intention,influence and debates on article 3 (d)of Indian Patent Law of 2005 and compares different measures and attitudes towards evergreening of pharmaceutical patent in the United States,EU and some emerging economies.Results and Conclusion The stipulation of article 3 (d)in Indian Patent Law will be detrimental to the incremental innovation in pharmaceutical industry and China should be cautious to deal with the issue of evergreening of pharmaceutical patent and the pharmaceutical inventiveness standerd should be correspondingly elevated in patent examination.%目的:讨论正确面对和处理药品专利常青问题,提出促进我国制药行业创新发展的应对策略。方法分析印度2005年专利法第三条(d)款对已知物质衍生物的药品专利常青禁止性规定的内容、立法背景、争论、意义,并比较美国、欧盟和其他新兴经济体对药品专利常青的规制措施与态度。结果与结论印度专利法第三条(d)款对制药行业增量创新产生负面影响;我国应谨慎对待药品专利常青问题,并考虑在专利审查中提高药品创造性标准。

  1. Simulation of Potential Distributions and Future Distributions for Four Evergreen Trees%四种常绿乔木潜在及未来分布区模拟研究

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    基于《中国木本植物分布图集》和ArcGIS地理信息平台,通过ClimateChina模型提取2000s(1990-2009)、2020s(2010-2039)、2050s(2040-2069)三个时段的13个气候变量数据为主要气候信息源,采用最大熵法( Max-Ent)生态位模型对四种常绿乔木在中国范围的潜在适生分布区进行模拟预测,得出该四种乔木在2000s、2020s、2050s的分布变化。结果表明:MaxEnt生态位模型模拟的该四种常绿乔木潜在适生分布范围大于文献记载中的分布区域;影响该四种常绿乔木分布的主要气候变量并不完全一致;在未来气候变化下,该四种常绿乔木潜在适生分布区的变化趋势不同。研究结果可为植物适生区划、园林绿化树种引种栽培区的选择提供理论指导。%Based on the Atlas of Woody Plants in China and ArcGIS geographic information platform, u-sing ClimateChina model, extracted 13 climate variable data in 2000s(1990 -2009), 2020s(2010 -2039) and 2050s(2040-2069) as main climate information, simulated four evergreen trees suitable po-tential distributions and future distributions in nationwide use the maximum entropy method ( MaxEnt model) to gain distribution changes of these four trees in 2000s, 2020s, 2050s. The results suggested that the potential distributions of the four evergreen trees through MaxEnt model are larger than the distri-butions in literature; the main climate variables that influencing the distribution of the four evergreen trees are not entirely consistent. When climate changes in the future,the trends of changes in potential suitable distribution areas of the four kinds of evergreen trees will be different. The results can provide theoretical guidance for plant suitable zoning and planting area selections for landscape trees.

  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)

    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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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).

  8. Initial Growth Effect of Mixed Forests with Eucalypt and Two Native Broadleaved Tree Species of Guangxi%桉树与乡土阔叶树种混交林的初期生长效应

    Institute of Scientific and Technical Information of China (English)

    姚瑞玲; 项东云; 陈健波

    2012-01-01

    以红锥(Castanopsis hystrix)、米老排(Mytilaria laosensis)2种广西乡土阔叶树种为混交树种,对不同混交模式下桉树与红锥、米老排的林木生长情况进行了分析。研究结果表明:在桉树与米老排(3∶1)混交模式下,桉树树高、胸径生长量明显高于桉树纯林。而混交模式下,红锥生长量增加,而米老排生长量降低。初步认为,混交能促进桉树生长,但最佳混交造林模式因混交树种而异。%Growth of eucalypt,Castanopsis hystrix and Mytilaria laisensis in different patterns of mixed forests was analyzed using two native broadleaved tree species,C.hystrix and M.laosensis of Guangxi as mixed tree species.The results showed that tree height and DBH of eucalypt from mixed plantations of eucalypt and C.hystrix(3∶1) were significantly greater than that from pure eucalypt plantations.The growth of C.hystrix increased,while that of M.laosensis decreased in the condition of mixed planting.In preliminary conclusion, mixed planting was able to promote the growth of eucalypt,but the optimal pattern of mixed planting depended on mixed tree species.

  9. [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.

  10. Ecogeographical Distribution of Soil Fauna in Pinus koraiensis Mixed Broad-leaved Forest of Changbai Mountains%长白山红松阔叶混交林土壤动物生态分布

    Institute of Scientific and Technical Information of China (English)

    殷秀琴; 蒋云峰; 陶岩; 安静超; 辛未冬

    2011-01-01

    对长白山红松阔叶混交林分布的上缘、典型分布区和分布下缘土壤动物群落进行研究。结果表明,红松阔叶混交林三个分布区土壤动物群落组成存在差异,其中典型分布区土壤动物多样性指数较高,群落组成均匀。甲螨亚目、辐螨亚目、节跳虫科、球角跳虫科、革螨亚目和山跳虫科相关性较大,共同出现在各分布区。土壤动物垂直分布具有明显的表聚性,且红松阔叶混交林的上缘和典型分布区表聚性更为突出。通过灰色综合关联度分析表明,土壤全钾、全氮和有机质含量对土壤动物群落影响较大,而土壤全磷含量和pH对土壤动物的影响次之。%The Changbai Mountains,located in the Northeast China(41°23′–42°36′N,126°55′–128°8′E),are rich in natural resources and have always been concerned by scientists.Soil faunas play crucial roles in forest ecosystem processes such as litter decomposition and nutrient mineralization,and also have effects on soil formation and quality.To understand the ecogeographical distribution of soil faunal community and provide the scientific basis for the conservation of forest ecosystems in Changbai Mountains,community composition,structure and biodiversity of soil fauna were investigated in top,typical and bottom distribution areas of Pinus koraiensis mixed broad-leaved forest of Changbai Mountain in July 2008.The sample area was 50 cm×50 cm for soil macrofauna and 10 cm×10 cm for soil meso-microfauna.Soil macrofauna was picked out by hands.Soil meso-microfauna was extracted by Tullgren funnel.All extracted soil samples were identified to the suborder or family level under a stereoscopic microscope.Soil pH was measured with PHS-3B acidity meter.Soil organic C was determined by K2Cr2O7 oxidation method and total N by Kjeldahl method.Total P was analyzed by using the colorimetric method with molybdenum in sulphuric acid.Total K was determined with flame photometer

  11. Measures on Planting Evergreen Turf in Middle and Lower Reaches of Yangtze River%长江中下游地区草坪周年常绿的技术措施*

    Institute of Scientific and Technical Information of China (English)

    周丽霞; 张艳

    2013-01-01

    营造周年常绿草坪一直是业界关注的热点问题。在简述了长江中下游地区气候特点的基础上,从选择相对耐热的冷季型草坪草种,在暖季型草坪上补播冷季型草,建立相对稳定持久的冷暖季型混植草坪,使用草坪染色增绿剂,以及加强养护管理等方面,较系统地分析了在长江中下游地区营造草坪周年基本常绿的基本途径。%Creating evergreen turf has been a hot issue of concern to the industry.Based on the climate characteristics in middle and lower rea-ches of Yangtze River,the paper briefly introduced several ways to create evergreen turf in the aera.The contents include selecting relative heat tolerant cool-season turf grasses,overseeding cool-season turf grasses on warm-season turf grasses,establishing a relatively stable and lasting turf by mixing warm-turf grasses with cool-season turf grasses,spraying chemical green agents,and reinforcing turf manage-ment.

  12. 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.

  13. 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…

  14. [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

  15. 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

    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......-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 δ 2 H and stem δ 2 H records...

  16. 长白山阔叶红松林系统发育和功能性状beta多样性%Phylogenetic and functional beta diversity in a broadleaved Korean pine mixed forest in Changbai Mountains, northeastern China

    Institute of Scientific and Technical Information of China (English)

    王均伟; 侯嫚嫚; 黄利亚; 张君; 周海城; 程艳霞

    2016-01-01

    4 functional traits of 45 woody species ( maximum plant height, leaf area, specific leaf area, and leaf nitrogen contents) in a well-mapped 40 ha broadleaved Korean pine mixed forest plot in Changbai Mountains, Northeast China. Next, we calculated the functional and phylogenetic beta diversity through the Sørensen index and compared observed pattern with null model approach to test for non-random functional and phylogenetic beta diversity at different spatial scales ( radius 10 , 20 , 25 , 50 , and 75 m ) . Our results showed that:1 ) the phylogenetic and functional similarity decreased with distances and increased with grain sizes. 2) All the phylogenetic and functional beta diversity showed non-random pattern. As the increase of grain size, the phylogenetic beta diversity showed random only in the 25--50 m scale, while lower than random in the scales of 10--20 m and 75 m. The functional beta diversity turned from random (10--50 m) to lower than random (75 m) . The results suggest that in the middle and small scales (10--50 m), neutral process is more important, but we cannot rule out the role of niche process, and with the increase of scale, habitat filtering determines the community assembly in the broadleaved Korean pine forest. 3 ) The mismatch between functional and phylogenetic beta diversity patterns could be partly explained by the lack of phylogenetic signal for most traits.

  17. Ecological Stoichiometry Characteristics of Young-and-middle Aged Conifer-broadleaved Plantation in Southern Subtropical Region%南亚热带中幼龄针阔混交林生态化学计量特征

    Institute of Scientific and Technical Information of China (English)

    周丽; 张卫强; 唐洪辉; 陈伟光; 盘李军; 冼伟光

    2014-01-01

    leaves were 26.60 and 28.55, 438.77 and 507.55, 16.52 and 17.95, respectively, while C:N, C:P and N:P of litter were 46.50, 1193.26 and 26.17. Although leaves N:P ratios indicated that Cunninghamia lanceolata with young age was N limited, and broad-leaved trees with 10~11 years ages were N limited, broad-leaved trees with 7~9 years and 3~5 years ages were P limited, shrub and herb were P limited. The total N content of plant leaves was significantly positively correlated with total P content of plant leaves (P<0.01), while the total P content of plant leaves was significantly negatively correlated with C:N, C:P, N:P (P<0.01, P<0.05)and C:N of plant leaves was significantly positively correlated with C:P (P<0.01). The organic C content of soil was significantly positively correlated with total N, C:P and N/P (P<0.01). The study provided scientific reference for the tending and sustainable management of young-and-middle aged plantation.

  18. 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

  19. Climatic and ecological implications of Late Pliocene palynoflora from Longling, Yunnan, China

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.X.; Ferguson, D.K.; Li, C.S.; Wang, Y.F.; Du, N.Q. [Chinese Academy of Science, Beijing (China). Inst. of Botany

    2004-07-01

    The Longling Coal Mine (W. Yunnan) is situated in an area of substantial geotectonic activity. Its Late Pliocene palynollora is of considerable interest, since the area represents a centre of biodiversity.Eighty-two palynomorphs belonging to 61 families were recovered from the lignite. The palynoflora is dominated by angiosperms (68.3%), with ferns (24.4%), gymnosperms (4.9%) and algae (2.4%). Comparisons indicate that most of the palynoflora was derived from the Montane Humid Evergreen Broad-leaved Forest, with lesser contributions from the Tsuga dumosa Forest and Evergreen Coniferous Broad-leaved Mixed Forest, as well as the Montane Mossy Evergreen Broad-leaved Forest. This indicates that the Late Pliocene climate was cooler than that of the present. In the course of the accumulation of the lignite, the climate underwent five major phases of warming and cooling.

  20. 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.

  1. 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

  2. Broad-Leaved Forest Community Structure Features in Different Habitats without Human Disturbance%无人为干扰下不同生境阔叶林的群落结构特征

    Institute of Scientific and Technical Information of China (English)

    雷平; 郭洪兴; 邹志安; 邹思成; 兰文军; 徐新宇; 袁荣斌

    2014-01-01

    以江西武夷山国家级自然保护区核心区为无干扰环境,选取河岸带、内陆森林和林线3种生境阔叶林群落为研究对象。群落结构特征分析结果显示:1)不同生境类型的群落建群种不同,但群落各层主要优势种的重要值均呈差异不显著,物种组成上均以壳斗科、樟科、山茶科、山矾科、杜鹃花科、蔷薇科、冬青科等为常见,且种属数较多。2)立木总株数(乔灌木)林线群落高于其他生境群落,但不同生境类型的群落间乔木与灌木平均株数均呈差异不显著。3)群落各层物种的种数及各物种多样性指数均有河岸带>内陆森林>林线,乔木层、草本层与层间植物物种种数以及物种多样性Patrick、Gleason、Margalef和Shannon-Weiner指数,河岸带均与其他生境类型群落差异呈显著性;而灌木层物种种数及多样性Simpson和Pielou指数差异不呈显著性。4)散点图和线性回归得出林线群落活立木平均高度和平均胸径均高于其他生境类型的群落。%In core area of Jiangxi Wuyishan National Nature Reserve, as the non-disturbance condition, three habitats broad-leaved community of riparian zone, inland and forest line were selected for study aspects. Community structure characteristics analysis results showed that: 1) there were different constructive species of the community in different habitats, but the important value of the main dominant species in the communities’ layers has no significant difference. Species composition dominated by Fagaceae, Theaceae, Lauraceae, Symplocaceae, Ericaceae, Rosaceae, Aquifoliaceae with much of genera and species in all types of the habitats. 2) The total number of the standing timber (including trees and shrubs) in the forest line community was more than other communities, but the average number of the trees and shrubs in different habitats has no significant difference. 3) Community species and each

  3. Characteristics of evaporation over broadleaved Korean pine forest in Changbai Mountains,Northeast China during snow cover period in winter%长白山阔叶红松林冬季雪面蒸发特征

    Institute of Scientific and Technical Information of China (English)

    李辉东; 关德新; 王安志; 吴家兵; 金昌杰; 施婷婷

    2013-01-01

    利用2002-2005年冬季积雪期涡度相关水汽通量和微气象观测资料,对长白山阔叶红松林雪面蒸发动态及其与气象因子的关系进行分析.结果表明:该涡度相关观测系统积雪期能量平衡闭合度为79.9%,潜热通量占净辐射的21.4%.研究期间,该区蒸发日变化呈单峰曲线形式,蒸发速率在融雪期大于稳定积雪期.30 min平均蒸发速率与净辐射呈线性关系,与气温呈二次曲线关系;蒸发日总量与净辐射呈二次曲线关系,与气温呈指数关系.积雪期蒸发日总量呈下降-稳定-上升的动态变化趋势,且上升期>下降期>稳定期,蒸发日总量最大值为0.73 mm·d-1,最小值为0.004 mm·d-1.2002-2003、2003-2004和2004-2005年积雪期蒸发总量分别为27.6、25.5和22.9 mm,占同期降水量的37.9%、19.5%和30.0%,平均蒸发日总量分别为0.17、0.19和0.17mm·d-1.%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

  4. 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.

  5. 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

  6. Seasonal dynamics in the stable carbon isotope composition δ¹³C from non-leafy branch, trunk and coarse root CO₂ efflux of adult deciduous (Fagus sylvatica) and evergreen (Picea abies) trees.

    Science.gov (United States)

    Kuptz, Daniel; Matyssek, Rainer; Grams, Thorsten E E

    2011-03-01

    Respiration is a substantial driver of carbon (C) flux in forest ecosystems and stable C isotopes provide an excellent tool for its investigation. We studied seasonal dynamics in δ¹³C of CO₂ efflux (δ¹³C(E)) from non-leafy branches, upper and lower trunks and coarse roots of adult trees, comparing deciduous Fagus sylvatica (European beech) with evergreen Picea abies (Norway spruce). In both species, we observed strong and similar seasonal dynamics in the δ¹³C(E) of above-ground plant components, whereas δ¹³C(E) of coarse roots was rather stable. During summer, δ¹³C(E) of trunks was about -28.2‰ (Beech) and -26.8‰ (Spruce). During winter dormancy, δ¹³C(E) increased by 5.6-9.1‰. The observed dynamics are likely related to a switch from growth to starch accumulation during fall and remobilization of starch, low TCA cycle activity and accumulation of malate by PEPc during winter. The seasonal δ¹³C(E) pattern of branches of Beech and upper trunks of Spruce was less variable, probably because these organs were additionally supplied by winter photosynthesis. In view of our results and pervious studies, we conclude that the pronounced increases in δ¹³C(E) of trunks during the winter results from interrupted access to recent photosynthates.

  7. 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

  8. Aplicação de misturas de diuron com MSMA, e com paraquat, no controle de plantas daninhas de folhas largas em cultura de algodão (Gossypium hirsutum L. Mixture of diuron whit MSMA and with paraquat for broadleaved weeds control in cotton

    Directory of Open Access Journals (Sweden)

    L. S. P. Cruz

    1978-01-01

    Full Text Available Em ensaio de campo conduzido em 1975/76 procurou-se avaliar a ação de misturas de MSMA com diuron e de paraquat com diuron, aplicadas em pós-emergência, em jato dirigido, em duas épocas diferentes, no controle de algumas plantas daninhas de folhas largas em algodão: carrapicho- do-campo (Acanthospermum australe (Loef O. Kuntze , falsa-poaia (Borreria ala ta (Aubl DC, poaia-branca (Richardia brasiliensis Gomez e guanxuma (Sida spp . A vegetação natural da área do ensaio era formada ainda pela gramínea capim-de-colchão (Digitaria sanguinalis (L. Scop . Os resultados mostraram que as misturas de 2,00 kg e 2,70 kg/ha de MSMA com, respectivamente 0,30 kg e 0,40 kg/ha de diuron, e a mistura de 0.60 kg/ha de paraquat com 0,60 kg/ ha de diuron, foram eficientes no co ntro le daquelas dicotiledôneas, e também no da gramínea. Todos os tratamentos provocaram leves sintomas de fitotoxicidade nos algodoeiros, mas desapareceram depois e não prejudicaram o desenvolvimento vegetativo das plantas, assim como a produção de algodão em caroço.In a field trial carried out in 1975/76, a diuron mixtu re with MSMA and another with paraquat was tested on broadleaved weeds in cotton crops. The applications were done in postemergence, directed-spray, in two different periods. The broadleaved weeds observed in the trial were Acanthospermum australe , Borreria alata, Richardia brasiliensis, and Sida spp, also the grass Digitaria sanguinalis. Best results were obtained with the mixture of 0,60 kg/ha of paraquat with 0,60 kg/ha of diuron, and 2,70 kg/ha of MSMA with 0,40 kg/ ha of diuron, or 2,00 kg/ha of MSMA with 0,30 kg/ha of diuron. All the treatments caused sl ight symptons of toxic ity in cotton, which disappeared later and did not damage the production.

  9. 美国长青州立学院跨学科教育管理的实践与启示%Practice and Its Enlightenment of Interdisciplinary Education Management in American Evergreen State College

    Institute of Scientific and Technical Information of China (English)

    郭雷振

    2016-01-01

    The Evergreen State College is a famous Interdisciplinary liberal arts college in the United States, characterized by implementing liberal education ideas and unique undergraduate education management system. It provides interdisciplinary programs instead of majors or departments,and the students finish learning by cooper-ation based on interdisciplinary programs,but without general education curriculum or required sequences of courses. Narrative evaluations rather than grade ones are taken. The faculty here have no ranks,and their sala-ries are determined by their time of teaching. This college’s educational practice is an adventurous challenge, which provides a new way for the undergraduate education.%长青州立学院是美国著名的跨学科文理学院,以跨学科教育落实自由教育育人理念为特色,围绕跨学科人才培养构建了别具一格的教育管理制度。学校以跨学科项目代替专业与学系,学生基于跨学科项目开展合作学习,没有通识课程的要求,没有必修的课程序列,其学业采用陈述性评价而非分数评价;教师基于跨学科项目进行团队教学,没有职称,以工龄确定工资等级。该学院的教育实践是对传统本科教育模式的一项大胆改革尝试,为学界深入思考本科教育教学改革问题提供了新的视角与思路。

  10. 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。

  11. 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.

  12. 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

  13. 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.

  14. Contents of Iron, Zinc, Copper and Manganese in the Leaves of 10 Evergreen Tree Species%10个常绿树种叶片中铁锌铜锰的含量特征

    Institute of Scientific and Technical Information of China (English)

    毕波; 刘云彩; 陈强; 周筑; 张学星; 孙宏

    2012-01-01

    通过对10个常绿树种在昆钢污染区和相对无污染区叶片中铁锌铜锰4种重金属元素含量的实验测定和分析,研究了各树种叶片中的金属含量特征和对污染的吸收净化能力.结果表明,不同的树种对不同重金属的抗性和吸收净化能力不同,参试的10个树种均对重金属元素表现出较好的抗性和吸收净化能力,叶片中铁含量最高的是飞蛾槭,锌含量最高的是鳞斑荚蒾,铜含量最高的是金叶子,锰含量最高的是滇青冈.叶片中铁和锌、铜含量的相关性达极显著和显著水平,其他元素之间相关性均不显著.按各树种的综合富积量进行排序,鳞斑荚蒾>红果树>飞蛾槭>茶条木>金叶子>云南泡花树>云南木樨榄>滇青冈>云南卫矛>子楝树.%Ten evergreen tree species growing in polluted area (Kunming Iron and Steel Plant) and a relatively pollution-free zone, respectively were selected to examine the characteristics of metal contents in the leaves and absorption capabilities by measuring the contents of 4 metals, including Fe, Zn. Cu, and Mn. The results showed that all the 10 tree species demonstrated better resistance to the metals and absorption capability, while differences were observed among different tree species. The highest contents of iron, zinc, copper, and manganese were found in the leaves of Acer oblongum , Viburnum punctatum , Craibio-dendron yunnanense, and Cyclubalanopsis glaucoides , respectively. The correlationships among the contents of iron and zinc and copper were most significant or significant, while no significant correlationships were found among other metals. Considering the integrated accumulation amount for the metals, an order was given among 10 tree species: V. punctatum >Stranvaesia davidiana>A. oblongum>Delavaya yun-nanensis>C. yunnanense >Meliosma yunnanensis>Olea yunnanensis>C. glaucoides >Euonymus yun-nanensis >Decaspermum fruticosum.

  15. 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

  16. The Decomposition Process of Abscisic Acid in Soils from Evergreen Broadleaf Forest in Xiaokeng, Nanling%南岭小坑常绿阔叶林土壤脱落酸分解特征

    Institute of Scientific and Technical Information of China (English)

    陈传胜; 黄从军; 赵厚本; 周光益; 邱治军; 梁瑞友

    2015-01-01

    Abscisic acid (ABA), a hormone synthesized by plants, can enter the soil solution and affect plant growth, seed germination, community composition and succession. Understanding the decomposition process of ABA in soil can help us to reveal the circulation of ABA in soils and its implication on plant growth. Soils were collected from an evergreen broadleaf forest in Xiaokeng, Nanling moutians, and soil physical and chemical properties and ABA concentration were measured. Additionally, an incubation experiment was conducted to measure soil ABA decomposition rate and the role of soil microorganism play in this process. Results showed that the concentration of ABA in soil solution was heterogeneous in space ranging from 29.8 ng·mL-1 to 167.0 ng·mL-1 (averaged at 91.5 ng·mL-1), and positively correlated with soil total nitrogen. About 33.5%of soil ABA was quickly decomposed by soil microorganisms during the first week of incubation, and then was decomposed slowly and linearly with a decomposition rate of about 0.24% per day afterwards. Soil ABA concentration and decomposition rate was positively correlated during the initial fast-decomposition period but was negatively correlated at the late slow-decomposition period. Soil microorganisms accelerated ABA decomposition on one hand and avoided the depletion of ABA in soil on the other hand.%植物产生的脱落酸(ABA)可进入土壤并在土壤溶液中保持一定浓度,对植物生长、种子萌发、群落组成和演替具有重要意义。研究土壤ABA的分解过程有助于了解ABA在土壤中的循环过程,揭示土壤ABA和植物生长的相互关系。以广东南岭小坑常绿阔叶林为研究对像,分析了土壤理化性质和土壤ABA质量浓度的关系,并通过室内培养法结合灭菌处理研究土壤ABA的分解过程和土壤微生物在ABA分解过程中的作用。结果表明,土壤ABA质量浓度在29.8~167.0 ng·mL-1间,均值为91.5 ng·mL-1,且存在较大的

  17. 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 .

  18. 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...

  19. 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.

  20. 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

  1. 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

  2. 长白山不同演替阶段针阔混交林群落物种多度分布格局%Species-abundance distribution patterns at different successional stages of conifer and broad-leaved mixed forest communities in Changbai Mountains, China

    Institute of Scientific and Technical Information of China (English)

    闫琰; 张春雨; 赵秀海

    2012-01-01

    Aims Our objective was to explain processes that dominate species-abundance distribution pattern and mechanism of community assembly in temperate forests. Methods We used three 5.2-hm2 permanent plots established in secondary Populus davidiana-Betula platyphylla forest, secondary conifer and broad-leaved mixed forest and Titia amurensis-Pinus koraiensis mixed forest in Changbai Mountains. Within each plot, we randomly selected 500 subplots within 260 m x 200 m at the scales of 10 m × 10 m, 30 m × 30 m, 60 m × 60 m and 90 m × 90 m. We calculated the mean value of species-abundance distributions taken from the 500 subplots as the observed species-abundance distribution. We estimated the fitted species-abundance distributions by neutral, log-normal, Zipf, broken stick and niche preemption models at different scales. Simulation effects were tested by Chi-square test, Kolmogorov-Smirnov (K-S) test and Akaike Information Criterion (AIC). For the neutral model, we first estimated two parameters 6 and m and then simulated 600 species-abundance distributions. The average of these 600 species-abundance distributions was the best-fit result of the neutral model. We employed the 95% confidence envelopes that were approximated by the 2.5 and 97.5 percentiles of the abundances of species of rank / = 1 to S over the 600 simulations to test goodness-of-fit for the neutral model. All of the computations were conducted in R 2.14.1 with UNTB and VAGEN packages. Important findings The neutral model fit species-abundance distribution at different successional stages of conifer and broad-leaved mixed temperate forest communities. All five models fit the observed value at the 10 m x 10 m sampling scale, and the goodness of fit of the log-normal, Zipf, broken stick and niche preemption models were better than that of the neutral model. That means at small sampling scale the species-abundance distribution is dominated by neutral process and niche process; however, the niche process is

  3. 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

  4. 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

  5. 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

  6. 温带阔叶红松林中不同树种和倒木对土壤性质的影响%Effects of tree species and fallen trees on the soil properties in a temperate Korean pine and broad-leaved mixed forest

    Institute of Scientific and Technical Information of China (English)

    罗献宝; 张颖清; 徐浩; 郑俊强

    2011-01-01

    以长白山温带阔叶红松林为研究对象,通过野外采集土壤样品,综合研究老龄树及倒木对周边表层土壤性质的影响.研究结果显示,在本研究样地条件下,不同树种周边的表层土壤性质存在显著性差异,红松(Pinus koraiensis)周边土壤中水溶性有机碳WSOC的质量分数和特征吸光系数SUVA254值都高于紫椴(Tilia amurensis)和水曲柳(Fraxinus mandshurica),但是土壤水溶性总氮WSTN和交换性无机氮的质量分数却是红松低于紫椴和水曲柳.对倒木影响的森林表层土壤性质的研究结果显示,倒木下方森林表层土壤中WSOC、WSTN以及交换性矿质氮的质量分数都明显地高于林间土壤,说明在小尺度空间区域内,倒木可能是森林表层土壤活性碳、氮库的重要输入源.此外,本研究还利用主成分分析探讨了受树种影响的森林表层土壤不同性质之间的关联性,并对树种和倒木影响周边土壤性质的可能性机制进行分析.%This paper focused on the temperate Korean pine and broad-leaved mixed forest of Changbai mountain, and investigated on the soil properties of forest floor influenced by old-growth trees or fallen trees in the direct vicinity. The results indicated that different tree species have significant effects on the soil properties of forest floor in current experimental plot. The water-soluble organic carbon (WSOC) and the specific ultra-violet absorbance (SUVA254) of forest soil in the vicinity of Pinus koraiensis were higher than that of Tilia amurensis and Fraximis mandshurica; but as to water-soluble total nitrogen (WSTN) and exchangeable inorganic nitrogen, it was higher in Tilia amurensis and Fraxinus mandshurica, and lower in Pinus koraiensis. The study of soil properties of forest floor influenced by fallen trees indicated that forest soil under fallen tree had greater content of WSOC, WSTN and exchangeable inorganic nitrogen than that of forest soil in interstem-areas. The

  7. 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.

  8. 黄土丘陵区3种典型人工阔叶纯林枯落物分解对土壤性质极化的影响%Effect of litter decomposition on soil properties polarization of three typical artificial pure broadleaved forests in the Loess Hilly Area

    Institute of Scientific and Technical Information of China (English)

    米彩红; 刘增文; 李茜

    2012-01-01

    【Objective】 The study was about the effect of litter decomposition on soil properties polarization of three typical artificial pure broadleaved forests in the Loess Hilly Area,which can provide scientific basis for the prevention of soil degradation and continuous plantation obstacle.【Method】 In Shaanxi Huangling county which is located in semi-humid loess hilly area,the middle of Loess Plateau,humus soil and litter(leaf litter and fine roots) were sampled in three typical artificial pure broadleaved forests including Robinia pseudoacacia,Quercus liaotungensis and Populus simonii,and set 4 treatments including "soil+leaf litter","soil+roots","soil+leaf litter+roots",and control "soil" for laboratory incubation experiments.All treatments were incubated for 120 days,then the effect of litter decomposition on soil biological and chemical properties polarization was analyzed.【Result】 1)In the R.pseudoacacia woodland,leaf litter decomposition resulted in negative polarization of soil pH value,catalase activity and microbe quantity;Roots decomposition resulted in negative polarization of soil pH value and available P.According to the comprehensive soil properties,both leaf litter and roots resulted in positive polarization,and roots showed greater effect than leaf litter;The mixed decomposition of leaf litter and roots showed inhibitory effect on soil properties.2)In the Q.liaotungensis woodland,leaf litter decomposition resulted in negative polarization of soil sucrase,polyphenoloxidase,catalase,available P and available K;Roots decomposition resulted in negative polarization of catalase activity and available K.According to the comprehensive soil properties,leaf litter decomposition resulted in negative polarization,but roots decomposition produced weak positive polarization;The interaction between them showed weak inhibitory effect on soil properties.3)In the P.simonii woodland,leaf litter decomposition resulted in

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. The biomass and aboveground net primary productivity of Schima superba-Castanopsis carlesii forests in east China.

    Science.gov (United States)

    Yang, TongHui; Song, Kun; Da, LiangJun; Li, XiuPeng; Wu, JianPing

    2010-07-01

    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(-2)a(-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.

  14. 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.

  15. 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

  16. 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

  17. 长白山阔叶红松林土壤呼吸对氮沉降增加的响应1)%Response of Soil Respiration to Enhanced Nitrogen Deposition in Broadleaved Korean Pine Foresti n Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    李伟斌; 金昌杰; 井艳丽; 吴家兵; 袁凤辉; 关德新; 王安志

    2014-01-01

    通过原位模拟氮沉降的试验研究了长白山阔叶红松林土壤呼吸及其对氮沉降的响应。分别在6、7、8月的月初采用喷洒尿素进行施氮处理,处理水平为对照、低氮(23 kg· hm-2· a-1)、中氮(46 kg· hm-2· a-1)和高氮(69 kg· hm-2· a-1)(以氮素质量计),每月用红外分析法测定各处理水平的土壤呼吸速率3、4次。结果显示:在生长季内长白山阔叶红松林土壤呼吸有明显的季节变化,10月份最低(0.72μmol· m-2· s-1),7月份最高(2.27μmol· m-2· s-1);低、中氮处理提高了土壤呼吸速率,分别比对照高出55.4%和60.3%,高氮则降低了土壤呼吸速率,比对照低21.7%;模拟氮沉降没有改变土壤呼吸的昼夜变化趋势,其变化趋势与土壤温度一致,土壤呼吸速率与5cm 土壤温度呈显著的指数关系;模拟氮沉降增加改变了土壤呼吸对温度的敏感性,对照、低氮、中氮和高氮处理的Q10值分别为1.93、2.34、2.94和1.54。结果表明,在我国北方温带森林地区,未来氮沉降增加会促进土壤呼吸排放,并增加呼吸的温度敏感性,但过高的氮沉降会抑制土壤呼吸并降低呼吸的温度敏感性。%This study was conducted in broadleaved Korean pine forest in Changbai Mountains to explore the effects of nitrogen deposition on soil respiration.The levels of nitrogen deposition were control (CK), low nitrogen (23 kg· hm-2· a-1), medium nitrogen (46 kg· hm-2· a-1) and high nitrogen (69 kg· hm-2· a-1) by adding urea at the beginning of June , July and August since 2011.Soil respiration was measured by three to four times at mid month from May to October by using infrared gas analyzer .Soil respiration showed a strong seasonal variation with the lowest rates occurred in October ( 0.72μmol· m-2· s-1) and the highest rates in July (2.27μmol· m-2· s-1).Low and medium

  18. 红松阔叶混交林中坑和丘的微立地特征及其对植被更新的影响%Microsite characteristics of pit and mound and their effects on the vegetation regeneration in Pinus koraiensis-dominated broadleaved mixed forest

    Institute of Scientific and Technical Information of China (English)

    杜珊; 段文标; 王丽霞; 陈立新; 魏全帅; 李猛; 王利冬

    2013-01-01

    2011年8月,在红松阔叶混交林2.55 hm2的样地内,调查了42株倒木及其形成的坑和丘复合体的微立地特征及其植被更新状况,测定了丘顶、丘面、坑壁、坑底、完整立地5个微立地的土壤含水量、土壤温度、空气相对湿度和光合有效辐射.结果表明:在5个微立地中,丘顶的光合有效辐射最高(527.9μmol·m-2·s-1),完整立地最低(58.7 μmol·m-2·s-1);丘顶的土壤温度最高(16.0℃),坑底最低(13.3℃);坑底的土壤含水量最高(34.6%),丘面最低(0.5%);完整立地的空气相对湿度最高(75.9%),丘顶最低(68.0%).形成坑和丘复合体的5个树种的频率大小依次是红松(42.9%)>云杉(31.0%)>白桦(16.7%)>冷杉(7.1%)>稠李(2.4%).42株掘根倒木中,有2/3偏向西北方向.倒木体积与坑深度、坑长度、丘高度、丘宽度均呈极显著正相关,与丘厚度呈负相关.坑的宽度和长度分别与倒木的胸径呈显著和极显著正相关.不同微立地之间物种丰富度的大小顺序为完整立地>坑>丘;所有树种盖度的大小顺序依次为完整立地>坑>丘.%An investigation was conducted in a 2.55 hm2 plot of Pinus koraiens is -dominated broad-leaved mixed forest to study the microsite characteristics of pit and mound formed by 42 treefalls and the status of vegetation regeneration on the microsites.The soil water content, soil temperature, relative air humidity, and photosynthetically active radiation ( PAR) on five microsites ( mound top, mound face, pit wall, pit bottom, and intact forest floor) were measured.Among the five miros-ites, mound top had the highest PAR (527.9 μmol· m-2·s-1 ) while intact forest floor had the lowest one (58.7 μmol·m-2·s-1 ) , mound top had the highest soil temperature (16.0℃) but pit bottom had the lowest one (13.3 ℃) , pit bottom had the highest soil water content (34.6% ) but mound face had the lowest one (0.5% ) , and intact forest floor had

  19. 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

  20. Vegetation classification of East China with multi-temporal NOAA-AVHRR data

    Institute of Scientific and Technical Information of China (English)

    LI Junxiang; DA Liangjun; WANG Yujie; SONG Yongchang

    2006-01-01

    East China lies in the subtropical monsoon climatic zone and is dominated by subtropical evergreen broad-leaved forests,a unique vegetation type mainly distributed in East Asia with the largest distnbution in China.It is important to be able to monitor and estimate forest biomass and production,regional carbon storage,and global climate change impacts on these important vegetation types.In this paper,we used coarse resolution remote sensing data to identify the vegetation types in East China and developed a map of the spatial distribution of vegetation types in this region.Nineteen maximum normalized difference vegetation index(NDVI)composite images(acquisition time span of 7 months from February to August),which were derived from 10 days National Oceanographic and Atmospheric Administration(NOAA)Advanced Very High Resolution Radiometer(AVHRR)channel 1 and channel 2 observations,an unsupervised classification method,and the ISODATA algorithm were employed to identify the vegetation types.To reduce the dimensions of the dataset resulted in a total of 28 spectral clusters of land-cover of which two clusters were urban/bare soil and water,the images were processed using principal component analysis(PCA).The 26 remaining spectral clusters were merged into six vegetation types using the Chinese vegetation taxonomy system:evergreen broad-leaved forest,coniferous forest,bamboo forest,shrub-grass,aquatic vegetation,and agricultural vegetation.The spatial distribution and areal extent for the coniferous forests,shrub-grass,evergreen broad-leaved forests,and agricultural vegetation were calculated and comscale.The spatial accuracy and the area accuracy for coniferous forests,shrub-grass,evergreen broad-leaved forests,and agricultural vegetation were 79.2%,91.3%,68.2% and 95.9% and 92.1%,95.9%,63.8% and 90.5%,respectively.The spatial accuracy and area accuracy of the bamboo forest were 28.7% and 96.5%,respectively;the spatial accuracy of aquatic vegetation was 69.6%,but there

  1. Diversity of Soil Ants at Vertical Zones on the West Slope of Ailao Mountain%哀牢山西坡垂直带土壤蚂蚁群落多样性

    Institute of Scientific and Technical Information of China (English)

    陈友; 罗长维; 李宏伟; 徐正会

    2011-01-01

    The four vertical zones with eight different types of vegetations on the west slop of Ailao mountain was sampled for studying community diversity of the soil ants.The results were as follows : The total number of soil ants was 74 species, among which there were 42 dominant species.There was a.correlation ofsoil ants diversity with increasing elevation.The percentage of dominant soil ants species in the total soil ants species increased,while dominant individual density,species number and.diversity index of soil ants decreased.In eight different vegetations,individual density, dominant species number, species number, diversity index and evenness index of soil ants were higher in Pinus kesiya forest,monsoon evergreen broad-leaved forest and mixed coniferous forest than those in dry evergreen broad-leaved forest, semi-humid evergreen broadleaved forest, evergreen broad-leaved moss forest, valley savanna forest and mid-mountain humid evergreen broad-leaved forest.%采用样地调查法,对哀牢山西坡4个垂直地带8种植被类型的土壤蚂蚁群落多样性进行调查.结果如下:共有74种土壤蚂蚁,其中42种为优势种;土壤蚂蚁群落多样性随海拔高度增加呈规律性的变化:优势种所占比例逐渐递增,优势种数目降低、物种数目递减、物种多样性指数降低;在8种植被类型中,土壤蚂蚁个体密度、优势种数量、物种数目、物种多样性指数、均匀度指数在思茅松林、针阔叶混交林和季风常绿阔叶林3种植被类型中较高,而在干性常绿阔叶林、半湿润常绿阔叶林、常绿阔叶苔藓矮林、河谷稀树灌木草丛和中山湿性常绿阔叶林4种植被类型中较低.

  2. 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

  3. 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

  4. 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

  5. Schiff bases: a short survey on an evergreen chemistry tool.

    Science.gov (United States)

    Qin, Wenling; Long, Sha; Panunzio, Mauro; Biondi, Stefano

    2013-10-08

    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.

  6. Schiff Bases: A Short Survey on an Evergreen Chemistry Tool

    OpenAIRE

    Mauro Panunzio; Stefano Biondi; Wenling Qin; Sha Long

    2013-01-01

    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 intermed...

  7. 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.

  8. 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.

  9. 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

  10. Within-twig leaf distribution patterns differ among plant life-forms in a subtropical Chinese forest.

    Science.gov (United States)

    Meng, Fengqun; Cao, Rui; Yang, Dongmei; Niklas, Karl J; Sun, Shucun

    2013-07-01

    In theory, plants can alter the distribution of leaves along the lengths of their twigs (i.e., within-twig leaf distribution patterns) to optimize light interception in the context of the architectures of their leaves, branches and canopies. We hypothesized that (i) among canopy tree species sharing similar light environments, deciduous trees will have more evenly spaced within-twig leaf distribution patterns compared with evergreen trees (because deciduous species tend to higher metabolic demands than evergreen species and hence require more light), and that (ii) shade-adapted evergreen species will have more evenly spaced patterns compared with sun-adapted evergreen ones (because shade-adapted species are generally light-limited). We tested these hypotheses by measuring morphological traits (i.e., internode length, leaf area, lamina mass per area, LMA; and leaf and twig inclination angles to the horizontal) and physiological traits (i.e., light-saturated net photosynthetic rates, Amax; light saturation points, LSP; and light compensation points, LCP), and calculated the 'evenness' of within-twig leaf distribution patterns as the coefficient of variation (CV; the higher the CV, the less evenly spaced leaves) of within-twig internode length for 9 deciduous canopy tree species, 15 evergreen canopy tree species, 8 shade-adapted evergreen shrub species and 12 sun-adapted evergreen shrub species in a subtropical broad-leaved rainforest in eastern China. Coefficient of variation was positively correlated with large LMA and large leaf and twig inclination angles, which collectively specify a typical trait combination adaptive to low light interception, as indicated by both ordinary regression and phylogenetic generalized least squares analyses. These relationships were also valid within the evergreen tree species group (which had the largest sample size). Consistent with our hypothesis, in the canopy layer, deciduous species (which were characterized by high LCP, LSP and

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 凉风坳亚热带次生常绿阔叶林土壤种子库和种子雨的特征研究%Primary research on the soil seed bank and seed rain of semi-tropical evergreen-broadleaf forests in LiangFengao of Sichuan

    Institute of Scientific and Technical Information of China (English)

    张丹桔; 宫渊波; 张健

    2012-01-01

    The soil seed banks, seed rain and natural germination are the main constructive parts of the forestry eco-system, which make an indispensable contribution to the vegetation regeneration, succession and diffusion. However, there are little information available for this. In the present study, semi-tropical evergreen-broad leaf forests in Muchuan of Sichuan basin in China were studied on the soil seed bank, seed rain and the germination of the seeds in the soil seed bank under natural conditions before and after the seed' s falling. Furthermore, the factors influencing the soil seed bank were evaluated. The density of the seed banks including 22 leading species arranges 643. 2 ~ 889. 2 ind · m -2 along with time. The soil seed banks in all sample sites were dominated by perennial herbaceous species in terms of species richness and density. Shannon-Wiener index decreased with time, Simpson index showed the reverse trend compared with the Shannon-Wiener index. Pielou index decreased in December, 2004 and then increased in May, 2005. The density of soil seed banks decreased with the depth of the soil layer. It was found that seeds at the litter layers were shorter than that in the superficial soil layer (0-10 cm) , however,most seeds of the arbor trees existed at the litter layers. The species richness and density of soil seed bank in the control plantations were significantly lower than that in studied forests. The seed input each year in the studies forests were 142. 3 ind · m-2 , the output of the valid seeds each year were 268. 9 ind · m-2 . Preying were the main factors resulting in the seed loss. The species similarity between the seed bank and the above ground vegetation were low but that in control plantations were high.%选择四川省沐川县凉风坳亚热带次生常绿阔叶林为研究对象,在2004年5月、2004年12月和2005年5月对其林下土壤种子库、种子雨以及种子天然萌发状况等方面进行系统调查及

  17. 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.

  18. 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.

  19. 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

  20. The Research of Vegetation Landscape Characteristics in Safflower Lake Greenways of Huizhou West Lake Scenic Area%惠州西湖风景名胜区红花湖绿道植被景观特征

    Institute of Scientific and Technical Information of China (English)

    丛占凤; 苏利英; 彭永宏; 王建兵

    2015-01-01

    采用样线法对惠州红花湖绿道植被进行调查,应用样地的欧氏距离计算的等级聚合分类法,结合样方实地调查资料,对惠州红花湖绿道植被类型进行研究。研究结果表明:红花湖绿道植被可划分4个植被类型:马占相思常绿阔叶林,马占相思、吊瓜常绿阔叶林,马占相思、杜英常绿阔叶林,木棉、马占相思落叶常绿阔叶混交林,并对其植被主要种类组成、植被结构、植被季相及主要的开花植物观赏特性等景观特征进行分析。%The vegetation,which was in Safflower Lake Greenways ,Huizhou City,Guangdong Province,had been investigated by line-ar quadrat method.The vegetations types were studied on the sample plots data and integrated with the grade cluster analysis method of Euclidean distance according to 18 sample plots in Safflower Lake Greenways , Huizhou City , Guangdong Province.The results showed that the Safflower Lake Greenways vegetation were divided into 4 types,including Acacia mangium evergreen broad-leaved forest,Acacia mangium-Kigelia Africana evergreen broad-leaved forest ,Acacia mangium-Elaeocarpus sylvestris evergreen broad-leaved forest,Bombax malabaricum-Acacia mangium defoliate evergreen broad-leaved mixed forest.The landscape characteristics of vegeta-tion types in species composition , vegetation structure , vegetation seasonal aspect and main ornamental characteristics of flowering plants were also analyzed.

  1. Forestry Landscape Patterns Changes and Dynamic Simulation of Nanling National Nature Reserve, Guangdong%南岭国家级自然保护区森林景观格局变化与动态模拟

    Institute of Scientific and Technical Information of China (English)

    廖芳均; 赵东升

    2014-01-01

    Forest landscape pattern and its change is a comprehensive reflection of interaction with natural and artificial factors. In this article, landscape pattern changes of Nanling National Nature Reserve from 1988 to 2009 were analyzed with landscape pattern index based on eCognition and ArcGIS. CA-Markov model was ad-opted to simulate the landscape pattern in 2010 and to predict the landscape pattern in 2021. The results showed that the study area was mainly forest-based landscapes, more than 95%of the total area, in which, ever-green broad-leaved forest and coniferous forest were two dominant landscape types, other landscape types were distributed in the study area with scattered or gathered, and forming a rich landscape mosaic pattern. From 1988 to 2009, the area of coniferous forest decreased whereas areas of other land and construction land increased. Coniferous mixed forest, evergreen broad-leaved forest, broad-leaved mixed forest and farmland first expanded and then shrank, whereas shrubs, other forests and waters first shrank and then expanded. The level of landscape fragmentation and plaque complexity was increased, the proportion of landscape type has a larger change;landscape diversity was increased after reduced, the dominance, evenness changed little, remain-ing stable, the fractal dimension of landscape patches was different at different periods, and the increase ten-dence of human disturbance increased complex to the conversion of various types of plaque. Analysis land-scape types changes of time and space, which found that the largest area ratio changes between with coniferous forest and other woodlands, evergreen broad-leaved forest and broad-leaved mixed forest transformation was frequent, also conversion frequency between mixed coniferous forest and coniferous forest, shrub and other landscape types. Construction land was mainly transformed from evergreen broad-leaved forest and coniferous forest, water, as a landscape type in the study area, mainly

  2. 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

  3. 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.

  4. Dead wood quality influences species diversity of rare cryptogams in temperate broadleaved forests

    OpenAIRE

    Preikša Z; Brazaitis G; Marozas V; Jaroszewicz B

    2016-01-01

    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. O...

  5. Estimating aboveground biomass of broadleaved woody plants in the understory of Florida Keys pine forests

    Science.gov (United States)

    Sah, J.P.; Ross, M.S.; Koptur, S.; Snyder, J.R.

    2004-01-01

    Species-specific allometric equations that provide estimates of biomass from measured plant attributes are currently unavailable for shrubs common to South Florida pine rocklands, where fire plays an important part in shaping the structure and function of ecosystems. We developed equations to estimate total aboveground biomass and fine fuel of 10 common hardwood species in the shrub layer of pine forests of the lower Florida Keys. Many equations that related biomass categories to crown area and height were significant (p aboveground shrub biomass and shrub fine fuel increased with time since last fire, but the relationships were non-linear. The relative proportion of biomass constituted by the major species also varied with stand age. Estimates based on mixed-species regressions differed slightly from estimates based on species-specific models, but the former could provide useful approximations in similar forests where species-specific regressions are not yet available. ?? 2004 Elsevier B.V. All rights reserved.

  6. 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.

  7. 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.

  8. Foliage chemistry and the distribution of Lepidoptera larvae on broad-leaved trees in southern Ontario.

    Science.gov (United States)

    Ricklefs, Robert E

    2008-08-01

    This study addresses the influence of foliage chemistry on the distribution of Lepidoptera larvae across species of trees. I used ordination and analysis of principal coordinates to describe the partitioning of the larvae of 24 species of Lepidoptera over 23 species of host trees taking into account 13 chemical properties of the foliage. Canonical analysis of principal coordinates (CAP) revealed two significant axes linking the two datasets. The first constrained axis (r(2)=0.83) was associated with increasing amounts of soluble carbohydrates and decreasing amounts of hemicellulose, polyphenols, and potassium per cm(2) leaf area. The second constrained axis (r(2)=0.68) was associated with increasing amounts of soluble carbohydrates and decreasing magnesium. Variation in nitrogen and phosphorus, which are major factors in larval nutrition, were not associated with turnover of Lepidoptera species between species of host tree. Of the total variance in the positions of tree species on the first four constrained CAP axes, 44% was correlated with positions determined by foliage chemistry, 32% on the first two constrained axes. Within the space described by the first two canonical axes, congeneric species of tree clustered together, with the exception that Acer negundo was removed from other species of Acer, which grouped in a tight cluster with species in the order Fagales, as well as with Tilia and Ulmus. Alnus and Prunus also grouped together. No species of tree with a negative score on constrained axis 2 exhibited high Lepidoptera species richness, but the average number of individuals per collection tended to be high. These tree species also contain triterpenes in their leaves and harbored disproportionately more tent- and web-making species of Lepidoptera. These analyses show that patterns of distribution across host tree species within an assemblage of Lepidoptera species can be understood, at least in part, in terms of the qualities of the resources upon which they feed.

  9. 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

  10. 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.

  11. 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.

  12. Transfer of the Fukushima Daiichi reactor accident-derived radionuclides in forest environments

    Science.gov (United States)

    Kato, Hiroaki; Onda, Yuichi; Kawamori, Ayumi; Hisadome, Keigo

    2013-04-01

    The Fukushima Daiichi nuclear power plant accident resulted in extensive radioactive contamination of the forest environment in Fukushima and the neighboring prefectures. In this study, we analyzed radiocesium concentrations in rainwater, throughfall, stemflow, and litterfall to characterize the transfer of the deposited radiocesium in various forest stands (evergreen conifers and broad-leaved forests), in Tochigi (Cs-137 fallout < 10 kBq/m^2) and Fukushima (Cs-137 fallout = 300-600 kBq/m^2) prefectures. Furthermore, in-situ measurement of radiocesium were conducted to delineate spatio-temporal variability of radiocesium in the canopy and forest floor. The result of this study demonstrated that a large proportion of radionuclides which deposited on forest were initially trapped by canopies, and subsequently transferred to forest floor in association with throughfall, stemflow, and litterfall. In the deciduous broad-leaved forest, the highest radioactivity was found at the forest floor; however, 25-40% of the total deposited radiocesium remained in the canopy of evergreen coniferous forests one year after the reactor accident.

  13. 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.

  14. 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.

  15. 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.

  16. Forest type effects on the retention of radiocesium in organic layers of forest ecosystems affected by the Fukushima nuclear accident

    Science.gov (United States)

    Koarashi, Jun; Atarashi-Andoh, Mariko; Matsunaga, Takeshi; Sanada, Yukihisa

    2016-12-01

    The Fukushima Daiichi nuclear power plant disaster caused serious radiocesium (137Cs) contamination of forest ecosystems over a wide area. Forest-floor organic layers play a key role in controlling the overall bioavailability of 137Cs in forest ecosystems; however, there is still an insufficient understanding of how forest types influence the retention capability of 137Cs in organic layers in Japanese forest ecosystems. Here we conducted plot-scale investigations on the retention of 137Cs in organic layers at two contrasting forest sites in Fukushima. In a deciduous broad-leaved forest, approximately 80% of the deposited 137Cs migrated to mineral soil located below the organic layers within two years after the accident, with an ecological half-life of approximately one year. Conversely, in an evergreen coniferous forest, more than half of the deposited 137Cs remained in the organic layers, with an ecological half-life of 2.1 years. The observed retention behavior can be well explained by the tree phenology and accumulation of 137Cs associated with litter materials with different degrees of degradation in the organic layers. Spatial and temporal patterns of gamma-ray dose rates depended on the retention capability. Our results demonstrate that enhanced radiation risks last longer in evergreen coniferous forests than in deciduous broad-leaved forests.

  17. 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。

  18. 白水江保护区植物物种多样性垂直带优先保护评价%Evaluation priority in protection of vertical vegetation zones in Baishuijiang nature reserve

    Institute of Scientific and Technical Information of China (English)

    黄华梨; 王建宏; 孙学刚; 卢镝; 任景成

    2011-01-01

    The natural unit for building a secondary priority in the protection of plant indicators and AHP was based on the results of operations and on the vertical distribution of vegetation in Baishuijiang nature reserve. The work was carried out with a conservation priority assessment, which showed that the priorities for plant conservation is in such an order: the evergreen and deciduous broad-leaved forest zone, deciduous broadleaf forest, evergreen broad-leaved forest, coniferous forest zone in Asia, high mountain coniferous forest and alpine shrub meadow. The comprehensive evaluation index values are 78.60, 57.32, 57.20, 38.18, 14.08, 3.27 respectively. Deciduous broad-leaved evergreen mixed forest contains a variety of subtropical and temperate plant species, but the state protection, rare and endangered, unique, single (widowed) types are concentrated in the most protected areas and plant conservation priority vegetation zones. The comprehensive evaluation index values along an elevation gradient from the evergreen broad-leaved evergreen to deciduous forest are from 57.20 to 78.60, following the broad-leaved forest zone which has had a continuous decrease and reflecting the diversity of species with a single peak distribution pattern of elevation. This distribution pattern is mainly generated at different altitudes where the thermal regime of water is formed, but it also has a strong low-altitude and high altitude anthropogenic interference with the smaller mountains and other factors.%以构建的次级自然单元植物优先保护评价指标体系及层次分析法运算的结果为依据,对白水江自然保护区植被垂直分布带进行了优先保护评价,评价结果表明植物优先保护的顺序依次为常绿落叶阔叶混交林带、落叶阔叶林带、常绿阔叶林带、针阔混交林带、亚高山针叶林带、高山灌丛草甸带,评价指标的综合值依次为78.60,57.32,57.20,38.18,14.08,3.27.常绿落叶阔叶混交

  19. 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

  20. Effects of Elevation on Surface Layer Soil Active Organic Carbon Content in Shennongjia Nature Reserve%海拔对神农架表层土壤活性有机碳含量的影响

    Institute of Scientific and Technical Information of China (English)

    卢慧; 丛静; 薛亚东; 杨敬元; 陈克龙; 李迪强; 张于光

    2014-01-01

    In this study,five typical vegetation types were selected along the elevational gradient in Shennongjia Nature Reserve,including shrubs, coniferous forest, mixed forest between coniferous and deciduous broad-leaved forest, deciduous broad-leaved forest,and evergreen broad-leaved forest. The content of soil organic carbon ( SOC ) ,water dissolved organic carbon ( WDOC ) ,labile organic carbon ( LOC ) ,and microbial biomass carbon ( MBC ) and their allocation proportions to SOC were analyzed. Furthermore,the Pearson relationship was analyzed between soil active organic carbon and plant diversity or soil physiochemical properties. The results showed that the soil organic carbon in the surface layer increased with the elevation increased, except for the deciduous broad-leaved forest. Distribution characteristics of MBC and LOC content along elevation gradient were obvious,but WDOC content was independent of the elevation gradient. The contents of the three kinds of active organic carbon in different elevational gradients were in the order of: LOC>MBC >WDOC. The allocation ratios of MBC,LOC and WDOC to SOC did not significantly alter with elevational gradient. Pearson relationship showed that SOC and MBC had a significant negative correlation with the diversity of trees and shrubs (P < 0. 05),while LOC and WDOC content had no significant correlation with plant diversity. In addition,SOC and MBC were significantly positively correlated with the content of soil moisture,total nitrogen,available nitrogen,total phosphorus and total sulfur (P<0. 01). LOC had a significant and positive correlation with the content of soil moisture,total nitrogen,available nitrogen and total sulfur (P <0. 01). There was a significant correlation between LOC and total phosphorus ( P<0 . 05 ) . The results revealed that these factors had a dominating impact on SOC,LOC and MBC. WDOC content had no obvious correlation with soil factors.

  1. 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

  2. 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。

  3. 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

  4. The water relations of two evergreen tree species in a karst savanna.

    Science.gov (United States)

    Schwinning, Susanne

    2008-12-01

    The ecohydrology of karst has not received much attention, despite the disproportionally large contribution of karst aquifers to freshwater supplies. Karst savannas, like many savannas elsewhere, are encroached by woody plants, with possibly negative consequences on aquifer recharge. However, the role of savanna tree species in hydrological processes remains unclear, not least because the location and water absorption zones of tree roots in the spatially complex subsurface strata are unknown. This study examined the water sources and water relations of two savanna trees, Quercus fusiformis (Small) and Juniperus ashei (Buchholz) in the karst region of the eastern Edwards Plateau, Texas (USA). Stable isotope analysis of stem water revealed that both species took up evaporatively enriched water during the warm season, suggesting a relatively shallow water source in the epikarst, the transition zone between soil and bedrock. Q. fusiformis had consistently higher predawn water potentials than J. ashei during drought, and thus was probably deeper-rooted and less capable of maintaining gas exchange at low water potentials. Although the water potential of both species recovered after drought-breaking spring and summer rain events, associated shifts in stem water isotope ratios did not indicate significant uptake of rainwater from the shallow soil. A hypothesis is developed to explain this phenomenon invoking a piston-flow mechanism that pushes water stored in macropores into the active root zones of the trees. Epikarst structure varied greatly with parent material and topography, and had strong effects on seasonal fluctuations in plant water status. The study suggests that tree species of the Edwards Plateau do not commonly reduce aquifer recharge by tapping directly into perched water tables, but more likely by reducing water storage in the epikarst. A more general conclusion is that models of savanna water relations based on Walter's two-layer model may not apply unequivocally to karst savannas.

  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

    (3)]. On a monthly basis, [O(3)] was always highest in the afternoon while nu(d) was typically higher in the morning, resulting in an equal F(c) over the day. Night-time F(c) was more than half of the daytime O(3) flux. The data reveal the importance of emissions of nitric oxide and terpenes as O(3...

  6. Comparing growth phenology of co-occurring deciduous and evergreen conifers exposed to drought.

    Science.gov (United States)

    Swidrak, Irene; Schuster, Roman; Oberhuber, Walter

    2013-12-01

    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.

  7. Partitioning the climatic and biological controls on photosynthetic fluxes in Amazonian tropical evergreen forests

    Science.gov (United States)

    Wu, J.; Guan, K.; Albert, L.; Hayek, M.; Restrepo-Coupe, N.; Prohaska, N.; Wiedemann, K. T.; Marostica, S. F.; Stark, S. C.; Smith, M.; Silva, R. D.; Dye, D. G.; Nelson, B. W.; Huete, A. R.; Saleska, S. R.

    2014-12-01

    Understanding the mechanistic controls on tropical forests photosynthetic metabolism is a central problem of ecology and global change biology. We hypothesize two different temporal scales for the mechanisms regulating tropical photosynthesis (Gross Ecosystem Productivity, GEP): (1) at seasonal scales, leaf phenology (changing age and amount of leaves) is the primary control on GEP seasonality; (2) at the hourly scale with a constant phenological stage, climatic variables are the first order controls on GEP. In order to test this hypothesis, we partitioned the sources of GEP variation measured on eddy flux towers in central Amazon forests into biological and climatic components. The biological component (photosynthetic capacity, or PC) was defined as the monthly mean value of GEP extracted under a fixed narrow range of climate conditions, representing phenological changes associated with the amount and age of leaves. The climatic component was extracted via a path analysis of the hourly flux data, conditioned on a given monthly PC, representing the effects of fluctuating climate operating on the given PC. The main climatic variables were PAR, air-temperature, VPD, and Cloudiness Index (CI), the fraction of reduction of incident solar radiance due to clouds and aerosols relative to that expected under clear sky conditions. We found that the variability in monthly GEP arises from both seasonality of PC and that of climate, but despite the strong seasonality of climate, GEP was dominated by PC seasonality (R2=0.92). We found that the variability in hourly GEP (relative to the potential represented by monthly PC) was controlled primarily by PAR and VPD (as modified by the influence of CI). The tradeoff between the positive GEP effects of increased PAR and the negative effects of higher VPD stress indicates that tropical forests are stable in the face of modest climatic variability. For example, a significant reduction in mean cloudiness (of 0.1 CI units, corresponding to a ~18% increase in PAR and ~19% increase in VPD) would cause only modest changes in GEP (~1.8% increase in the wet season and ~2.9% decline in the dry season). This work provides an improved framework for understanding the climate drivers of canopy scale photosynthesis by separately analyzing the influence of phenological and climatic components.

  8. Copper resistance of the evergreen dwarf shrub Arctostaphylos uva-ursi: an experimental exposure

    Energy Technology Data Exchange (ETDEWEB)

    Salemaa, Maija; Monni, Satu

    2003-12-01

    The copper (Cu) resistance of Arctostaphylos uva-ursi was tested in a pot experiment (lasting 8 weeks) using rooted cuttings originating from an area near the Harjavalta Cu-Ni smelter, SW Finland. The fine roots were moderately infected by arbutoid mycorrhizae. The plants were exposed to five Cu levels (1, 10, 22, 46 and 100 mg l{sup -1}) given repeatedly together with a nutrient solution. The critical Cu concentration in the nutrient solution inhibiting the growth of A. uva-ursi was below 10 mg l{sup -1} Cu (EC{sub 50} value for biomass production 3.3 mg l{sup -1} Cu). This concentration was clearly lower than the value we have found earlier for other dwarf shrubs under similar experimental conditions. Most of the Cu given accumulated in the roots and old stems. The results suggest that A. uva-ursi cuttings were relatively sensitive to Cu despite the ability of the adult clones to grow in Cu-contaminated soil. The adult clones extend their roots into the less toxic deeper soil layers, which may facilitate the avoidance of heavy metals. - Root extension into deeper layers of soil may aid in avoidance of heavy metals.

  9. 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

  10. 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...

  11. Radiation Climate and Turbulence Structure of a Tropical Dry Evergreen Forest.

    Science.gov (United States)

    1985-11-01

    Bahm and Nakos (1979) examined the calibration of pyrheliometers at several individual laboratories within the U.S. and found that presently...J. Meteor., 18, 429-431. Bahm, R. J., and J. C. Nakos , 1979: The calibration of solar radiation measuring instruments. Final report, Bureau of

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

    NARCIS (Netherlands)

    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 a

  13. 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.

  14. 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…

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Differential winter stemflow generation under contrasting storm conditions in a southern New England broad-leaved deciduous forest

    Science.gov (United States)

    Levia, Delphis F., Jr.

    2004-04-01

    Despite the importance of stemflow as a hydroecological process, differential winter stemflow generation among and within precipitation types (e.g. snow, rain-to-snow) is poorly understood. The purpose of the present study is to understand winter stemflow generation better under contrasting meteorological conditions in a leafless deciduous forest. It is hypothesized that stemflow volume and production, expressed as a funnelling ratio, will differ significantly among and within precipitation event types. Acceptance of this hypothesis would mean that intra-event meteorological conditions have a significant and discernible effect on stemflow production in deciduous forests, differentially affecting soil moisture, groundwater recharge, soil solution chemistry, and nutrient cycling. Stemflow volumes generated from seven canopy trees were monitored in a leafless deciduous forest of southern New England on a precipitation event basis over two successive winter seasons. Stemflow volume was found to differ significantly among different and same-type precipitation events. A rain event that occurred on 8 December 1998 and snow-to-rain event on 18 January 1999 were of similar duration, magnitude, and intensity, yet produced stemflow volumes that differed by a factor of 4. For two snow-to-rain events, stemflow volumes differed by a factor of 11. Stemflow production even varies widely within a discrete precipitation event as a function of meteorological conditions. Significant differential stemflow yield under contrasting storm conditions obviates generalizations concerning stemflow production as a function of precipitation event type and necessitates a deeper, process-level understanding of winter stemflow generation before modelling exercises are undertaken.

  1. 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.

  2. Modeling rockfall frequency and bounce height from three-dimensional simulation process models and growth disturbances in submontane broadleaved trees

    Science.gov (United States)

    Corona, Christophe; Lopez-Saez, Jérôme; Favillier, Adrien; Mainieri, Robin; Eckert, Nicolas; Trappmann, Daniel; Stoffel, Markus; Bourrier, Franck; Berger, Frédéric

    2017-03-01

    The use of dynamic computational methods has become indispensable for the assessment of rockfall hazards and the quantification of uncertainties. Although a substantial number of models with various degrees of complexity has become available over the past few years, models have only rarely been parameterized against observations, especially because long-term records of rockfalls have proven to be scarce and typically incomplete. On forested slopes, tree-ring analyses may help to fill this gap, as they have been shown to provide annually resolved data on past rockfall activity over long periods. In this paper, a total of 1495 rockfall scars recorded on the stem surface of 1004 trees have been studied at a site in the Vercors massif (French Alps) to calibrate the 3D process based simulation model RockyFor3D. Uncertainties related to the choice of parameters accounting for energy dissipation and surface roughness have been investigated in detail. Because of the lack of reliable data, these parameters typically are estimated based on expert judgments, despite the fact that they have significant impacts on runout distances and bounce height. We demonstrate that slight variations in roughness can indeed strongly affect the performance of runout modeling and that the decreasing downward gradient, observed in field data, is properly reproduced only if reduced roughness (< 10 cm) enables blocks to reach the distal parts of the study plot. With respect to the height of impacts, our results also reveal that differences between simulations and observations can indeed be minimized if softer soil types are preferred during simulation, as they typically limit bouncing. We conclude that field-based dendrogeomorphic approaches represent an objective tool to improve rockfall simulations and to enhance our understanding of parameterization, which is of key importance for process dynamics and thus hazard zoning.

  3. 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.

  4. 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.

  5. 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.

  6. Carbon allocation to defense, storage, and growth in seedlings of two temperate broad-leaved tree species.

    Science.gov (United States)

    Imaji, Aya; Seiwa, Kenji

    2010-02-01

    Optimal carbon allocation to growth, defense, or storage is a critical trait in determining the shade tolerance of tree species. Thus, examining interspecific differences in carbon allocation patterns is useful when evaluating niche partitioning in forest communities. We hypothesized that shade-tolerant species allocate more carbon to defense and storage and less to growth compared to shade-intolerant species. In gaps and forest understory, we measured relative growth rates (RGR), carbon-based defensive compounds (condensed tannin, total phenolics), and storage compounds (total non-structural carbohydrate; TNC) in seedlings of two tree species differing in shade tolerance. RGR was greater in the shade-intolerant species, Castanea crenata, than in the shade-tolerant species, Quercus mongolica var. grosseserrata, in gaps, but did not differ between the species in the forest understory. In contrast, concentrations of condensed tannin and total phenolics were greater in Quercus than in Castanea at both sites. TNC pool sizes did not differ between the species. Condensed tannin concentrations increased with increasing growth rate of structural biomass (GRstr) in Quercus but not in Castanea. TNC pool sizes increased with increasing GRstr in both species, but the rate of increase did not differ between the species. Accordingly, the amount of condensed tannin against TNC pool sizes was usually higher in Quercus than in Castanea. Hence, Quercus preferentially invested more carbon in defense than in storage. Such a large allocation of carbon to defense would be advantageous for a shade-tolerant species, allowing Quercus to persist in the forest understory where damage from herbivores and pathogens is costly. In contrast, the shade-intolerant Castanea preferentially invested more carbon in growth rather than defense (and similar amounts in storage as Quercus), ensuring establishment success in gaps, where severe competition occurs for light among neighboring plants. These contrasting carbon allocation patterns are closely associated with strategies for persistence in these species' respective habitats.

  7. 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.

  8. 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.

  9. 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.

  10. 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

    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...... NH4+-N in the mature forest. In contrast, inorganic N (both NH4+-N and NO3--N) in soil 20-cm below the surface was significantly elevated by the N additions. From 42% to 74% of N added was retained by the upper 20 cm soils in the pine and mixed forests, while 0%-70% was retained in the mature forest...

  11. Holocene vegetation and fire history of the mountains of northern Sicily (Italy)

    Science.gov (United States)

    Tinner, Willy; Vescovi, Elisa; Van Leeuwen, Jacqueline; Colombaroli, Daniele; Henne, Paul; Kaltenrieder, Petra; Morales-Molino, Cesar; Beffa, Giorgia; Gnaegi, Bettina; Van der Knaap, Pim W O; La Mantia, Tommaso; Pasta, Salvatore

    2016-01-01

    Knowledge about vegetation and fire history of the mountains of Northern Sicily is scanty. We analysed five sites to fill this gap and used terrestrial plant macrofossils to establish robust radiocarbon chronologies. Palynological records from Gorgo Tondo, Gorgo Lungo, Marcato Cixé, Urgo Pietra Giordano and Gorgo Pollicino show that under natural or near natural conditions, deciduous forests (Quercus pubescens, Q. cerris, Fraxinus ornus, Ulmus), that included a substantial portion of evergreen broadleaved species (Q. suber, Q. ilex, Hedera helix), prevailed in the upper meso-mediterranean belt. Mesophilous deciduous and evergreen broadleaved trees (Fagus sylvatica, Ilex aquifolium) dominated in the natural or quasi-natural forests of the oro-mediterranean belt. Forests were repeatedly opened for agricultural purposes. Fire activity was closely associated with farming, providing evidence that burning was a primary land use tool since Neolithic times. Land use and fire activity intensified during the Early Neolithic at 5000 bc, at the onset of the Bronze Age at 2500 bc and at the onset of the Iron Age at 800 bc. Our data and previous studies suggest that the large majority of open land communities in Sicily, from the coastal lowlands to the mountain areas below the thorny-cushion Astragalus belt (ca. 1,800 m a.s.l.), would rapidly develop into forests if land use ceased. Mesophilous Fagus-Ilex forests developed under warm mid Holocene conditions and were resilient to the combined impacts of humans and climate. The past ecology suggests a resilience of these summer-drought adapted communities to climate warming of about 2 °C. Hence, they may be particularly suited to provide heat and drought-adaptedFagus sylvatica ecotypes for maintaining drought-sensitive Central European beech forests under global warming conditions.

  12. 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...

  13. 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.

  14. 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.

  15. [Effects of simulated nitrogen deposition on soil acid phosphomonoesterase activity and soil available phosphorus content in subtropical forests in Dinghushan Mountain].

    Science.gov (United States)

    Li, Yin; Zeng, Shu-cai; Huang, Wen-juan

    2011-03-01

    An in situ field experiment was conducted to study the effects of simulated nitrogen (N) deposition on soil acid phosphomonoesterase activity (APA) and soil available phosphorous (AP) content in Pinus massoniana forest (PF), coniferous and broad-leaved mixed forest (MF), and monsoon evergreen broad-leaved forest (MEBF) in Dinghushan Mountain. In PF and MF, three treatments were installed, i.e., CK (0 kg N x hm(-2) x a(-1)), low N (50 kg N x hm(-2) x a(-1)), and medium N (100 kg N x hm(-2) x a(-1)); in MEBF, four treatments were installed, i.e., CK, low N, medium N, and high N (150 kg N x hm(-2) x a(-1)). The soil APA and soil AP content decreased with soil depth. The soil APA was the highest in MEBF, while the AP content had no significant difference in the three forests. The effects of N addition on soil APA differed with forest types. In MEBF, the APA was the highest (19.52 micromol x g(-1) x h(-1)) in low N treatment; while in PF and MF, the APA was the highest (12.74 and 11.02 micromol x g(-1) x h(-1), respectively) in medium N treatment. In the three forests, soil AP content was the highest in low N treatment, but had no significant differences among the N treatments. There was a significant positive correlation between soil APA and soil AP content.

  16. Nutrient Allocation Strategies of Woody Plants: An Approach From the Scaling of Nitrogen and Phosphorus Between Twigs and Leaves

    Science.gov (United States)

    Yan, Z.; Li, P.; Chen, Y.; Han, W.; Fang, J.

    2015-12-01

    Allocation of limited nutrients, such as nitrogen (N) and phosphorus (P), among plant organs reflects the influences of evolutionary and ecological processes on functional traits of plants, and thus is related to functional groups and environmental conditions. In this study, we tested this hypothesis by exploring the stoichiometric scaling of N and P concentrations between twigs and leaves of 335 woody species from 12 forest sites across eastern China. There were significant scaling relationships between twig N (or P) and leaf N (or P) using reduced major axis (RMA) regression analysis; yet their scaling exponents varied among functional groups and changed with environmental factors. Evergreen broad-leaved plants had a higher exponent (αP) of twig P to leaf P than that of deciduous broad-leaved plants (1.26 vs. 0.96, p 1 at low latitude (23.2°N) to nutrient concentration increased, plants at low latitudes showed a faster increase in twig nutrient concentration, whereas plants at high latitudes presented a faster increase in leaf nutrient concentration. Such shifts in nutrient allocation strategy from low to high latitudes may be controlled by temperature. Overall, our findings provide a new approach to explore plant nutrient allocation strategies by analysing the stoichiometric scaling of nutrients among organs, which could broaden our understanding of the interactions between plants and their environments.

  17. 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.

  18. Altitudinal Pattern of Plant Species Diversity in Shennongjia Mountains, Central China

    Institute of Scientific and Technical Information of China (English)

    Chang-Ming ZHAO; Wei-Lie CHEN; Zi-Qiang TIAN; Zong-Qiang XIE

    2005-01-01

    One hundred and sixty plots, approximately every 100 m above sea level (a.s.l.) along an altitudinal gradient from 470 to 3 080 m a.s.l, at the southern and northern watershed of Mt. Shennongjia,China, were examined to determine the altitudinal pattern of plant species diversity. Mt. Shennongjia was found to have high plant species diversity, with 3 479 higher plants recorded. Partial correlation analysis and detrended canonical correspondence analysis (DCCA) based on plant species diversity revealed that altitude was the main factor affecting the spatial pattern of plant species diversity on Mt. Shennongjia and that canopy coverage of the arbor layer also had a considerable effect on plant species diversity. The DCCA based on species data of importance value further revealed that altitude gradient was the primary factor shaping the spatial pattern of plant species. In addition, the rule of the "mid-altitude bulge" was supported on Mt. Shennongjia. Plant species diversity was closely related to vegetation type and the transition zone usually had a higher diversity. Higher plant species diversity appeared in the mixed evergreen and deciduous broadleaved forest zone (900-1 500 m a.s.l.) and its transition down to evergreen broadleaved forest zone or up to deciduous broadleaved forest zone. The largest plant species diversity in whole communities on Mt. Shennongjia lay at approximately 1 200 m a.s.l. Greatest tree diversity, shrub diversity, and grass diversity was found at approximately 1 500, 1 100, and 1 200 m a.s.l., respectively. The southern watershed showed higher plant species diversity than the northern watershed, with maximum plant species diversity at a higher altitude in the southern watershed than the northern watershed. These results indicate that Mt.Shennongjia shows characteristics of a transition region. The relationship between the altitudinal pattern of plant species diversity and the vegetation type in eastern China are also discussed and a

  19. [Dynamics of nitrogen and sulfur wet deposition in typical forest stand at different spatial levels in Simian Mountain, mid-subtropical region].