WorldWideScience

Sample records for broadleaved evergreens

  1. [Biomass allometric equations of nine common tree species in an evergreen broadleaved forest of subtropical China].

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    Zuo, Shu-di; Ren, Yin; Weng, Xian; Ding, Hong-feng; Luo, Yun-jian

    2015-02-01

    Biomass allometric equation (BAE) considered as a simple and reliable method in the estimation of forest biomass and carbon was used widely. In China, numerous studies focused on the BAEs for coniferous forest and pure broadleaved forest, and generalized BAEs were frequently used to estimate the biomass and carbon of mixed broadleaved forest, although they could induce large uncertainty in the estimates. In this study, we developed the species-specific and generalized BAEs using biomass measurement for 9 common broadleaved trees (Castanopsis fargesii, C. lamontii, C. tibetana, Lithocarpus glaber, Sloanea sinensis, Daphniphyllum oldhami, Alniphyllum fortunei, Manglietia yuyuanensis, and Engelhardtia fenzlii) of subtropical evergreen broadleaved forest, and compared differences in species-specific and generalized BAEs. The results showed that D (diameter at breast height) was a better independent variable in estimating the biomass of branch, leaf, root, aboveground section and total tree than a combined variable (D2 H) of D and H (tree height) , but D2H was better than D in estimating stem biomass. R2 (coefficient of determination) values of BAEs for 6 species decreased when adding H as the second independent variable into D- only BAEs, where R2 value for S. sinensis decreased by 5.6%. Compared with generalized D- and D2H-based BAEs, standard errors of estimate (SEE) of BAEs for 8 tree species decreased, and similar decreasing trend was observed for different components, where SEEs of the branch decreased by 13.0% and 20.3%. Therefore, the biomass carbon storage and its dynamic estimates were influenced largely by tree species and model types. In order to improve the accuracy of the estimates of biomass and carbon, we should consider the differences in tree species and model types.

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

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

    2013-01-01

    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...

  3. Genetic diversity and seed production in Santa Lucia fir (Abies bracteata),a relict of the Miocene broadleaved evergreen forest

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    F. Thomas Ledig; Paul D. Hodgskiss; David R. Johnson

    2006-01-01

    Santa Lucia fir (Abies bracteata), is a unique fir, the sole member of the subgenus Pseudotorreya. It is a relict of the Miocene broadleaved evergreen sclerophyll forest, and is now restricted to a highly fragmented range in the Santa Lucia Mountains of central coastal California. Expected heterozygosity for 30 isozyme loci in 18 enzyme systems...

  4. The rapid climate change-caused dichotomy on subtropical evergreen broad-leaved forest in Yunnan: Reduction in habitat diversity and increase in species diversity

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    Zhe Ren

    2016-06-01

    Full Text Available Yunnan's biodiversity is under considerable pressure and subtropical evergreen broad-leaved forests in this area have become increasingly fragmented through agriculture, logging, planting of economic plants, mining activities and changing environment. The aims of the study are to investigate climate change-induced changes of subtropical evergreen broad-leaved forests in Yunnan and identify areas of current species richness centers for conservation preparation. Stacked species distribution models were created to generate ensemble forecasting of species distributions, alpha diversity and beta diversity for Yunnan's subtropical evergreen broad-leaved forests in both current and future climate scenarios. Under stacked species distribution models in rapid climate changes scenarios, changes of water-energy dynamics may possibly reduce beta diversity and increase alpha diversity. This point provides insight for future conservation of evergreen broad-leaved forest in Yunnan, highlighting the need to fully consider the problem of vegetation homogenization caused by transformation of water-energy dynamics.

  5. 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.

  6. [Influences of petrophytia moss on vegetation development in evergreen broad-leaved forest].

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    Wang, Zhongsheng; Fang, Yanming

    2003-06-01

    In order to examine the role of Petrophytia moss in maintaining the stability and integrity of forest vegetation, the distribution patterns of vascular plants among Petrophytia moss layer were investigated in five heterogeneous patches of evergreen broad-leaved forest at Longwangshan, Zhejiang Province. The distribution and composition of vascular plants were jointly affected by various factors, such as disturbance degree in patch, moss growth condition, and water and soil conservation ability of moss layer. Original habitats patch 1 and patch 5 were kept well, and hence, the even depth, dry weight and maximum water-holding capacity of moss layer, as well as the dry weight of soil and the soil water-absorbing rate in moss layer for patch 1 and patch 5 were much more than other patches. For example, the even depth (cm) of moss layer were decreased in the order of patch 5(2.2) > patch 1(2.0) > patch 2(1.5) > patch 3(1.1) > patch 4(0.9); the ranking of vascular plant diversities among moss layer in each patch was patch 5(16) > patch 1(14) > patch 3(9) > patch 4(7), and the general cover of these plants was followed as patch 3(30.0%) > patch 1(28.5%) > patch 5 (26.5%) > patch 2 (17.0%) > patch 4(4.5%). It was concluded that Petrophytia moss had the roles of reserving water and soil, holding litter, concentrating nutrient elements, and corrupting rock, which could improve the environmental condition of rock surface, help to the regeneration of vascular plants, and bring positive effects on the restoration or conversation of vegetation in disturbance sites and on the extension of forest scale.

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

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    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

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

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    Kyung Ah Koo

    Full Text Available 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

  9. Responses of the photosynthetic apparatus to winter conditions in broadleaved evergreen trees growing in warm temperate regions of Japan.

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    Tanaka, Chizuru; Nakano, Takashi; Yamazaki, Jun-Ya; Maruta, Emiko

    2015-01-01

    Photosynthetic characteristics of two broadleaved evergreen trees, Quercus myrsinaefolia and Machilus thunbergii, were compared in autumn and winter. The irradiance was similar in both seasons, but the air temperature was lower in winter. Under the winter conditions, net photosynthesis under natural sunlight (Anet) in both species dropped to 4 μmol CO2 m(-2) s(-1), and the quantum yield of photosystem II (PSII) photochemistry in dark-adapted leaves (Fv/Fm) also dropped to 0.60. In both species the maximum carboxylation rates of Rubisco (V(cmax)) decreased, and the amount of Rubisco increased in winter. A decline in chlorophyll (Chl) concentration and an increase in the Chl a/b ratio in winter resulted in a reduction in the size of the light-harvesting antennae. From measurements of Chl a fluorescence parameters, both the relative fraction and the energy flux rates of thermal dissipation through other non-photochemical processes were markedly elevated in winter. The results indicate that the photosynthetic apparatus in broadleaved evergreen species in warm temperate regions responds to winter through regulatory mechanisms involving the downregulation of light-harvesting and photosynthesis coupled with increased photoprotective thermal energy dissipation to minimize photodamage in winter. These mechanisms aid a quick restart of photosynthesis without the development of new leaves in the following spring. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  10. Geographical and climatic gradients of evergreen versus deciduous broad-leaved tree species in subtropical China: Implications for the definition of the mixed forest.

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    Ge, Jielin; Xie, Zongqiang

    2017-06-01

    Understanding climatic influences on the proportion of evergreen versus deciduous broad-leaved tree species in forests is of crucial importance when predicting the impact of climate change on broad-leaved forests. Here, we quantified the geographical distribution of evergreen versus deciduous broad-leaved tree species in subtropical China. The Relative Importance Value index (RIV) was used to examine regional patterns in tree species dominance and was related to three key climatic variables: mean annual temperature (MAT), minimum temperature of the coldest month (MinT), and mean annual precipitation (MAP). We found the RIV of evergreen species to decrease with latitude at a lapse rate of 10% per degree between 23.5 and 25°N, 1% per degree at 25-29.1°N, and 15% per degree at 29.1-34°N. The RIV of evergreen species increased with: MinT at a lapse rate of 10% per °C between -4.5 and 2.5°C and 2% per °C at 2.5-10.5°C; MAP at a lapse rate of 10% per 100 mm between 900 and 1,600 mm and 4% per 100 mm between 1,600 and 2,250 mm. All selected climatic variables cumulatively explained 71% of the geographical variation in dominance of evergreen and deciduous broad-leaved tree species and the climatic variables, ranked in order of decreasing effects were as follows: MinT > MAP > MAT. We further proposed that the latitudinal limit of evergreen and deciduous broad-leaved mixed forests was 29.1-32°N, corresponding with MAT of 11-18.1°C, MinT of -2.5 to 2.51°C, and MAP of 1,000-1,630 mm. This study is the first quantitative assessment of climatic correlates with the evergreenness and deciduousness of broad-leaved forests in subtropical China and underscores that extreme cold temperature is the most important climatic determinant of evergreen and deciduous broad-leaved tree species' distributions, a finding that confirms earlier qualitative studies. Our findings also offer new insight into the definition and distribution of the mixed forest and an accurate

  11. Community composition and cellulase activity of cellulolytic bacteria from forest soils planted with broad-leaved deciduous and evergreen trees.

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    Yang, Jiang-Ke; Zhang, Jing-Jing; Yu, Heng-Yu; Cheng, Jian-Wen; Miao, Li-Hong

    2014-02-01

    Cellulolytic bacteria in forest soil provide carbon sources to improve the soil fertility and sustain the nutrient balance of the forest ecological system through the decomposition of cellulosic remains. These bacteria can also be utilized for the biological conversion of biomass into renewable biofuels. In this study, the community compositions and activities of cellulolytic bacteria in the soils of forests planted with broad-leaved deciduous (Chang Qing Garden, CQG) and broad-leaved evergreen (Forest Park, FP) trees in Wuhan, China were resolved through restriction fragment length polymorphism (RFLP) and sequencing analysis of the 16S rRNA gene. All of the isolates exhibited 35 RFLP fingerprint patterns and were clustered into six groups at a similarity level of 50 %. The phylogeny analysis based on the 16S rRNA gene sequence revealed that these RFLP groups could be clustered into three phylogenetic groups and further divided into six subgroups at a higher resolution. Group I consists of isolates from Bacillus cereus, Bacillus subtilis complex (I-A) and from Paenibacillus amylolyticus-related complex (I-B) and exhibited the highest cellulase activity among all of the cellulolytic bacteria isolates. Cluster II consists of isolates belonging to Microbacterium testaceum (II-A), Chryseobacterium indoltheticum (II-B), and Flavobacterium pectinovorum and the related complex (II-C). Cluster III consists of isolates belonging to Pseudomonas putida-related species. The community shift with respect to the plant species and the soil properties was evidenced by the phylogenetic composition of the communities. Groups I-A and I-B, which account for 36.0 % of the cellulolytic communities in the CQG site, are the dominant groups (88.4 %) in the FP site. Alternatively, the ratio of the bacteria belonging to group III (P. putida-related isolates) shifted from 28.0 % in CQG to 4.0 % in FP. The soil nutrient analysis revealed that the CQG site planted with deciduous broad-leaved

  12. 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.

  13. Snow damage strongly reduces the strength of the carbon sink in a primary subtropical evergreen broadleaved forest

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

    2017-10-01

    A primary subtropical evergreen broadleaved forest in southwest China experienced a particularly extreme snowfall event during January 2015. The 2015 event enabled the quantification of the impact of the extreme meteorological event on the forest carbon balance. We analyzed five years of continuous measurements of CO2 exchange across the biosphere/atmosphere interface in the forest using an eddy covariance technique. We quantified how exposure to an extreme meteorological event affected ecosystem processes that determine gross primary productivity (GPP) and ecosystem respiration (R eco), and thus annual net carbon (C) sequestration. The forest canopy was severely damaged by the heavy snow, and the leaf area index (LAI) decreased significantly from January to July 2015. GPP, net ecosystem exchange (NEE), and R eco all sharply decreased in 2015 after the heavy snow. On average, a strong decrease of 544 g C m‑2 year‑1 in annual NEE in 2015 was associated with a decrease of 829 g C m‑2 year‑1 in annual GPP and a decrease of 285 g C m‑2 year‑1 in annual R eco. Overall, annual net C uptake in 2015 was reduced by 76% compared to the mean C uptake of the previous four years. A sharp increase in carbon uptake was also observed in 2016, indicating that long-term, continuous measurements should be carried out to evaluate the overall response to the disturbance.

  14. Phylogeny and biogeography of East Asian evergreen oaks (Quercus section Cyclobalanopsis; Fagaceae): Insights into the Cenozoic history of evergreen broad-leaved forests in subtropical Asia.

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    Deng, Min; Jiang, Xiao-Long; Hipp, Andrew L; Manos, Paul S; Hahn, Marlene

    2018-02-01

    The evolutionary history of Quercus section Cyclobalanopsis, a dominant lineage in East Asian evergreen broadleaved forests (EBLFs), has not been comprehensively studied using molecular tools. In this study, we reconstruct the first comprehensive phylogeny of this lineage using a genomic approach (restriction-site associated DNA sequencing, RAD-seq), sampling 35 of the ca. 90 species currently recognized, representing all main morphological groups of section Cyclobalanopsis. In addition, 10 other species of Quercus and two outgroups were also sampled. Divergence times were estimated using a relaxed clock model and two fossil calibrations. Ancestral areas and dispersal routes were inferred using statistical dispersal-vicariance analysis and the dispersal-extinction-cladogenesis (DEC) model. The phylogeny of Quercus section Cyclobalanopsis demonstrates the section to be monophyletic, comprising two main lineages and six subclades that are well supported by anatomical traits. Biogeographical reconstructions indicate that the wide northern hemisphere distribution of Quercus was disrupted in the Late Eocene, leading to the main extant groups at about 33 Ma. The earliest divergences in section Cyclobalanopsis correspond to the phased uplift of the Himalayas and lateral extrusion of Indochina at the transition of the Oligocene and Miocene, where the highest rate of diversification occurred in the late Miocene. Dispersal from Sino-Himalaya and the Palaeotropics to Sino-Japan in the Miocene was facilitated by the increased intensity of East Asian summer monsoons and by the Middle Miocene Climatic Optimum. Our results highlight the importance of climatic changes and Indo-Eurasian collision-induced tectonic activities from the Neogene onward to the spatial-temporal diversification patterns of Asian EBLF lineages. Copyright © 2017. Published by Elsevier Inc.

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

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    Dunmei Lin

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

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

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    Kyoko Aoki

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

  17. [A comparative study on soil fauna in native secondary evergreen broad-leaved forest and Chinese fir plantation forests in subtropics].

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    Yan, Shaokui; Wang, Silong; Hu, Yalin; Gao, Hong; Zhang, Xiuyong

    2004-10-01

    In this study, we investigated the response of soil animal communities to the replacement of native secondary forest by Chinese fir plantation forest and successive rotation of Chinese fir in subtropics. Three adjacent forest stands, i.e., native secondary evergreen broad-leaved forest stand (control) and Chinese fir plantation stands of first (20 yr) and second (20 yr) rotations were selected for the comparison of soil fauna. All animals were extracted from the floor litter and 0-15 cm soil layer of the stands in Summer, 2003 by using Tullgren method, wet funnel method and hand-sorting method. Compared to two Chinese fir plantation forests, the native secondary evergreen broad-leaved forest had a higher abundance and a higher taxonomic diversity of animals in soil and litter, but there were no significant differences in the biomass and productivity of soil fauna between all study stands. The abundance or diversity did not differ significantly between the first rotation and second rotation stands, too. The results supported that vegetation cover might be one of the main forces driving the development of soil animal communities, and the effect of successive rotation of Chinese fir on the development of soil fauna was a slow-running process.

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

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    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.

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

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    Aoki, Kyoko; Kato, Makoto; Murakami, Noriaki

    2011-04-21

    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.

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

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    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

  1. Phylogeographical patterns of a generalist acorn weevil: insight into the biogeographical history of broadleaved deciduous and evergreen forests.

    Science.gov (United States)

    Aoki, Kyoko; Kato, Makoto; Murakami, Noriaki

    2009-05-16

    Climatic changes during glacial periods have had a major influence on the recent evolutionary history of living organisms, even in temperate forests on islands, where the land was not covered with ice sheets. We investigated the phylogeographical patterns of the weevil Curculio sikkimensis (Curculionidae), a generalist seed predator of Fagaceae plants living in both deciduous oak and evergreen forests of Japan. Its genetic structure was compared to that of another host-specific seed predator, C. hilgendorfi, inhabiting only evergreen forests. We examined 921 bp of mitochondrial DNA for 115 individuals collected from 33 populations of C. sikkimensis from 11 plant species of three genera, Quercus, Lithocarpus, and Castanopsis. An analysis of molecular variance revealed that a large proportion (almost 50%, P ages, in the southwestern and northeastern parts of the main islands, although these two types of forests are presently distributed in cool and warm temperate zones of Japan, respectively.

  2. Phylogeographical patterns of a generalist acorn weevil: insight into the biogeographical history of broadleaved deciduous and evergreen forests

    Directory of Open Access Journals (Sweden)

    Kato Makoto

    2009-05-01

    Full Text Available Abstract Background Climatic changes during glacial periods have had a major influence on the recent evolutionary history of living organisms, even in temperate forests on islands, where the land was not covered with ice sheets. We investigated the phylogeographical patterns of the weevil Curculio sikkimensis (Curculionidae, a generalist seed predator of Fagaceae plants living in both deciduous oak and evergreen forests of Japan. Its genetic structure was compared to that of another host-specific seed predator, C. hilgendorfi, inhabiting only evergreen forests. Results We examined 921 bp of mitochondrial DNA for 115 individuals collected from 33 populations of C. sikkimensis from 11 plant species of three genera, Quercus, Lithocarpus, and Castanopsis. An analysis of molecular variance revealed that a large proportion (almost 50%, P Conclusion Our results suggest that geology and historical environment have contributed to shaping the present genetic structure of C. sikkimensis. The geographical patterns of genetic differentiation in the Chugoku-Shikoku region observed in the two types of Fagaceae-associated Curculio in this study have also been observed in several plant species growing in warm and cool temperate zones of Japan. The occurrence of this common pattern suggests that deciduous oak and evergreen forests of Japan survived together, or adjacent to each other, in small refugia during glacial ages, in the southwestern and northeastern parts of the main islands, although these two types of forests are presently distributed in cool and warm temperate zones of Japan, respectively.

  3. 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

  4. 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.

  5. [Species-area relationship at different succession stages of monsoon evergreen broad-leaved forest in south subtropical area of Yunnan Province].

    Science.gov (United States)

    Liu, Wan-De; Su, Jian-Rong; Li, Shuai-Feng; Zhang, Zhi-Jun; Lang, Xue-Dong

    2011-02-01

    Based on the investigation data of monsoon evergreen broad-leaved forest at its different succession stages (primary, CP; 15 years of succession, CF; and 30 years of succession, CT) in Pu' er of Yunnan Province, this paper studied the species-area relationship of this forest at each succession stage. It was found that in the communities at each succession stage, the number of total species, trees, shrubs, and lianas had a significant correlation with sampling area, with the area explained over 94% of the total variation. The Z value of the total species (0.334) and trees (0.394) was the lowest at CT, whereas that of shrubs (0.437) and lianas (0.326) was the lowest at CF. No significant differences were observed in the intercepts of the species-area curve of total species, trees, shrubs, and lianas among different succession stages, but the coefficient of determination (R2) of the species-area curve of total species and lianas was the highest at CP. The richness of trees and shrubs at CF explained 99.9% of the variance of Z value, but the richness of total species, trees, shrubs, and lianas at CP and CT had no significant correlations with the Z value.

  6. 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.

  7. 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...

  8. Chemistry is Evergreen

    Indian Academy of Sciences (India)

    Srimath

    RESONANCE ⎜ March 2009. GENERAL ⎜ ARTICLE. Keywords. Green fluorescent protein,. FRET. Chemistry is Evergreen. 2008 Nobel Prize in Chemistry. Swagata Dasgupta. Swagata Dasgupta is an. Associate Professor in the. Department of Chemistry at IIT Kharagpur. Her research interests revolve around proteins and ...

  9. 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.

  10. How Do Evergreens Stay Ever-Green? Hands on Science.

    Science.gov (United States)

    Kepler, Lynne

    1993-01-01

    Provides instructional techniques, using samples from evergreen trees, to explain to school children the concept of adaptation. The techniques help children develop skills in observation, classification, communication, inferring, and predicting. A teacher's reproducible is included. (GLR)

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

    Science.gov (United States)

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

    2012-12-01

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

  12. The leaf size-twig size spectrum in evergreen broadleaved forest of ...

    African Journals Online (AJOL)

    The results showed that twig cross-sectional area of plant twigs were found to allometrically scale to individual leaf area and total leaf area that the twig supported, all with the common SMA (standardized major axis) slope being significantly larger than 1.0. However, the spectrum of twig leaf mass–stem mass was found to ...

  13. The transitional semi-evergreen bushland in Ethiopia

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  14. Nearest Neighborhood Characteristics of a Tropical Mixed Broadleaved Forest Stand

    Directory of Open Access Journals (Sweden)

    Hong Hai Nguyen

    2018-01-01

    Full Text Available Structural complexity and local biodiversity of species-rich tropical forests can be characterized by their spatial patterns, which contribute to species intra- and interspecific interactions. Aiming to describe spatial patterns of species at fine spatial scales, we applied the quantitative analyses based on the relationships of nearest neighbors of conspecific and heterospecific trees. In a two-hectare plot of a tropical broadleaved forest stand in central Vietnam with minimal human influence, all tree individuals with diameter at breast height ≥ 2.5 cm were mapped and their characteristics were recorded. We applied two different types of analyses: (1 Intraspecific structural characteristics using nearest neighbor statistics; (2 overall interspecific associations through a classification scheme based on bivariate nearest neighbor distribution function D12(r and Ripley’s K function K12(r. The findings showed that: (1 Most of studied species in the forest were highly mixed with other species, while conspecifics were regular to aggregated distribution at small spatial scales. Tree individuals with different diameter values were surrounded by heterospecific trees; (2 The majority of 306 species-species pairs showed spatial independence (66.7%, whereas 29.8% of all species showed an overall positive association and negative association consisted only a small percentage (3.5% up to spatial scales of 50 m. We found significant evidences of the main ecological theories such as dispersal limitation, Neutral theory, Janzen-Connell hypothesis, and other effects like the stochastic dilution. We suggest using both the bivariate distribution of the structural parameters and the spatial point pattern analysis based on nearest neighbor distance as advantageous approaches for further understanding of population structure, as well as discovering and protecting biodiversity in the future.

  15. Coarse root spatial distribution determined using a ground-penetrating radar technique in a subtropical evergreen broad-leaved forest, China.

    Science.gov (United States)

    Yan, Hui; Dong, Xinliang; Feng, Gang; Zhang, Shouren; Mucciardi, Anthony

    2013-11-01

    Coarse roots play a critical role in forest ecosystems and both abiotic and biotic factors affect their spatial distribution. To some extent, coarse root density may reflect the quantity of root biomass and biotic competition in forests. However, using traditional methods (e.g., excavation) to study coarse roots is challenging, because those methods are time-consuming and laborious. Furthermore, these destructive methods cannot be repeated in the same forests. Therefore, the discovery of non-destructive methods for root studies will be very significant. In this study, we used a ground-penetrating radar technique to detect the coarse root density of three habitats (ridge, slope and valley) and the dominant tree species (Castanopsis eyrei and Schima superba) in a subtropical forest. We found that (i) the mean of coarse root density for these three habitats was 88.04 roots m(-2), with roots being mainly distributed at depths of 0-40 cm. Coarse root densities were lower in deeper soils and in areas far from the trunk. (ii) Coarse root densities differed significantly among the three habitats studied here with slope habitat having the lowest coarse root density. Compared with S. superba, C. eyrei had more roots distributed in deeper soils. Furthermore, coarse roots with a diameter >3 cm occurred more frequently in the valleys, compared with root densities in ridge and slope habitats, and most coarse roots occurred at soil depths of 20-40 cm. (iii) The coarse root density correlated negatively with tree species richness at soil depths of 40-60 cm. The abundances of the dominant species, such as C. eyrei, Cyclobalanopsis glauca, Pinus massoniana, had significant impacts on coarse root density. (iv) The soil depth of 0-40 cm was the "basic distribution layer" for coarse roots since the majority of coarse roots were found in this soil layer with an average root density of 84.18 roots m(-2), which had no significant linear relationships with topography, tree species richness, rarefied tree species richness and tree density. Significant relationships between coarse root density and these factors were found at the soil depth of 40-60 cm, which was the "potential distribution layer" for coarse root distribution.

  16. Regenerative potential and functional composition of soil seed banks in remnant evergreen broad-leaved forests under urbanization in South China

    Science.gov (United States)

    J. Wang; L. Huang; H. Ren; Z. Sun; Q. Guo

    2015-01-01

    Soil seed banks can act as an important source in forest regeneration, and the information on the seed bank composition is vital for determining the resilience of plant communities under severe environments such as urban settings. In this study, we examined the seed bank density and functional composition, and their relationships with aboveground vegetation in three...

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

    Directory of Open Access Journals (Sweden)

    Tran Van Do

    2015-07-01

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

  18. 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 effects of SAR on soil solution chemistry became increasingly apparent as the experiment proceeded (except for Na(+) and dissolved organic carbon (DOC)). The net exports of NO₃(-), SO₄(2-), Mg(2+), and Ca(2+) increased about 42-86% under pH 2.5 treatment as compared to CK. The Ca(2+) was sensitive to SAR, and the soil could release Ca(2+) through mineral weathering to mitigate soil acidification. The concentration of exchangeable Al(3+) in the soil increased with increasing the 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.

  19. 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.

  20. Structure and Regeneration Status of Gedo Dry Evergreen Montane ...

    African Journals Online (AJOL)

    This study was conducted on Gedo Dry Evergreen Montane Forest in West Shewa Zone of Oromia National Regional State, 182-196 km west of Addis Ababa (Finfinne). The objective of the study was to determine structure and regeneration status of Gedo Forest. All trees and shrubs with Diameter at Breast Height (DBH) ...

  1. 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,…

  2. 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…

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

    NARCIS (Netherlands)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2010-11-01

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

  5. Evergreening by whom? A review of secondary patents for omeprazole.

    Science.gov (United States)

    Lloyd, Mike

    2013-11-01

    Evergreening, or the practice of technology developers to retain legal protection over valuable drugs beyond the normal patent term, is a well known practice by originators of successful drugs. Generic competitors also attempt similar strategies for commercial reasons. In this paper we look at secondary US and European patents in relation to the 'blockbuster' drug omeprazole (e.g., Prilosec® by AstraZeneca among other brands), with these secondary patents selected because they refer to the 'omeprazole' in either the title, abstract, Derwent Title or first claim. We find that 485 patents meet this criteria, with only 29% owned by the drugs originator (or known subsidiaries or predecessors). AstraZeneca was also the leading applicant by a number of measures, including grant ratio, number of patents filed, forward citation count, family member count and claim breadth.

  6. 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.

  7. Fragmentation patterns of evergreen oak woodlands in Southwestern Iberia

    DEFF Research Database (Denmark)

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

    2014-01-01

    Mediterranean evergreen oak woodlands (composed of Quercus suber L. and Quercus rotundifolia Lam.) are becoming increasingly fragmented in the human-modified landscapes of Southwestern Portugal and Spain. Previous studies have largely neglected to assess the spatial changes of oak woodlands...... in 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...

  8. [NDVI difference rate recognition model of deciduous broad-leaved forest based on HJ-CCD remote sensing data].

    Science.gov (United States)

    Wang, Yan; Tian, Qing-Jiu; Huang, Yan; Wei, Hong-Wei

    2013-04-01

    The present paper takes Chuzhou in Anhui Province as the research area, and deciduous broad-leaved forest as the research object. Then it constructs the recognition model about deciduous broad-leaved forest was constructed using NDVI difference rate between leaf expansion and flowering and fruit-bearing, and the model was applied to HJ-CCD remote sensing image on April 1, 2012 and May 4, 2012. At last, the spatial distribution map of deciduous broad-leaved forest was extracted effectively, and the results of extraction were verified and evaluated. The result shows the validity of NDVI difference rate extraction method proposed in this paper and also verifies the applicability of using HJ-CCD data for vegetation classification and recognition.

  9. 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 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.

  10. Tree-oriented silviculture for growing valuable broadleaved tree species in Turkey oak coppices

    Directory of Open Access Journals (Sweden)

    Diego Giuliarelli

    2016-11-01

    Full Text Available Valuable broadleaved tree species can play an important role in mixed-forest management; in these forests, silviculture may play an important role in getting high value timber. This paper illustrates a tree-oriented silviculture approach with an application in a Turkey oak coppice stand in Central Italy. This silvicultural approach has been developed in the last decades in France, Germany, Switzerland. The rationale behind the tree-oriented approach is to select a number of target sporadic tree species with valuable timber and to support their growth through repeated thinning from above. We tested the effectiveness of this silviculture approach as an alternative to customary coppice management in Italy, which is traditionally focused on the dominant tree species and does not consider valuable broadleaved tree species. The two silviculture approaches (tree-oriented and customary coppicing were compared through a financial evaluation of the economic convenience of the two alternatives in a Turkey oak coppice stand in Central Italy

  11. The C-household of young broad-leaved and conifer tree species exposed to long-term carbon limitation by shading

    Science.gov (United States)

    Weber, Raphael; Hoch, Günter

    2017-04-01

    Non-structural carbohydrates (NSC, i.e. free sugars and starch) are regarded as freely available carbon (C) reserves in plants. They are often quantified to estimate a plant's C-balance, assuming that NSC are controlled by the net-balance between photo-assimilation and C-usage (respiration, growth and other sinks). Within a recent field experiment, we investigated the extent, to which C-reserves (NSC) can be formed in young trees against prevailing C-sink demands (growth) under C-limitation. A total of almost 1000 individuals of two-year-old tree saplings from 6 deciduous, broadleaved species and 4 evergreen conifer species were planted on a field side. Half of the trees per species were treated with long-term C-limitation by exposing them to continuous deep shade conditions (5% of natural PPFD) under a permanent shading tent. C gas-exchange, growth and NSC tissue concentrations were analyzed in shaded and unshaded saplings for two consecutive years. Three months after the beginning of the experiment, leaf photosynthesis acclimatized to the low light conditions, with leaves of shaded trees showing significantly higher SLA and lower light saturation and maximum photosynthesis. During the second season of the experiment, most species exhibited very strong reductions in NSC, but much less pronounced reductions in growth. In contrast, other species, with few exceptions, kept NSC concentrations similar to unshaded controls, while growth virtually stopped under deep shade. In conclusion, we found species-specific strategies in the trees' C-household after two years of C-limitation, that fall into two major carbon allocation strategies: 1) "C-spenders", which deplete C reserves in order to keep up significant growth, and 2) "C-savers", which reduce C sink activities to a minimum in order to store substantial amounts of C reserves. Overall, early-successional species tended to follow the first strategy, while late-successional species tended to save higher C reserve pools

  12. Water uptake of Alaskan tundra evergreens during the winter–spring transition

    National Research Council Canada - National Science Library

    Moser, Jonathan G; Oberbauer, Steven F; Sternberg, Leonel da S. L; Ellsworth, Patrick Z; Starr, Gregory; Mortazavi, Behzad; Olivas, Paulo C

    2016-01-01

    .... However, liquid water available for plant uptake may be limited at this time. The study objective was to determine whether evergreen plants are actively taking up water while under snow and/or immediately following snowmelt during spring thaw...

  13. 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.

  14. 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

  15. 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.

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

    Science.gov (United States)

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

    2012-03-01

    Plant defence can be induced by exposing plants to the plant hormone jasmonic acid (JA) or its volatile ester, methyl jasmonate (MeJA). Carrageenans (Carr) - sulphated D-galactans extracted from red algae - can also induce plant defences. In this study, the effects of exogenous MeJA and Carr application (concentration 300 and 12.7 μmol, respectively) on volatile emissions from two widespread evergreen woody species, Pinus sylvestris (nine Turkish and one Finnish provenance) and Quercus ilex (Italian provenance) were investigated. We collected headspace samples from seedlings and analysed the quality and quantity of volatile compounds emitted by treated and control plants. In total, 19 monoterpenes, 10 sesquiterpenes, 10 green leaf volatiles (GLVs) and two aromatic compounds were emitted by P. sylvestris from all the provenances studied. Foliar MeJA application clearly affected the volatile profiles of trees from all the provenances. Effects of Carr were genotype specific. In Q. ilex, emissions of sesquiterpenes, GLVs and the homoterpene (E)-DMNT were all induced by MeJA application. However, emissions of most constitutively emitted monoterpenes were significantly reduced. Carr application also led to a significant reduction in monoterpene emissions, but without corresponding increases in other emissions. Our results indicate that exogenously applied MeJA and Carr can both significantly modify the volatile profiles of P. sylvestris and Q. ilex, but also that there are important provenance- and species-specific differences in the overall degree of elicitation and compositions of elicited compounds. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. The rhizospheric microbial community structure and diversity of deciduous and evergreen forests in Taihu Lake area, China

    National Research Council Canada - National Science Library

    Zhiwen Wei; Xiaolong Hu; Xunhang Li; Yanzhou Zhang; Leichun Jiang; Jing Li; Zhengbing Guan; Yujie Cai; Xiangru Liao

    2017-01-01

    .... However, how the soil and vegetation factors affect the diversity and community composition of bacteria is poorly understood, especially for bacteria associated with evergreen and deciduous trees...

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

    Science.gov (United States)

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

    2015-12-01

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

  19. Unrestricted quality of seeds in European broad-leaved tree species growing at the cold boundary of their distribution

    Science.gov (United States)

    Kollas, C.; Vitasse, Y.; Randin, C. F.; Hoch, G.; Körner, C.

    2012-01-01

    Background and Aims The low-temperature range limit of tree species may be determined by their ability to produce and disperse viable seeds. Biological processes such as flowering, pollen transfer, pollen tube growth, fertilization, embryogenesis and seed maturation are expected to be affected by cold temperatures. The aim of this study was to assess the quality of seeds of nine broad-leaved tree species close to their elevational limit. Methods We studied nine, mostly widely distributed, European broad-leaved tree species in the genera Acer, Fagus, Fraxinus, Ilex, Laburnum, Quercus, Sorbus and Tilia. For each species, seeds were collected from stands close to optimal growth conditions (low elevation) and from marginal stands (highest elevation), replicated in two regions in the Swiss Alps. Measurements included seed weight, seed size, storage tissue quality, seed viability and germination success. Key Results All species examined produced a lot of viable seeds at their current high-elevation range limit during a summer ranked ‘normal’ by long-term temperature records. Low- and high-elevation seed sources showed hardly any trait differences. The concentration of non-structural carbohydrates tended to be higher at high elevation. Additionally, in one species, Sorbus aucuparia, all measured traits showed significantly higher seed quality in high-elevation seed sources. Conclusions For the broad-leaved tree taxa studied, the results are not in agreement with the hypothesis of reduced quality of seeds in trees at their high-elevation range limits. Under the current climatic conditions, seed quality does not constitute a serious constraint in the reproduction of these broad-leaved tree species at their high-elevation limit. PMID:22156401

  20. Natural regeneration of broadleaved tree species in southern Sweden - Effects of silvicultural treatments and seed dispersal from surrounding stands

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Matts [Swedish Univ. of Agricultural Sciences, Alnarp (Sweden). Southern Swedish Forest Research Centre

    2001-07-01

    The objective of the present thesis was to examine the effects of silvicultural treatments and seed dispersal from surrounding stands on the establishment of natural regeneration of broad-leaved tree species in southern Sweden. Most of the broad-leaved tree species that occur naturally in forests in southern Sweden were studied but birch (Betula pendula Ehrh./B. pubescens Roth) was the most common species and present in equal numbers in all studies. The wind dispersal of seeds of seven species was studied and great variations were found. This could mainly be explained by differences in seed morphology. The effect of soil scarification was examined in all five studies and was generally found to be positive for the establishment of the studied broad-leaved species. However, in some cases the scarification was not positive for the establishment. The reason for this was hypothesised to be that the seed supply was limited, or an effect of large and/or animal-dispersed seeds. The effect of shelterwood was examined in three studies and was found to be positive for animal-dispersed species but negative for shade-intolerant species, although a sparse shelterwood can be used to regenerate birch. Slash removal was included in one study and found to be positive for the establishment of birch. This thesis showed that regeneration treatments can be used to increase the establishment of naturally regenerated broad-leaved tree seedlings, but the stand structure and species composition must be regulated with pre-commercial thinning. However, the effect of variations in seed production and seed dispersal must be closely examined from a time and a space perspective prior to any forecasts regarding the effects of regeneration treatments.

  1. Unrestricted quality of seeds in European broad-leaved tree species growing at the cold boundary of their distribution.

    Science.gov (United States)

    Kollas, C; Vitasse, Y; Randin, C F; Hoch, G; Körner, C

    2012-02-01

    The low-temperature range limit of tree species may be determined by their ability to produce and disperse viable seeds. Biological processes such as flowering, pollen transfer, pollen tube growth, fertilization, embryogenesis and seed maturation are expected to be affected by cold temperatures. The aim of this study was to assess the quality of seeds of nine broad-leaved tree species close to their elevational limit. We studied nine, mostly widely distributed, European broad-leaved tree species in the genera Acer, Fagus, Fraxinus, Ilex, Laburnum, Quercus, Sorbus and Tilia. For each species, seeds were collected from stands close to optimal growth conditions (low elevation) and from marginal stands (highest elevation), replicated in two regions in the Swiss Alps. Measurements included seed weight, seed size, storage tissue quality, seed viability and germination success. All species examined produced a lot of viable seeds at their current high-elevation range limit during a summer ranked 'normal' by long-term temperature records. Low- and high-elevation seed sources showed hardly any trait differences. The concentration of non-structural carbohydrates tended to be higher at high elevation. Additionally, in one species, Sorbus aucuparia, all measured traits showed significantly higher seed quality in high-elevation seed sources. For the broad-leaved tree taxa studied, the results are not in agreement with the hypothesis of reduced quality of seeds in trees at their high-elevation range limits. Under the current climatic conditions, seed quality does not constitute a serious constraint in the reproduction of these broad-leaved tree species at their high-elevation limit.

  2. CO2-induced decrease of canopy stomatal conductance of mature conifer and broadleaved trees

    Science.gov (United States)

    Tor-ngern, P.; Oren, R.; Ward, E. J.; Palmroth, S.; McCarthy, H. R.; domec, J.

    2013-12-01

    Together with canopy leaf area, mean canopy stomatal conductance (GS) controls forest-atmosphere exchanges of energy and mass. Expectations for stomatal response to elevated atmospheric [CO2] (CO2E) based on seedling studies range from large decreases of conductance in foliage of broadleaved species to little or no response in conifers. These responses are not directly translatable to forest canopies, and their underlying mechanisms are ill-defined. The uncertainty of canopy-scale stomatal response to CO2E reduces confidence in modeled predictions of future forest productivity and carbon sequestration, and of partitioning of net radiation between latent and sensible heat flux. Thus, debates on the potential effects of CO2E-induced stomatal closure continue. We used a Free-Air CO2 Enrichment (FACE) experiment in a 27-year-old, 25 m tall forest, to generate a whole-canopy CO2-response and test whether canopy-scale GS response to CO2E of widely distributed, fast growing shade-intolerant species, Pinus taeda (L.) and co-occurring broadleaved species dominated by Liquidambar styraciflua (L.), was indirectly affected by slow changes such as hydraulic adjustments and canopy development, as opposed to quickly responding to CO2 concentrations in the leaf-internal air space. Our results show indirect CO2E-induced reductions of GS of 10% and 30%, respectively, and no signs of a direct stomatal response even as CO2E was pushed to 685 μmol mol-1 (~1.8 of ambient). Modeling the effect of CO2E on the water, energy and carbon cycles of forests must consider slow-response indirect mechanisms producing large variation in the reduction of GS, such as the previously observed inconsistent CO2E effect on canopy leaf area and plant hydraulics. Moreover, the new generation of CO2E studies in forests must allow indirect effects caused by, e.g., hydraulic adjustments and canopy development, to play out. Such acclimation will be particularly prolonged in slowly developing ecosystems, such

  3. 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

  4. Biological control of broad-leaved dock infestation in wheat using plant antagonistic bacteria under field conditions.

    Science.gov (United States)

    Abbas, Tasawar; Zahir, Zahir Ahmad; Naveed, Muhammad; Aslam, Zubair

    2017-06-01

    Conventional weed management systems have produced many harmful effects on weed ecology, human health and environment. Biological control of invasive weeds may be helpful to minimize these harmful effects and economic losses incurred to crops by weeds. In our earlier studies, plant antagonistic bacteria were obtained after screening a large number of rhizobacteria for production of phytotoxic substances and effects on wheat and its associated weeds under laboratory conditions. In this study, five efficient strains inhibitory to broad-leaved dock and non-inhibitory to wheat were selected and applied to broad-leaved dock co-seeded with wheat both in pot trial and chronically infested field trial. Effects of plant antagonistic bacteria on the weed and infested wheat were studied at tillering, booting and harvesting stage of wheat. The applied strains significantly inhibited the germination and growth of the weed to variable extent. Similarly, variable recovery in losses of grain and straw yield of infested wheat from 11.6 to 68 and 13 to 72.6% was obtained in pot trial while from 17.3 to 62.9 and 22.4 to 71.3% was obtained in field trial, respectively. Effects of plant antagonistic bacteria were also evident from the improvement in physiology and nutrient contents of infested wheat. This study suggests the use of these plant antagonistic bacteria to biologically control infestation of broad-leaved dock in wheat under field conditions.

  5. Predicting Potential Habitat of Conifer and Broad-leaved Tree Using Environmental Variables and Seed Dispersal Ability

    Science.gov (United States)

    Heo, H. K.; Lee, D. K.; Mo, Y.; Kim, H. G.

    2016-12-01

    Research into predicting potential species distribution within forests is ongoing in relation to forest management. Conifer and broad-leaved tree, two main distinctive components in forests which are important concerning the management of forest, are used to predict potential forest distribution. Regarding prediction of potential tree species habitat distribution, environmental variables are commonly used to determine conditions that species can inhabit. However, seed dispersal ability was not used in species distribution model because it reflects succession process which is difficult to use.In this research, in addition to environmental variables, distance value was used to represent seed dispersal ability to predict tree distribution. Research was done in Namsan (Mt.) Sangju-si, Gyeongsangbuk-do, Korea, where few tree species exist according to detailed vegetation map, as a case study. To analyze the suitable environmental conditions and dispersal ability of conifer and broad-leaved trees, past distribution changing patterns were used. Past forest distribution maps (1984, 1995, 2005 and 2014) were used which was classified by Landsat images. Using these results, potential habitats of conifer and broad-leaved trees were predicted for 2024 and 2034. Furthermore, to quantify the uncertainty of prediction, monte carlo simulation was proceeded. As a result, it was possible to predict potential habitats using environmental variables and seed dispersal ability. Moreover, the dispersal ability turned out to be an important variable to predict change of potential habitat.

  6. 76 FR 51367 - China Shipping Container Lines Co., Ltd.; COSCO Container Lines Company Limited; Evergreen Line A...

    Science.gov (United States)

    2011-08-18

    ... China Shipping Container Lines Co., Ltd.; COSCO Container Lines Company Limited; Evergreen Line A Joint Service Agreement; Hanjin Shipping Co., Ltd.; Horizon Lines, LLC; Kawasaki Kisen Kaisha, Ltd.; Nippon... Container Lines Co., Ltd.; COSCO Container Lines Company Limited; Evergreen Line A Joint Service Agreement...

  7. 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 for...

  8. A simple algorithm for large-scale mapping of evergreen forests in tropical America, Africa and Asia

    Science.gov (United States)

    Xiangming Xiao; Chandrashekhar M. Biradar; Christina Czarnecki; Tunrayo Alabi; Michael Keller

    2009-01-01

    The areal extent and spatial distribution of evergreen forests in the tropical zones are important for the study of climate, carbon cycle and biodiversity. However, frequent cloud cover in the tropical regions makes mapping evergreen forests a challenging task. In this study we developed a simple and novel mapping algorithm that is based on the temporal profile...

  9. 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.

  10. Trade-offs between seedling growth and survival in deciduous broadleaved trees in a temperate forest.

    Science.gov (United States)

    Seiwa, Kenji

    2007-03-01

    In spatially heterogeneous environments, a trade-off between seedling survival and relative growth rate may promote the coexistence of plant species. In temperate forests, however, little support for this hypothesis has been found under field conditions, as compared with shade-house experiments. Performance trade-offs were examined over a large resource gradient in a temperate hardwood forest. The relationship between seedling survival and seedling relative growth rate in mass (RGR(M)) or height (RGR(H)) was examined at three levels of canopy cover (forest understorey, FU; small gap, SG; and large gap, LG) and at two microsites within each level of canopy cover (presence or absence of leaf litter) for five deciduous broad-leaved tree species with different seed sizes. Within each species, both RGR(M) and RGR(H) usually increased with increasing light levels (in the order FU temperate forests, and that further species diversity would be promoted by increased spatial heterogeneity. The intraspecific trade-off between survival and RGR in Acer suggests that it has broad habitat requirements, whereas Betula has narrow habitat requirements and specializes in high-light environments.

  11. 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.

  12. Effect of broad-leaved dock (Rumex obtusifolius L. on grass silage quality

    Directory of Open Access Journals (Sweden)

    Stanislav Hejduk

    2008-01-01

    Full Text Available The effect of broad-leaved dock (BLD on nutritive value and fermentation process of grassland fo­ra­ges was studied together with the effect of formic acid addition (4.0 vs. 2.0 l.t−1 and inoculation by lactic acid bacteria (LAB. Herbage of dock exhibits low DM content, crude protein and fibre contents, yet its NEL concentration is low.Despite of the low DM content in BLD silages, the fermentation process was successful, but the si­la­ges show significantly higher contents of lactic acid (176.5 %, acetic acid (198.2 % and lover pH va­lues (4.24 vs. 4.39 as compared with than the grass silage. Silages made of dock do not contain bu­ty­ric acid and exhibit low rates of proteolysis (9.2 % NH3 from total N. Addition of formic acid shows in the group of assessed silages significant reduction content of lactic acid (−6.5 % and acetic acid (−9.3 % and significant decrease of pH value (−0.05. The use of probiotic preparation leads to significantly higher lactic acid production (+39.3 % and to lover pH value (−0.23 as compare with control without additions.

  13. Allometric biomass equations for 12 tree species in coniferous and broadleaved mixed forests, Northeastern China.

    Science.gov (United States)

    He, Huaijiang; Zhang, Chunyu; Zhao, Xiuhai; Fousseni, Folega; Wang, Jinsong; Dai, Haijun; Yang, Song; Zuo, Qiang

    2018-01-01

    Understanding forest carbon budget and dynamics for sustainable resource management and ecosystem functions requires quantification of above- and below-ground biomass at individual tree species and stand levels. In this study, a total of 122 trees (9-12 per species) were destructively sampled to determine above- and below-ground biomass of 12 tree species (Acer mandshuricum, Acer mono, Betula platyphylla, Carpinus cordata, Fraxinus mandshurica, Juglans mandshurica, Maackia amurensis, P. koraiensis, Populus ussuriensis, Quercus mongolica, Tilia amurensis and Ulmus japonica) in coniferous and broadleaved mixed forests of Northeastern China, an area of the largest natural forest in the country. Biomass allocation was examined and biomass models were developed using diameter as independent variable for individual tree species and all species combined. The results showed that the largest biomass allocation of all species combined was on stems (57.1%), followed by coarse root (21.3%), branch (18.7%), and foliage (2.9%). The log-transformed model was statistically significant for all biomass components, although predicting power was higher for species-specific models than for all species combined, general biomass models, and higher for stems, roots, above-ground biomass, and total tree biomass than for branch and foliage biomass. These findings supplement the previous studies on this forest type by additional sample trees, species and locations, and support biomass research on forest carbon budget and dynamics by management activities such as thinning and harvesting in the northeastern part of China.

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. A remotely sensed pigment index reveals photosynthetic phenology in evergreen conifers

    Science.gov (United States)

    John A. Gamon; K. Fred Huemmrich; Christopher Y. S. Wong; Ingo Ensminger; Steven Garrity; David Y. Hollinger; Asko Noormets; Josep Peñuelas

    2016-01-01

    In evergreen conifers, where the foliage amount changes little with season, accurate detection of the underlying “photosynthetic phenology” from satellite remote sensing has been difficult, presenting challenges for global models of ecosystem carbon uptake. Here, we report a close correspondence between seasonally changing foliar pigment levels, expressed as...

  19. 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

    Patterns of ozone concentration ([O(3)]), O(3) deposition velocity (nu(d)) and O(3) flux (F(c)) over an evergreen forest canopy are shown in relation to measuring method, physiological activity of the trees, and lime of year. The gradient and eddy correlation methods were compared and showed...

  20. Similar variation in carbon storage between deciduous and evergreen treeline species across elevational gradients.

    Science.gov (United States)

    Fajardo, Alex; Piper, Frida I; Hoch, Günter

    2013-08-01

    The most plausible explanation for treeline formation so far is provided by the growth limitation hypothesis (GLH), which proposes that carbon sinks are more restricted by low temperatures than by carbon sources. Evidence supporting the GLH has been strong in evergreen, but less and weaker in deciduous treeline species. Here a test is made of the GLH in deciduous-evergreen mixed species forests across elevational gradients, with the hypothesis that deciduous treeline species show a different carbon storage trend from that shown by evergreen species across elevations. Tree growth and concentrations of non-structural carbohydrates (NSCs) in foliage, branch sapwood and stem sapwood tissues were measured at four elevations in six deciduous-evergreen treeline ecotones (including treeline) in the southern Andes of Chile (40°S, Nothofagus pumilio and Nothofagus betuloides; 46°S, Nothofagus pumilio and Pinus sylvestris) and in the Swiss Alps (46°N, Larix decidua and Pinus cembra). Tree growth (basal area increment) decreased with elevation for all species. Regardless of foliar habit, NSCs did not deplete across elevations, indicating no shortage of carbon storage in any of the investigated tissues. Rather, NSCs increased significantly with elevation in leaves (P treeline species are sink limited when faced with decreasing temperatures. Despite the overall higher requirements of deciduous tree species for carbon storage, no indication was found of carbon limitation in deciduous species in the alpine treeline ecotone.

  1. Winter-Deciduous versus Evergreen Habit in Mediterranean Regions: A Model

    Science.gov (United States)

    Mark A. Blumler

    1991-01-01

    Although winter-deciduous species are presumed to be "out-of-phase" with the mediterranean climate regime, distributional evidence suggests some taxa may be more tolerant of summer drought than evergreen sclerophylls. Deciduous species possess several features that confer advantage in extreme summer dry regions: drought-deciduousness, an efficient response to...

  2. Artocarpus hirsutus Lam. of Moraceae is a large evergreen tree with ...

    Indian Academy of Sciences (India)

    Artocarpus hirsutus Lam. of Moraceae is a large evergreen tree with milky latex. This species occurs wild and is also cultivated for its fruit, which is edible. Leaves are simple and dark green. The branchlets are covered with rust-brown hairs. Inflorescence is axillary. The female inflorescence is globose with individualjlowers ...

  3. A gap-filling model for eddy covariance CO2 flux: Estimating carbon assimilated by a subtropical evergreen broad-leaved forest at the Lien-Hua-Chih flux observation site

    Science.gov (United States)

    Lan, C. Y.; Li, M. H.; Chen, Y. Y.

    2016-12-01

    Appropriate estimations of gaps appeared in eddy covariance (EC) flux observations are critical to the reliability of long-term EC applications. In this study we present a semi-parametric multivariate gap-filling model for tower-based measurement of CO2 flux. The raw EC data passing QC/QA was separated into two groups, clear sky, having net radiation greater than 50 W/m2, and nighttime/cloudy. For the clear sky conditions, the principle component analysis (PCA) was used to resolve the multicollinearity relationships among various environmental variables, including net radiation, wind speed, vapor pressure deficit, soil moisture deficit, leaf area index, and soil temperature, in association with CO2 assimilated by forest. After the principal domains were determined by the PCA, the relationships between CO2 fluxes and selected PCs (key factors) were built up by nonlinear interpolations to estimate the gap-filled CO2 flux. In view of limited photosynthesis at nighttime/cloudy conditions, respiration rate of the forest ecosystem was estimated by the Lloyd-Tylor equation. Artificial gaps were randomly selected to exam the applicability of our PCA approach. Based on tower-based measurement of CO2 flux at the Lien-Hua-Chih site, a total of 5.8 ton-C/ha/yr was assimilated in 2012.

  4. Do evergreen and deciduous trees have different effects on net N mineralization in soil?

    Science.gov (United States)

    Mueller, Kevin E; Hobbie, Sarah E; Oleksyn, Jacek; Reich, Peter B; Eissenstat, David M

    2012-06-01

    Evergreen and deciduous plants are widely expected to have different impacts on soil nitrogen (N) availability because of differences in leaf litter chemistry and ensuing effects on net N mineralization (N(min)). We evaluated this hypothesis by compiling published data on net N(min) rates beneath co-occurring stands of evergreen and deciduous trees. The compiled data included 35 sets of co-occurring stands in temperate and boreal forests. Evergreen and deciduous stands did not have consistently divergent effects on net N(min) rates; net N(min) beneath deciduous trees was higher when comparing natural stands (19 contrasts), but equivalent to evergreens in plantations (16 contrasts). We also compared net N(min) rates beneath pairs of co-occurring genera. Most pairs of genera did not differ consistently, i.e., tree species from one genus had higher net N(min) at some sites and lower net N(min) at other sites. Moreover, several common deciduous genera (Acer, Betula, Populus) and deciduous Quercus spp. did not typically have higher net N(min) rates than common evergreen genera (Pinus, Picea). There are several reasons why tree effects on net N(min) are poorly predicted by leaf habit and phylogeny. For example, the amount of N mineralized from decomposing leaves might be less than the amount of N mineralized from organic matter pools that are less affected by leaf litter traits, such as dead roots and soil organic matter. Also, effects of plant traits and plant groups on net N(min) probably depend on site-specific factors such as stand age and soil type.

  5. Water uptake of Alaskan tundra evergreens during the winter-spring transition.

    Science.gov (United States)

    Moser, Jonathan G; Oberbauer, Steven F; Sternberg, Leonel da S L; Ellsworth, Patrick Z; Starr, Gregory; Mortazavi, Behzad; Olivas, Paulo C

    2016-02-01

    The cold season in the Arctic extends over 8 to 9 mo, yet little is known about vascular plant physiology during this period. Evergreen species photosynthesize under the snow, implying that they are exchanging water with the atmosphere. However, liquid water available for plant uptake may be limited at this time. The study objective was to determine whether evergreen plants are actively taking up water while under snow and/or immediately following snowmelt during spring thaw. In two in situ experiments, one at the plot level and another at the individual species level, (2)H-labeled water was used as a tracer injected beneath the snow, after which plant stems and leaves were tested for the presence of the label. In separate experiments, excised shoots of evergreen species were exposed to (2)H-labeled water for ∼5 s or 60 min and tested for foliar uptake of the label. In both the plot-level and the species-level experiments, some (2)H-labeled water was found in leaves and stems. Additionally, excised individual plant shoots exposed to labeled water for 60 min took up significantly more (2)H-label than shoots exposed ∼5 s. Evergreen tundra plants take up water under snow cover, some via roots, but also likely by foliar uptake. The ability to take up water in the subnivean environment allows evergreen tundra plants to take advantage of mild spring conditions under the snow and replenish carbon lost by winter respiration. © 2016 Botanical Society of America.

  6. Temperature sensitivity of microbial respiration of fine root litter in a temperate broad-leaved forest.

    Directory of Open Access Journals (Sweden)

    Naoki Makita

    Full Text Available The microbial decomposition respiration of plant litter generates a major CO2 efflux from terrestrial ecosystems that plays a critical role in the regulation of carbon cycling on regional and global scales. However, the respiration from root litter decomposition and its sensitivity to temperature changes are unclear in current models of carbon turnover in forest soils. Thus, we examined seasonal changes in the temperature sensitivity and decomposition rates of fine root litter of two diameter classes (0-0.5 and 0.5-2.0 mm of Quercus serrata and Ilex pedunculosa in a deciduous broad-leaved forest. During the study period, fine root litter of both diameter classes and species decreased approximately exponentially over time. The Q10 values of microbial respiration rates of root litter for the two classes were 1.59-3.31 and 1.28-6.27 for Q. serrata and 1.36-6.31 and 1.65-5.86 for I. pedunculosa. A significant difference in Q10 was observed between the diameter classes, indicating that root diameter represents the initial substrate quality, which may determine the magnitude of Q10 value of microbial respiration. Changes in these Q10 values were related to seasonal soil temperature patterns; the values were higher in winter than in summer. Moreover, seasonal variations in Q10 were larger during the 2-year decomposition period than the 1-year period. These results showed that the Q10 values of fine root litter of 0-0.5 and 0.5-2.0 mm have been shown to increase with lower temperatures and with the higher recalcitrance pool of the decomposed substrate during 2 years of decomposition. Thus, the temperature sensitivity of microbial respiration in root litter showed distinct patterns according to the decay period and season because of the temperature acclimation and adaptation of the microbial decomposer communities in root litter.

  7. Temperature sensitivity of microbial respiration of fine root litter in a temperate broad-leaved forest.

    Science.gov (United States)

    Makita, Naoki; Kawamura, Ayumi

    2015-01-01

    The microbial decomposition respiration of plant litter generates a major CO2 efflux from terrestrial ecosystems that plays a critical role in the regulation of carbon cycling on regional and global scales. However, the respiration from root litter decomposition and its sensitivity to temperature changes are unclear in current models of carbon turnover in forest soils. Thus, we examined seasonal changes in the temperature sensitivity and decomposition rates of fine root litter of two diameter classes (0-0.5 and 0.5-2.0 mm) of Quercus serrata and Ilex pedunculosa in a deciduous broad-leaved forest. During the study period, fine root litter of both diameter classes and species decreased approximately exponentially over time. The Q10 values of microbial respiration rates of root litter for the two classes were 1.59-3.31 and 1.28-6.27 for Q. serrata and 1.36-6.31 and 1.65-5.86 for I. pedunculosa. A significant difference in Q10 was observed between the diameter classes, indicating that root diameter represents the initial substrate quality, which may determine the magnitude of Q10 value of microbial respiration. Changes in these Q10 values were related to seasonal soil temperature patterns; the values were higher in winter than in summer. Moreover, seasonal variations in Q10 were larger during the 2-year decomposition period than the 1-year period. These results showed that the Q10 values of fine root litter of 0-0.5 and 0.5-2.0 mm have been shown to increase with lower temperatures and with the higher recalcitrance pool of the decomposed substrate during 2 years of decomposition. Thus, the temperature sensitivity of microbial respiration in root litter showed distinct patterns according to the decay period and season because of the temperature acclimation and adaptation of the microbial decomposer communities in root litter.

  8. Physiological minimum temperatures for root growth in seven common European broad-leaved tree species.

    Science.gov (United States)

    Schenker, Gabriela; Lenz, Armando; Körner, Christian; Hoch, Günter

    2014-03-01

    Temperature is the most important factor driving the cold edge distribution limit of temperate trees. Here, we identified the minimum temperatures for root growth in seven broad-leaved tree species, compared them with the species' natural elevational limits and identified morphological changes in roots produced near their physiological cold limit. Seedlings were exposed to a vertical soil-temperature gradient from 20 to 2 °C along the rooting zone for 18 weeks. In all species, the bulk of roots was produced at temperatures above 5 °C. However, the absolute minimum temperatures for root growth differed among species between 2.3 and 4.2 °C, with those species that reach their natural distribution limits at higher elevations also tending to have lower thermal limits for root tissue formation. In all investigated species, the roots produced at temperatures close to the thermal limit were pale, thick, unbranched and of reduced mechanical strength. Across species, the specific root length (m g(-1) root) was reduced by, on average, 60% at temperatures below 7 °C. A significant correlation of minimum temperatures for root growth with the natural high elevation limits of the investigated species indicates species-specific thermal requirements for basic physiological processes. Although these limits are not necessarily directly causative for the upper distribution limit of a species, they seem to belong to a syndrome of adaptive processes for life at low temperatures. The anatomical changes at the cold limit likely hint at the mechanisms impeding meristematic activity at low temperatures.

  9. 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.

  10. Temperature Sensitivity of Microbial Respiration of Fine Root Litter in a Temperate Broad-Leaved Forest

    Science.gov (United States)

    Makita, Naoki; Kawamura, Ayumi

    2015-01-01

    The microbial decomposition respiration of plant litter generates a major CO2 efflux from terrestrial ecosystems that plays a critical role in the regulation of carbon cycling on regional and global scales. However, the respiration from root litter decomposition and its sensitivity to temperature changes are unclear in current models of carbon turnover in forest soils. Thus, we examined seasonal changes in the temperature sensitivity and decomposition rates of fine root litter of two diameter classes (0–0.5 and 0.5–2.0 mm) of Quercus serrata and Ilex pedunculosa in a deciduous broad-leaved forest. During the study period, fine root litter of both diameter classes and species decreased approximately exponentially over time. The Q10 values of microbial respiration rates of root litter for the two classes were 1.59–3.31 and 1.28–6.27 for Q. serrata and 1.36–6.31 and 1.65–5.86 for I. pedunculosa. A significant difference in Q10 was observed between the diameter classes, indicating that root diameter represents the initial substrate quality, which may determine the magnitude of Q10 value of microbial respiration. Changes in these Q10 values were related to seasonal soil temperature patterns; the values were higher in winter than in summer. Moreover, seasonal variations in Q10 were larger during the 2-year decomposition period than the 1-year period. These results showed that the Q10 values of fine root litter of 0–0.5 and 0.5–2.0 mm have been shown to increase with lower temperatures and with the higher recalcitrance pool of the decomposed substrate during 2 years of decomposition. Thus, the temperature sensitivity of microbial respiration in root litter showed distinct patterns according to the decay period and season because of the temperature acclimation and adaptation of the microbial decomposer communities in root litter. PMID:25658106

  11. Isoprene Emission from Quercus Serrata in the deciduous broad-leaved forest

    Science.gov (United States)

    Okumura, M.; Tani, A.; Kominami, Y.; Takanashi, S.; Kosugi, Y.; Tohno, S.

    2006-12-01

    1. INTRODUCTION Isoprene is a biogenic volatile organic compound (BVOC) emitted by many plant species. Isoprene emission contributes to the reactive carbon budget entering the troposphere. In Japan efforts to measure and understand the mechanism controlling BVOC emissions and to establish their emission inventories for the country have not been extensive, despite the fact that Japan has a large area of forests composed of coniferous and/or deciduous tree species (about 70% of total land area) and that forestry statistics across Japan are available (Tani et al. 2002). 2. METHODS The measurements were taken in the deciduous broad-leaved forest, Yamashiro, Kyoto. The isoprene emission, net assimilation rate, stomatal conductance, photosynthetically active radiation (PAR), air and leaf temperature, relative humidity was measured on June, July, August 2006 using a LI-6400 portable photosynthesis system (Li-Cor Inc., Lincoln, NE, USA). Isoprene samples from the LI-6400 cuvette was trapped by adsorbents (Tenax 200mg and Carbotrap 100mg) packed into stainless steel tubes (Perkin Elmer). Samples were analyzed using GC-MS system (Shimadzu QP5050A). Samples underwent two stage thermal desorption (Perkin-Elmer ATD). 3. RESULTS The obvious effect of PAR on isoprene emissions and photosynthesis rates were investigated. Temporal variations of isoprene emissions and photosynthesis rates for sun leaves and a shade leaves were investigated. Isoprene sampling term is 7:00-9:00, 9:00-11:00, 11:00-13:00, 13:00-15:00, 15:00-17:00, and 17:00-18:30. Number of samples is 4-6 leaves. Both sun leaves and shade leaves, isoprene emissions reached their peak around noon, while for sun leaves the largest photosynthesis rates during morning and the subsequent decrease were observed as shown. Carbon ratio (carbon of isoprene emission /carbon of photosynthesis by mass unit) were about 1-3%. REFERENCES Tani, A., Nozoe, S., Aoki, M., Hewiit, C. N., 2002. Monoterpene fluxes measured above a Japanese

  12. Resource partitioning by evergreen and deciduous species in a tropical dry forest.

    Science.gov (United States)

    Álvarez-Yépiz, Juan C; Búrquez, Alberto; Martínez-Yrízar, Angelina; Teece, Mark; Yépez, Enrico A; Dovciak, Martin

    2017-02-01

    Niche differentiation can lead to coexistence of plant species by partitioning limiting resources. Light partitioning promotes niche differentiation in tropical humid forests, but it is unclear how niche partitioning occurs in tropical dry forests where both light and soil resources can be limiting. We studied the adult niche of four dominant evergreen (cycad, palm) and drought-deciduous (legume, oak) species co-occurring along environmental gradients. We analyzed light intensity and soil fertility effects on key functional traits related to plant carbon and water economy, how these traits determine species' functional strategies, and how these strategies relate to relative species abundance and spatial patterns. Light intensity was negatively associated with a key trait linked to plant water economy (leaf δ 13 C, a proxy for long-term water-use efficiency-WUE), while soil fertility was negatively associated with a key trait for plant carbon economy (LNC, leaf nitrogen content). Evergreens were highly sclerophyllous and displayed an efficient water economy but poor carbon economy, in agreement with a conservative resource-use strategy (i.e., high WUE but low LNC, photosynthetic rates and stature). Conversely, deciduous species, with an efficient carbon economy but poor water economy, exhibited an exploitative resource-use strategy (i.e., high LNC, photosynthetic rates and stature, but low WUE). Evergreen and deciduous species segregated spatially, particularly at fine-scales, as expected for species with different resource-use strategies. The efficient water economy of evergreens was related to their higher relative abundance, suggesting a functional advantage against drought-deciduous species in water-limited environments within seasonally dry tropical forests.

  13. The effects of gap size on some microclimate variables during late summer and autumn in a temperate broadleaved deciduous forest.

    Science.gov (United States)

    Abd Latif, Zulkiflee; Blackburn, George Alan

    2010-03-01

    The creation of gaps can strongly influence forest regeneration and habitat diversity within forest ecosystems. However, the precise characteristics of such effects depend, to a large extent, upon the way in which gaps modify microclimate and soil water content. Hence, the aim of this study was to understand the effects of gap creation and variations in gap size on forest microclimate and soil water content. The study site, in North West England, was a mixed temperate broadleaved deciduous forest dominated by mature sessile oak (Quercus petraea), beech (Fagus sylvatica) and ash (Fraxinus excelsior) with some representatives of sycamore (Acer pseudoplatanus). Solar radiation (I), air temperature (T(A)), soil temperature (T(S)), relative humidity (h), wind speed (v) and soil water content (Psi) were measured at four natural treefall gaps created after a severe storm in 2006 and adjacent sub-canopy sites. I, T(A), T(S), and Psi increased significantly with gap size; h was consistently lower in gaps than the sub-canopy but did not vary with gap size, while the variability of v could not be explained by the presence or size of gaps. There were systematic diurnal patterns in all microclimate variables in response to gaps, but no such patterns existed for Psi. These results further our understanding of the abiotic and consequent biotic responses to gaps in broadleaved deciduous forests created by natural treefalls, and provide a useful basis for evaluating the implications of forest management practices.

  14. The effects of gap size on some microclimate variables during late summer and autumn in a temperate broadleaved deciduous forest

    Science.gov (United States)

    Abd Latif, Zulkiflee; Blackburn, George Alan

    2010-03-01

    The creation of gaps can strongly influence forest regeneration and habitat diversity within forest ecosystems. However, the precise characteristics of such effects depend, to a large extent, upon the way in which gaps modify microclimate and soil water content. Hence, the aim of this study was to understand the effects of gap creation and variations in gap size on forest microclimate and soil water content. The study site, in North West England, was a mixed temperate broadleaved deciduous forest dominated by mature sessile oak ( Quercus petraea), beech ( Fagus sylvatica) and ash ( Fraxinus excelsior) with some representatives of sycamore ( Acer pseudoplatanus). Solar radiation ( I), air temperature ( T A), soil temperature ( T S), relative humidity ( h), wind speed ( v) and soil water content (Ψ) were measured at four natural treefall gaps created after a severe storm in 2006 and adjacent sub-canopy sites. I, T A, T S, and Ψ increased significantly with gap size; h was consistently lower in gaps than the sub-canopy but did not vary with gap size, while the variability of v could not be explained by the presence or size of gaps. There were systematic diurnal patterns in all microclimate variables in response to gaps, but no such patterns existed for Ψ. These results further our understanding of the abiotic and consequent biotic responses to gaps in broadleaved deciduous forests created by natural treefalls, and provide a useful basis for evaluating the implications of forest management practices.

  15. THE SPATIO-TEMPORAL ANALYSIS OF THE CLIMATE CHANGING IN THE ZONE OF THE BROAD-LEAVED WOODS OF THE VOLGA RIVER RIGHT-BANK

    Directory of Open Access Journals (Sweden)

    N. G. Ivlieva

    2013-01-01

    Full Text Available The results of the carried out researches directed on studying of regional manifestations of the climate changing in the zone of the broad-leaved woods of the Volga river right-bank at the end of the XX century according to meteorological observations and monthly values of a vegetation index (NDVI are described in the article.

  16. Korean pine-broadleaved forests of the Far East: proceedings from the international conference—September 30-October 6,1996, Khabarovsk, Russian Federation.

    Science.gov (United States)

    Peyton W Owston; William E. Schlosser; Dmitri F. Efremov; Cynthia L. Miner

    2000-01-01

    Korean pine-broadleaved forests are very biologically diverse. In the Russian Far East, these forests are subject to a high level of use by humans and are systematically influenced by fire. Intensive exploitation in the past has led to a decrease in the resource potential. Sound decisionmaking and scientific advancement have lacked sufficient exchange of scientific...

  17. [Spatial autocorrelation of genetic structure of Prunus padus population in broadleaved Korean pine forest of Changbai Mountains].

    Science.gov (United States)

    Niu, Xiao-Min; Shi, Shuai; Wang, Zheng-Feng; Ye, Wan-Hui; Hao, Zhan-Qing

    2014-02-01

    All 396 Prunus padus individuals of the population with DBH (diameter at breast height) > or = 1 cm were sampled in a 25 hm2 broadleaved Korean pine forest plot of Changbai Mountains and divided into three DBH classes: 1-3 cm, 3-10 cm, and >10 cm. They were then genotyped using microsatellite loci. The spatial autocorrelation of their genetic structure was analyzed at different distance classes and life stages. The results showed that positive autocorrelation mainly occurred at scales less than 70 m, while negative autocorrelation occurred at scales larger than 110 m. The spatial genetic structure (SGS) at different life stages was similar due to limited pollen/seed dispersal and asexual reproduction. No significant self-thinning occurred in the studied population.

  18. 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

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

    Science.gov (United States)

    Beall, Reed F; Nickerson, Jason W; Kaplan, Warren A; Attaran, Amir

    2016-01-01

    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 therapeutic

  20. From leaf longevity to canopy seasonality: a carbon optimality phenology model for tropical evergreen forests

    Science.gov (United States)

    Xu, X.; Medvigy, D.; Wu, J.; Wright, S. J.; Kitajima, K.; Pacala, S. W.

    2016-12-01

    Tropical evergreen forests play a key role in the global carbon, water and energy cycles. Despite apparent evergreenness, this biome shows strong seasonality in leaf litter and photosynthesis. Recent studies have suggested that this seasonality is not directly related to environmental variability but is dominated by seasonal changes of leaf development and senescence. Meanwhile, current terrestrial biosphere models (TBMs) can not capture this pattern because leaf life cycle is highly underrepresented. One challenge to model this leaf life cycle is the remarkable diversity in leaf longevity, ranging from several weeks to multiple years. Ecologists have proposed models where leaf longevity is regarded as a strategy to optimize carbon gain. However previous optimality models can not be readily integrated into TBMs because (i) there are still large biases in predicted leaf longevity and (ii) it is never tested whether the carbon optimality model can capture the observed seasonality in leaf demography and canopy photosynthesis. In this study, we develop a new carbon optimality model for leaf demography. The novelty of our approach is two-fold. First, we incorporate a mechanistic photosynthesis model that can better estimate leaf carbon gain. Second, we consider the interspecific variations in leaf senescence rate, which strongly influence the modelled optimal carbon gain. We test our model with a leaf trait database for Panamanian evergreen forests. Then, we apply the model at seasonal scale and compare simulated seasonality of leaf litter and canopy photosynthesis with in-situ observations from several Amazonian forest sites. We find that (i) compared with original optimality model, the regression slope between observed and predicted leaf longevity increases from 0.15 to 1.04 in our new model and (ii) that our new model can capture the observed seasonal variations of leaf demography and canopy photosynthesis. Our results suggest that the phenology in tropical evergreen

  1. Fast growth involves high dependence on stored resources in seedlings of Mediterranean evergreen trees

    Science.gov (United States)

    Uscola, Mercedes; Villar-Salvador, Pedro; Gross, Patrick; Maillard, Pascale

    2015-01-01

    Background and Aims The carbon (C) and nitrogen (N) needed for plant growth can come either from soil N and current photosynthesis or through remobilization of stored resources. The contribution of remobilization to new organ growth on a whole-plant basis is quite well known in deciduous woody plants and evergreen conifers, but this information is very limited in broadleaf evergreen trees. This study compares the contribution of remobilized C and N to the construction of new organs in spring, and assesses the importance of different organs as C and N sources in 1-year-old potted seedlings of four ecologically distinct evergreen Mediterranean trees, namely Quercus ilex, Q. coccifera, Olea europaea and Pinus hapelensis. Methods Dual 13C and 15N isotope labelling was used to unravel the contribution of currently taken up and stored C and N to new growth. Stored C was labelled under simulated winter conditions. Soil N was labelled with the fertilization during the spring growth. Key results Oaks allocated most C assimilated under simulated winter conditions to coarse roots, while O. europaea and P. halepensis allocated it to the leaves. Remobilization was the main N source (>74 %) for new fine-root growth in early spring, but by mid-spring soil supplied most of the N required for new growth (>64 %). Current photosynthesis supplied >60 % of the C in new fine roots by mid-spring in most species. Across species, the proportion of remobilized C and N in new shoots increased with the relative growth rate. Quercus species, the slowest growing trees, primarily used currently acquired resources, while P. halepensis, the fastest growing species, mainly used reserves. Increases in the amount of stored N increased N remobilization, which fostered absolute growth both within and across species. Old leaves were major sources of remobilized C and N, but stems and roots also supplied considerable amounts of both in all species except in P. halepensis, which mainly relied on foliage

  2. Whole-tree distribution and temporal variation of non-structural carbohydrates in broadleaf evergreen trees.

    Science.gov (United States)

    Smith, Merryn G; Miller, Rebecca E; Arndt, Stefan K; Kasel, Sabine; Bennett, Lauren T

    2017-11-03

    Non-structural carbohydrates (NSCs) form a fundamental yet poorly quantified carbon pool in trees. Studies of NSC seasonality in forest trees have seldom measured whole-tree NSC stocks and allocation among organs, and are not representative of all tree functional types. Non-structural carbohydrate research has primarily focussed on broadleaf deciduous and coniferous evergreen trees with distinct growing seasons, while broadleaf evergreen trees remain under-studied despite their different growth phenology. We measured whole-tree NSC allocation and temporal variation in Eucalyptus obliqua L'Hér., a broadleaf evergreen tree species typically occurring in mixed-age temperate forests, which has year-round growth and the capacity to resprout after fire. Our overarching objective was to improve the empirical basis for understanding the functional importance of NSC allocation and stock changes at the tree- and organ-level in this tree functional type. Starch was the principal storage carbohydrate and was primarily stored in the stem and roots of young (14-year-old) trees rather than the lignotuber, which did not appear to be a specialized starch storage organ. Whole-tree NSC stocks were depleted during spring and summer due to significant decreases in starch mass in the roots and stem, seemingly to support root and crown growth but potentially exacerbated by water stress in summer. Seasonality of stem NSCs differed between young and mature trees, and was not synchronized with stem basal area increments in mature trees. Our results suggest that the relative magnitude of seasonal NSC stock changes could vary with tree growth stage, and that the main drivers of NSC fluctuations in broadleaf evergreen trees in temperate biomes could be periodic disturbances such as summer drought and fire, rather than growth phenology. These results have implications for understanding post-fire tree recovery via resprouting, and for incorporating NSC pools into carbon models of mixed

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

    Science.gov (United States)

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

    2014-07-01

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

  4. Leaf ontogeny and demography explain photosynthetic seasonality in Amazon evergreen forests

    Science.gov (United States)

    Wu, J.; Albert, L.; Lopes, A. P.; Restrepo-Coupe, N.; Hayek, M.; Wiedemann, K. T.; Guan, K.; Stark, S. C.; Prohaska, N.; Tavares, J. V.; Marostica, S. F.; Kobayashi, H.; Ferreira, M. L.; Campos, K.; Silva, R. D.; Brando, P. M.; Dye, D. G.; Huxman, T. E.; Huete, A. R.; Nelson, B. W.; Saleska, S. R.

    2015-12-01

    Photosynthetic seasonality couples the evolutionary ecology of plant leaves to large-scale rhythms of carbon and water exchanges that are important feedbacks to climate. However, the extent, magnitude, and controls on photosynthetic seasonality of carbon-rich tropical forests are poorly resolved, controversial in the remote sensing literature, and inadequately represented in most earth system models. Here we show that ecosystem-scale phenology (measured by photosynthetic capacity), rather than environmental seasonality, is the primary driver of photosynthetic seasonality at four Amazon evergreen forests spanning gradients in rainfall seasonality, forest composition, and flux seasonality. We further demonstrate that leaf ontogeny and demography explain most of this ecosystem phenology at two central Amazon evergreen forests, using a simple leaf-cohort canopy model that integrates eddy covariance-derived CO2 fluxes, novel near-surface camera-detected leaf phenology, and ground observations of litterfall and leaf physiology. The coordination of new leaf growth and old leaf divestment (litterfall) during the dry season shifts canopy composition towards younger leaves with higher photosynthetic efficiency, driving large seasonal increases (~27%) in ecosystem photosynthetic capacity. Leaf ontogeny and demography thus reconciles disparate observations of forest seasonality from leaves to eddy flux towers to satellites. Strategic incorporation of such whole-plant coordination processes as phenology and ontogeny will improve ecological, evolutionary and earth system theories describing tropical forests structure and function, allowing more accurate representation of forest dynamics and feedbacks to climate in earth system models.

  5. Two types of matter economy for the wintering of evergreen shrubs in regions of heavy snowfall.

    Science.gov (United States)

    Ino, Yoshio; Maekawa, Tomoyuki; Shibayama, Tomohiro; Sakamaki, Yoshiaki

    2003-08-01

    Plant adaptation to an environment subject to heavy snowfalls was investigated in four species of evergreen shrubs growing in a Fagus crenata forest in an area of Honshu on the Sea of Japan. These shrubs stored carbohydrates in some organs before the snowy season and were covered with snow for 4-5 months. Aucuba japonica var. borealis, Camellia rusticana, and Ilex crenata var. paludosa maintained a reserve of carbohydrates during the snowy season. In Daphniphyllum macropodum var. humile, the reserve of carbohydrates decreased during winter. The respiration rates in the first three species decreased from autumn to winter, whereas the decrease in D. macropodum was slight. It was found that the first three species could use reserve carbohydrates for the growth of new shoots after the thaw, whereas in the last species the growth of new shoots depends on high photosynthetic activity in late spring. Our findings suggest some types of matter economy in evergreen shrubs for wintering in an environment of heavy snow.

  6. 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.

  7. Deciduous and evergreen trees differ in juvenile biomass allometries because of differences in allocation to root storage.

    Science.gov (United States)

    Tomlinson, Kyle W; van Langevelde, Frank; Ward, David; Bongers, Frans; da Silva, Dulce Alves; Prins, Herbert H T; de Bie, Steven; Sterck, Frank J

    2013-08-01

    Biomass partitioning for resource conservation might affect plant allometry, accounting for a substantial amount of unexplained variation in existing plant allometry models. One means of resource conservation is through direct allocation to storage in particular organs. In this study, storage allocation and biomass allometry of deciduous and evergreen tree species from seasonal environments were considered. It was expected that deciduous species would have greater allocation to storage in roots to support leaf regrowth in subsequent growing seasons, and consequently have lower scaling exponents for leaf to root and stem to root partitioning, than evergreen species. It was further expected that changes to root carbohydrate storage and biomass allometry under different soil nutrient supply conditions would be greater for deciduous species than for evergreen species. Root carbohydrate storage and organ biomass allometries were compared for juveniles of 20 savanna tree species of different leaf habit (nine evergreen, 11 deciduous) grown in two nutrient treatments for periods of 5 and 20 weeks (total dry mass of individual plants ranged from 0·003 to 258·724 g). Deciduous species had greater root non-structural carbohydrate than evergreen species, and lower scaling exponents for leaf to root and stem to root partitioning than evergreen species. Across species, leaf to stem scaling was positively related, and stem to root scaling was negatively related to root carbohydrate concentration. Under lower nutrient supply, trees displayed increased partitioning to non-structural carbohydrate, and to roots and leaves over stems with increasing plant size, but this change did not differ between leaf habits. Substantial unexplained variation in biomass allometry of woody species may be related to selection for resource conservation against environmental stresses, such as resource seasonality. Further differences in plant allometry could arise due to selection for different types

  8. 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

  9. 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

  10. 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

  11. 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…

  12. 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

  13. 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.

  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. Seasonal patterns of reflectance indices, carotenoid pigments and photosynthesis of evergreen chaparral species.

    Science.gov (United States)

    Stylinski, C; Gamon, J; Oechel, W

    2002-05-01

    This study examined the ability of the Photochemical Reflectance Index (PRI) to track seasonal variations in carotenoid pigments and photosynthetic activity of mature evergreen chaparral shrubs. Our results confirm that PRI scales with photosystem two (PSII) photochemical efficiency across species and seasons, as demonstrated by PRI's strong correlation with de-epoxidized (photoprotective) xanthophyll cycle pigment levels (normalized to chlorophyll) and with the chlorophyll fluorescence index, ΔF/Fm'. PRI and carotenoid pigment levels (de-epoxidized xanthophyll cycle pigments normalized to chlorophyll or total carotenoid pigments normalized to chlorophyll) were correlated with seasonal fluctuations in midday net CO2 uptake of top-canopy leaves. By contrast, chlorophyll levels (as measured by the Chlorophyll Index) were not as strongly linked to photosynthetic activity, particularly when all species were considered together. Likewise, the Normalized Difference Vegetation Index (NDVI, an index of canopy greenness) did not correlate with net CO2 uptake. Canopy NDVI also did not correlate with canopy PRI, demonstrating that these indices were largely independent over the temporal and spatial scales of this study. Together, these patterns provide evidence for coordinated regulation of carotenoid pigments, PSII electron transport, and carboxylation across seasons and indicate that physiological adjustments are more important than structural ones in modifying CO2-fixation capacity during periods of photosynthetic down-regulation for these evergreen species. The strong correlation between PRI of whole canopies and PRI of top-canopy leaves suggests that the canopy can be treated as a "big leaf" in terms of this reflectance index and that PRI can be used in "scalable" models. This along with the links between carotenoid pigments, PSII photochemical efficiency and carboxylation across species and seasons supports the use of optical assays of pigment levels and PSII activity

  16. [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 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.

  17. Comparisons of seasonal water and carbon flux dynamics between temperate natural mixed broadleaved forest and Korean pine (Pinus koraiensis) plantation

    Science.gov (United States)

    Cho, S.; Kim, H.; Park, J.; Park, M.; Kang, M.; Choi, S. W.; Kim, H. S.

    2016-12-01

    Plantation forests with proper management are considered as the solution to forest destruction by increasing the productivity and reducing the water use. However, the assumptions on plantation forests' efficiency in carbon assimilation and water use are facing a lot questions, recently. To answer these questions, we compared the carbon assimilation and water use between two nearby and similar aged forests. One is a young natural mixed broadleaved forests, which are composed of various oak species and the other was 50-year-old Pinus koraiensis with proper management including thinning and weeding. We compared the seasonal changes of water and carbon flux and their use efficiencies. To compare net ecosystem carbon dioxide and water vapor exchange between to different forest, eddy covariance (EC) system and sap flow measurement have been installed. Also, the contribution of different species of carbon and water fluxes partitioned. As a preliminary result, annual estimated of ET was 491.44 mm in TMK and 446.65 mm in TCK, and annual net ecosystem CO2 exchange (NEE) was 531.66 gC m-2 year-1, 698.58 gC m-2 year-1 in 2015. Water use efficiency of TMK was 3.25 gC Kg-1 H2O and TCK was 4.05 gC Kg-1 H2O. This study will provide key information on plantation forests' efficiency be comparing the nearby and similar aged natural and well-managed plantation forest.

  18. 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.

  19. Tree species richness as the element of structure and diversity in mixed stands of beech and valuable broadleaves

    Directory of Open Access Journals (Sweden)

    Stajić Branko

    2012-01-01

    Full Text Available In our forest science and forest operations, the tree species richness and diversity of woody species in forest stands are most often evaluated based on the total number of tree species, which is a methodologically partly inadequate approach. For this reason, the quantification and the evaluation of diversity of woody species in mixed forests of beech with valuable broadleaves in the area of the National Park „Đerdap” were analyzed by five different indices of tree species richness: number of species (S index, two indices of the species richness (R1 and R2, expected number of species in the sample with equal numbers of trees (E(S84, and expected number of species in the sample with equal areas (E(S0,25ha. The results showed that the level of woody species diversity in forest stands depended on the applied index characterizing the tree species richness. It was concluded that the tree species richness and diversity were the highest in the stands of ecological unit B (E(S84=8.6 species and in the stands of ecological unit G (E(S0,25ha=9.4 species, and they were the lowest in the stands of ecological unit V (E(S84=5.8 species, E(S0,25ha=5.5 species.

  20. 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

  1. 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

    -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....... 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...

  2. [Error analysis of CO2 storage flux in a temperate deciduous broadleaved forest based on different scalar variables].

    Science.gov (United States)

    Wang, Jing; Wang, Xing-chang; Wang, Chuan-kuan

    2013-04-01

    Using the measurement data from an 8-level vertical profile of CO2/H2 0 in a temperate deciduous broadleaved forest at the Maoershan Forest Ecosystem Research Station, Northeast China, this paper quantified the errors of CO2 storage flux (Fs ) calculated with three scalar variables, i. e. , CO2 density (rho c), molar fraction (cc), and molar mixing ratio relative to dry air (Xc). The dry air storage in the control volume of flux measurement was not a constant, and thus, the fluctuation of the dry air storage could cause the CO2 molecules transporting out of or into the control volume, i. e. , the variation of the dry air storage adjustment term (Fsd). During nighttime and day-night transition periods, the relative magnitude of Fsd to eddy flux was larger, and ignoring the Fsd could introduce errors in calculating the net CO2 exchange between the forest ecosystem and the atmosphere. Three error sources in the Fs calculation could be introduced from the atmospheric hydrothermal processes, i. e. , 1) air temperature fluctuation, which could cause the largest error, with one order of magnitude larger than that caused by atmospheric pressure (P) , 2) water vapor, its effect being larger than that of P in warm and moist summer but smaller in cold and dry winter, and 3) P, whose effect was generally smaller throughout the year. In estimating the effective CO2 storage (Fs_E) , the Fs value calculated with rho c, cc, and Xc was overestimated averagely by 8. 5%, suggested that in the calculation of Fs, adopting the Xc conservation to atmospheric hydrothermal processes could be more appropriate to minimize the potential errors.

  3. [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.

  4. [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.

  5. 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.

  6. 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.

  7. The rhizospheric microbial community structure and diversity of deciduous and evergreen forests in Taihu Lake area, China

    OpenAIRE

    Wei, Zhiwen; Hu, Xiaolong; Li, Xunhang; Zhang, Yanzhou; Jiang, Leichun; Li, Jing; Guan, Zhengbing; Cai, Yujie; Liao, Xiangru

    2017-01-01

    Soil bacteria are important drivers of biogeochemical cycles and participate in many nutrient transformations in the soil. Meanwhile, bacterial diversity and community composition are related to soil physic-chemical properties and vegetation factors. However, how the soil and vegetation factors affect the diversity and community composition of bacteria is poorly understood, especially for bacteria associated with evergreen and deciduous trees in subtropical forest ecosystems. In the present p...

  8. Element accumulation patterns of deciduous and evergreen tree seedlings on acid soils: implications for sensitivity to manganese toxicity.

    Science.gov (United States)

    St Clair, Samuel B; Lynch, Jonathan P

    2005-01-01

    Foliar nutrient imbalances, including the hyperaccumulation of manganese (Mn), are correlated with symptoms of declining health in sensitive tree species growing on acidic forest soils. The objectives of this study were to: (1) compare foliar nutrient accumulation patterns of six deciduous (sugar maple (Acer saccharum Marsh.), red maple (Acer rubrum L.), red oak (Quercus rubra L.), white oak (Quercus alba L.), black cherry (Prunus serotina Ehrh.) and white ash (Fraxinus americana L.)) and three evergreen (eastern hemlock (Tsuga canadensis L.), white pine (Pinus strobus L.) and white spruce (Picea glauca (Moench) Voss.)) tree species growing on acidic forest soils; and (2) examine how leaf phenology and other traits that distinguish evergreen and deciduous tree species influence foliar Mn accumulation rates and sensitivity to excess Mn. For the first objective, leaf samples of seedlings from five acidic, non-glaciated field sites on Pennsylvania's Allegheny Plateau were collected and analyzed for leaf element concentrations. In a second study, we examined growth and photosynthetic responses of seedlings exposed to excess Mn in sand culture. In field samples, Mn in deciduous foliage hyperaccumulated to concentrations more than twice as high as those found in evergreen needles. Among species, sugar maple was the most sensitive to excess Mn based on growth and photosynthetic measurements. Photosynthesis in red maple and red oak was also sensitive to excess Mn, whereas white oak, black cherry, white ash and the three evergreen species were tolerant of excess Mn. Among the nine species, relative rates of photosynthesis were negatively correlated with foliar Mn concentrations, suggesting that photosynthetic sensitivity to Mn is a function of its rate of accumulation in seedling foliage.

  9. 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. 

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

    OpenAIRE

    A.J. Solomon Raju; B. Rajesh

    2014-01-01

    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. 

  11. Do photosynthetic limitations of evergreen Quercus ilex leaves change with long-term increased drought severity?

    Science.gov (United States)

    Limousin, Jean-Marc; Misson, Laurent; Lavoir, Anne-Violette; Martin, Nicolas K; Rambal, Serge

    2010-05-01

    Seasonal drought can severely impact leaf photosynthetic capacity. This is particularly important for Mediterranean forests, where precipitation is expected to decrease as a consequence of climate change. Impacts of increased drought on the photosynthetic capacity of the evergreen Quercus ilex were studied for two years in a mature forest submitted to long-term throughfall exclusion. Gas exchange and chlorophyll fluorescence were measured on two successive leaf cohorts in a control and a dry plot. Exclusion significantly reduced leaf water potential in the dry treatment. In both treatments, light-saturated net assimilation rate (A(max)), stomatal conductance (g(s)), maximum carboxylation rate (V(cmax)), maximum rate of electron transport (J(max)), mesophyll conductance to CO2 (g(m)) and nitrogen investment in photosynthesis decreased markedly with soil water limitation during summer. The relationships between leaf photosynthetic parameters and leaf water potential remained identical in the two treatments. Leaf and canopy acclimation to progressive, long-term drought occurred through changes in leaf area index, leaf mass per area and leaf chemical composition, but not through modifications of physiological parameters.

  12. Relating ring width of Mediterranean evergreen species to seasonal and annual variations of precipitation and temperature

    Directory of Open Access Journals (Sweden)

    W. Nijland

    2011-05-01

    Full Text Available Plant growth in Mediterranean landscapes is limited by the typical summer-dry climate. Forests in these areas are only marginally productive and may be quite susceptible to modern climate change. To improve our understanding of forest sensitivity to annual and seasonal climatic variability, we use tree-ring measurements of two Mediterranean evergreen tree species: Quercus ilex L. and Arbutus unedo L. We sampled 34 stems of these species on three different types of substrates in the Peyne study area in southern France. The resulting chronologies were analysed in combination with 38 yr of monthly precipitation and temperature data to reconstruct the response of stem growth to climatic variability. Results indicate a strong positive response to May and June precipitation, as well as a significant positive influence of early-spring temperatures and a negative growth response to summer heat. Comparison of the data with more detailed productivity measurements in two contrasting years confirms these observations and shows a strong productivity limiting effect of low early-summer precipitation. The results show that tree-ring data from Q.ilex and A.unedo can provide valuable information about the response of these tree species to climate variability, improving our ability to predict the effects of climate change in Mediterranean ecosystems.

  13. 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?

  14. 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.

  15. Decaying Wood Preference of Stag Beetles (Coleoptera: Lucanidae) in a Tropical Dry-Evergreen Forest.

    Science.gov (United States)

    Songvorawit, Nut; Butcher, Buntika Areekul; Chaisuekul, Chatchawan

    2017-12-08

    Larvae of many insect species, including stag beetles, have a limited mobility from their initial oviposition site. The fate of immature stages, therefore, depends on the maternal choice of oviposition site. Decaying wood preference by stag beetles was studied in a dry-evergreen forest in Chanthaburi province, Thailand. From a total of 270 examined logs, 52 contained stag beetles (255 total), which were identified to eight species from five genera. Aegus chelifer chelifer MacLeay, 1819 (Coleoptera: Lucanidae) was the dominant species both by occurrence and by number of individuals. The occurrence and numbers of stag beetle larvae found in logs was more frequent in those of a moderate decay class, which had moderate hardness and water content. Principal component analysis (PCA) revealed that logs with stag beetles had relatively high nitrogen content and fungal biomass. Thus, selection of oviposition sites by stag beetles was likely to depend on both the log decay stage (or hardness) to protect immature stages from natural enemies and its nutritional properties to enhance the larval performance. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Simulation of rainfall interception using multilayer model in evergreen broadleaf forest, Cambodia

    Science.gov (United States)

    Nobuhiro, T.; Shimizu, A.; Tanaka, K.; Kabeya, N.; Tamai, K.; Chann, S.; Keth, N.

    2006-12-01

    The proportion of forest area is relatively high in Cambodia compared with neighboring countries. Therefore forest is one of the important factors on the water cycle in this country. The rainfall interception by a tree canopy and evaporation after the rainfall event are one of the important factors for considering such a water cycle. To clarify those processes, a rainfall interception measurement plot (25 x 25 m) was constructed in the evergreen broadleaf forest area in Kampong Thom province, central part of Cambodia. We measured rainfall, through fall and stem flow in the interception plot, and then we analyzed the relationship between those components. Moreover, the simulation of rainfall interception was carried out using multilayer model. Model parameters such as canopy structure and leaf characteristics were estimated using observed interception components and meteorological elements during large rainfall event. Annual rainfall interception was reproduced using multilayer model with obtained parameters and observed meteorological elements. The simulation results were in agreement with the observed value. The rainfall interception rate in the interception plot was considered to be about 15 % against annual rainfall.

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

    Directory of Open Access Journals (Sweden)

    Vu Thanh Nam

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

  18. 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.

  19. Growth reduction after defoliation is independent of CO2 supply in deciduous and evergreen young oaks.

    Science.gov (United States)

    Schmid, Sandra; Palacio, Sara; Hoch, Günter

    2017-06-01

    Reduced productivity of trees after defoliation might be caused by limited carbon (C) availability. We investigated the combined effect of different atmospheric CO2 concentrations (160, 280 and 560 ppm) and early season defoliation on the growth and C reserves (nonstructural carbohydrates (NSC)) of saplings of two oak species with different leaf habits (deciduous Quercus petraea and evergreen Quercus ilex). In both species, higher CO2 supply significantly enhanced growth. Defoliation had a strong negative impact on growth (stronger for Q. ilex), but the relative reduction of growth caused by defoliation within each CO2 treatment was very similar across all three CO2 concentrations. Low CO2 and defoliation led to decreased NSC tissue concentrations mainly in the middle of the growing season in Q. ilex, but not in Q. petraea. However, also in Q. ilex, NSC increased in woody tissues in defoliated and low-CO2 saplings towards the end of the growing season. Although the saplings were C limited under these specific experimental conditions, growth reduction after defoliation was not directly caused by C limitation. Rather, growth of trees followed a strong allometric relationship between total leaf area and conductive woody tissue, which did not change across species, CO2 concentrations and defoliation treatments. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  20. 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.

  1. Parameterization of the Stomatal Component of the DO3SE Model for Mediterranean Evergreen Broadleaf Species

    Directory of Open Access Journals (Sweden)

    Roccío Alonso

    2007-01-01

    Full Text Available An ozone (O3 deposition model (DO3SE is currently used in Europe to define the areas where O3 concentrations lead to absorbed O3 doses that exceed the flux-based critical levels above which phytotoxic effects would be likely recorded. This mapping exercise relies mostly on the accurate estimation of O3 flux through plant stomata. However, the present parameterization of the modulation of stomatal conductance (gs behavior by different environmental variables needs further adjustment if O3 phytotoxicity is to be assessed accurately at regional or continental scales. A new parameterization of the model is proposed for Holm oak (Quercus ilex, a tree species that has been selected as a surrogate for all Mediterranean evergreen broadleaf species. This parameterization was based on a literature review, and was calibrated and validated using experimentally measured data of gs and several atmospheric and soil parameters recorded at three sites of the Iberian Peninsula experiencing long summer drought, and very cold and dry winter air (El Pardo and Miraflores or milder conditions (Tietar. A fairly good agreement was found between modeled and measured data (R2 = 0.64 at Tietar. However, a reasonable performance (R2 = 0.47–0.62 of the model was only achieved at the most continental sites when gs and soil moisture deficit relationships were considered. The influence of root depth on gs estimation is discussed and recommendations are made to build up separate parameterizations for continental and marine-influenced Holm oak sites in the future.

  2. Species differences in evergreen tree transpiration at daily, seasonal, and interannual timescales

    Science.gov (United States)

    Link, P.; Simonin, K. A.; Oshun, J.; Dietrich, W.; Dawson, T. E.; Fung, I.

    2012-12-01

    Mediterranean climates have rainy winter and dry summer seasons, so the season of water availability (winter) is out of phase with the season of light availability and atmospheric demand (summer). In this study, we investigate the seasonality of tree transpiration in a Mediterranean climate, using observations from a small (8000 m2), forested, steep (~35 degree) hillslope at the UC Angelo Reserve, in the northern California Coast Range. The site is instrumented with over 850 sensors transmitting hydrologic and meteorological data at less than 30-minute intervals. Here, we analyze four years of high-frequency measurements from 45 sap flow sensors in 30 trees, six depth profiles of soil moisture measured by TDR, and spatially distributed measurements of air temperature, relative humidity, solar radiation, and other meteorological variables. The sap flow measurements show a difference in transpiration seasonality between common California Coast Range evergreen tree species. Douglas firs (Pseudotsuga menziesii) maintain significant transpiration through the winter rainy season and transpire maximally in the spring, but Douglas fir transpiration declines sharply in the summer dry season. Madrones (Arbutus menziesii), in contrast, transpire maximally in the summer dry season. The seasonal patterns are quantified using principal component analysis. Nonlinear regressions against environmental variables show that the difference in transpiration seasonality arises from different sensitivities to atmospheric demand (VPD) and root-zone moisture. The different sensitivities to VPD and root-zone moisture cause species differences not just in seasonal patterns, but also in high temporal frequency (daily to weekly) variability of transpiration. We also contrast the interannual variability of dry season transpiration among the different species, and show that precipitation above a threshold triggers a Douglas fir response. Finally, we use a simple 1-D model of the atmospheric

  3. Expression of anatomical leaf traits in homoploid hybrids between deciduous and evergreen species of Vaccinium.

    Science.gov (United States)

    Piwczyński, M; Ponikierska, A; Puchałka, R; Corral, J M

    2013-05-01

    We investigated the anatomical expression of leaf traits in hybrids between evergreen Vaccinium vitis-idaea and deciduous V. myrtillus. We compared parents from four populations with their respective F1 hybrids and tested whether (i) transgression can be the source of novel anatomical traits in hybrids; (ii) expression of transgressive traits is more probable for traits with similar values in parents and intermediate for more distinct values, as predicted by theory; and (iii) independent origin of hybrids leads to identical trait expression profiles among populations. We found that anatomical leaf traits can be divided into four categories based on their similarity to parents: intermediate, parental-like, transgressive and non-significant. Contrary to the common view, parental-like trait values were equally important in shaping the hybrid profile, as were intermediate traits. Transgression was revealed in 17/144 cases and concerned mainly cell and tissue sizes. As predicted by theory, we observed transgressive segregation more often when there was little phenotypic divergence, but intermediate values when parental traits were differentiated. It is likely that cell and tissue sizes are phylogenetically more conserved due to stabilising selection, whereas traits such as leaf thickness and volume fraction of the intercellular spaces, showing a consistent intermediate pattern across populations, are more susceptible to directional selection. Hybrid populations showed little similarity in expression profile, with only three traits identically expressed across all populations. Thus local adaptation of parental species and specific genetic background may be of importance. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  4. Biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections.

    Science.gov (United States)

    Reich, Peter B; Rich, Roy L; Lu, Xingjie; Wang, Ying-Ping; Oleksyn, Jacek

    2014-09-23

    Leaf life span is an important plant trait associated with interspecific variation in leaf, organismal, and ecosystem processes. We hypothesized that intraspecific variation in gymnosperm needle traits with latitude reflects both selection and acclimation for traits adaptive to the associated temperature and moisture gradient. This hypothesis was supported, because across 127 sites along a 2,160-km gradient in North America individuals of Picea glauca, Picea mariana, Pinus banksiana, and Abies balsamea had longer needle life span and lower tissue nitrogen concentration with decreasing mean annual temperature. Similar patterns were noted for Pinus sylvestris across a north-south gradient in Europe. These differences highlight needle longevity as an adaptive feature important to ecological success of boreal conifers across broad climatic ranges. Additionally, differences in leaf life span directly affect annual foliage turnover rate, which along with needle physiology partially regulates carbon cycling through effects on gross primary production and net canopy carbon export. However, most, if not all, global land surface models parameterize needle longevity of boreal evergreen forests as if it were a constant. We incorporated temperature-dependent needle longevity and %nitrogen, and biomass allocation, into a land surface model, Community Atmosphere Biosphere Land Exchange, to assess their impacts on carbon cycling processes. Incorporating realistic parameterization of these variables improved predictions of canopy leaf area index and gross primary production compared with observations from flux sites. Finally, increasingly low foliage turnover and biomass fraction toward the cold far north indicate that a surprisingly small fraction of new biomass is allocated to foliage under such conditions.

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

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    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

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

    Science.gov (United States)

    Alkhafaji, Ali A; Trinquart, Ludovic; Baron, Gabriel; Desvarieux, Moïse; Ravaud, Philippe

    2012-11-20

    "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. 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). 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. The clinical benefit of escitalopram versus citalopram remains uncertain. In our case of evergreening, escitalopram represented a substantially high proportion of the overall reimbursement cost burden as

  7. 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

  8. [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

  9. Facilitating the recovery of natural evergreen forests in South Africa via invader plant stands

    Directory of Open Access Journals (Sweden)

    Coert J. Geldenhuys

    2017-11-01

    Full Text Available Contrary to general belief, planted and naturalized stands of introduced species facilitate the recovery of natural evergreen forests and their diversity. Forest rehabilitation actions are often performed at great cost: mature forest species are planted, while species with adaptations to recover effectively and quickly after severe disturbance are ignored; or stands are cleared of invasive alien species before native tree species are planted. By contrast, cost-effective commercial plantation forestry systems generally use fast-growing pioneer tree species introduced from other natural forest regions. Such planted tree stands often facilitate the recovery of shade-tolerant native forest species. This paper provides a brief overview of disturbance-recovery processes at landscape level, and how pioneer stands of both native and introduced tree species develop from monocultures to diverse mature forest communities. It uses one example of a study of how natural forest species from small forest patches of 3 ha in total invaded a 90-ha stand of the invasive Black wattle, Acacia mearnsii, over a distance of 3.1 ha at Swellendam near Cape Town, South Africa. The study recorded 329 forest species clusters across the wattle stand: more large clusters closer to and more smaller clusters further away from natural forest patches. The 28 recorded forest species (of potentially 40 species in the surrounding forest patches included 79% tree and 21% shrub species. Colonizing forest species had mostly larger fleshy fruit and softer small seeds, and were dispersed by mostly birds and primate species. Maturing forest trees within developing clusters in the wattle stand became a source for forest regeneration away from the clusters, showing different expansion patterns. Four sets of fenced-unfenced plots in the wattle stand showed the impact of browsing by livestock, antelope, rodents and insects on the successful establishment of regenerating forest species, and the

  10. 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.

  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. 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...... of their tissues, higher soil moisture and favourable conditions for earthworms. Forest floors consequently tend to be thicker in EG forests compared to DA forests. Many factors, such as litter lignin content, influence litter decomposition and it is difficult to identify specific litter-quality parameters...... that distinguish litter decomposition rates of EGs from DAs. Although it has been suggested that DAs can result in higher accumulation of soil carbon stocks, evidence from field studies does not show any obvious trend. Further research is required to clarify if accumulation of carbon in soils (i.e. forest floor...

  13. Within-tree variation in transpiration in isolated evergreen oak trees: evidence in support of the pipe model theory.

    Science.gov (United States)

    Infante, J M; Mauchamp, A; Fernández-Alé, R; Joffre, R; Rambal, S

    2001-04-01

    Within-tree variation in sap flow density (SFD) was measured in two isolated evergreen oak (Quercus ilex L.) trees growing in an oak savannah (dehesa) in southwest Spain. Sap flow was estimated by the constant heating method. Three sensors were installed in the trunk of each tree in three orientations: northeast (NE), northwest (NW) and south (S). Sap flow density was monitored continuously from May 18 to September 27, 1993. Daily values of SFD ranged between 500 and 4500 mm3 mm-2 day-1. There were significant differences in SFD between orientations; SFD was higher in the NE and NW orientations than in the S orientation. These differences were noted on both a daily and seasonal time scale, and were less pronounced on cloudy days and at the end of the drought period, when SFD was relatively low. Our results support the idea that branches of trees can be viewed as a collection of small independent plants.

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

    Science.gov (United States)

    Ulsig, Laura; Nichol, Caroline J.; Huemmrich, Karl F.; Landis, David R.; Middleton, Elizabeth M.; Lyapustin, Alexei I.; Mammarella, Ivan; Levula, Janne; Porcar-Castell, Albert

    2017-01-01

    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 (R (sup 2) equals 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 (R (sup 2) is greater than 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. 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.

  16. The rhizospheric microbial community structure and diversity of deciduous and evergreen forests in Taihu Lake area, China.

    Directory of Open Access Journals (Sweden)

    Zhiwen Wei

    Full Text Available Soil bacteria are important drivers of biogeochemical cycles and participate in many nutrient transformations in the soil. Meanwhile, bacterial diversity and community composition are related to soil physic-chemical properties and vegetation factors. However, how the soil and vegetation factors affect the diversity and community composition of bacteria is poorly understood, especially for bacteria associated with evergreen and deciduous trees in subtropical forest ecosystems. In the present paper, the microbial communities of rhizospheric soils associated with different types of trees were analyzed by Illumina MiSeq sequencing the V3-V4 region of the 16S rRNA gene. A total of 121,219 effective 16S rRNA gene sequences were obtained, which were classified into 29 bacterial phyla and 2 archaeal phyla. The dominant phyla across all samples (>5% of good-quality sequences in each sample were Proteobacteria, Acidobacteria, Firmicutes and Bacteroidetes. The bacterial community composition and diversity were largely affected by both soil pH and tree species. The soil pH was the key factor influencing bacterial diversity, with lower pH associated with less diverse communities. Meanwhile, the contents of NO3- were higher in evergreen tree soils than those associated with deciduous trees, while less NH4+ than those associated with deciduous trees, leading to a lower pH and indirectly influencing the diversity and composition of the bacteria. The co-occurrence patterns were assessed by network analysis. A total of 415 pairs of significant and robust correlations (co-occurrence and negative were identified from 89 genera. Sixteen hubs of co-occurrence patterns, mainly under the phyla Acidobacteria, Proteobacteria, Firmicutes and Bacteroidetes, may play important roles in sustaining the stability of the rhizospheric microbial communities. In general, our results suggested that local environmental conditions and soil pH were important in shaping the bacterial

  17. Partitioning Tree Species Diversity and Developmental Changes in Habitat Associations in a Subtropical Evergreen Broadleaf Secondary Forest in Southern China

    Directory of Open Access Journals (Sweden)

    Wei Cui

    2016-10-01

    Full Text Available The classical environmental control model assumes that species diversity is primarily determined by environmental conditions (e.g., microclimate and soil on the local scale. This assumption has been challenged by the neutral theory that assumes that the maintenance of biodiversity mainly depends on the ecological drift and dispersal limitation. Understanding the mechanisms that maintain biodiversity depends on decomposing the variation of species diversity into the contributions from the various components that affect it. We investigated and partitioned the effects of the biotic component (productivity, forest spatial structure and the environmental component (topography and soil fertility on the distribution of tree species richness jointly (the combined effect of environment and biotic process and separately (the effect of environment or biotic process alone in 25 permanent plots of 600 m2 in a subtropical evergreen broadleaf secondary forest in southern China. The analysis was also completed for trees at different growth stages based on diameter breast height (young trees: 5 cm ≤ DBH < 10 cm, mature trees: 10 cm < DBH ≤ 20 cm, old trees: DBH > 20 cm within each plot. Our results indicated that (1 tree species richness had significant negative relationship with productivity and a unimodal relationship with its spatially structured distribution; (2 biotic and environmental factors both have significant influence on species richness and jointly explain ~60% of the variation for the overall tree assemblage, and the variation explained by the two components jointly increased across growth stages (34%, 44%, and 75%, respectively; (3 additive variation partitioning revealed that the tree species richness was dominantly controlled by environmental factors (32%, while the biotic component also independently contributed a non-negligible effect (16%; and (4 the dominant fraction changed from the biotic component to the environmental component across

  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.

  19. Photosynthetic limitation and mechanisms of photoprotection under drought and recovery of Calotropis procera, an evergreen C3 from arid regions.

    Science.gov (United States)

    Rivas, Rebeca; Frosi, Gabriella; Ramos, Diego G; Pereira, Silvia; Benko-Iseppon, Ana M; Santos, Mauro G

    2017-09-01

    Calotropis procera is a C3 plant native from arid environmental zones. It is an evergreen, shrubby, non-woody plant with intense photosynthetic metabolism during the dry season. We measured photosynthetic parameters and leaf biochemical traits, such as gas exchange, photochemical parameters, A/Ci analysis, organic solutes, and antioxidant enzymes under controlled conditions in potted plants during drought stress, and following recovery conditions to obtain a better insight in the drought stress responses of C. procera. Indeed, different processes contribute to the drought stress resilience of C. procera and to the fast recovery after rehydration. The parameters analyzed showed that C. procera has a high efficiency for energy dissipation. The photosynthetic machinery is protected by a robust antioxidant system and photoprotective mechanisms such as alternative pathways for electrons (photorespiration and day respiration). Under severe drought stress, increased stomatal limitation and decreased biochemical limitation permitted C. procera to maintain maximum rate of Rubisco carboxylation (Vc,max) and photosynthetic rate (Amax). On the other hand, limitation of stomatal or mesophyll CO2 diffusion did not impair fast recovery, maintaining Vc,max, chloroplast CO2 concentration (Cc) and mesophyll conductance (gm) unchanged while electron flow used for RuBP carboxylation (Jc) and Amax increased. The ability to tolerate drought stress and the fast recovery of this evergreen C3 species was also due to leaf anti-oxidative stress enzyme activity, and photosynthetic pigments. Thus, these different drought tolerance mechanisms allowed high performance of photosynthetic metabolism by drought stressed plants during the re-watering period. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Xanthophyll cycle pigment and antioxidant profiles of winter-red (anthocyanic) and winter-green (acyanic) angiosperm evergreen species.

    Science.gov (United States)

    Hughes, Nicole M; Burkey, Kent O; Cavender-Bares, Jeannine; Smith, William K

    2012-03-01

    Leaves of many angiosperm evergreen species change colour from green to red during winter, corresponding with the synthesis of anthocyanin pigments. The ecophysiological function of winter colour change (if any), and why it occurs in some species and not others, are not yet understood. It was hypothesized that anthocyanins play a compensatory photoprotective role in species with limited capacity for energy dissipation. Seasonal xanthophyll pigment content, chlorophyll fluorescence, leaf nitrogen, and low molecular weight antioxidants (LMWA) of five winter-red and five winter-green angiosperm evergreen species were compared. Our results showed no difference in seasonal xanthophyll pigment content (V+A+Z g(-1) leaf dry mass) or LMWA between winter-red and winter-green species, indicating red-leafed species are not deficient in their capacity for non-photochemical energy dissipation via these mechanisms. Winter-red and winter-green species also did not differ in percentage leaf nitrogen, corroborating previous studies showing no difference in seasonal photosynthesis under saturating irradiance. Consistent with a photoprotective function of anthocyanin, winter-red species had significantly lower xanthophyll content per unit chlorophyll and less sustained photoinhibition than winter-green species (i.e. higher pre-dawn F(v)/F(m) and a lower proportion of de-epoxidized xanthophylls retained overnight). Red-leafed species also maintained a higher maximum quantum yield efficiency of PSII at midday (F'(v)/F'(m)) during winter, and showed characteristics of shade acclimation (positive correlation between anthocyanin and chlorophyll content, and negative correlation with chlorophyll a/b). These results suggest that the capacity for photon energy dissipation (photochemical and non-photochemical) is not limited in red-leafed species, and that anthocyanins more likely function as an alternative photoprotective strategy to increased VAZ/Chl during winter.

  1. The rhizospheric microbial community structure and diversity of deciduous and evergreen forests in Taihu Lake area, China.

    Science.gov (United States)

    Wei, Zhiwen; Hu, Xiaolong; Li, Xunhang; Zhang, Yanzhou; Jiang, Leichun; Li, Jing; Guan, Zhengbing; Cai, Yujie; Liao, Xiangru

    2017-01-01

    Soil bacteria are important drivers of biogeochemical cycles and participate in many nutrient transformations in the soil. Meanwhile, bacterial diversity and community composition are related to soil physic-chemical properties and vegetation factors. However, how the soil and vegetation factors affect the diversity and community composition of bacteria is poorly understood, especially for bacteria associated with evergreen and deciduous trees in subtropical forest ecosystems. In the present paper, the microbial communities of rhizospheric soils associated with different types of trees were analyzed by Illumina MiSeq sequencing the V3-V4 region of the 16S rRNA gene. A total of 121,219 effective 16S rRNA gene sequences were obtained, which were classified into 29 bacterial phyla and 2 archaeal phyla. The dominant phyla across all samples (>5% of good-quality sequences in each sample) were Proteobacteria, Acidobacteria, Firmicutes and Bacteroidetes. The bacterial community composition and diversity were largely affected by both soil pH and tree species. The soil pH was the key factor influencing bacterial diversity, with lower pH associated with less diverse communities. Meanwhile, the contents of NO3- were higher in evergreen tree soils than those associated with deciduous trees, while less NH4+ than those associated with deciduous trees, leading to a lower pH and indirectly influencing the diversity and composition of the bacteria. The co-occurrence patterns were assessed by network analysis. A total of 415 pairs of significant and robust correlations (co-occurrence and negative) were identified from 89 genera. Sixteen hubs of co-occurrence patterns, mainly under the phyla Acidobacteria, Proteobacteria, Firmicutes and Bacteroidetes, may play important roles in sustaining the stability of the rhizospheric microbial communities. In general, our results suggested that local environmental conditions and soil pH were important in shaping the bacterial community of the

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

    Science.gov (United States)

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

    2014-01-01

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

  3. 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.

  4. Investigating distribution pattern of species in a warm-temperate conifer-broadleaved-mixed forest in China for sustainably utilizing forest and soils.

    Science.gov (United States)

    Song, Houjuan; Xu, Yudan; Hao, Jing; Zhao, Bingqing; Guo, Donggang; Shao, Hongbo

    2017-02-01

    The maintaining mechanisms and potential ecological processes of species diversity in warm temperate- conifer-broadleaved-mixed forest are far from clear understanding. In this paper, the relative neighborhood density Ω was used to analyze the spatial distribution patterns of 34 species with ≥11 individuals in a warm- temperate-conifer-broadleaved-mixed forest, northern China. Then we used canonical correspondence analysis (CCA) and Torus-translation test (TTT) to explain the distribution of observed species. Our results show that aggregated distribution is the dominant pattern in warm-temperate natural forest and four species regular distribution at the spatial scale >30m. The aggregated percentage and intensity decline with spatial scale, abundance and size classes increasing. Rare species are aggregated more than intermediate and abundant species. These results prove sufficiently the effects existence of scale separation, self-thinning and Janzen-Connell hypothesis. In addition, functional traits (dispersal modes and shade tolerance) also have a significant influence on distribution of species. The results of CCA confirm that slope and convexity are the most important factors affecting the distribution of tree species distribution, elevation and slope of shrub species though the combination of topographic variables only explained 1% of distribution of tree species and 2% of shrub species. Most species don't have habitat preference; however 47.1% (16/34) species including absolutely dominant tree (Pinus tabulaeformis and Quercus wutaishanica) and shrub species (Rosa xanthina) and most other species with important value in the front, are strongly positively or negatively associated with at least one habitat. The valley and ridge are most distinct habitat with association of 12 species in the plot. However, high elevation slope with 257 quadrats is the most extensive habitat with only four species. Therefore, there is obvious evidence that habitat heterogeneity

  5. 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.

  6. 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

  7. 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

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

    Directory of Open Access Journals (Sweden)

    Lionel Hernández

    2012-03-01

    Full Text Available 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

  9. 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 09 November 1979 to 27 November 1979 (NODC Accession 8000180)

    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 Ships of...

  10. Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC EVERGREEN in the East Coast - US/Canada in support of the Integrated Global Ocean Services System (IGOSS) project from 01 April 1978 to 21 April 1978 (NODC Accession 7800360)

    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) project. Data were collected by the US Coast Guard...

  11. Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC EVERGREEN in the East Coast - US/Canada in support of the Integrated Global Ocean Services System (IGOSS) project from 16 February 1978 to 27 February 1978 (NODC Accession 7800196)

    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) project. Data were collected by the US Coast Guard...

  12. 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 23...

  13. Predicting vegetation type through physiological and environmental interactions with leaf traits: evergreen and deciduous forests in an earth system modeling framework.

    Science.gov (United States)

    Weng, Ensheng; Farrior, Caroline E; Dybzinski, Ray; Pacala, Stephen W

    2017-06-01

    Earth system models are incorporating plant trait diversity into their land components to better predict vegetation dynamics in a changing climate. However, extant plant trait distributions will not allow extrapolations to novel community assemblages in future climates, which will require a mechanistic understanding of the trade-offs that determine trait diversity. In this study, we show how physiological trade-offs involving leaf mass per unit area (LMA), leaf lifespan, leaf nitrogen, and leaf respiration may explain the distribution patterns of evergreen and deciduous trees in the temperate and boreal zones based on (1) an evolutionary analysis of a simple mathematical model and (2) simulation experiments of an individual-based dynamic vegetation model (i.e., LM3-PPA). The evolutionary analysis shows that these leaf traits set up a trade-off between carbon- and nitrogen-use efficiency at the scale of individual trees and therefore determine competitively dominant leaf strategies. As soil nitrogen availability increases, the dominant leaf strategy switches from one that is high in nitrogen-use efficiency to one that is high in carbon-use efficiency or, equivalently, from high-LMA/long-lived leaves (i.e., evergreen) to low-LMA/short-lived leaves (i.e., deciduous). In a region of intermediate soil nitrogen availability, the dominant leaf strategy may be either deciduous or evergreen depending on the initial conditions of plant trait abundance (i.e., founder controlled) due to feedbacks of leaf traits on soil nitrogen mineralization through litter quality. Simulated successional patterns by LM3-PPA from the leaf physiological trade-offs are consistent with observed successional dynamics of evergreen and deciduous forests at three sites spanning the temperate to boreal zones. © 2016 John Wiley & Sons Ltd.

  14. 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...

  15. Particulate matter deposited on leaf of five evergreen species in Beijing, China: Source identification and size distribution

    Science.gov (United States)

    Song, Yingshi; Maher, Barbara A.; Li, Feng; Wang, Xiaoke; Sun, Xiao; Zhang, Hongxing

    2015-03-01

    Airborne particulate matter (PM) has become a serious problem, and urban plants can play important roles in reducing PM concentrations in the air. The morphology, size, and elemental composition of PM on tree leaves (five evergreen species) from Beijing, China, were obtained, together with number density of PM size fraction, by using scanning electron microscopy (SEM) and energy dispersive X-rays (EDX). The rinse and weigh method was used to characterize PM in three size categories (0.2-2.5 μm, 2.5-10 μm, and 10-100 μm). The results showed that PM up to 2 μm can get into the stomatal cavity, and the most furrowed areas of the leaf surfaces were sites of maximum PM deposition. The leaf-deposited PM mainly comprised C, O, Si, and Fe. The number of particles per leaf per cm2 was 1.95 × 107, and 96% of the particles were less than 2.5 μm. The mass concentration was 148.44 μg/cm2, and PM2.5 comprised only 2.09% by weight while PM larger than 10 μm comprised 79%. Juniperus formosana was most effective at mitigating airborne PM on the leaf scale. Pinus bungeana accumulated the most PM on the tree scale. The results showed that urban plants can play important roles in mitigating urban airborne PM.

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

    Science.gov (United States)

    Faunce, Thomas; Vines, Tim; Gibbons, Helen

    2008-10-01

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

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

    Science.gov (United States)

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

    2014-05-01

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

  19. 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.

  20. Differences in construction costs and chemical composition between deciduous and evergreen woody species are small as compared to differences among families.

    Science.gov (United States)

    Villar, Rafael; Robleto, Jeannette Ruiz; De Jong, Yvonne; Poorter, Hendrik

    2006-08-01

    We tested to what extent differences in construction costs (CC) and chemical composition of woody species are attributed to leaf habit. Eight evergreen and eight deciduous species belonging to six families were selected to form eight phylogenetic independent contrasts (PICs). The plants were grown from seed in a glasshouse. Differences in leaf, stem and root CC between evergreen and deciduous species were minor, the proportion of variance explained by leaf habit generally being less than 6%. Surprisingly, differences in leaf chemical composition between deciduous and evergreen species were small as well. Variation in CC and chemical composition among families was substantial, the factor 'family' explaining 50-85% of variance. We therefore conclude that in this case, phylogeny is a more important factor than functional group. Leaves of the fast-growing species in this experiment showed high levels of minerals, organic acids, proteins and lipids, whereas leaves of the slow-growing species had higher concentrations of soluble phenolics, lignin as well as higher carbon/nitrogen (C/N) ratio. These relationships suggest a trade-off between growth and defence. In contrast, CC of leaves, stems, roots or whole plants showed no or only a weak correlation with relative growth rate (RGR). The C/N ratio of the leaves is an easily measured parameter that correlated strongly in a negative way with the RGR of the plants and reflected better the balance between investment in structure and physiological functioning than CC.

  1. Contributions of low molecular weight carboxylic acids to aerosols and wet deposition in a natural subtropical broad-leaved forest environment

    Science.gov (United States)

    Tsai, Ying I.; Kuo, Su-Ching

    2013-12-01

    The carboxylic acid component of autumn aerosol and wet deposition (fog water and rainwater) in a broad-leaved forest in central Taiwan was investigated. High levels of low molecular weight carboxylic acids (LMWCAs) were noted in all deposition types. Acetic acid, oxalic acid and formic acid were the most prevalent carboxylic acids, together accounting for 72.2% (fog water), 86.7% (rain water), 77.2% (PM2.5) and 88.3% (PM2.5-10) of total carboxylic acid. The forest fog water contained 2453.9 ± 1030.5 ng mL-1 of carboxylic acid, 2.71 times more than was contained in forest rainwater. In PM, most carboxylic acid existed in the fine PM2.5 aerosol (576.6 ± 254.1 ng m-3 or 6.28 times more than was contained in PM2.5-10. Most carboxylic acids in PM had higher concentrations during the day. Pyruvic acid concentration was higher during the night (2.97 times), however, owing to its rapid photodegradation during the day. Citric acid accounted for 9.1% of the total carboxylic acid in fog water compared with just 1.8% in rainwater, confirming its origin from emissions from leaves. Raman spectroscopy was used to observe the photochemical conversion of citric acid into intermediate products and this observation confirmed that the carboxylic acids identified in the forest dry and wet depositions originated directly from biological emissions in the forest environment.

  2. [Microsite characteristics of pit and mound and their effects on the vegetation regeneration in Pinus koraiensis-dominated broadleaved mixed forest].

    Science.gov (United States)

    Du, Shan; Duan, Wen-Biao; Wang, Li-Xia; Chen, Li-Xin; Wei, Quan-Shuai; Li, Meng; Wang, Li-dong

    2013-03-01

    Abstract: An investigation was conducted in a 2.55 hm2 plot of Pinus koraiensis-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 mirosites, mound top had the highest PAR (527.9 micromol.m-2.s-1 ) while intact forest floor had the lowest one (58.7 micromol.m-2.s-), mound top had the highest soil temperature (16.0 degrees C) but pit bottom had the lowest one (13.3 degrees C), pit bottom had the highest soil water content (34.6%) but mound face had the lowest one (0.5%), and intact forest floor had the highest relative air humidity (75.9%) but mound top had the lowest one (68.0%). The frequency of forming pit/ mound complex by the tree species was decreased in the order of Pinus koraiensis (42. 9%) >Picea asperata (31.0%) > Betula platyphylla (16.7%) > Abies fabri (7. 1%) > Prunus padus (2.4%). Among the 42 treefalls, two-thirds of them were in northwest direction. The treefalls volume had significant positive correlations with pit depth, pit length, mound height, and mound width, but negative correlation with mound thickness. The treefall mean diameter at breast height had significant positive correlations with pit width (r=0.328, P=0.017) and pit length (r=0.527, P= 0). The tree species richness at the microsites decreased in the order of intact forest floor > pit > mound, and the tree species coverage was in the sequence of intact forest floor > pit > mound.

  3. Estimating forest aboveground biomass by low density lidar data in mixed broad-leaved forests in the Italian Pre-Alps

    Directory of Open Access Journals (Sweden)

    Antonio Montagnoli

    2015-04-01

    Full Text Available Background: Estimation of forest biomass on the regional and global scale is of great importance. Many studies have demonstrated that lidar is an accurate tool for estimating forest aboveground biomass. However, results vary with forest types, terrain conditions and the quality of the lidar data. Methods: In this study, we investigated the utility of low density lidar data (<2 points∙m−2 for estimating forest aboveground biomass in the mountainous forests of northern Italy. As a study site we selected a 4 km2 area in the Valsassina mountains in Lombardy Region. The site is characterized by mixed and broad-leaved forests with variable stand densities and tree species compositions, being representative for the entire Pre-Alps region in terms of type of forest and geomorphology. We measured and determined tree height, DBH and tree species for 27 randomly located circular plots (radius =10 m in May 2008. We used allometric equations to calculate total aboveground tree biomass and subsequently plot-level aboveground biomass (mg∙ha−1. Lidar data were collected in June 2004. Results: Our results indicate that low density lidar data can be used to estimate forest aboveground biomass with acceptable accuracies. The best height results show a R2 = 0.87 from final model and the root mean square error (RMSE 1.02 m (8.3% of the mean. The best biomass model explained 59% of the variance in the field biomass. Leave-one-out cross validation yielded an RMSE of 30.6 mg∙ha−1 (20.9% of the mean. Conclusions: Low-density lidar data can be used to develop a forest aboveground biomass model from plot-level lidar height measurements with acceptable accuracies. In order to monitoring the National Forest Inventory, and respond to Kyoto protocol requirements, this analysis might be applied to a larger area. Keywords: LiDAR; Allometric equations; Plant height; Mixed forest

  4. A novel method of measuring leaf epidermis and mesophyll stiffness shows the ubiquitous nature of the sandwich structure of leaf laminas in broad-leaved angiosperm species.

    Science.gov (United States)

    Onoda, Yusuke; Schieving, Feike; Anten, Niels P R

    2015-05-01

    Plant leaves commonly exhibit a thin, flat structure that facilitates a high light interception per unit mass, but may increase risks of mechanical failure when subjected to gravity, wind and herbivory as well as other stresses. Leaf laminas are composed of thin epidermis layers and thicker intervening mesophyll layers, which resemble a composite material, i.e. sandwich structure, used in engineering constructions (e.g. airplane wings) where high bending stiffness with minimum weight is important. Yet, to what extent leaf laminas are mechanically designed and behave as a sandwich structure remains unclear. To resolve this issue, we developed and applied a novel method to estimate stiffness of epidermis- and mesophyll layers without separating the layers. Across a phylogenetically diverse range of 36 angiosperm species, the estimated Young's moduli (a measure of stiffness) of mesophyll layers were much lower than those of the epidermis layers, indicating that leaf laminas behaved similarly to efficient sandwich structures. The stiffness of epidermis layers was higher in evergreen species than in deciduous species, and strongly associated with cuticle thickness. The ubiquitous nature of sandwich structures in leaves across studied species suggests that the sandwich structure has evolutionary advantages as it enables leaves to be simultaneously thin and flat, efficiently capturing light and maintaining mechanical stability under various stresses. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  5. Drought reduced monoterpene emissions from the evergreen Mediterranean oak Quercus ilex: results from a throughfall displacement experiment

    Directory of Open Access Journals (Sweden)

    S. Rambal

    2009-07-01

    Full Text Available The effects of water limitations on the emission of biogenic volatile organic compounds are not well understood. Experimental approaches studying drought effects in natural conditions are still missing. To address this question, a throughfall displacement experiment was set up in a natural forest of Quercus ilex, an evergreen Mediterranean oak emitting monoterpenes. Mature trees were exposed in 2005 and 2006 either to an additional drought, to irrigation or to natural drought (untreated control. In both years, absolute monoterpene emission rates as well as the respective standard factors of the trees exposed to normal and additional drought strongly declined during the drought periods. Monoterpene emissions were lower in year 2006 than in year 2005 (factor 2 due to a more pronounced summer drought period in this respective year. We observed a significant difference between the irrigation and additional drought or control treatment: irrigated trees emitted 82% more monoterpenes during the drought period 2006 than the trees of the other treatments. However, no significant effect on monoterpene emission was observed between normal and additional drought treatments, despite a significant effect on leaf water potential and photochemical efficiency. During the development of drought, monoterpene emissions responded exponentially rather than linearly to decreasing leaf water potential. Emissions rapidly declined when the water potential dropped below −2 MPa and photosynthesis was persistently inhibited. Monoterpene synthase activities measured in vitro showed no clear reduction during the same period. From our results we conclude that drought significantly reduces monoterpene fluxes of Mediterranean Holm oak forest into the atmosphere due to a lack of primary substrates coming from photosynthetic processes.

  6. Improving winter leaf area index estimation in evergreen coniferous forests and its significance in carbon and water fluxes modeling

    Science.gov (United States)

    Wang, R.; Chen, J. M.; Luo, X.

    2016-12-01

    Modeling of carbon and water fluxes at the continental and global scales requires remotely sensed LAI as inputs. For evergreen coniferous forests (ENF), severely underestimated winter LAI has been one of the issues for mostly available remote sensing products, which could cause negative bias in the modeling of Gross Primary Productivity (GPP) and evapotranspiration (ET). Unlike deciduous trees which shed all the leaves in winter, conifers retains part of their needles and the proportion of the retained needles depends on the needle longevity. In this work, the Boreal Ecosystem Productivity Simulator (BEPS) was used to model GPP and ET at eight FLUXNET Canada ENF sites. Two sets of LAI were used as the model inputs: the 250m 10-day University of Toronto (U of T) LAI product Version 2 and the corrected LAI based on the U of T LAI product and the needle longevity of the corresponding tree species at individual sites. Validating model daily GPP (gC/m2) against site measurements, the mean RMSE over eight sites decreases from 1.85 to 1.15, and the bias changes from -0.99 to -0.19. For daily ET (mm), mean RMSE decreases from 0.63 to 0.33, and the bias changes from -0.31 to -0.16. Most of the improvements occur in the beginning and at the end of the growing season when there is large correction of LAI and meanwhile temperature is still suitable for photosynthesis and transpiration. For the dormant season, the improvement in ET simulation mostly comes from the increased interception of precipitation brought by the elevated LAI during that time. The results indicate that model performance can be improved by the application the corrected LAI. Improving the winter RS LAI can make a large impact on land surface carbon and energy budget.

  7. Modeling biophysical properties of broad-leaved stands in the hyrcanian forests of Iran using fused airborne laser scanner data and ultraCam-D images

    Science.gov (United States)

    Mohammadi, Jahangir; Shataee, Shaban; Namiranian, Manochehr; Næsset, Erik

    2017-09-01

    Inventories of mixed broad-leaved forests of Iran mainly rely on terrestrial measurements. Due to rapid changes and disturbances and great complexity of the silvicultural systems of these multilayer forests, frequent repetition of conventional ground-based plot surveys is often cost prohibitive. Airborne laser scanning (ALS) and multispectral data offer an alternative or supplement to conventional inventories in the Hyrcanian forests of Iran. In this study, the capability of a combination of ALS and UltraCam-D data to model stand volume, tree density, and basal area using random forest (RF) algorithm was evaluated. Systematic sampling was applied to collect field plot data on a 150 m × 200 m sampling grid within a 1100 ha study area located at 36°38‧- 36°42‧N and 54°24‧-54°25‧E. A total of 308 circular plots (0.1 ha) were measured for calculation of stand volume, tree density, and basal area per hectare. For each plot, a set of variables was extracted from both ALS and multispectral data. The RF algorithm was used for modeling of the biophysical properties using ALS and UltraCam-D data separately and combined. The results showed that combining the ALS data and UltraCam-D images provided a slight increase in prediction accuracy compared to separate modeling. The RMSE as percentage of the mean, the mean difference between observed and predicted values, and standard deviation of the differences using a combination of ALS data and UltraCam-D images in an independent validation at 0.1-ha plot level were 31.7%, 1.1%, and 84 m3 ha-1 for stand volume; 27.2%, 0.86%, and 6.5 m2 ha-1 for basal area, and 35.8%, -4.6%, and 77.9 n ha-1 for tree density, respectively. Based on the results, we conclude that fusion of ALS and UltraCam-D data may be useful for modeling of stand volume, basal area, and tree density and thus gain insights into structural characteristics in the complex Hyrcanian forests.

  8. The impact of broadleaved woodland on water resources in lowland UK: II. Evaporation estimates from sensible heat flux measurements over beech woodland and grass on chalk sites in Hampshire

    Directory of Open Access Journals (Sweden)

    J. Roberts

    2005-01-01

    Full Text Available The impact on recharge to the Chalk aquifer of substitution of broadleaved woodland for pasture is a matter of concern in the UK. Hence, measurements of energy balance components were made above beech woodland and above pasture, both growing on shallow soils over chalk in Hampshire. Latent heat flux (evaporation was calculated as the residual from these measurements of energy balances in which sensible heat flux was measured with an eddy correlation instrument that determined fast response vertical wind speeds and associated temperature changes. Assessment of wind turbulence statistics confirmed that the eddy correlation device performed satisfactorily in both wet and dry conditions. There was excellent agreement between forest transpiration measurements made by eddy correlation and stand level tree transpiration measured with sap flow devices. Over the period of the measurements, from March 1999 to late summer 2000, changes in soil water content were small and grassland evaporation and transpiration estimated from energy balance-eddy flux measurements were in excellent agreement with Penman estimates of potential evaporation. Over the 18-month measurement period, the cumulative difference between broadleaved woodland and grassland was small but evaporation from the grassland was 3% higher than that from the woodland. In the springs of 1999 and 2000, evaporation from the grassland was greater than that from the woodland. However, following leaf emergence in the woodland, the difference in cumulative evaporation diminished until the following spring.

  9. Decoupled leaf and root carbon economics is a key component in the ecological diversity and evolutionary divergence of deciduous and evergreen lineages of genus Rhododendron.

    Science.gov (United States)

    Medeiros, Juliana S; Burns, Jean H; Nicholson, Jaynell; Rogers, Louisa; Valverde-Barrantes, Oscar

    2017-06-01

    We explored trait-trait and trait-climate relationships for 27 Rhododendron species while accounting for phylogenetic relationships and within-species variation to investigate whether leaf and root traits are coordinated across environments and over evolutionary time, as part of a whole-plant economics spectrum. We examined specific leaf area (SLA) and four root traits: specific root length (SRL), specific root tip abundance (SRTA), first order diameter, and link average length, for plants growing in a cold, seasonal climate (Kirtland, Ohio) and a warmer, less seasonal climate (Federal Way, Washington) in the United States. We estimated a phylogeny and species' climate of origin, determined phylogenetic signal on mean traits and within-species variation, and used phylogenetically informed analysis to compare trait-trait and trait-climate relationships for deciduous and evergreen lineages. Mean SLA and within-species variation in SRL were more similar between close relatives than expected by chance. SLA and root traits differed according to climate of origin and across growth environments, though SLA differed within- and among-species less than roots. A negative SRL-SRTA correlation indicates investment in foraging scale vs. precision as a fundamental trade-off defining the root economic spectrum. Also, the deciduous clade exhibited a strong negative relationship between SLA and SRL, while evergreen clades showed a weaker positive or no relationship. Our work suggests that natural selection has shaped relationships between above- and belowground traits in genus Rhododendron and that leaf and root traits may evolve independently. Morphological decoupling may help explain habitat diversity among Rhododendron species, as well as the changes accompanying the divergence of deciduous and evergreen lineages. © 2017 Botanical Society of America.

  10. 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

  11. Chemistry is Evergreen

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 3. Chemistry is Everygreen - 2008 Nobel Prize in Chemistry. Swagata Dasgupta. General Article Volume 14 Issue 3 March 2009 pp 248-258. Fulltext. Click here to view fulltext PDF. Permanent link:

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

    Directory of Open Access Journals (Sweden)

    Lionel Hernández

    2012-03-01

    Full Text Available 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

  13. Greater diversity of soil fungal communities and distinguishable seasonal variation in temperate deciduous forests compared with subtropical evergreen forests of eastern China.

    Science.gov (United States)

    He, Jinhong; Tedersoo, Leho; Hu, Ang; Han, Conghai; He, Dan; Wei, Hui; Jiao, Min; Anslan, Sten; Nie, Yanxia; Jia, Yongxia; Zhang, Gengxin; Yu, Guirui; Liu, Shirong; Shen, Weijun

    2017-07-01

    Whether and how seasonality of environmental variables impacts the spatial variability of soil fungal communities remain poorly understood. We assessed soil fungal diversity and community composition of five Chinese zonal forests along a latitudinal gradient spanning 23°N to 42°N in three seasons to address these questions. We found that soil fungal diversity increased linearly or parabolically with latitude. The seasonal variations in fungal diversity were more distinguishable in three temperate deciduous forests than in two subtropical evergreen forests. Soil fungal diversity was mainly correlated with edaphic factors such as pH and nutrient contents. Both latitude and its interactions with season also imposed significant impacts on soil fungal community composition (FCC), but the effects of latitude were stronger than those of season. Vegetational properties such as plant diversity and forest age were the dominant factors affecting FCC in the subtropical evergreen forests while edaphic properties were the dominant ones in the temperate deciduous forests. Our results indicate that latitudinal variation patterns of soil fungal diversity and FCC may differ among seasons. The stronger effect of latitude relative to that of season suggests a more important influence by the spatial than temporal heterogeneity in shaping soil fungal communities across zonal forests. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

    Zhang, Weiwei; Feng, Zhaozhong; Wang, Xiaoke; Niu, Junfeng

    2014-01-01

    To assess the effects of leaf age/layer on the response of photosynthesis to chronic ozone (O3), Cyclobalanopsis glauca seedlings, a dominant evergreen broadleaf tree species in sub-tropical regions, were exposed to either ambient air (AA) or elevated O3 (AA + 60 ppb O3, E-O3) for two growing seasons in open-top chambers. Chlorophyll content, gas exchange and chlorophyll a fluorescence were investigated three times throughout the 2nd year of O3 exposure. Results indicated that E-O3 decreased photosynthetic parameters, particularly light-saturated photosynthesis rate, stomatal conductance and effective quantum yield of PSII photochemistry of current-year leaves but not previous-year leaves. Stomatal conductance of plants grown under ambient conditions partially contributed to the different response to E-O3 between leaf layers. Light radiation or other physiological and biochemical processes closely related to photosynthesis might play important roles. All suggested that leaf ages or layers should be considered when assessing O3 risk on evergreen woody species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Xylem traits mediate a trade-off between resistance to freeze-thaw-induced embolism and photosynthetic capacity in overwintering evergreens.

    Science.gov (United States)

    Choat, Brendan; Medek, Danielle E; Stuart, Stephanie A; Pasquet-Kok, Jessica; Egerton, John J G; Salari, Hooman; Sack, Lawren; Ball, Marilyn C

    2011-09-01

    Hydraulic traits were studied in temperate, woody evergreens in a high-elevation heath community to test for trade-offs between the delivery of water to canopies at rates sufficient to sustain photosynthesis and protection against disruption to vascular transport caused by freeze-thaw-induced embolism. Freeze-thaw-induced loss in hydraulic conductivity was studied in relation to xylem anatomy, leaf- and sapwood-specific hydraulic conductivity and gas exchange characteristics of leaves. We found evidence that a trade-off between xylem transport capacity and safety from freeze-thaw-induced embolism affects photosynthetic activity in overwintering evergreens. The mean hydraulically weighted xylem vessel diameter and sapwood-specific conductivity correlated with susceptibility to freeze-thaw-induced embolism. There was also a strong correlation of hydraulic supply and demand across species; interspecific differences in stomatal conductance and CO(2) assimilation rates were correlated linearly with sapwood- and leaf-specific hydraulic conductivity. Xylem vessel anatomy mediated an apparent trade-off between resistance to freeze-thaw-induced embolism and hydraulic and photosynthetic capacity during the winter. These results point to a new role for xylem functional traits in determining the degree to which species can maintain photosynthetic carbon gain despite freezing events and cold winter temperatures. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

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

    Science.gov (United States)

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

    2015-05-01

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

  17. Monitoring phenology of photosynthesis in temperate evergreen and mixed deciduous forests using the normalized difference vegetation index (NDVI) and the photochemical reflectance index (PRI) at leaf and canopy scales

    Science.gov (United States)

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

    2016-12-01

    Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which determines their phenology of high photosynthetic activity in the growing season and downregulation during the winter. Monitoring the timing of the transition between summer activity and winter downregulation in evergreens is difficult since this is a largely invisible process, unlike in deciduous trees that have a visible budding and a sequence of leaf unfolding in the spring and leaf abscission in the fall. The light-use efficiency (LUE) model estimates gross primary productivity (GPP) and may be parameterized using remotely sensed vegetation indices. Using spectral reflectance data, we derived the normalized difference vegetation index (NDVI), a measure of leaf "greenness", and the photochemical reflectance index (PRI), a proxy for chlorophyll:carotenoid ratios which is related to photosynthetic activity. To better understand the relationship between these vegetation indices and photosynthetic activity and to contrast this relationship between plant functional types, the phenology of NDVI, PRI and photosynthesis was monitored in an evergreen forest and a mixed deciduous forest at the leaf and canopy scale. Our data indicates that the LUE model can be parameterized by NDVI and PRI to track forest phenology. Differences in the sensitivity of PRI and NDVI will be discussed. These findings have implications to address the phenology of evergreen conifers by using PRI to complement NDVI in the LUE model, potentially improving model productivity estimates in northern hemisphere forests, that are dominated by conifers.

  18. Presence of understory shrubs constrains carbon gain in sunflecks by advance-regeneration seedlings: evidence from Quercus Rubra seedling grouwing in understory forest patches with or without evergreen shrubs present

    Science.gov (United States)

    E.T. Nilsen; T.T. Lei; S.W. Semones

    2009-01-01

    We investigated whether dynamic photosynthesis of understory Quercus rubra L. (Fagaceae) seedlings can acclimate to the altered pattern of sunflecks in forest patches with Rhododendron maximum L. (Ericaceae), an understory evergreen shrub. Maximum photosynthesis (A) and total CO2 accumulated during lightflecks was greatest for 400-s lightflecks, intermediate for 150-s...

  19. The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California

    Science.gov (United States)

    Jachens, Robert C.; Wentworth, Carl M.; Graymer, Russell W.; Williams, Robert; Ponce, David A.; Mankinen, Edward A.; Stephenson, William J.; Langenheim, Victoria

    2017-01-01

    The Evergreen basin is a 40-km-long, 8-km-wide Cenozoic sedimentary basin that lies mostly concealed beneath the northeastern margin of the Santa Clara Valley near the south end of San Francisco Bay (California, USA). The basin is bounded on the northeast by the strike-slip Hayward fault and an approximately parallel subsurface fault that is structurally overlain by a set of west-verging reverse-oblique faults which form the present-day southeastward extension of the Hayward fault. It is bounded on the southwest by the Silver Creek fault, a largely dormant or abandoned fault that splays from the active southern Calaveras fault. We propose that the Evergreen basin formed as a strike-slip pull-apart basin in the right step from the Silver Creek fault to the Hayward fault during a time when the Silver Creek fault served as a segment of the main route by which slip was transferred from the central California San Andreas fault to the Hayward and other East Bay faults. The dimensions and shape of the Evergreen basin, together with palinspastic reconstructions of geologic and geophysical features surrounding it, suggest that during its lifetime, the Silver Creek fault transferred a significant portion of the ∼100 km of total offset accommodated by the Hayward fault, and of the 175 km of total San Andreas system offset thought to have been accommodated by the entire East Bay fault system. As shown previously, at ca. 1.5–2.5 Ma the Hayward-Calaveras connection changed from a right-step, releasing regime to a left-step, restraining regime, with the consequent effective abandonment of the Silver Creek fault. This reorganization was, perhaps, preceded by development of the previously proposed basin-bisecting Mount Misery fault, a fault that directly linked the southern end of the Hayward fault with the southern Calaveras fault during extinction of pull-apart activity. Historic seismicity indicates that slip below a depth of 5 km is mostly transferred from the Calaveras

  20. Endophytic Fungi of Various Medicinal Plants Collected From Evergreen Forest Baluran National Park and Its Potential as Laboratory Manual for Mycology Course

    Directory of Open Access Journals (Sweden)

    Siti Murdiyah

    2017-03-01

    Full Text Available Endophytic fungi found on a variety of medicinal plants may express particular benefit. These fungi provide an alternative to overcome the progressive microbial resistance and as an effort to combat infectious diseases that became one of the leading causes of mortality. The main objective of this study was to isolate endophytic fungi from leaf samples of five medicinal plants species collected from evergreen forests Baluran National Park and its use as laboratory manual for Micology. Research findings showed there were 3 isolates of endophytic fungi isolated from 2 medicinal plants namely Kesambi (Schleicera oleosa and Ketapang (Terminalia catappa. All three isolates formed sporangiophores as asexual reproductive structures, while the structure of sexual still undiscovered therefore its classification has not been determined. The validity tests also showed that the lab manual is feasible for use with the percentage achievement 85.37% and 88.56%.

  1. Interspecific differences in whole-plant respiration vs. biomass scaling relationships: a case study using evergreen conifer and angiosperm tree seedlings.

    Science.gov (United States)

    Cheng, Dongliang; Niklas, Karl J; Zhong, Quanlin; Yang, Yusheng; Zhang, Jianhua

    2014-04-01

    Empirical studies and theory indicate that respiration rates (R) of small plants scale nearly isometrically with both leaf biomass (ML) and total plant biomass (MT). These predictions are based on angiosperm species and apply only across a small range of body mass. Whether these relationships hold true for different plants, such as conifers, remains unclear. We tested these predictions using the whole-plant maintenance respiration rates and the biomass allocation patterns of the seedlings of two conifer tree species and two angiosperm tree species. Model Type II regression protocols were used to compare the scaling exponents (α) and normalization constants (β) across all four species and within each of the four species. The data show that the scaling exponents varied among the four species and that all differed significantly from isometry. For conifers, scaling exponents for R vs. MT, and R and ML were numerically smaller than those of the broadleaved angiosperm species. However, across the entire data set, R scaled isometrically with ML and with MT as predicted by the West, Brown, and Enquist (WBE) theory. We also observed higher respiration rates for small conifer seedlings compared to comparably sized angiosperm seedlings. Our data add credence to the view that the R vs. M scaling relationship differs among species, and that in general, the numerical values of this interspecific scaling relationship will depend on the species pooled in the analysis and on the range of body sizes within the data set.

  2. 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 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.

  3. 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. 

  4. Forest Restoration in China: Advances, Obstacles, and Perspectives

    Science.gov (United States)

    Hai Ren; Hongfang Lu; Jun Wang; Nan Liu; Qinfeng Guo

    2012-01-01

    Because of the prolonged history of disturbance caused by intense human activities, restoration in China has been a major task facing many ecologists and land managers. There are six major forest types in China: cold temperate coniferous forest, temperate coniferous and broad-leaved mixed forest, warm temperate deciduous broad-leaved forest, subtropical evergreen broad...

  5. Soil nitrate accumulation dominates the nonlinear responses of soil CO2 and CH4 fluxes to multi-level nitrogen addition in a temperate needle-broadleaved mixed forest

    Science.gov (United States)

    Fang, Huajun

    2017-04-01

    The responses of soil-atmosphere carbon (C) exchange fluxes to increased atmospheric nitrogen (N) deposition are controversial, leading to great uncertainty in the evaluation on the C sink capacity of global forest ecosystems elicited by anthropogenic N inputs. To date, we hardly knew how much was the critical level of N input for the alteration of the soil C fluxes, and what factors controlled the changes in soil CO2 and CH4 fluxes under N enrichment. Nine levels of urea addition experiment (0, 10, 20, 40, 60, 80, 100, 120, 140 kg N ha-1 yr-1) was conducted in the needle-broadleaved mixed forest in Changbai Mountain, Northeast China. Soil CO2 and CH4 fluxes were monitored weekly using the static chamber and gas chromatograph technique. Environmental variables (soil temperature and moisture in the 0-10 cm depth) and dissolved N (NH4+-N, NO3-N, total dissolved N (TDN), and dissolved organic N (DON)) in the organic layer and the 0-10 cm mineral soil layer were simultaneously measured. High rates of N addition (≥ 60 kg N ha-1 yr-1) significantly increased soil NO3-N contents in the organic layer and the mineral layer by 120%-180% and 56.4%-84.6%, respectively. However, N application did not lead to a significant accumulation of soil NH4+-N contents in the two soil layers except for a few treatments. N addition at a low rate of 10 kg N ha-1 yr-1 significantly promoted soil CO2 emission and CH4 uptake, whereas high rate of N addition (140 kg N ha-1 yr-1) significantly inhibited them. Significant negative relationships were observed between changes in soil CO2 emission and CH4 uptake and changes in soil NO3-N and moisture contents under N enrichment. These results suggest that soil nitrification and NO3-N accumulation could be important regulators of soil CO2 emission and CH4 uptake in the temperate needle-broadleaved mixed forest. The nonlinear responses to exogenous N inputs and the critical levels for the alteration of soil C fluxes should be considered in the

  6. 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

  7. 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.

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

    Science.gov (United States)

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

    2015-04-01

    Warm-temperate evergreen (WTE) forest represents the typical vegetation type of subtropical China, but how its component species responded to past environmental change remains largely unknown. Here, we reconstruct the evolutionary history of Tetrastigma hemsleyanum, an herbaceous climber restricted to the WTE forest. Twenty populations were genotyped using chloroplast DNA sequences and nuclear microsatellite loci to assess population structure and diversity, supplemented by phylogenetic dating, ancestral area reconstructions and ecological niche modeling (ENM) of the species distributions during the Last Glacial Maximum (LGM) and at present. Lineages in Southwest vs Central-South-East China diverged through climate/tectonic-induced vicariance of an ancestral southern range during the early Pliocene. Long-term stability in the Southwest contrasts with latitudinal range shifts in the Central-South-East region during the early-to-mid-Pleistocene. Genetic and ENM data strongly suggest refugial persistence in situ at the LGM. Pre-Quaternary environmental changes appear to have had a persistent influence on the population genetic structure of this subtropical WTE forest species. Our findings suggest relative demographic stability of this biome in China over the last glacial-interglacial cycle, in contrast with palaeobiome reconstructions showing that this forest biome retreated to areas of today's tropical South China during the LGM. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  9. 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

  10. Increasing carbon discrimination rates and depth of water uptake favor the growth of Mediterranean evergreen trees in the ecotone with temperate deciduous forests.

    Science.gov (United States)

    Barbeta, Adrià; Peñuelas, Josep

    2017-12-01

    Tree populations at the low-altitudinal or -latitudinal limits of species' distributional ranges are predicted to retreat toward higher altitudes and latitudes to track the ongoing changes in climate. Studies have focused on the climatic sensitivity of the retreating species, whereas little is known about the potential replacements. Competition between tree species in forest ecotones will likely be strongly influenced by the ecophysiological responses to heat and drought. We used tree-ring widths and δ13 C and δ18 O chronologies to compare the growth rates and long-term ecophysiological responses to climate in the temperate-Mediterranean ecotone formed by the deciduous Fagus sylvatica and the evergreen Quercus ilex at the low altitudinal and southern latitudinal limit of F. sylvatica (NE Iberian Peninsula). F. sylvatica growth rates were similar to those of other southern populations and were surprisingly not higher than those of Q. ilex, which were an order of magnitude higher than those in nearby drier sites. Higher Q. ilex growth rates were associated with high temperatures, which have increased carbon discrimination rates in the last 25 years. In contrast, stomatal regulation in F. sylvatica was proportional to the increase in atmospheric CO2 . Tree-ring δ18 O for both species were mostly correlated with δ18 O in the source water. In contrast to many previous studies, relative humidity was not negatively correlated with tree-ring δ18 O but had a positive effect on Q. ilex tree-ring δ18 O. Furthermore, tree-ring δ18 O decreased in Q. ilex over time. The sensitivity of Q. ilex to climate likely reflects the uptake of deep water that allowed it to benefit from the effect of CO2 fertilization, in contrast to the water-limited F. sylvatica. Consequently, Q. ilex is a strong competitor at sites currently dominated by F. sylvatica and could be favored by increasingly warmer conditions. © 2017 John Wiley & Sons Ltd.

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

    Directory of Open Access Journals (Sweden)

    E. V. J. Tanner

    2016-11-01

    Full Text Available 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.

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

    Science.gov (United States)

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

    2012-10-01

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

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

    Science.gov (United States)

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

    2013-12-01

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

  14. [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.

  15. Vegetation shift from deciduous to evergreen dwarf shrubs in response to selective herbivory offsets carbon losses: evidence from 19 years of warming and simulated herbivory in the subarctic tundra.

    Science.gov (United States)

    Ylänne, Henni; Stark, Sari; Tolvanen, Anne

    2015-10-01

    Selective herbivory of palatable plant species provides a competitive advantage for unpalatable plant species, which often have slow growth rates and produce slowly decomposable litter. We hypothesized that through a shift in the vegetation community from palatable, deciduous dwarf shrubs to unpalatable, evergreen dwarf shrubs, selective herbivory may counteract the increased shrub abundance that is otherwise found in tundra ecosystems, in turn interacting with the responses of ecosystem carbon (C) stocks and CO2 balance to climatic warming. We tested this hypothesis in a 19-year field experiment with factorial treatments of warming and simulated herbivory on the dominant deciduous dwarf shrub Vaccinium myrtillus. Warming was associated with a significantly increased vegetation abundance, with the strongest effect on deciduous dwarf shrubs, resulting in greater rates of both gross ecosystem production (GEP) and ecosystem respiration (ER) as well as increased C stocks. Simulated herbivory increased the abundance of evergreen dwarf shrubs, most importantly Empetrum nigrum ssp. hermaphroditum, which led to a recent shift in the dominant vegetation from deciduous to evergreen dwarf shrubs. Simulated herbivory caused no effect on GEP and ER or the total ecosystem C stocks, indicating that the vegetation shift counteracted the herbivore-induced C loss from the system. A larger proportion of the total ecosystem C stock was found aboveground, rather than belowground, in plots treated with simulated herbivory. We conclude that by providing a competitive advantage to unpalatable plant species with slow growth rates and long life spans, selective herbivory may promote aboveground C stocks in a warming tundra ecosystem and, through this mechanism, counteract C losses that result from plant biomass consumption. © 2015 John Wiley & Sons Ltd.

  16. Ecological Value of Soil Organic Matter at Tropical Evergreen Aglaia-Streblus Forest of Meru Betiri National Park, East Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Hari Sulistiyowati

    2016-09-01

    Full Text Available As part of carbon pools, forest soil stores soil organic matter (SOM that contains many elements including organic C, N, P, and K. These elements contribute nutrients for biogeochemical cycles within the ecosystem. This study was done to determine the ecological value of forest soil organic matter at tropical evergreen Aglaia-Streblus forest of Meru Betiri National Park (MBNP, East Java, Indonesia. The data were sampled along gradient topography in Pringtali tropical forest of TMBNP. Direct measurements of soil moisture, temperature, and pH were taken in the field. The soil samples were extracted from 6 points of soil solum using soil auger, and then oven-dried to get value of dry-weight. The elements content of organic C, N, P, and K were analyzed and estimated at the laboratory. The ecoval of SOM was appraised using developed ecological valuation tool. The result showed that SOM contributed higher ecoval of organic C (66.03 Mg ha-1 than other elements. Compared to P and K elements, N had the highest stock of element content. However, comparing to other two tropical forest ecosystems of Asia the ecoval of SOM elements in TMBNP was relatively low because of its natural geomorphological features.The ecoval of SOM elements in TMBNP was relatively low because of its natural geomorphological features. The ecovals contributed about 2.440,64 - 6.955,50 USD or 31.271.923,73 - 89.120.837,23 IDR per hectare of ecological value (d to the ecosystem. This value was mainly contributed by organic C stock in the TMBNP forest SOM. It means the forest SOM had higher element content of organic C than N, P, and K elements. This d value is an indicator for TMBNP to protect the SOM elements meaning protecting their resources to sustain the biogeochemical cycles in the forest ecosystem. All the management and policy correlated to this protected area should consider this valuable information for their plan and actions.

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

    Directory of Open Access Journals (Sweden)

    E.-D. Schulze

    2012-04-01

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

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

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

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

    Science.gov (United States)

    Schulze, E.-D.; Wirth, C.; Mollicone, D.; von Lüpke, N.; Ziegler, W.; Achard, F.; Mund, M.; Prokushkin, A.; Scherbina, S.

    2012-04-01

    The relative role of fire and of climate in determining canopy species composition and aboveground carbon stocks were investigated. Measurements were made along a transect extending from the dark taiga zone of central Siberia, where Picea and Abies dominate the canopy, into the Larix zone of eastern Siberia. We test the hypotheses that the change in canopy species composition is based (1) on climate-driven performance only, (2) on fire only, or (3) on fire-performance interactions. We show that the evergreen conifers Picea obovata and Abies sibirica are the natural late-successional species both in central and eastern Siberia, provided there has been no fire for an extended period of time. There are no changes in performance of the observed species along the transect. Fire appears to be the main factor explaining the dominance of Larix and of soil carbon. Of lesser influence were longitude as a proxy for climate, local hydrology and active-layer thickness. We can only partially explain fire return frequency, which is not only related to climate and land cover, but also to human behavior. Stand-replacing fires decreased from 300 to 50 yrs between the Yenisei Ridge and the upper Tunguska. Repeated non-stand-replacing surface fires eliminated the regeneration of Abies and Picea. With every 100 yrs since the last fire, the percentage of Larix decreased by 20%. Biomass of stems of single trees did not show signs of age-related decline. Relative diameter increment was 0.41 ± 0.20% at breast height and stem volume increased linearly over time with a rate of about 0.36 t C ha-1 yr-1 independent of age class and species. Stand biomass reached about 130 t C ha-1(equivalent to about 520 m3 ha-1). Individual trees of Larix were older than 600 yrs. The maximum age and biomass seemed to be limited by fungal rot of heart wood. 60% of old Larix and Picea and 30% of Pinus sibirica trees were affected by stem rot. Implications for the future role of fire and of plant diseases are

  19. [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

  20. Complex adjustments of photosynthetic potentials and internal diffusion conductance to current and previous light availabilities and leaf age in Mediterranean evergreen species Quercus ilex.

    Science.gov (United States)

    Niinemets, Ulo; Cescatti, Alessandro; Rodeghiero, Mirco; Tosens, Tiina

    2006-06-01

    Mature non-senescent leaves of evergreen species become gradually shaded as new foliage develops and canopy expands, but the interactive effects of integrated light during leaf formation (Q(int)G), current light (Q(int)C) and leaf age on foliage photosynthetic competence are poorly understood. In Quercus ilex L., we measured the responses of leaf structural and physiological variables to Q(int)C and Q(int)G for four leaf age classes. Leaf aging resulted in increases in leaf dry mass per unit area (M(A)), and leaf dry to fresh mass ratio (D(F)) and decreases in N content per dry mass (N(M)). N content per area (N(A)) was independent of age, indicating that decreases in N(M) reflected dilution of leaf N because of accumulation of dry mass (NA = N(M) M(A)). M(A), D(F) and N(A) scaled positively with irradiance, whereas these age-specific correlations were stronger with leaf growth light than with current leaf light. Area-based maximum ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylase activity (V(cmax)A), capacity for photosynthetic electron transport (J(max)A) and the rate of non-photorespiratory respiration in light (R(d)A) were also positively associated with irradiance. Differently from leaf structural characteristics, for all data pooled, these relationships were stronger with current light with little differences among leaves of different age. Acclimation to current leaf light environment was achieved by light-dependent partitioning of N in rate-limiting proteins. Mass-based physiological activities decreased with increasing leaf age, reflecting dilution of leaf N and a larger fraction of non-photosynthetic N in older leaves. This resulted in age-dependent modification of leaf photosynthetic potentials versus N relationships. Internal diffusion conductance (g(m)) per unit area (g(m)A) increased curvilinearly with increasing irradiance for two youngest leaf age classes and was independent of light for older leaves. In contrast, g(m) per dry

  1. Species-specific and seasonal differences in chlorophyll fluorescence and photosynthetic light response among three evergreen species in a Madrean sky island mixed conifer forest

    Science.gov (United States)

    Potts, D. L.; Minor, R. L.; Braun, Z.; Barron-Gafford, G. A.

    2012-12-01

    -use efficiency (AQE) was similar among P. strobiformis and P. ponderosa and least in P. menziesii (repeated-measures ANOVA; species, F2,8 = 13.83, P = 0.002). Across all three species, monsoon onset increased AQE (repeated-measures ANOVA; time, F1,8= 10.04, P = 0.01). Likewise, P. strobiformis and P. ponderosa shared a similar, greater light compensation point than P. menziesii (repeated-measures ANOVA; species, F2,8 = 5.89, P = 0.02). However, across species, monsoon onset did not influence light compensation points. These results support the hypothesis that the monsoon has species-specific effects on evergreen physiological performance and are broadly consistent with predictions of stress tolerance based on species' latitudinal and elevational range distributions. Moreover, with year-to-year rainfall variability predicted to increase under future climate scenarios, species-specific functional traits related to stress tolerance and photosynthesis may promote ecosystem functional resilience in Madrean sky island mixed conifer forests.

  2. 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.

  3. 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. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

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

    Science.gov (United States)

    Kitao, Mitsutoshi; Komatsu, Masabumi; Hoshika, Yasutomo; Yazaki, Kenichi; Yoshimura, Kenichi; Fujii, Saori; Miyama, Takafumi; Kominami, Yuji

    2014-01-01

    Canopy-level stomatal conductance over a warm-temperate mixed deciduous and evergreen broadleaf forest in Japan was estimated by the Penman-Monteith approach, as compensated by a semi-empirical photosynthesis-dependent stomatal model, where photosynthesis, relative humidity, and CO2 concentration were assumed to regulate stomatal conductance. This approach, using eddy covariance data and routine meteorological observations at a flux tower site, permits the continuous estimation of canopy-level O3 uptake, even when the Penman-Monteith approach is unavailable (i.e. in case of direct evaporation from soil or wet leaves). Distortion was observed between the AOT40 exposure index and O3 uptake through stomata, as AOT40 peaked in April, but with O3 uptake occurring in July. Thus, leaf pre-maturation in the predominant deciduous broadleaf tree species (Quercus serrata) might suppress O3 uptake in springtime, even when the highest O3 concentrations were observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. 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. © 2010 Blackwell Publishing Ltd.

  6. The Mediterranean evergreen Quercus ilex and the semi-deciduous Cistus albidus differ in their leaf gas exchange regulation and acclimation to repeated drought and re-watering cycles.

    Science.gov (United States)

    Galle, Alexander; Florez-Sarasa, Igor; Aououad, Hanan El; Flexas, Jaume

    2011-10-01

    Plants may exhibit some degree of acclimation after experiencing drought, but physiological adjustments to consecutive cycles of drought and re-watering (recovery) have scarcely been studied. The Mediterranean evergreen holm oak (Q. ilex) and the semi-deciduous rockrose (C. albidus) showed some degree of acclimation after the first of three drought cycles (S1, S2, and S3). For instance, during S2 and S3 both species retained higher relative leaf water contents than during S1, despite reaching similar leaf water potentials. However, both species showed remarkable differences in their photosynthetic acclimation to repeated drought cycles. Both species decreased photosynthesis to a similar extent during the three cycles (20-40% of control values). However, after S1 and S2, photosynthesis recovered only to 80% of control values in holm oak, due to persistently low stomatal (g(s)) and mesophyll (g(m)) conductances to CO(2). Moreover, leaf intrinsic water use efficiency (WUE) was kept almost constant in this species during the entire experiment. By contrast, photosynthesis of rockrose recovered almost completely after each drought cycle (90-100% of control values), while the WUE was largely and permanently increased (by 50-150%, depending on the day) after S1. This was due to a regulation which consisted in keeping g(s) low (recovering to 50-60% of control values after re-watering) while maintaining a high g(m) (even exceeding control values during re-watering). While the mechanisms to achieve such particular regulation of water and CO(2) diffusion in leaves are unknown, it clearly represents a unique acclimation feature of this species after a drought cycle, which allows it a much better performance during successive drought events. Thus, differences in the photosynthetic acclimation to repeated drought cycles can have important consequences on the relative fitness of different Mediterranean species or growth forms within the frame of climate change scenarios.

  7. A new species of Stigmatomma from Taiwan (Hymenoptera, Formicidae, Amblyoponinae).

    Science.gov (United States)

    Hsu, Feng-Chuan; Esteves, Flavia A; Chou, Lien-Siang; Lin, Chung-Chi

    2017-01-01

    Stigmatomma is the most speciose ant genus in the subfamily Amblyoponinae. In the present paper, the worker caste of a new species is described, S. luyiaesp. n., which was collected from a soil sample in a subtropical evergreen broad-leaved forest in Taiwan. An identification key to the females of Stigmatomma species with 11 antennomeres occurring in Asia is also provided.

  8. Saikosaponins a and d roots concentration in five Bupleurum ...

    African Journals Online (AJOL)

    Yomi

    2012-01-16

    Jan 16, 2012 ... Outcome. B. scorzonerifolium appeared only in the deciduous forest. We found B. Bicaule favorable environment might be evergreen and grassland in term of global sum ∑a+d saikosaponins roots concentration. B. scorzonerifolium favorable environment might be broadleaves forest in term of global sum ...

  9. Relationships between the timing of budburst, plant traits, and distribution of 24 coexisting woody species in a warm-temperate forest in Japan.

    Science.gov (United States)

    Osada, Noriyuki

    2017-04-01

    Timing of budburst (DBB) may be related to the functional traits and distributions of woody species in temperate regions. Although many previous studies have investigated DBB in a number of temperate species, it has seldom been linked to multiple plant trait relationships. DBB and plant traits were investigated for 24 woody species for 2 years in a warm-temperate secondary forest in Japan. Particular attention was paid to differences in trait relationships between coexisting deciduous and evergreen broad-leaved species. DBB was correlated with plant traits in deciduous but not evergreen broad-leaved species; DBB was later for deciduous species with greater leaf mass, leaf area, vessel diameter, and leaf nitrogen content per unit mass. In addition, DBB was later for species with more northern distributions in deciduous and evergreen species. Clear differences in the trait relationships between deciduous and evergreen broad-leaved species might be caused by different selection pressures on DBB; selection is expected to be more severe in deciduous species. Overall, the continuous variable of vessel diameter might be used as a simple and effective trait to predict DBB of deciduous species regardless of wood anatomy; however, no such traits were detected as effective predictors of DBB in evergreen species at this study site. In addition, DBB was earlier for the species of more southern distributions, suggesting that such species benefit more from warming. © 2017 Botanical Society of America.

  10. Regionalización biogeográfica de la mastofauna de los bosques tropicales perennifolios de Mesoamérica Biogeographic regionalization of the mammals of tropical evergreen forests in Mesoamerica

    Directory of Open Access Journals (Sweden)

    Héctor C. Olguín-Monroy

    2013-06-01

    Full Text Available Este trabajo presenta una propuesta de regionalización biogeográfica de los bosques tropicales perennifolios de Mesoamérica, resultado de un análisis de parsimonia de endemismos (PAE, utilizando modelos de nicho ecológico (GARP con mamíferos terrestres, usando 41 527 registros para las 233 especies de mamíferos reconocidas. La regionalización propuesta muestra que los bosques tropicales perennifolios de Mesoamérica se dividen por el istmo de Tehuantepec en Oaxaca en: a un grupo septentrional que comprende la Sierra Madre de Chiapas-Guatemala y la Península de Yucatán, y b un grupo austral, que contiene la vertiente pacífica hacia el sur incluyendo Centroamérica. Además se encontró congruencia con trabajos filogenéticos, lo que sugiere una historia biogeográfica común.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

  11. 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

  12. 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...

  13. 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

  14. Vegetation structure and greenness in Central Africa from Modis multi-temporal data

    OpenAIRE

    Gond, Valéry; Fayolle, A.; PENNEC A.; Cornu, Guillaume; Mayaux, Philippe; Camberlin, Pierre; DOUMENGE Charles; Fauvet, Nicolas; Gourlet-Fleury, S.

    2013-01-01

    African forests within the Congo Basin are generally mapped at a regional scale as broad-leaved evergreen forests, with the main distinction being between terra-firme and swamp forest types. At the same time, commercial forest inventories, as well as national maps, have highlighted a strong spatial heterogeneity of forest types. A detailed vegetation map generated using consistent methods is needed to inform decision makers about spatial forest organization and their relationships with enviro...

  15. MAPPING TROPICAL FOREST FOR SUSTAINABLE MANAGEMENT USING SPOT 5 SATELLITE IMAGE

    OpenAIRE

    Nguyen, Huong Thi Thanh

    2016-01-01

    This paper describes the combination of multi-data in stratifying the natural evergreen broadleaved tropical forest of the Central Highlands of Vietnam. The forests were stratified using both unsupervised and supervised classification methods based on SPOT5 and field data. The forests were classified into 3 and 4 strata separably. Correlation between stratified forest classes and forest variables was analyzed in order to find out 1) how many classes is suitable to stratify for the forest in t...

  16. Glacial bottleneck and postglacial recolonization of a seed parasitic weevil, Curculio hilgendorfi, inferred from mitochondrial DNA variation.

    Science.gov (United States)

    Aoki, K; Kato, M; Murakami, N

    2008-07-01

    Climatic changes during glacial periods have had a major influence on the recent evolutionary history of living organisms, even in the warm temperate zone. We investigated phylogeographical patterns of a weevil Curculio hilgendorfi (Curculionidae), a host-specific seed predator of Castanopsis (Fagaceae) growing in the broadleaved evergreen forests in Japan. We examined 2709 bp of mitochondrial DNA for 204 individuals collected from 62 populations of the weevil. Four major haplogroups were detected, in southwestern and northeastern parts of the main islands and in central and southern parts of the Ryukyu Islands. The demographic population expansion was detected for the two groups in the main islands but not for the Ryukyu groups. The beginning time of the expansion was dated to 39,000-59,000 years ago, which is consistent with the end of the last glacial period. Our data also demonstrated that the southwestern population of the main islands has experienced a more severe bottleneck and more rapid population growth after glacial ages than the northeastern population. At least three refugial areas in the main islands were likely to have existed during the last glacial periods, one of which had not previously been recognized by analyses of intraspecific chloroplast DNA variation of several plant species growing in the broadleaved evergreen forests. Our results represent the first phylogeographical and population demographic analysis of an insect species associated with the broadleaved evergreen forests in Japan, and reveal more detailed postglacial history of the forests.

  17. 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

  18. Myxomycetes from the bark of the evergreen oak Quercus ilex

    Directory of Open Access Journals (Sweden)

    Wrigley de Basanta, Diana

    1998-06-01

    Full Text Available The results of 81 moist chamber cultures of bark from living Quercus ilex trees are reponed. A total of 37 taxa are cited, extending the number of species found on this substrate to 55. The presence of Licea deplanata on the Iberian Península is confirmed. Seven new records are included for the province of Madrid. Some data are contributed on species frequency and incubation times.Se presentan los resultados de 81 cultivos en cámara húmeda de corteza de Quercus ilex vivo. Se citan 37 táxones, que amplían a 55 el número de especies de mixomicetes encontrados sobre este sustrato. Se confirma la presencia en la Península Ibérica de Licea deplanata, y se incluyen siete nuevas citas para la provincia de Madrid. Se aportan datos sobre frecuencia de aparición y tiempos de incubación de algunas especies.

  19. Annotated bibliography of South African indigenous evergreen forest ecology

    CSIR Research Space (South Africa)

    Geldenhuys, CJ

    1985-01-01

    Full Text Available Annotated references to 519 publications are presented, together with keyword listings and keyword, regional, place name and taxonomic indices. This bibliography forms part of the first phase of the activities of the Forest Biome Task Group....

  20. The rigid pendulum - an antique but evergreen physical model

    Science.gov (United States)

    Butikov, Eugene I.

    1999-11-01

    Various kinds of motion of a rigid pendulum (including swinging with arbitrarily large amplitudes and complete revolutions) are investigated both analytically and with the help of computerized simulations. The simulation experiments reveal many interesting peculiarities of this famous physical model and complement the analytical study of the subject in a manner that is mutually reinforcing.

  1. From green to evergreen: Updating the food revolution | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-01-26

    Jan 26, 2011 ... The techniques of biotechnology pioneered by Swaminathan and his colleagues were adopted by other developing countries, and produced the food security that helped set the stage for the rapid ... One is natural resources conservation and enhancement — of soil fertility, water, flora and fauna, and so on.

  2. \\. Santalum album L. (sandalwood) is a small evergreen tree that ...

    Indian Academy of Sciences (India)

    once in late summer and again between October and December, are small and purplish brown. Sandal trees show considerable variation with respect to the shape, size of their leaf and fruit and the extent of heartwood. The heartwood and the essential oil obtained from it are among the oldest known perfumery material and ...

  3. An Evergreen Challenge for Translators – The Translation of Idioms

    Directory of Open Access Journals (Sweden)

    Kovács Gabriella

    2016-12-01

    Full Text Available Translating idioms has always been a challenging decision-making process for translators mainly because not all idioms have direct equivalents in the target language. Translators usually and ideally have a solid knowledge of the target language and its cultural aspects, but even so they cannot match the ability of a native speaker in deciding when – i.e. in what context and text type – an idiom would or would not be appropriate. This study aims to explore the main characteristics of idioms and the difficulties which might occur when translating them. A needs analysis will also be presented, where the various solutions which a group of translator trainees chose while translating certain idioms from the novel “A Game of Thrones” by George R. R. Martin into Hungarian are examined. Their strategies and the appropriateness of their choices are analysed and compared with the options of the experienced literary translator (Tamás Pétersz. We consider this an important endeavour because, based on our experience, we believe that the topic of the translation of idioms should be included into the curriculum and appropriate materials and tasks should be designed to develop the translator trainees’ knowledge and skills in this domain. Therefore, the aim of this analysis is to obtain a clearer view of the difficulties they are dealing with and bear them in mind when designing teaching materials for them.

  4. 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.

  5. 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

  6. Effects of Topographical and Edaphic Factors on Tree Community Structure and Diversity of Subtropical Mountain Forests in the Lower Lancang River Basin

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    Changshun Zhang

    2016-10-01

    Full Text Available We investigated community structure and tree species diversity of six subtropical mountain forests in relation to 11 topographical and edaphic factors in Lower Lancang River Basin, Yunnan Province, China, based on a census of all trees with diameter at breast height ≥5 cm in 45 0.06-ha plots. The forests were as follows: a river valley monsoon forest, semi-humid evergreen broad-leaved forest, monsoon evergreen broad-leaved forest, mid-mountain humid evergreen broad-leaved forest, summit mossy dwarf forest, and warm needle-leaved forest. Owing to the variation in microenvironment, forest structure (tree density, mean height, mean diameter at breast height, mean basal area at breast height and tree diversity indices (the number of species, Margalef richness, Shannon-Wiener diversity, Simpson’s index, and Pielou’s evenness differed significantly among forest types but did not differ among sites. We recorded a total of 5155 canopy trees belonging to 204 tree species, 104 genera, and 50 families at three sites, and the co-occurrence of tree species between adjacent communities was higher. A clear forest community distribution along an altitudinal gradient suggested that elevation was important in tree species distribution. Ordination identified elevation, slope degree, slope position, soil pH, organic matter, total nitrogen, and available nitrogen as significant explanatory variables of tree species distribution and showed that elevation was more important than the rest of the environmental variables in affecting local woody plant distribution. Understanding relationships between tree species distribution and environmental factors in subtropical mountain forests of the Lower Lancang River Basin would enable us to apply these findings to forest management and vegetation restoration.

  7. Pre-dispersal strategies by Quercus schottkyana to mitigate the effects of weevil infestation of acorns

    OpenAIRE

    Ke Xia; William L. Harrower; Roy Turkington; Hong-Yu Tan; Zhe-Kun Zhou

    2016-01-01

    We investigated how pre-dispersal strategies may mitigate the effects of weevil infestation of acorns in a population of Quercus schottkyana, a dominant oak in Asian evergreen broad-leaved forests, and assess if weevil infestation contributes to low seedling recruitment. We counted the number of acorns produced, daily from the end of August to mid-late November for 9 years from 2006?2014. We also recorded the rate of acorn infestation by weevils and acorn germination rates of weekly collectio...

  8. Quantifying Rainfall Interception Loss of a Subtropical Broadleaved Forest in Central Taiwan

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    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.

  9. Functional composition drives ecosystem function through multiple mechanisms in a broadleaved subtropical forest.

    Science.gov (United States)

    Chiang, Jyh-Min; Spasojevic, Marko J; Muller-Landau, Helene C; Sun, I-Fang; Lin, Yiching; Su, Sheng-Hsin; Chen, Zueng-Sang; Chen, Chien-Teh; Swenson, Nathan G; McEwan, Ryan W

    2016-11-01

    Understanding the role of biodiversity (B) in maintaining ecosystem function (EF) is a foundational scientific goal with applications for resource management and conservation. Two main hypotheses have emerged that address B-EF relationships: niche complementarity (NC) and the mass-ratio (MR) effect. We tested the relative importance of these hypotheses in a subtropical old-growth forest on the island nation of Taiwan for two EFs: aboveground biomass (ABG) and coarse woody productivity (CWP). Functional dispersion (FDis) of eight plant functional traits was used to evaluate complementarity of resource use. Under the NC hypothesis, EF will be positively correlated with FDis. Under the MR hypothesis, EF will be negatively correlated with FDis and will be significantly influenced by community-weighted mean (CWM) trait values. We used path analysis to assess how these two processes (NC and MR) directly influence EF and may contribute indirectly to EF via their influence on canopy packing (stem density). Our results indicate that decreasing functional diversity and a significant influence of CWM traits were linked to increasing AGB for all eight traits in this forest supporting the MR hypothesis. Interestingly, CWP was primarily influenced by NC and MR indirectly via their influence on canopy packing. Maximum height explained more of the variation in both AGB and CWP than any of the other plant functional traits. Together, our results suggest that multiple mechanisms operate simultaneously to influence EF, and understanding their relative importance will help to elucidate the role of biodiversity in maintaining ecosystem function.

  10. Foliar temperature-respiration response functions for broad-leaved tree species in the southern Appalachians.

    Science.gov (United States)

    Bolstad; Mitchell; Vose

    1999-11-01

    We measured leaf respiration in 18 eastern deciduous forest tree species to determine if there were differences in temperature-respiration response functions among species or among canopy positions. Leaf respiration rates were measured in situ and on detached branches for Acer pensylvanicum L., A. rubrum L., Betula spp. (B. alleghaniensis Britt. and B. lenta L.), Carya glabra (Mill.) Sweet, Cornus florida L., Fraxinus spp. (primarily F. americana L.), Liriodendron tulipifera L., Magnolia fraseri Walt., Nyssa sylvatica Marsh., Oxydendrum arboreum L., Platanus occidentalis L., Quercus alba L., Q. coccinea Muenchh., Q. prinus L., Q. rubra L., Rhododendron maximum L., Robinia psuedoacacia L., and Tilia americana L. in the southern Appalachian Mountains, USA. Dark respiration was measured on fully expanded leaves at 10, 15, 20, 25, and 30 degrees C with an infrared gas analyzer equipped with a temperature-controlled cuvette. Temperature-respiration response functions were fit for each leaf. There were significant differences in response functions among species and by canopy position within species. These differences were observed when respiration was expressed on a mass, nitrogen, or area basis. Cumulative nighttime leaf respiration was calculated and averaged over ten randomly selected nights for each leaf. Differences in mean cumulative nighttime respiration were statistically significant among canopy positions and species. We conclude that effects of canopy position and species on temperature-respiration response functions may need to be considered when making estimates of whole-tree or canopy respiration.

  11. Assessment of Light Environment Variability in Broadleaved Forest Canopies Using Terrestrial Laser Scanning

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    Dimitry Van der Zande

    2010-06-01

    Full Text Available Light availability inside a forest canopy is of key importance to many ecosystem processes, such as photosynthesis and transpiration. Assessment of light availability and within-canopy light variability enables a more detailed understanding of these biophysical processes. The changing light-vegetation interaction in a homogeneous oak (Quercus robur L. stand was studied at different moments during the growth season using terrestrial laser scanning datasets and ray tracing technology. Three field campaigns were organized at regular time intervals (24 April 2008; 07 May 2008; 23 May 2008 to monitor the increase of foliage material. The laser scanning data was used to generate 3D representations of the forest stands, enabling structure feature extraction and light interception modeling, using the Voxel-Based Light Interception Model (VLIM. The VLIM is capable of estimating the relative light intensity or Percentage of Above Canopy Light (PACL at any arbitrary point in the modeled crown space. This resulted in a detailed description of the dynamic light environments inside the canopy. Mean vertical light extinction profiles were calculated for the three time frames, showing significant differences in light attenuation by the canopy between April 24 on the one hand, and May 7 and May 23 on the other hand. The proposed methodology created the opportunity to link these within-canopy light distributions to the increasing amount of photosynthetically active leaf material and its distribution in the considered 3D space.

  12. 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

  13. Phenolics and compartmentalization in the sapwood of broad-leaved trees

    Science.gov (United States)

    Kevin T. Smith

    1997-01-01

    Tree survival depends on the chemistry of phenolic compounds, a broad class of chemicals characterized by a hydroxylated benzene ring. In trees, phenolics occur frequently as polymers, acids, or glycosylated esters and perform diverse functions. For example, lignin, a phenylpropane heteropolymer, provides structural strength to wood. The induced production of phenols...

  14. Sensitivity of stand transpiration to wind velocity in a mixed broadleaved deciduous forest

    Science.gov (United States)

    Dohyoung Kim; Ram Oren; A. Christopher Oishi; Cheng-I Hsieh; Nathan Phillips; Kimberly A. Novick; Paul C. Stoy

    2014-01-01

    Wind velocity (U) within and above forest canopies can alter the coupling between the vapor-saturated sub-stomatal airspace and the drier atmosphere aloft, thereby influencing transpiration rates. In practice, however, the actual increase in transpiration with increasing U depends on the aerodynamic resistance (RA) to vapor transfer compared to canopy resistance to...

  15. Status of Nature Reserves in Inner Mongolia, China

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    Wenjing Ma

    2016-09-01

    Full Text Available Nature reserves are an important component of the strategy to halt biodiversity loss caused by habitat fragmentation and loss, climate change and other anthropogenic factors. In the past decades, 184 nature reserves were designed for biodiversity conservation in Inner Mongolia. However, no studies have quantified the general condition of these reserves. In this paper, we summarized the history, distribution and effects of human interference on these reserves in Inner Mongolia. The results showed that: (1 The total area of nature reserves is 138,047 km2 in Inner Mongolia. This constitutes 11.7% of its geographic area, which is lower than the national (14.9%, and the global average (13%. These reserves are mainly forest (68 and inland wetland (31 ecosystems. However, in terms of area, desert (40,948 km2, forest (26,141 km2 and inland wetland ecosystems (25,540 km2 are predominant; (2 nature reserves have increased rapidly in number and area since 1995, especially at the province, city, and county levels; (3 the evergreen coniferous (26.4%, wetland (20.2% and deciduous needle-leaf forests (19.6% were sufficiently protected according to the 2020 target of 17% set by the Convention on Biological Diversity, while the other eight natural vegetation types, i.e., evergreen broad-leaved forests (14.2%, shrubs (13.5%, meadow vegetation (12.5%, typical steppe (10.2%, open forests (8.9%, desert vegetation (6.2%, desert steppe (2.9%, and sand vegetation (1.6% were insufficiently protected; (4 the effects of human activities on these vegetation types were different. Open forest, sand vegetation, shrub, typical steppe, meadow steppe, evergreen broad-leaved, and evergreen coniferous forest were more affected than other vegetation types. Our results indicated that a more scientific approach is needed to effectively manage nature reserves in Inner Mongolia.

  16. 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

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    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

  17. The influence of canopy-layer composition on understory plant diversity in southern temperate forests

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    Luciana Mestre

    2017-05-01

    Full Text Available Background Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest functioning. Despite their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed forests. The aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types (monospecific deciduous Nothofagus pumilio (Np, monospecific evergreen Nothofagus betuloides (Nb, and mixed N. pumilio-N. betuloides (M forests, comparing also between two geographical locations (coast and mountain to estimate differences at landscape level. Results We recorded 46 plant species: 4 ferns, 12 monocots, and 30 dicots. Canopy-layer composition influences the herb-layer structure and diversity in two different ways: while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant assemblage. Deciduous pure stands were the most diverse, meanwhile evergreen stands were least diverse. Lack of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and integrate. Moreover, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive species. Conclusions Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain sites. Maintaining the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant

  18. 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. © 2015 Society for Conservation Biology.

  19. 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.

  20. Vegetation structure and greenness in Central Africa from Modis multi-temporal data.

    Science.gov (United States)

    Gond, Valéry; Fayolle, Adeline; Pennec, Alexandre; Cornu, Guillaume; Mayaux, Philippe; Camberlin, Pierre; Doumenge, Charles; Fauvet, Nicolas; Gourlet-Fleury, Sylvie

    2013-01-01

    African forests within the Congo Basin are generally mapped at a regional scale as broad-leaved evergreen forests, with the main distinction being between terra-firme and swamp forest types. At the same time, commercial forest inventories, as well as national maps, have highlighted a strong spatial heterogeneity of forest types. A detailed vegetation map generated using consistent methods is needed to inform decision makers about spatial forest organization and their relationships with environmental drivers in the context of global change. We propose a multi-temporal remotely sensed data approach to characterize vegetation types using vegetation index annual profiles. The classifications identified 22 vegetation types (six savannas, two swamp forests, 14 forest types) improving existing vegetation maps. Among forest types, we showed strong variations in stand structure and deciduousness, identifying (i) two blocks of dense evergreen forests located in the western part of the study area and in the central part on sandy soils; (ii) semi-deciduous forests are located in the Sangha River interval which has experienced past fragmentation and human activities. For all vegetation types enhanced vegetation index profiles were highly seasonal and strongly correlated to rainfall and to a lesser extent, to light regimes. These results are of importance to predict spatial variations of carbon stocks and fluxes, because evergreen/deciduous forests (i) have contrasted annual dynamics of photosynthetic activity and foliar water content and (ii) differ in community dynamics and ecosystem processes.

  1. Altitudinal Variation in Leaf Nitrogen Concentration on the Eastern Slope of Mount Gongga on the Tibetan Plateau, China

    Science.gov (United States)

    Shi, Weiqi; Wang, Guoan; Han, Wenxuan

    2012-01-01

    Mount Gongga spans 6500 m in elevation and has intact and continuous vertical vegetation belts, ranging from subtropical evergreen broad-leaved vegetation to an alpine frigid sparse grass and desert zone. Investigating the altitudinal trends in leaf nitrogen (N) on Mount Gongga can increase our understanding of the global biogeography of foliar N. In this study, 460 leaf samples from mosses, ferns, and seed plants were collected along an altitudinal gradient on the eastern slope of Mount Gongga, and the variation in leaf N concentration (mass basis) with elevation was analyzed. There are considerable differences in leaf N between mosses and ferns, mosses and seed plants, C4 and C3 plants, and evergreen and deciduous woody plants. The general altitudial pattern of leaf N in Mount Gongga plants was that leaf N kept increasing until an elevation of about 2200 m above sea level, with a corresponding mean annual temperature (MAT) of 8.5°C, and then decreased with increasing elevation. However, the evergreen woody plants displayed a decline trend in leaf N across the altitude gradient. Our findings provide an insight into the altitudinal variation in leaf N. PMID:23028570

  2. Altitudinal variation in leaf nitrogen concentration on the eastern slope of Mount Gongga on the Tibetan Plateau, China.

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    Weiqi Shi

    Full Text Available Mount Gongga spans 6500 m in elevation and has intact and continuous vertical vegetation belts, ranging from subtropical evergreen broad-leaved vegetation to an alpine frigid sparse grass and desert zone. Investigating the altitudinal trends in leaf nitrogen (N on Mount Gongga can increase our understanding of the global biogeography of foliar N. In this study, 460 leaf samples from mosses, ferns, and seed plants were collected along an altitudinal gradient on the eastern slope of Mount Gongga, and the variation in leaf N concentration (mass basis with elevation was analyzed. There are considerable differences in leaf N between mosses and ferns, mosses and seed plants, C(4 and C(3 plants, and evergreen and deciduous woody plants. The general altitudial pattern of leaf N in Mount Gongga plants was that leaf N kept increasing until an elevation of about 2200 m above sea level, with a corresponding mean annual temperature (MAT of 8.5°C, and then decreased with increasing elevation. However, the evergreen woody plants displayed a decline trend in leaf N across the altitude gradient. Our findings provide an insight into the altitudinal variation in leaf N.

  3. First identification of the pathogen causing tumor malformations in evergreen oaks in Spain

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    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.

  4. Faunal diversity in a semi-evergreen forest of Bornadi-Khalingduar Complex of Assam, India

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    Pallabi Chakraborty

    2015-09-01

    Full Text Available The Bornadi-Khalingduar Complex under the Manas Tiger Reserve, Assam is known to be an important area for wildlife movement to and from India and Bhutan. The contiguous landscape encompassing the two neighbouring countries provides a good habitat for diversity of wildlife and also as an important corridor area.  We carried out an opportunistic camera-trapping exercise to document the faunal diversity in the area. A month-long exercise photo-captured a total of 19 species belonging to 12 families, including the Leopard, Wild Dog, Leopard Cat, Binturong, Elephant, Sambar, Barking Deer and various birds. These findings of the study reveal the importance, threats and potential of the area and recommendations have been made to secure this corridor for continuous animal movement. Anthropogenic disturbance is a major deterrent to undisturbed animal movement in this area with resultant forest fragmentation and degradation. This indicates the need for effective conservation strategies in order to maintain the remnants of this corridor complex.  

  5. Impacts of Resettlement Programs on Deforestation of Moist Evergreen Afromontane Forests in Southwest Ethiopia

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    Kefelegn Getahun

    2017-11-01

    Full Text Available Severe land degradation and the consequent series of drought and famine episodes have caused major waves of human migration in Ethiopia over the past 5 decades. The main objective of this study was to assess the impacts of consecutive resettlement programs (spontaneous and planned on the forests in southwest Ethiopia. The spatial distribution and extent of forest cover were mapped for the periods 1957, 1975, and 2007 based on visual interpretation of aerial photographs and satellite images. The rate of deforestation was analyzed using overlay and buffer analysis techniques available in ArcGIS software. Focus group discussions and household surveys were conducted to collect information on landscape (forest change and the causes and consequences of deforestation. Results from the forest cover change analysis revealed that the study area lost large tracts (80% of its forest cover between 1957 and 2007. Demographic, socioeconomic, and cultural changes introduced by migrants were the leading drivers of deforestation in the study area. In addition, the rate of deforestation in the region has been exacerbated by a low level of education and awareness of the local people about the benefits of forests, lack of regulations to protect the forests, habitat destruction to deter crop-damaging wild pests, forest clearing for fuelwood and charcoal making, and wood extraction for construction and household furniture purposes.

  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. Fuel characteristics and pyrolysis studies of solvent extractables and residues from the evergreen shrub Calotropis procera

    Energy Technology Data Exchange (ETDEWEB)

    Erdman, M.D.; Gregorski, K.S.; Pavlath, A.E.

    1984-01-01

    Solvent extractables and residues from milkweed were evaluated as sources of liquid and solid fuels. Selected chemical, physical and pyrolytic determinations of the extractables and residues indicated that hexane extract is a potentially valuable, high density fuel resource. Methanol extract was shown to be a lower energy, highly toxic extract. Extracted residues were demonstrated to be valuable as solid fuel energy resources. 31 references.

  8. 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

    Dispersal limitations contribute to shaping plant distribution patterns and thus are significant for biodiversity conservation and urban ecology. In fleshy-fruited plants, for example, any preference of frugivorous birds affects dispersal capacities of certain fruit species. We conducted a removal...... 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...

  9. Effects of forest age on soil autotrophic and heterotrophic respiration differ between evergreen and deciduous forests.

    Science.gov (United States)

    Wang, Wei; Zeng, Wenjing; Chen, Weile; Yang, Yuanhe; Zeng, Hui

    2013-01-01

    We examined the effects of forest stand age on soil respiration (SR) including the heterotrophic respiration (HR) and autotrophic respiration (AR) of two forest types. We measured soil respiration and partitioned the HR and AR components across three age classes ~15, ~25, and ~35-year-old Pinus sylvestris var. mongolica (Mongolia pine) and Larix principis-rupprechtii (larch) in a forest-steppe ecotone, northern China (June 2006 to October 2009). We analyzed the relationship between seasonal dynamics of SR, HR, AR and soil temperature (ST), soil water content (SWC) and normalized difference vegetation index (NDVI, a plant greenness and net primary productivity indicator). Our results showed that ST and SWC were driving factors for the seasonal dynamics of SR rather than plant greenness, irrespective of stand age and forest type. For ~15-year-old stands, the seasonal dynamics of both AR and HR were dependent on ST. Higher Q10 of HR compared with AR occurred in larch. However, in Mongolia pine a similar Q10 occurred between HR and AR. With stand age, Q10 of both HR and AR increased in larch. For Mongolia pine, Q10 of HR increased with stand age, but AR showed no significant relationship with ST. As stand age increased, HR was correlated with SWC in Mongolia pine, but for larch AR correlated with SWC. The dependence of AR on NDVI occurred in ~35-year-old Mongolia pine. Our study demonstrated the importance of separating autotrophic and heterotrophic respiration components of SR when stimulating the response of soil carbon efflux to environmental changes. When estimating the response of autotrophic and heterotrophic respiration to environmental changes, the effect of forest type on age-related trends is required.

  10. Taxonomy, Traits, and Environment Determine Isoprenoid Emission from an Evergreen Tropical forest.

    Science.gov (United States)

    Taylor, T.; Alves, E. G.; Tota, J.; Oliveira Junior, R. C.; Camargo, P. B. D.; Saleska, S. R.

    2016-12-01

    Volatile isoprenoid emissions from the leaves of tropical forest trees significantly affects atmospheric chemistry, aerosols, and cloud dynamics, as well as the physiology of the emitting leaves. Emission is associated with plant tolerance to heat and drought stress. Despite a potentially central role of isoprenoid emissions in tropical forest-climate interactions, we have a poor understanding of the relationship between emissions and ecological axes of forest function. We used a custom instrument to quantify leaf isoprenoid emission rates from over 200 leaves and 80 trees at a site in the eastern Brazilian Amazon. We related standardized leaf emission capacity (EC: leaf emission rate at 1000 PAR) to tree taxonomy, height, light environment, wood traits, and leaf traits. Taxonomy was the strongest predictor of EC, and non-emitters could be found throughout the canopy. But we found that environment and leaf carbon economics constrained the upper bound of EC. For example, the relationship between EC and specific leaf area (SLA; fresh leaf area / dry mass) is described by an envelope with a decreasing upper bound on EC as SLA increases (quantile regression: 85th quantile, p<0.01). That result suggests a limitation on emissions related to leaf carbon investment strategies. EC was highest in the mid-canopy, and in leaves growing under less direct light. While inferences of ecosystem emissions focus on environmental conditions in the canopy, our results suggest that sub-canopy leaves are more responsive. This work is allowing us to develop an ecological understanding of isoprenoid emissions from forests, the basis for a predictive model of emissions that depends on both environmental factors and biological emission capacity that is grounded in plant traits and phylogeny.

  11. Evaluation of seasonal variations of remotely sensed leaf area index over five evergreen coniferous forests

    Science.gov (United States)

    Wang, Rong; Chen, Jing M.; Liu, Zhili; Arain, Altaf

    2017-08-01

    Seasonal variations of leaf area index (LAI) have crucial controls on the interactions between the land surface and the atmosphere. Over the past decades, a number of remote sensing (RS) LAI products have been developed at both global and regional scales for various applications. These products are so far only validated using ground LAI data acquired mostly in the middle of the growing season. The accuracy of the seasonal LAI variation in these products remains unknown and there are few ground data available for this purpose. We performed regular LAI measurements over a whole year at five coniferous sites using two methods: (1) an optical method with LAI-2000 and TRAC; (2) a direct method through needle elongation monitoring and litterfall collection. We compared seasonal trajectory of LAI from remote sensing (RS LAI) with that from a direct method (direct LAI). RS LAI agrees very well with direct LAI from the onset of needle growth to the seasonal peak (R2 = 0.94, RMSE = 0.44), whereas RS LAI declines earlier and faster than direct LAI from the seasonal peak to the completion of needle fall. To investigate the possible reasons for the discrepancy, the MERIS Terrestrial Chlorophyll Index (MTCI) was compared with RS LAI. Meanwhile, phenological metrics, i.e. the start of growing season (SOS) and the end of growing season (EOS), were extracted from direct LAI, RS LAI and MTCI time series. SOS from RS LAI is later than that from direct LAI by 9.3 ± 4.0 days but earlier than that from MTCI by 2.6 ± 1.9 days. On the contrary, for EOS, RS LAI is later than MTCI by 3.3 ± 8.4 days and much earlier than direct LAI by 30.8 ± 7.2 days. Our results suggest that the seasonal trajectory of RS LAI well captures canopy structural information from the onset of needle growth to the seasonal peak, but is greatly influenced by the decrease in leaf chlorophyll content, as indicated by MTCI, from the seasonal peak to the completion of needle fall. These findings have significant implications for improving existing RS LAI products and terrestrial productivity modeling.

  12. 76 FR 69222 - Radio Broadcasting Services; Evergreen, AL, and Shalimar, FL

    Science.gov (United States)

    2011-11-08

    .... Walton Beach License Company, LLC, proponent of a petition for reconsideration of the Memorandum Opinion... released October 7, 2011. The full text of this Commission decision is available for inspection and copying..., (800) 378-3160, or via the company's Web site, http://www.bcpiweb.com . The Order is not subject to the...

  13. 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…

  14. Temporal matching among diurnal photosynthetic patterns within the crown of the evergreen sclerophyll Olea europaea L.

    Science.gov (United States)

    Granado-Yela, C; García-Verdugo, C; Carrillo, K; Rubio DE Casas, R; Kleczkowski, L A; Balaguer, L

    2011-05-01

    Trees are modular organisms that adjust their within-crown morphology and physiology in response to within-crown light gradients. However, whether within-plant variation represents a strategy for optimizing light absorption has not been formally tested. We investigated the arrangement of the photosynthetic surface throughout one day and its effects on the photosynthetic process, at the most exposed and most sheltered crown layers of a wild olive tree (Olea europaea L.). Similar measurements were made for cuttings taken from this individual and grown in a greenhouse at contrasted irradiance-levels (100 and 20% full sunlight). Diurnal variations in light interception, carbon fixation and carbohydrate accumulation in sun leaves were negatively correlated with those in shade leaves under field conditions when light intensity was not limiting. Despite genetic identity, these complementary patterns were not found in plants grown in the greenhouse. The temporal disparity among crown positions derived from specialization of the photosynthetic behaviour at different functional and spatial scales: architectural structure (crown level) and carbon budget (leaf level). Our results suggest that the profitability of producing a new module may not only respond to construction costs or light availability, but also rely on its spatio-temporal integration within the productive processes at the whole-crown level. © 2011 Blackwell Publishing Ltd.

  15. Effects of forest age on soil autotrophic and heterotrophic respiration differ between evergreen and deciduous forests.

    Directory of Open Access Journals (Sweden)

    Wei Wang

    Full Text Available We examined the effects of forest stand age on soil respiration (SR including the heterotrophic respiration (HR and autotrophic respiration (AR of two forest types. We measured soil respiration and partitioned the HR and AR components across three age classes ~15, ~25, and ~35-year-old Pinus sylvestris var. mongolica (Mongolia pine and Larix principis-rupprechtii (larch in a forest-steppe ecotone, northern China (June 2006 to October 2009. We analyzed the relationship between seasonal dynamics of SR, HR, AR and soil temperature (ST, soil water content (SWC and normalized difference vegetation index (NDVI, a plant greenness and net primary productivity indicator. Our results showed that ST and SWC were driving factors for the seasonal dynamics of SR rather than plant greenness, irrespective of stand age and forest type. For ~15-year-old stands, the seasonal dynamics of both AR and HR were dependent on ST. Higher Q10 of HR compared with AR occurred in larch. However, in Mongolia pine a similar Q10 occurred between HR and AR. With stand age, Q10 of both HR and AR increased in larch. For Mongolia pine, Q10 of HR increased with stand age, but AR showed no significant relationship with ST. As stand age increased, HR was correlated with SWC in Mongolia pine, but for larch AR correlated with SWC. The dependence of AR on NDVI occurred in ~35-year-old Mongolia pine. Our study demonstrated the importance of separating autotrophic and heterotrophic respiration components of SR when stimulating the response of soil carbon efflux to environmental changes. When estimating the response of autotrophic and heterotrophic respiration to environmental changes, the effect of forest type on age-related trends is required.

  16. Evaporation of intercepted rainfall from isolated evergreen oak trees: Do the crowns behave as wet bulbs?

    NARCIS (Netherlands)

    Pereira, F.L.; Gash, J.H.C.; David, J.S.; Valente, F,

    2009-01-01

    A new approach is suggested for estimating evaporation of intercepted rainfall from single trees in sparse forests. It is shown that, theoretically, the surface temperature of a wet tree crown will depend on the available energy and windspeed. But for a fully saturated canopy under rainy conditions,

  17. 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

  18. The leaf size-twig size spectrum in evergreen broad- leaved forest of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-06-07

    Jun 7, 2010 ... The calculation related to allometric equation para- meters was conducted using (S) MATR Version 2.0 (Falster et al.,. 2006; Warton et al., 2006). RESULTS. Twig cross-sectional area versus total leaf area and individual leaf area. The total leaf area supported on the twig was significantly correlated with the ...

  19. 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

  20. Twenty years of community dynamics in a mixed conifer : broadleaved forest under a selection system in northern Japan

    OpenAIRE

    Yoshida, Toshiya; Noguchi, Mahoko; Akibayashi, Yukio; Noda, Masato; KADOMATSU, Masahiko; Sasa, Kaichiro

    2006-01-01

    Single-tree selection has been employed widely in northern Japanese mixed forests, but management-induced changes in forests are not well understood. This study examined demographic parameters of major tree species during a 20-year study of a 68 ha stand in which single-tree selection has been conducted since 1971. Results showed that growth and survival of conifers (mostly Abies sachalinensis (Fr. Schm.) Masters) was the most strongly positively affected by the treatment. Nevertheless, recru...

  1. Common allometric response of open-grown leader shoots to tree height in co-occurring deciduous broadleaved trees.

    Science.gov (United States)

    Miyata, Rie; Kubo, Takuya; Nabeshima, Eri; Kohyama, Takashi S

    2011-11-01

    Morphology of crown shoots changes with tree height. The height of forest trees is usually correlated with the light environment and this makes it difficult to separate the effects of tree size and of light conditions on the morphological plasticity of crown shoots. This paper addresses the tree-height dependence of shoot traits under full-light conditions where a tree crown is not shaded by other crowns. Focus is given to relationships between tree height and top-shoot traits, which include the shoot's leaf-blades and non-leafy mass, its total leaf-blade area and the length and basal diameter of the shoot's stem. We examine the allometric characteristics of open-grown current-year leader shoots at the tops of forest tree crowns up to 24 m high and quantify their responses to tree height in 13 co-occurring deciduous hardwood species in a cool-temperate forest in northern Japan. Dry mass allocated to leaf blades in a leader shoot increased with tree height in all 13 species. Specific leaf area decreased with tree height. Stem basal area was almost proportional to total leaf area in a leader shoot, where the proportionality constant did not depend on tree height, irrespective of species. Stem length for a given stem diameter decreased with tree height. In the 13 species observed, height-dependent changes in allometry of leader shoots were convergent. This finding suggests that there is a common functional constraint in tree-height development. Under full-light conditions, leader shoots of tall trees naturally experience more severe water stress than those of short trees. We hypothesize that the height dependence of shoot allometry detected reflects an integrated response to height-associated water stress, which contributes to successful crown expansion and height gain.

  2. 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...

  3. The spring and autumn phenophases of the broadleaves trees indicate the extension of growing season in the boreal forest environment

    Science.gov (United States)

    Kubin, Eero; Poikolainen, Jarmo; Karhu, Jouni; Tolvanen, Anne

    2014-05-01

    The long-term historical data since 1752 shows an advancement in the timing of flowering by five days per century in Prunus padus. The onset of flowering in Sorbus aucuparia has become correspondingly earlier in Finland at the rate of three days per century. The results of the Finnish National Phenological Network fit well in the historical data. The Finnish National Phenological Network was established in 1996 in collaboration with research institutes and universities. The phenomena being studied by trained observers using a standardized manner are flowering and flushing of trees, yellowing and shedding of leaves, height growth and flowering of conifers, flowering of Vaccinium vitis-idaea and Vaccinium myrtillus and the ripening of berries. The monitoring covers eight tree species: Betula pubescens, Betula pendula, Pinus silvestris, Picea abies, Populus tremula, Juniperus communis, Prunus padus and Sorbus aucuparia. The observations are made repeatedly of the same tree individuals at least twice per week. The real time results are visible in the form of animations and charts (http://www.metla.fi/metinfo/fenologia/index-en.htm). The green wave from south to north and yellowishing from north to south will be presented in the conference. The onset of downy birch leaves occurred in northernmost Lapland about a month later compared with southern Finland and began to turn yellow already at the beginning of September. The onset and progress of growth are primarily dependeing on air temperature. The results of the network confirm that spring phenophases have especially in northern Finland advanced with respect to climatic conditions. For autumn phenopases we found in several sites delaying trend, but not as strong as in spring phenopases. Downy birch, Betula pubescens, has been found to leaf on average when the effective temperature sum has reached 54 dd. in the southern part of the country, but in the north only 38 dd. is needed. The less temperature sum requirement within the boreal zone in the north compared with south is not reported earlier. In the north less temperature sum was also needed for the flowering of bird cherry. Phenological monitoring by using field observations is nowadays more important than ever especially in arctic and boreal regions, where spring temperatures are elevated. Compilation and documentation of observations on plant phenophases play a key role in working out the rate of global climate change. There occurs however great variation of phenophases between the years and sites causing uncertainty for the use of data. The observation term of the Finnish National Phenological Network, seventeen years, starts to be long enough for recent responses, but it is still too short to tell whether the advancement of spring or delaying autumn is a constant phenomenon or a consequence of normal climatic variability. The timing of especially autumn phenophases and onset of leafing with respect to temperature sum will be discussed in the conference.

  4. [Dimensional characteristics and spatial distribution patterns of pit and mound complexes in Pinus koraiensis-dominated broadleaved mixed forest].

    Science.gov (United States)

    Duan, Wen-Biao; Wei, Quan-Shuai; Qiao, Lu; Chen, Li-Xin; Wang, Ting; Zhang, Xin; Gu, Wei; Sun, Hu

    2014-11-01

    Characteristics of pit and mound complexes in different sizes of forest gaps and closed stands and their distribution patterns were compared and analyzed. The results showed that mean mound width, mound height, mound thickness of all pit and mound complexes were larger than corresponding mean pit length, pit width, pit depth in large, medium and small gaps as well as in closed stands. Mound width, mound height, mound thickness, pit length, pit width, pit depth were the largest in large gap, being 2.85, 0.37, 2.00, 2.99, 2.10, 0.39 m, respectively, and the smallest in closed stands, being 2.35, 0.19, 1.60, 2.66, 1.65, 0.21, respectively. Mean mound volume (1.66 m3) was larger than mean pit volume (1.44 m3). The difference in characteristic values between the most of pit and mound complexes was significant for the same size of forest gap, not significant for closed stands, significant for different sizes of forest gaps and closed stands. Most of characteristic values for pit and mound complexes within the plot in 2012 were significantly less than those in 2011. 89.5% and 60.5% of type and shape of pit and mound complexes were hinge and semiellipse, respectively. Their distribution was relatively centralized.

  5. Stemflow-induced spatial heterogeneity of radiocesium concentrations and stocks in the soil of a broadleaved deciduous forest.

    Science.gov (United States)

    Imamura, Naohiro; Levia, Delphis F; Toriyama, Jumpei; Kobayashi, Masahiro; Nanko, Kazuki

    2017-12-01

    The transport of radiocesium from the canopy and quantification of the spatial distribution of radiocesium in the soil of konara oak forests are important to better understand the variability of (137)Cs stocks in the soil between proximal and distal stem areas as well as fine-scale variations around the tree trunk. Moreover, a better understanding of fine-scale spatial variabilities of (137)Cs concentrations and stocks will provide insights for optimizing soil sampling strategies to provide a more robust estimation of contamination at the stand scale. This study aims to elucidate the transport of (137)Cs by stemflow in a radioactively contaminated konara oak forest in Tsukuba, Japan by describing and quantifying the fine-scale spatial distribution of (137)Cs in the soil and preferential flowpaths of stemflow on the tree stem by a dye tracing experiment. (137)Cs concentrations and stocks were higher in the soils of the proximal stem area than distal stem area when they corresponded with the preferential flowpaths of stemflow. There was a significant relationship between canopy projection area of individual trees and average soil (137)Cs concentrations and stocks, even though canopies of the trees overlapped. Our results demonstrate that the spatiality of (137)Cs concentrations and stocks in the soil of the proximal stem area are governed (at least partially) by the preferential flowpaths of stemflow along the tree trunk. In addition, higher (137)Cs concentrations and stocks in the near-trunk soils of trees with larger crown areas might be caused by an enhanced ability to capture dry deposition. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. 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.

  7. First report of albugo lepidi causing white rust on broadleaved pepperweed (lepidium latifolium) in Nevada and California

    Science.gov (United States)

    The biology and taxonomy of a white rust that is commonly found on the exotic invasive weed Lepidium latifolium were studied in order to assess its potential as a bioherbicide. Previously assumed to be Albugo candida, a common disease of Brassicaceae crops, comparisons of spore morphology and DNA s...

  8. Spatial heterogeneity of radiocesium in the soil of a broadleaved deciduous forest: the marked role of stemflow

    Science.gov (United States)

    Levia, Delphis; Imamura, Naohiro; Toriyama, Jumpei; Kobayashi, Masahiro; Nanko, Kazuki

    2017-04-01

    This project amplifies our understanding of the transport of Cs-137 via stemflow in a konara oak forest by examining the spatial distribution of Cs-137 in the soil in both proximal (near-trunk) and distal ( > 1 m form tree trunk) stem areas. We report the Cs-137 concentrations and stocks for twenty-four soil samples harvested from the proximal and distal stem areas around individual trees in a radioactively contaminated konara oak forest in east-central Honshu, Japan. Preferential flowpaths of stemflow on the tree trunk and its point of infiltration into the forest floor was observed by conducting a dye tracer experiment. Experimental results showed that Cs-137 concentrations and stocks were higher in the soils of the proximal stem area as compared to the distal stem area when they corresponded with the preferential flowpaths of stemflow. Moreover, there was a significant relationship between the canopy projection area of individual trees and average soil Cs-137 concentrations and stocks, despite some canopy overlap among even trees. Our findings demonstrate that the spatial patterning of Cs-137 concentrations and stocks in the soil of the proximal stem area are governed (at least partially) by the preferential flowpaths of stemflow along the tree trunk. [Note: This presentation is currently under peer-review for journal publication.

  9. Estimate of leaf area index in an old-growth mixed broadleaved-Korean pine forest in northeastern China.

    Directory of Open Access Journals (Sweden)

    Zhili Liu

    Full Text Available Leaf area index (LAI is an important variable in the study of forest ecosystem processes, but very few studies are designed to monitor LAI and the seasonal variability in a mixed forest using non-destructive sampling. In this study, first, true LAI from May 1(st and November 15(th was estimated by making several calibrations to LAI as measured from the WinSCANOPY 2006 Plant Canopy Analyzer. These calibrations include a foliage element (shoot, that is considered to be a collection of needles clumping index measured directly from the optical instrument, TRAC (Tracing Radiation and Architecture of Canopies; a needle-to-shoot area ratio obtained from shoot samples; and a woody-to-total area ratio. Second, by periodically combining true LAI (May 1(st with the seasonality of LAI for deciduous and coniferous species throughout the leaf-expansion season (from May to August, we estimated LAI of each investigation period in the leaf-expansion season. Third, by combining true LAI (November 15(th with litter trap data (both deciduous and coniferous species, we estimated LAI of each investigation period during the leaf-fall season (from September to mid-November. Finally, LAI for the entire canopy then was derived from the initial leaf expansion to the leaf fall. The results showed that LAI reached its peak with a value of 6.53 m(2 m(-2 (a corresponding value of 3.83 m(2 m(-2 from optical instrument in early August, and the mean LAI was 4.97 m(2 m(-2 from May to November using the proposed method. The optical instrument method underestimated LAI by an average of 41.64% (SD = 6.54 throughout the whole study period compared to that estimated by the proposed method. The result of the present work implied that our method would be suitable for measuring LAI, for detecting the seasonality of LAI in a mixed forest, and for measuring LAI seasonality for each species.

  10. Ideas and perspectives: how coupled is the vegetation to the boundary layer?

    Science.gov (United States)

    De Kauwe, Martin G.; Medlyn, Belinda E.; Knauer, Jürgen; Williams, Christopher A.

    2017-10-01

    Understanding the sensitivity of transpiration to stomatal conductance is critical to simulating the water cycle. This sensitivity is a function of the degree of coupling between the vegetation and the atmosphere and is commonly expressed by the decoupling factor. The degree of coupling assumed by models varies considerably and has previously been shown to be a major cause of model disagreement when simulating changes in transpiration in response to elevated CO2. The degree of coupling also offers us insight into how different vegetation types control transpiration fluxes, which is fundamental to our understanding of land-atmosphere interactions. To explore this issue, we combined an extensive literature summary from 41 studies with estimates of the decoupling coefficient estimated from FLUXNET data. We found some notable departures from the values previously reported in single-site studies. There was large variability in estimated decoupling coefficients (range 0.05-0.51) for evergreen needleleaf forests. This is a result that was broadly supported by our literature review but contrasts with the early literature which suggests that evergreen needleleaf forests are generally well coupled. Estimates from FLUXNET indicated that evergreen broadleaved forests were the most tightly coupled, differing from our literature review and instead suggesting that it was evergreen needleleaf forests. We also found that the assumption that grasses would be strongly decoupled (due to vegetation stature) was only true for high precipitation sites. These results were robust to assumptions about aerodynamic conductance and, to a lesser extent, energy balance closure. Thus, these data form a benchmarking metric against which to test model assumptions about coupling. Our results identify a clear need to improve the quantification of the processes involved in scaling from the leaf to the whole ecosystem. Progress could be made with targeted measurement campaigns at flux sites and greater

  11. 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......Three forests with different historical land-use, forest age, and species assemblages in subtropical China were selected to evaluate current soil N status and investigate the responses of soil inorganic N dynamics to monthly ammonium nitrate additions. Results showed that the mature monsoon...... retention capacity, higher inorganic N leaching, and higher soil C/N ratios. Mineral soil extractable NH4+-N and NO3--N concentrations were significantly increased by experimental N additions on several sampling dates, but repeated ANOVA showed that the effect was not significant over the whole year except...

  12. [Litterfalls of major forest stands at Baiyunshan scenic spot of Guangzhou].

    Science.gov (United States)

    Zeng, Shucai; Su, Zhiyao; Gu, Yankun; Xie, Zhengsheng; Liu, Yuexiu

    2003-01-01

    The productions, seasonal dynamics, macronutrient contents and decomposition rates of the litterfalls of four typical stands, e.g., Pinus massoniana plantation, secondary evergreen broadleaved forest, Acacia mangium plantation and Schima superba-Acacia mangium plantation at the scenic Baiyunshan of Guangzhou were studied. The litterfall productions of four stands in 1998 were 8.34, 6.77, 6.31 and 11.54 t.hm-2, respectively. The seasonal dynamics of litterfall amounts demonstrated the single-peak model with the peak period in June and July. The total amounts of macronutrients returned to the forest land by means of litters in the four stands in 1998 were 26.30, 69.81, 54.9 and 152.24 kg.hm-2, respectively. The annual decomposition rates of the litterfalls were 24.4%, 53.4%, 52.4% and 57.4%.

  13. 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.

  14. 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...

  15. 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 forest types (i.e., tropical, temperate and boreal forests) across the study area. These results suggested that, as plant 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.

  16. Macrofungal diversity in the Western Ghats, Kerala, India: members of Russulaceae

    Directory of Open Access Journals (Sweden)

    C. Mohanan

    2014-04-01

    Full Text Available A macrofungal biodiversity inventory carried out in different forest ecosystems viz., west coast tropical evergreen forests, west coast tropical semi-evergreen forests, south Indian moist deciduous forests, southern subtropical broadleaved hill forests, southern montane wet temperate forests (shola forests, southern tropical dry deciduous forests, grasslands, Myristica swamp forests, and forest plantations falling in different forest divisions in the Western Ghats, Kerala employing opportunistic as well as fixed-size plot sampling methods from 2006-2011 yielded several rare and hitherto unrecorded macrofungi. In Russulaceae 15 species of macrofungi belonging to the genera Russula and Lactarius were recorded. Of these, 12 species of Russula viz. Russula aciculocystis, R. adusta, R. atropurpurea, R. cinerella, R. congoana, R. delicula, R. hygrophytica, R. luteotacta, R. mariae, R. martinica, R. michiganensis and R. periglypta and white coloured latex exuding Lactarius nebulosus are new records for the Western Ghats. All the Russulaceae members exhibit an ectomycorrhizal association with tree species like Hopea ponga, H. parviflora, Myristica malabarica, Vateria indica, Calophyllum apetalaum, among others.

  17. Non Destructive Method for Biomass Prediction Combining TLS Derived Tree Volume and Wood Density

    Directory of Open Access Journals (Sweden)

    Jan Hackenberg

    2015-04-01

    Full Text Available This paper presents a method for predicting the above ground leafless biomass of trees in a non destructive way. We utilize terrestrial laserscan data to predict the volume of the trees. Combining volume estimates with density measurements leads to biomass predictions. Thirty-six trees of three different species are analyzed: evergreen coniferous Pinus massoniana, evergreen broadleaved Erythrophleum fordii and leafless deciduous Quercus petraea. All scans include a large number of noise points; denoising procedures are presented in detail. Density values are considered to be a minor source of error in the method if applied to stem segments, as comparison to ground truth data reveals that prediction errors for the tree volumes are in accordance with biomass prediction errors. While tree compartments with a diameter larger than 10 cm can be modeled accurately, smaller ones, especially twigs with a diameter smaller than 4 cm, are often largely overestimated. Better prediction results could be achieved by applying a biomass expansion factor to the biomass of compartments with a diameter larger than 10 cm. With this second method the average prediction error for Q. petraea could be reduced from 33.84% overestimation to 3.56%. E. fordii results could also be improved reducing the average prediction error from

  18. Yield tables for Italian coppice stands

    Energy Technology Data Exchange (ETDEWEB)

    Bernetti, G.

    1980-01-01

    A critical review of results from 32 yield tables for Italian coppice stands. Particular attention is paid to age of maximum m.a.i., distribution of total volume of fuelwood up to 3 cm in diameter and of brushwood, and relation between mean height and volume. A provisional general yield table is given for Quercus cerris and mixed deciduous coppice stands, based on data from 12 local tables. Maximum m.a.i. occurs relatively early, with rather low values. For Quercus ilex and mixed evergreen broadleaved coppice stands on the coast of Tuscany, tables perpared separately by Giordano and Patrone are broadly in agreement. In terms of total volume, the evergreen coppice stands of the Mediterranean maquis have a higher yield than deciduous coppice stands, and contain a higher % of brushwood. Data for Fagus sylvatica are somewhat incomplete, but m.a.i. for fuelwood appears to remain constant between the ages of 12 and 24, with maximum values of 5 and 2.1 cu.m/ha for the best and poorest quality classes respectively. Castanea sativa coppice stands can show very high rates of increment e.g. maximum m.a.i. of 20 cu.m/ha on highly fertile volcanic soils.

  19. [Estimation for vegetation carbon storage in Tiantong National Forest Park].

    Science.gov (United States)

    Guo, Chun-Zi; Wu, Yang-Yang; Ni, Jian

    2014-11-01

    Based on the field investigation and the data combination from literature, vegetation carbon storage, carbon density, and their spatial distribution were examined across six forest community types (Schima superba--Castanopsis fargesii community, S. superba--C. fargesii with C. sclerophylla community, S. superba--C. fargesii with Distylium myricoides community, Illicium lanceolatum--Choerospondias axillaris community, Liquidambar formosana--Pinus massoniana community and Hedyotis auricularia--Phylostachys pubescens community) in Tiantong National Forest Park, Zhejiang Province, by using the allometric biomass models for trees and shrubs. Results showed that: Among the six communities investigated, carbon storage and carbon density were highest in the S. superba--C. fargesii with C. sclerophylla community (storage: 12113.92 Mg C; density: 165.03 Mg C · hm(-2)), but lowest in the I. lanceolatum--C. axillaris community (storage: 680.95 Mg C; density: 101.26 Mg C · hm(-2)). Carbon storage was significantly higher in evergreen trees than in deciduous trees across six communities. Carbon density ranged from 76.08 to 144.95 Mg C · hm(-2), and from 0. 16 to 20. 62 Mg C · hm(-2) for evergreen trees and deciduous trees, respectively. Carbon storage was highest in stems among tree tissues in the tree layer throughout communities. Among vegetation types, evergreen broad-leaved forest had the highest carbon storage (23092.39 Mg C), accounting for 81.7% of the total carbon storage in all forest types, with a car- bon density of 126.17 Mg C · hm(-2). Total carbon storage for all vegetation types in Tiantong National Forest Park was 28254.22 Mg C, and the carbon density was 96.73 Mg C · hm(-2).

  20. Miocene fossil plants from Bukpyeong Formation of Bukpyeong Basin in Donghae City, Gangwon-do Province, Korea and their palaeoenvironmental implications

    Science.gov (United States)

    Jeong, Eun Kyoung; Kim, Hyun Joo; Uemura, Kazuhiko; Kim, Kyungsik

    2016-04-01

    The Tertiary sedimentary basins are distributed along the eastern coast of Korean Peninsula. The northernmost Bukpyeong Basin is located in Donghae City, Gangwon-do Province, Korea. The Bukpyeong Basin consists of Bukpyeong Formation and Dogyeongri Conglomerate in ascending order. The geologic age of Bukpyeong Formation has been suggested as from Early Miocene to Pliocene, In particular, Lee & Jacobs (2010) suggested the age of the Bukpyeong Formation as late Early Miocene to early Middle Miocene based on the fossils of rodent teeth. Sedimentary environment has been thought as mainly fresh water lake and/or swamp partly influenced by marine water. Lately, new outcrops of Bukpyeong Formation were exposed during the road construction and abundant fossil plants were yielded from the newly exposed outcrops. As a result of palaeobotanical studies 47 genera of 23 families have been found. This fossil plant assemblage is composed of gymnosperms and dicotyledons. Gymnosperms were Pinaceae (e.g., Pinus, Tsuga), Sciadopityaceae (e.g., Sciadopitys) and Cupressaceae with well-preserved Metasequoia cones. Dicotyledons were deciduous trees such as Betulaceae (e.g., Alnus, Carpinus) and Sapindaceae (e.g., Acer, Aesculus, Sapindus), and evergreen trees such as evergreen Fagaceae (e.g., Castanopsis, Cyclobalanopsis, Pasania) and Lauraceae (e.g., Cinnamomum, Machilus). In addition, fresh water plants such as Hemitrapa (Lytraceae) and Ceratophyllum (Ceratophyllaceae) were also found. The fossil plant assemblage of the Bukpyeong Formation supported the freshwater environment implied by previous studies. It can be suggested that the palaeoflora of Bukpyeong Formation was oak-laurel forest with broad-leaved evergreen and deciduous trees accompanying commonly by conifers of Pinaceae and Cupressaceae under warm-temperate climate.

  1. Forest stand dynamics and sudden oak death: Mortality in mixed-evergreen forests dominated by coast live oak

    Science.gov (United States)

    L.B. Brown; B. Allen-Diaz

    2009-01-01

    Sudden oak death (SOD), caused by the recently discovered non-native invasive pathogen, Phytophthora ramorum, has already killed tens of thousands of native coast live oak and tanoak trees in California. Little is known of potential short and long term impacts of this novel plant–pathogen interaction on forest structure and composition. Coast live...

  2. Pollination ecology and reproductive biology of Canarium strictum Roxb. from evergreen forests of Central Western Ghats, India.

    Science.gov (United States)

    Kumar, C N Prasanna; Somashekar, R K; Nagaraja, B C; Shivaprasad, D

    2015-09-01

    Pollination and reproductive biology of a dioecious tree Canarium strictum Roxb. (Burseraceae) was extensively studied within the Agumbe forest range of Western Ghats, Karnataka to identify primary pollen vectors and to enumerate interrelationship with the pollinators. The study also investigated phenology, floral biology, pollen production, pollen viability, stigma receptivity and nectar production. Trees produced functionally unisexual flowers with white petals, organized densely on inflorescences. Staminate flowers produced high percentage of viable pollen and relatively abundant nectar (15.75 μl) as a reward to the pollinators, while pistillate flowers produced only nectar (12 μl). Successful fruit set with wind pollination was facilitated by synchronization of flowering male and female trees, long term receptivity of stigma in female flowers and extended lifespan of flowers. The highest mean percent of fruit set with hand cross-pollination (μ = 91.06) suggests the influence of local male tree density, as well as, frequency and abundance of pollinator community on fruit set by open pollination.

  3. Effect of Disturbance Regimes on Spatial Patterns of Tree Species in Three Sites in a Tropical Evergreen Forest in Vietnam

    Directory of Open Access Journals (Sweden)

    Do Thi Ngoc Le

    2016-01-01

    Full Text Available The effects of disturbance regimes on the spatial patterns of the five most abundant species were investigated in three sites in a tropical forest at Xuan Nha Nature Reserve, Vietnam. Three permanent one-ha plots were established in undisturbed forest (UDF, lightly disturbed forest (LDF, and highly disturbed forest (HDF. All trees ≥5 cm DBH were measured in twenty-five 20 m × 20 m subplots. A total of 57 tree species belonging to 26 families were identified in the three forest types. The UDF had the highest basal area (30 m2 ha−1, followed by the LDF (17 m2 ha−1 and the HDF (13.0 m2 ha−1. The UDF also had the highest tree density (751 individuals ha−1 while the HDF held the lowest (478 individuals ha−1. Across all species, there were 417 “juveniles,” 267 “subadults,” and 67 “adults” in the UDF, while 274 “juveniles,” 230 “subadults,” and 36 “adults” were recorded in the LDF. 238 “juveniles,” 227 “subadults,” and 13 “adults” were obtained in the HDF. The univariate and bivariate data with pair- and mark-correlation functions of intra- and interspecific interactions of the five most abundant species changed in the three forest types. Most species indicated clumping or regular distributions at small scale, but a high ratio of negative interspecific small-scale associations was recorded in both the LDF and HDF sites. These were, however, rare in the UDF.

  4. Coping with drought-induced xylem cavitation: coordination of embolism repair and ionic effects in three Mediterranean evergreens.

    Science.gov (United States)

    Trifilò, Patrizia; Barbera, Piera M; Raimondo, Fabio; Nardini, Andrea; Lo Gullo, Maria A

    2014-02-01

    Embolism repair and ionic effects on xylem hydraulic conductance have been documented in different tree species. However, the diurnal and seasonal patterns of both phenomena and their actual role in plants' responses to drought-induced xylem cavitation have not been thoroughly investigated. This study provides experimental evidence of the ability of three Mediterranean species to maintain hydraulic function under drought stress by coordinating the refilling of xylem conduits and ion-mediated enhancement of stem hydraulic conductance (K stem). Vessel grouping indices and starch content in vessel-associated parenchyma cells were quantified to verify eventual correlations with ionic effects and refilling, respectively. Experiments were performed on stems of Ceratonia siliqua L., Olea europaea L. and Laurus nobilis L. Seasonal, ion-mediated changes in K stem (ΔK stem) and diurnal and/or seasonal embolism repair were recorded for all three species, although with different temporal patterns. Field measurements of leaf specific stem hydraulic conductivity showed that it remained quite constant during the year, despite changes in the levels of embolism. Starch content in vessel-associated parenchyma cells changed on diurnal and seasonal scales in L. nobilis and O. europaea but not in C. siliqua. Values of ΔK stem were significantly correlated with vessel multiple fraction values (the ratio of grouped vessels to total number of vessels). Our data suggest that the regulation of xylem water transport in Mediterranean plants relies on a close integration between xylem refilling and ionic effects. These functional traits apparently play important roles in plants' responses to drought-induced xylem cavitation.

  5. Antimicrobial Potential, Identification and Phylogenetic Affiliation of Wild Mushrooms from Two Sub-Tropical Semi-Evergreen Indian Forest Ecosystems.

    Science.gov (United States)

    Lallawmsanga; Passari, Ajit Kumar; Mishra, Vineet Kumar; Leo, Vincent Vineeth; Singh, Bhim Pratap; Valliammai Meyyappan, Geetha; Gupta, Vijai Kumar; Uthandi, Sivakumar; Upadhyay, Ramesh Chandra

    2016-01-01

    The diversity of wild mushrooms was investigated from two protected forest areas in India and 231 mushroom specimens were morphologically identified. Among them, 76 isolates were screened for their antimicrobial potential against seven bacterial and fungal pathogens. Out of 76 isolates, 45 isolates which displayed significant antimicrobial activities were identified using ITS rRNA gene amplification and subsequently phylogenetically characterized using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Sequencing of the ITS rRNA region classified the isolates into 16 genera belonging to 11 families. In total, 11 RAPD and 10 ISSR primers were selected to evaluate genetic diversity based on their banding profile produced. In total 337 RAPD and 312 ISSR bands were detected, among which percentage of polymorphism ranges from 34.2% to 78.8% and 38.6% to 92.4% by using RAPD and ISSR primers respectively. Unweighted Pair-Group Method with Arithmetic Mean (UPGMA) trees of selected two methods were structured similarly, grouping the 46 isolates into two clusters which clearly showed a significant genetic distance among the different strains of wild mushroom, with an similarity coefficient ranges from 0.58 to 1.00 and 0.59 to 1.00 with RAPD and ISSR analysis respectively. This reporthas highlighted both DTR and MNP forests provide a habitat for diverse macrofungal species, therefore having the potential to be used for the discovery of antimicrobials. The report has also demonstrated that both RAPD and ISSR could efficiently differentiate wild mushrooms and could thus be considered as efficient markers for surveying genetic diversity. Additionally, selected six wild edible mushroom strains (Schizophyllum commune BPSM01, Panusgiganteus BPSM27, Pleurotussp. BPSM34, Lentinussp. BPSM37, Pleurotusdjamor BPSM41 and Lentinula sp. BPSM45) were analysed for their nutritional (proteins, carbohydrates, fat and ash content), antioxidant potential. The present findings also suggested that the wild edible mushroom strains do not have only nutritional values but also can be used as an accessible source of natural antioxidants.

  6. Mediterranean evergreen vegetation dynamics : detection and modelling of forest and shrub-land development in the Peyne catchment

    NARCIS (Netherlands)

    Nijland, W.

    2011-01-01

    Vegetation development in Mediterranean landscapes is often a slow process. The typical Mediterranean climate -with long dry periods in summer, mild winters and concentrated rainfall events in spring and autumn- is an important constraint on growth, enhanced by the often marginal and degraded soil

  7. Winter variation in physiological status of cold stored and freshly lifted semi-evergreen quercus nigra seedlings

    Science.gov (United States)

    Rosa C. Goodman; Douglass F. Jacobs; Kent G. Apostol; Barrett C. Wilson; Emile S. Gardiner

    2009-01-01

    Water oak (Quercus nigra L.) is a tardily deciduous species commonly planted in afforestation projects in the Lower Mississippi River Alluvial Valley, USA. Field performance is often marked by low survival rates and top dieback, which may be associated with poor physiological quality of planting stock.

  8. Seasonal patterns and control of gas exchange in local populations of the Mediterranean evergreen shrub Pistacia lentiscus L.

    Science.gov (United States)

    Flexas, Jaume; Gulías, Javier; Jonasson, Sven; Medrano, Hipólito; Mus, Mauricio

    2001-02-01

    We examined temporal and spatial variations in net photosynthesis, stomatal conductance, intrinsic water-use efficiency, sub-stomatal CO 2 concentration, apparent carboxylation efficiency and chlorophyll fluorescence in the Mediterranean shrub Pistacia lentiscus. The study was done at the extremes of a precipitation and temperature gradient on the coast and in the mountains of Mallorca, Spain, with gas exchange measurements at different times of the year, and combined measurements of gas exchange and chlorophyll fluorescence in a controlled experiment. The objectives were to relate annual variation in photosynthetic functions to environmentally induced constraints and to quantify to which extent local differences in climate can affect photosynthesis in shrub populations. In the mountain population, net photosynthesis peaked in spring and autumn, when water was abundant and temperature was moderately high. It was reduced in winter paralleling reduced carboxylation efficiency. Photosynthesis was at the annual minimum in summer at both sites due to drought-induced stomata closure combined with impaired function of the Calvin cycle. The coastal population maintained high photosynthesis in mid winter but had a pronounced decline in spring, and the summer decline lasted longer than in the mountains. Integrated over the seasons, net photosynthesis was about 25 % lower in the coastal than in the mountain population, in spite of maintained high mid winter photosynthesis. Hence, the reduction at the coast was mainly due to early onset of drought in spring and a long period of summer drought, showing that local climatic differences can cause pronounced spatial differences in plant carbon balance. As a consequence, similar differences probably also occur as a function of year-to-year variability of precipitation patterns and temperatures.

  9. Vegetation response to a short interval between high-severity wildfires in a mixed-evergreen forest

    Science.gov (United States)

    Daniel C. Donato; Joseph B. Fontaine; W. Douglas Robinson; J. Boone Kauffman; Beverly E. Law

    2009-01-01

    Variations in disturbance regime strongly influence ecosystem structure and function. A prominent form of such variation is when multiple high-severity wildfires occur in rapid succession (i.e. short-interval (SI) severe fires, or ‘re-burns’). These events have been proposed as key mechanisms altering successional rates and pathways....

  10. Midday stomatal conductance is more related to stem rather than leaf water status in subtropical deciduous and evergreen broadleaf trees

    Science.gov (United States)

    Yong-Jiang Zhang; Frederick C. Meinzer; Qi Jin-Hua; Guillermo Goldstein; Cao. Kun-Fang

    2012-01-01

    Midday depressions in stomatal conductance (gs/>) and photosynthesis are common in plants. The aim of this study was to understand the hydraulic determinants of midday gs, the coordination between leaf and stem hydraulics and whether regulation of midday gs/> differed between...

  11. Deciduous and evergreen trees differ in juvenile biomass allometries because of differences in allocation to root storage

    NARCIS (Netherlands)

    Tomlinson, K.W.; Langevelde, van F.; Ward, D.; Bongers, F.J.J.M.; Alves da Silva, D.; Prins, H.H.T.; Bie, de S.; Sterck, F.J.

    2013-01-01

    Background and Aims - Biomass partitioning for resource conservation might affect plant allometry, accounting for a substantial amount of unexplained variation in existing plant allometry models. One means of resource conservation is through direct allocation to storage in particular organs. In this

  12. 78 FR 69932 - Tedesco Family ESB Trust, et al.-Purchase of Certain Assets and Membership Interests-Evergreen...

    Science.gov (United States)

    2013-11-21

    ... Transportation Board, DOT. ACTION: Notice tentatively authorizing finance transaction. SUMMARY: On October 22... environment and the conservation of energy resources. Finally, Applicants state that the transaction would... the conservation of energy resources. It is ordered: 1. The proposed transactions are approved and...

  13. Responses of fine roots and soil N availability to short-term nitrogen fertilization in a broad-leaved Korean pine mixed forest in northeastern China.

    Directory of Open Access Journals (Sweden)

    Cunguo Wang

    Full Text Available Knowledge of the responses of soil nitrogen (N availability, fine root mass, production and turnover rates to atmospheric N deposition is crucial for understanding fine root dynamics and functioning in forest ecosystems. Fine root biomass and necromass, production and turnover rates, and soil nitrate-N and ammonium-N in relation to N fertilization (50 kg N ha(-1 year(-1 were investigated in a temperate forest over the growing season of 2010, using sequential soil cores and ingrowth cores methods. N fertilization increased soil nitrate-N by 16% (P<0.001 and ammonium-N by 6% (P<0.01 compared to control plots. Fine root biomass and necromass in 0-20 cm soil were 13% (4.61 vs. 5.23 Mg ha(-1, P<0.001 and 34% (1.39 vs. 1.86 Mg ha(-1, P<0.001 less in N fertilization plots than those in control plots. The fine root mass was significantly negatively correlated with soil N availability and nitrate-N contents, especially in 0-10 cm soil layer. Both fine root production and turnover rates increased with N fertilization, indicating a rapid underground carbon cycling in environment with high nitrogen levels. Although high N supply has been widely recognized to promote aboveground growth rates, the present study suggests that high levels of nitrogen supply may reduce the pool size of the underground carbon. Hence, we conclude that high levels of atmospheric N deposition will stimulate the belowground carbon cycling, leading to changes in the carbon balance between aboveground and underground storage. The implications of the present study suggest that carbon model and prediction need to take the effects of nitrogen deposition on underground system into account.

  14. Calcium and aluminum cycling in a temperate broadleaved deciduous forest of the eastern USA: relative impacts of tree species, canopy state, and flux type.

    Science.gov (United States)

    Levia, Delphis F; Shiklomanov, Alexey N; Van Stan, John T; Scheick, Carrie E; Inamdar, Shreeram P; Mitchell, Myron J; McHale, Patrick J

    2015-07-01

    Ca/Al molar ratios are commonly used to assess the extent of aluminum stress in forests. This is among the first studies to quantify Ca/Al molar ratios for stemflow. Ca/Al molar ratios in bulk precipitation, throughfall, stemflow, litter leachate, near-trunk soil solution, and soil water were quantified for a deciduous forest in northeastern MD, USA. Data were collected over a 3-year period. The Ca/Al molar ratios in this study were above the threshold for aluminum stress (500 examined). This study supplies new data on Ca/Al molar ratios for stemflow from two common deciduous tree species. Future work should examine Ca/Al molar ratios in stemflow of other species and examine both inorganic and organic aluminum species to better gauge the potential for, and understand the dynamics of, aluminum toxicity in the proximal area around tree boles.

  15. Top-down control of herbivory by birds and bats in the canopy of temperate broad-leaved oaks (Quercus robur)

    National Research Council Canada - National Science Library

    Böhm, Stefan M; Wells, Konstans; Kalko, Elisabeth K V

    2011-01-01

    The intensive foraging of insectivorous birds and bats is well known to reduce the density of arboreal herbivorous arthropods but quantification of collateral leaf damage remains limited for temperate forest canopies...

  16. Biomass and morphology of fine roots in temperate broad-leaved forests differing in tree species diversity: is there evidence of below-ground overyielding?

    Science.gov (United States)

    Meinen, Catharina; Hertel, Dietrich; Leuschner, Christoph

    2009-08-01

    Biodiversity effects on ecosystem functioning in forests have only recently attracted increasing attention. The vast majority of studies in forests have focused on above-ground responses to differences in tree species diversity, while systematic analyses of the effects of biodiversity on root systems are virtually non-existent. By investigating the fine root systems in 12 temperate deciduous forest stands in Central Europe, we tested the hypotheses that (1) stand fine root biomass increases with tree diversity, and (2) 'below-ground overyielding' of species-rich stands in terms of fine root biomass is the consequence of spatial niche segregation of the roots of different species. The selected stands represent a gradient in tree species diversity on similar bedrock from almost pure beech forests to medium-diverse forests built by beech, ash, and lime, and highly-diverse stands dominated by beech, ash, lime, maple, and hornbeam. We investigated fine root biomass and necromass at 24 profiles per stand and analyzed species differences in fine root morphology by microscopic analysis. Fine root biomass ranged from 440 to 480 g m(-2) in the species-poor to species-rich stands, with 63-77% being concentrated in the upper 20 cm of the soil. In contradiction to our two hypotheses, the differences in tree species diversity affected neither stand fine root biomass nor vertical root distribution patterns. Fine root morphology showed marked distinctions between species, but these root morphological differences did not lead to significant differences in fine root surface area or root tip number on a stand area basis. Moreover, differences in species composition of the stands did not alter fine root morphology of the species. We conclude that 'below-ground overyielding' in terms of fine root biomass does not occur in the species-rich stands, which is most likely caused by the absence of significant spatial segregation of the root systems of these late-successional species.

  17. North American nonmarine climates and vegetation during the Late Cretaceous

    Science.gov (United States)

    Wolfe, J.A.; Upchurch, G.R.

    1987-01-01

    Analyses of physiognomy of Late Cretaceous leaf assemblages and of structural adaptations of Late Cretaceous dicotyledonous woods indicate that megathermal vegetation was an open-canopy, broad-leaved evergreen woodland that existed under low to moderate amounts of rainfall evenly distributed through the year, with a moderate increase at about 40-45??N. Many dicotyledons were probably large, massive trees, but the tallest trees were evergreen conifers. Megathermal climate extended up to paleolatitude 45-50??N. Mesothermal vegetation was at least partially an open, broad-leaved evergreen woodland (perhaps a mosaic of woodland and forest), but the evapotranspirational stress was less than in megathermal climate. Some dicotyledons were large trees, but most were shrubs or small trees; evergreen conifers were the major tree element. Some mild seasonality is evidenced in mesothermal woods; precipitational levels probably varied markedly from year to year. Northward of approximately paleolatitude 65??N, evergreen vegetation was replaced by predominantly deciduous vegetation. This replacement is presumably related primarily to seasonality of light. The southern part of the deciduous vegetation probably existed under mesothermal climate. Comparisons to leaf and wood assemblages from other continents are generally consistent with the vegetational-climatic patterns suggested from North American data. Limited data from equatorial regions suggest low rainfall. Late Cretaceous climates, except probably those of the Cenomanian, had only moderate change through time. Temperatures generally appear to have warmed into the Santonian, cooled slightly into the Campanian and more markedly into the Maastrichtian, and then returned to Santonian values by the late Maastrichtian. The early Eocene was probably warmer than any period of the Late Cretaceous. Latitudinal temperature gradients were lower than at present. For the Campanian and Maastrichtian, a gradient of about 0.3??C/1

  18. Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

    Science.gov (United States)

    Zhang, M.; Yu, G.-R.; Zhang, L.-M.; Sun, X.-M.; Wen, X.-F.; Han, S.-J.; Yan, J.-H.

    2010-02-01

    Clouds can significantly affect carbon exchange process between forest ecosystems and the atmosphere by influencing the quantity and quality of solar radiation received by ecosystem's surface and other environmental factors. In this study, we analyzed the effects of cloudiness on net ecosystem exchange of carbon dioxide (NEE) in a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS) and a subtropical evergreen broad-leaved forest at Dinghushan (DHS), based on the flux data obtained during June-August from 2003 to 2006. The results showed that the response of NEE of forest ecosystems to photosynthetically active radiation (PAR) differed under clear skies and cloudy skies. Compared with clear skies, the light-saturated maximum photosynthetic rate (Pec,max) at CBS under cloudy skies during mid-growing season (from June to August) increased by 34%, 25%, 4% and 11% in 2003, 2004, 2005 and 2006, respectively. In contrast, Pec,max of the forest ecosystem at DHS was higher under clear skies than under cloudy skies from 2004 to 2006. When the clearness index (kt) ranged between 0.4 and 0.6, the NEE reached its maximum at both CBS and DHS. However, the NEE decreased more dramatically at CBS than at DHS when kt exceeded 0.6. The results indicate that cloudy sky conditions are beneficial to net carbon uptake in the temperate forest ecosystem and the subtropical forest ecosystem. Under clear skies, vapor pressure deficit (VPD) and air temperature increased due to strong light. These environmental conditions led to greater decrease in gross ecosystem photosynthesis (GEP) and greater increase in ecosystem respiration (Re) at CBS than at DHS. As a result, clear sky conditions caused more reduction of NEE in the temperate forest ecosystem than in the subtropical forest ecosystem. The response of NEE of different forest ecosystems to the changes in cloudiness is an important factor that should be included in evaluating regional carbon budgets under climate change

  19. Responses of soil respiration and its temperature/moisture sensitivity to precipitation in three subtropical forests in southern China

    Science.gov (United States)

    Jiang, H.; Deng, Q.; Zhou, G.; Hui, D.; Zhang, D.; Liu, S.; Chu, G.; Li, J.

    2013-06-01

    Both long-term observation data and model simulations suggest an increasing chance of serious drought in the dry season and extreme flood in the wet season in southern China, yet little is known about how changes in precipitation pattern will affect soil respiration in the region. We conducted a field experiment to study the responses of soil respiration to precipitation manipulations - precipitation exclusion to mimic drought, double precipitation to simulate flood, and ambient precipitation as control (abbr. EP, DP and AP, respectively) - in three subtropical forests in southern China. The three forest sites include Masson pine forest (PF), coniferous and broad-leaved mixed forest (MF) and monsoon evergreen broad-leaved forest (BF). Our observations showed that altered precipitation strongly influenced soil respiration, not only through the well-known direct effects of soil moisture on plant and microbial activities, but also by modification of both moisture and temperature sensitivity of soil respiration. In the dry season, soil respiration and its temperature sensitivity, as well as fine root and soil microbial biomass, showed rising trends with precipitation increases in the three forest sites. Contrarily, the moisture sensitivity of soil respiration decreased with precipitation increases. In the wet season, different treatments showed different effects in three forest sites. The EP treatment decreased fine root biomass, soil microbial biomass, soil respiration and its temperature sensitivity, but enhanced soil moisture sensitivity in all three forest sites. The DP treatment significantly increased soil respiration, fine root and soil microbial biomass in the PF only, and no significant change was found for the soil temperature sensitivity. However, the DP treatment in the MF and BF reduced soil temperature sensitivity significantly in the wet season. Our results indicated that soil respiration would decrease in the three subtropical forests if soil moisture

  20. Effects of precipitation on soil acid phosphatase activity in three successional forests in southern China

    Science.gov (United States)

    Huang, W.; Liu, J.; Zhou, G.; Zhang, D.; Deng, Q.

    2011-07-01

    Phosphorus (P) is often a limiting nutrient for plant growth in tropical and subtropical forests. Global climate change has led to alterations in precipitation in the recent years, which inevitably influences P cycling. Soil acid phosphatase plays a vital role in controlling P mineralization, and its activity reflects the capacity of organic P mineralization potential in soils. In order to study the effects of precipitation on soil acid phosphatase activity, an experiment with precipitation treatments (no precipitation, natural precipitation and doubled precipitation) in three successional forests in southern China was carried out. The three forests include Masson pine forest (MPF), coniferous and broad-leaved mixed forest (MF) and monsoon evergreen broad-leaved forest (MEBF). Results showed that driven by seasonality of precipitation, changes in soil acid phosphatase activities coincided with the seasonal climate pattern, with significantly higher values in the wet season than in the dry season. Soil acid phosphatase activities were closely linked to forest successional stages, with enhanced values in the later stages of forest succession. In the dry season, soil acid phosphatase activities in the three forests showed a rising trend with increasing precipitation treatments. In the wet season, soil acid phosphatase activity was depressed by no precipitation treatment in the three forests. However, doubled precipitation treatment exerted a significantly negative effect on it only in MEBF. These results indicate that the potential transformation rate of organic P might be more dependent on water in the dry season than in the wet season. A decrease in organic P turnover would occur in the three forests if there was a drought in a whole year in the future. More rainfall in the wet season would also be adverse to organic P turnover in MEBF due to its high soil moisture.

  1. Phenology of temperate trees in tropical climates

    Science.gov (United States)

    Borchert, Rolf; Robertson, Kevin; Schwartz, Mark D.; Williams-Linera, Guadalupe

    2005-09-01

    Several North American broad-leaved tree species range from the northern United States at ˜47°N to moist tropical montane forests in Mexico and Central America at 15-20°N. Along this gradient the average minimum temperatures of the coldest month (T Jan), which characterize annual variation in temperature, increase from -10 to 12°C and tree phenology changes from deciduous to leaf-exchanging or evergreen in the southern range with a year-long growing season. Between 30 and 45°N, the time of bud break is highly correlated with T Jan and bud break can be reliably predicted for the week in which mean minimum temperature rises to 7°C. Temperature-dependent deciduous phenology—and hence the validity of temperature-driven phenology models—terminates in southern North America near 30°N, where T Jan>7°C enables growth of tropical trees and cultivation of frost-sensitive citrus fruits. In tropical climates most temperate broad-leaved species exchange old for new leaves within a few weeks in January-February, i.e., their phenology becomes similar to that of tropical leaf-exchanging species. Leaf buds of the southern ecotypes of these temperate species are therefore not winter-dormant and have no chilling requirement. As in many tropical trees, bud break of Celtis, Quercus and Fagus growing in warm climates is induced in early spring by increasing daylength. In tropical climates vegetative phenology is determined mainly by leaf longevity, seasonal variation in water stress and day length. As water stress during the dry season varies widely with soil water storage, climate-driven models cannot predict tree phenology in the tropics and tropical tree phenology does not constitute a useful indicator of global warming.

  2. Monitoring Landscape Changes in Japan Using Classification of Modis Data Combined with a Landscape Transformation Sere (LTS Model

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    Harada Ippei

    2015-01-01

    Full Text Available Japan, with over 75% forest cover, is one of the most heavily forested countries in the world. Various types of climax forest are distributed according to latitude and altitude. At the same time, human intervention in Japan has historically been intensive, and many forest habitats show the influence of various levels of disturbance. Furthermore, Japanese landscapes are changing rapidly, and a system of efficient monitoring is needed. The aim of this research was to identify major historical trends in Japanese landscape change and to develop a system for identifying and monitoring patterns of landscape change at the national level. To provide a base for comparison, Warmth Index (WI climatic data was digitalized and utilized to map potential climax vegetation for all of Japan. Extant Land Use Information System (LUIS data were then modified and digitalized to generate national level Land Use/Land Cover (LU/LC distribution maps for 1900, 1950 and 1985. In addition, MODIS data for 2001 acquired by the Tokyo University of Information Sciences were utilized for remote LU/LC classification using an unsupervised method on multi-temporal composite data. Eight classification categories were established using the ISODATA (cluster analyses method; alpine plant communities, evergreen coniferous forest, evergreen broad-leaved forest, deciduous broad-leaved forest, mixed forest, arable land (irrigated rice paddy, non-irrigated, grassland, urban area, river and marsh. The results of the LUIS analyses and MODIS classifications were interpreted in terms of a Landscape Transformation Sere model assuming that under increasing levels of human disturbance the landscape will change through a series of stages. The results showed that overall forest cover in Japan has actually increased over the century covered by the data; from 72.1% in 1900 to 76.9% in 2001. Comparison of the actual vegetation and the potential vegetation as predicted by WI, however, indicated that in

  3. Early Oligocene plant diversity along the Upper Rhine Graben: The fossil flora of Rauenberg, Germany

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    Kovar-Eder Johanna

    2016-12-01

    Full Text Available The macroflora of Rauenberg, Baden-Württemberg, Germany, is treated monographically. The plant-bearing sediments are marine, mainly well-bedded clay- to siltstones, the so-called Fischschiefer, which are part of the Bodenheim Formation. Based on nannoplankton they are dated to nannoplankton zone NP 23 (Rupelian, Lower Oligocene. The plant remains, mainly leaves and some fructifications, are preserved as compressions. The taxonomic assignment is based on gross morphology and cuticle characteristics. The flora yields marine algae and remains of the very diverse terrestrial flora. A total of 68 taxa, including three types of algae, one cycad, 12 conifers, and 49 dicots, among them 5 palms, are described. The following fossil species are described for the first time: Laurophyllum rauenbergense, Myrica obliquifolia, Distylium metzleri, ? Berchemia altorhenana, ? Ternstroemites maritiae, Trachelospermum kelleri, Oleinites altorhenana, O. rauenbergensis, Dicotylophyllum badense, D. oechsleri, D. vesiculaeferens, D. ziegleri, ? Viscophyllum hendriksiae, and Cladites vesiculaeferens. Dicotylophyllum vesiculaeferens and Cladites vesiculaeferens bear peculiar, complex cuticular structures presumably representing salt-secreting glands. Both taxa are interpreted to derive from one plant species of yet uncertain systematic affinity. The flora bears a high proportion of broad-leaved, presumably evergreen taxa, whereas the diversity of modern Arcto-Tertiary taxa (sensu Kvaček 1994 is rather low. Most abundant are Platanus neptuni, Daphnogene cinnamomifolia, and Tetraclinis salicornioides. On the family level, Lauraceae (10 species and Pinaceae (8 are most diverse, followed by Arecaceae (4-5, Cupressaceae, and Myricaceae (4 species each. Surprisingly, Fagaceae are documented solely by a single leaf of Eotrigonobalanus furcinervis f. haselbachensis, and the record of Pentaphyllaceae remains ambiguous (? Ternstroemites maritiae. Sloanea olmediaefolia is recorded

  4. Sustained acceleration of soil carbon decomposition observed in a 6-year warming experiment in a warm-temperate forest in southern Japan

    Science.gov (United States)

    Teramoto, Munemasa; Liang, Naishen; Takagi, Masahiro; Zeng, Jiye; Grace, John

    2016-10-01

    To examine global warming’s effect on soil organic carbon (SOC) decomposition in Asian monsoon forests, we conducted a soil warming experiment with a multichannel automated chamber system in a 55-year-old warm-temperate evergreen broadleaved forest in southern Japan. We established three treatments: control chambers for total soil respiration, trenched chambers for heterotrophic respiration (Rh), and warmed trenched chambers to examine warming effect on Rh. The soil was warmed with an infrared heater above each chamber to increase soil temperature at 5 cm depth by about 2.5 °C. The warming treatment lasted from January 2009 to the end of 2014. The annual warming effect on Rh (an increase per °C) ranged from 7.1 to17.8% °C-1. Although the warming effect varied among the years, it averaged 9.4% °C-1 over 6 years, which was close to the value of 10.1 to 10.9% °C-1 that we calculated using the annual temperature-efflux response model of Lloyd and Taylor. The interannual warming effect was positively related to the total precipitation in the summer period, indicating that summer precipitation and the resulting soil moisture level also strongly influenced the soil warming effect in this forest.

  5. Instantaneous and historical temperature effects on alpha-pinene emissions in Pinus halepensis and Quercus ilex.

    Science.gov (United States)

    Blanch, Josep-Salvador; Llusia, Joan; Niinemets, Ulo; Noe, Steffen M; Penuelas, Josep

    2011-01-01

    We compared the role of instantaneous temperature and temperature history in the determination of alpha-pinene emissions in Mediterranean conifer Pinus halepensis that stores monoterpenes in resin ducts, and in Mediterranean broad-leaved evergreen Quercus ilex that lacks such specialized storage structures. In both species, alpha-pinene emission rates (E) exhibited a significant exponential correlation with leaf temperature and the rates of photosynthetic electron transport (Jco2+o2) started to decrease after an optimum at approximately 35 degrees C. However, there was a higher dependence of E on mean temperature of previous days than on mean temperature of current day for P. halepensis but not for Q. ilex. Jco2+o2 showed a maximum relationship to mean temperature of previous 3 and 5 days for P. halepensis and Q. ilex respectively. We conclude that although the best correlation of emission rates were found for instantaneous foliar temperatures, the effect of accumulated previous temperature conditions should also be considered in models of monoterpene emission, especially for terpene (see text) species.

  6. Climatic implications of fruit and seed assemblage from Miocene of Yunnan, southwestern China

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.C.; Wang, Y.F.; Liu, C.J.; Li, C.S. [Chinese Academy of Science, Beijing (China). Inst. of Botany

    2004-07-01

    A Miocene assemblage of fruits and seeds from Mangdan coal mine, Longchuan County, Yunnan Province, southwestern China is reported in this paper. This carpoflora consists of 11 taxa of angiosperms, Corylopsis, Ficus, Hypericum, Lauraceae, Lithoearpus, Magnolia, Myrica, Nyssa, Sabia, Symplocos and Zanthoxylum. The investigation of the nearest living relatives (NLRs) of the 11 taxa suggests that an evergreen broad-leaved forest was growing in Mangdan region in the Miocene. Based on the climatic preferences of the NLRs, the climate at that time was a warm and humid subtropical climate, with the mean annual temperature of 18.8-20.5{sup o}C, the mean temperature of the coldest month was 7.9-11.3{sup o}C, the mean temperature of the warmest month was 27.6-28.0{sup o}C, the difference of temperature of coldest and warmest month was 15.2-17.9{sup o}C, the mean annual precipitation was 1170-1300mm and the relative humidity 70-74%.

  7. MAPPING TROPICAL FOREST FOR SUSTAINABLE MANAGEMENT USING SPOT 5 SATELLITE IMAGE

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    H. T. T. Nguyen

    2016-06-01

    Full Text Available This paper describes the combination of multi-data in stratifying the natural evergreen broadleaved tropical forest of the Central Highlands of Vietnam. The forests were stratified using both unsupervised and supervised classification methods based on SPOT5 and field data. The forests were classified into 3 and 4 strata separably. Correlation between stratified forest classes and forest variables was analyzed in order to find out 1 how many classes is suitable to stratify for the forest in this area and 2 how closely the forest variables are related with forest classes. The correlation coefficient shows although all forest variables did have a significant correlation with the forest classes, stand volume appeared to have the strongest correlation with forest classes. These are 0.64 and 0.59 for four and three strata respectively. The results of supervised classification also show the four strata of heavily degraded forest, moderate disturbance, insignificant disturbance, and dense forest were discriminated more clearly comparing to the forest stratified into three classes. The proof is that overall accuracy of supervised classification was 86% with Kappa of 0.8 for four classes, meanwhile, these are 77% and 0.62 respectively for forest area classified into 3 classes.

  8. Ecosystem carbon stock influenced by plantation practice: implications for planting forests as a measure of climate change mitigation.

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    Chengzhang Liao

    Full Text Available Uncertainties remain in the potential of forest plantations to sequestrate carbon (C. We synthesized 86 experimental studies with paired-site design, using a meta-analysis approach, to quantify the differences in ecosystem C pools between plantations and their corresponding adjacent primary and secondary forests (natural forests. Totaled ecosystem C stock in plant and soil pools was 284 Mg C ha(-1 in natural forests and decreased by 28% in plantations. In comparison with natural forests, plantations decreased aboveground net primary production, litterfall, and rate of soil respiration by 11, 34, and 32%, respectively. Fine root biomass, soil C concentration, and soil microbial C concentration decreased respectively by 66, 32, and 29% in plantations relative to natural forests. Soil available N, P and K concentrations were lower by 22, 20 and 26%, respectively, in plantations than in natural forests. The general pattern of decreased ecosystem C pools did not change between two different groups in relation to various factors: stand age ( or = 25 years, stand types (broadleaved vs. coniferous and deciduous vs. evergreen, tree species origin (native vs. exotic of plantations, land-use history (afforestation vs. reforestation and site preparation for plantations (unburnt vs. burnt, and study regions (tropic vs. temperate. The pattern also held true across geographic regions. Our findings argued against the replacement of natural forests by the plantations as a measure of climate change mitigation.

  9. [Quantitative relationships of intra- and interspecific competition in Cryptocarya concinna].

    Science.gov (United States)

    Zhang, Chi; Huang, Zhongliang; Li, Jiong; Shi, Junhui; Li, Lin

    2006-01-01

    The monsoon evergreen broad-leaved forest (MEBF) in Dinghushan Nature Reserve (DNR) has been considered as a zonal vegetation in lower subtropical China, with a history of more than 400 years. In this paper, the intra- and interspecific competition intensity in Cryptocarya concinna, one of the constructive species in MEBF in DNR was quantitatively analyzed by Hegyi single-tree competition index model. The results showed that the intraspecific competition intensity in C. concinna decreased gradually with increasing tree diameter. For C. concinna, its intraspecific competition was weaker than its interspecific competition with Aporosa yunnanensis. The competition intensity of interspecific competition with C. concinna followed the order of A. yunnanensis > Schima superba > Gironniera subaequalis > Acmena acuminatissima > Castanopsis chinensis > Syzygium rehderianum > Pygeum topengii > Blastus cochinchinensis > Sarcosperma laurinum > Pterospermum lanceaefolium > Cryptocarya chinensis. The relationship of the DBH of objective tree and the competition intensity between competitive tree and objective tree in the whole forest and C. concinna population nearly conformed to power function, while that between other competitive tree and the objective C. concinna tree conformed to logarithm function. There was a significantly negative correlation between the competition intensity and the DBH of objective tree.

  10. Elevational Distribution of Adult Trees and Seedlings in a Tropical Montane Transect, Southwest China

    Directory of Open Access Journals (Sweden)

    Xiaoyang Song

    2016-08-01

    Full Text Available Montane habitats are characterized by high variation of environmental factors within small geographic ranges, which offers opportunities to explore how forest assemblages respond to changes in environmental conditions. Understanding the distributional transition of adult trees and seedlings will provide insight into the fate of forest biodiversity in response to future climate change. We investigated the elevational distribution of 156 species of adult trees and 152 species of seedlings in a tropical montane forest in Xishuangbanna, southwest China. Adult trees and seedlings were surveyed within 5 replicate plots established at each of 4 elevational bands (800, 1000, 1200, and 1400 m above sea level. We found that species richness of both adult trees and seedlings changed with elevation, showing a notable decline in diversity values from 1000 to 1200 m. Tree species composition also demonstrated distinct differences between 1000 and 1200 m, marking the division between tropical seasonal rain forest (800 and 1000 m and tropical montane evergreen broad-leaved forest (1200 and 1400 m. The results suggested that soil moisture and temperature regimes were associated with elevational distribution of tree species in this region. We also observed that seedlings from certain species found at high elevations were also distributed in low-elevation zones, but no seedlings of species from low elevations were distributed in high-elevation zones. The increase in temperature and droughts predicted for this region may result in the contraction of tropical seasonal rain forest at lower elevations and a downhill shift of higher tropical montane tree species.

  11. Mapping forest functional type in a forest-shrubland ecotone using SPOT imagery and predictive habitat distribution modelling

    Science.gov (United States)

    Assal, Timothy J.; Anderson, Patrick J.; Sibold, Jason

    2015-01-01

    The availability of land cover data at local scales is an important component in forest management and monitoring efforts. Regional land cover data seldom provide detailed information needed to support local management needs. Here we present a transferable framework to model forest cover by major plant functional type using aerial photos, multi-date Système Pour l’Observation de la Terre (SPOT) imagery, and topographic variables. We developed probability of occurrence models for deciduous broad-leaved forest and needle-leaved evergreen forest using logistic regression in the southern portion of the Wyoming Basin Ecoregion. The model outputs were combined into a synthesis map depicting deciduous and coniferous forest cover type. We evaluated the models and synthesis map using a field-validated, independent data source. Results showed strong relationships between forest cover and model variables, and the synthesis map was accurate with an overall correct classification rate of 0.87 and Cohen’s kappa value of 0.81. The results suggest our method adequately captures the functional type, size, and distribution pattern of forest cover in a spatially heterogeneous landscape.

  12. Mercury dynamics and mass balance in a subtropical forest, southwestern China

    Directory of Open Access Journals (Sweden)

    M. Ma

    2016-04-01

    Full Text Available The mid-subtropical forest area in southwest China was affected by anthropogenic mercury (Hg emissions over the past 3 decades. We quantified mercury dynamics on the forest field and measured fluxes and pools of Hg in litterfall, throughfall, stream water and forest soil in an evergreen broadleaved forest field in southwestern China. Total Hg (THg input by the throughfall and litterfall was assessed at 32.2 and 42.9 µg m−2 yr−1, respectively, which was remarkably higher than those observed from other forest fields in the background of North America and Europe. Hg fluxes across the soil–air interface (18.6 mg m−2 yr−1 and runoff and/or stream flow (7.2 µg m−2 yr−1 were regarded as the dominant ways for THg export from the forest field. The forest field hosts an enormous amount of atmospheric Hg, and its reserves is estimated to be 25 341 µg m2. The ratio of output to input Hg fluxes (0.34 is higher compared with other study sites. The higher output / input ratio may represent an important ecological risk for the downstream aquatic ecosystems, even if the forest field could be an effective sink of Hg.

  13. A comparative study on genetic effects of artificial and natural habitat fragmentation on Loropetalum chinense (Hamamelidaceae) in Southeast China.

    Science.gov (United States)

    Yuan, N; Comes, H P; Cao, Y N; Guo, R; Zhang, Y H; Qiu, Y X

    2015-06-01

    Elucidating the demographic and landscape features that determine the genetic effects of habitat fragmentation has become fundamental to research in conservation and evolutionary biology. Land-bridge islands provide ideal study areas for investigating the genetic effects of habitat fragmentation at different temporal and spatial scales. In this context, we compared patterns of nuclear microsatellite variation between insular populations of a shrub of evergreen broad-leaved forest, Loropetalum chinense, from the artificially created Thousand-Island Lake (TIL) and the Holocene-dated Zhoushan Archipelago of Southeast China. Populations from the TIL region harboured higher levels of genetic diversity than those from the Zhoushan Archipelago, but these differences were not significant. There was no correlation between genetic diversity and most island features, excepting a negative effect of mainland-island distance on allelic richness and expected heterozygosity in the Zhoushan Archipelago. In general, levels of gene flow among island populations were moderate to high, and tests of alternative models of population history strongly favoured a gene flow-drift model over a pure drift model in each region. In sum, our results showed no obvious genetic effects of habitat fragmentation due to recent (artificial) or past (natural) island formation. Rather, they highlight the importance of gene flow (most likely via seed) in maintaining genetic variation and preventing inter-population differentiation in the face of habitat 'insularization' at different temporal and spatial scales.

  14. High-resolution data on the impact of warming on soil CO2 efflux from an Asian monsoon forest

    Science.gov (United States)

    Liang, Naishen; Teramoto, Munemasa; Takagi, Masahiro; Zeng, Jiye

    2017-01-01

    This paper describes a project for evaluation of global warming’s impacts on soil carbon dynamics in Japanese forest ecosystems. We started a soil warming experiment in late 2008 in a 55-year-old evergreen broad-leaved forest at the boundary between the subtropical and warm-temperate biomes in southern Japan. We used infrared carbon-filament heat lamps to increase soil temperature by about 2.5 °C at a depth of 5 cm and continuously recorded CO2 emission from the soil surface using a multichannel automated chamber system. Here, we present details of the experimental processes and datasets for the CO2 emission rate, soil temperature, and soil moisture from control, trenched, and warmed trenched plots. The long term of the study and its high resolution make the datasets meaningful for use in or development of coupled climate-ecosystem models to tune their dynamic behaviour as well as to provide mean parameters for decomposition of soil organic carbon to support future predictions of soil carbon sequestration. PMID:28291228

  15. Current ambient concentrations of ozone in Panama modulate the leaf chemistry of the tropical tree Ficus insipida.

    Science.gov (United States)

    Schneider, Gerald F; Cheesman, Alexander W; Winter, Klaus; Turner, Benjamin L; Sitch, Stephen; Kursar, Thomas A

    2017-04-01

    Tropospheric ozone (O 3 ) is a major air pollutant and greenhouse gas, affecting carbon dynamics, ecological interactions, and agricultural productivity across continents and biomes. Elevated [O 3 ] has been documented in tropical evergreen forests, the epicenters of terrestrial primary productivity and plant-consumer interactions. However, the effects of O 3 on vegetation have not previously been studied in these forests. In this study, we quantified ambient O 3 in a region shared by forests and urban/commercial zones in Panama and found levels two to three times greater than in remote tropical sites. We examined the effects of these ambient O 3 levels on the growth and chemistry of seedlings of Ficus insipida, a regionally widespread tree with high stomatal conductance, using open-top chambers supplied with ozone-free or ambient air. We evaluated the differences across treatments in biomass and, using UPLC-MS-MS, leaf secondary metabolites and membrane lipids. Mean [O 3 ] in ambient air was below the levels that induce chronic stress in temperate broadleaved trees, and biomass did not differ across treatments. However, leaf secondary metabolites - including phenolics and a terpenoid - were significantly downregulated in the ambient air treatment. Membrane lipids were present at lower concentrations in older leaves grown in ambient air, suggesting accelerated senescence. Thus, in a tree species with high O 3 uptake via high stomatal conductance, current ambient [O 3 ] in Panamanian forests are sufficient to induce chronic effects on leaf chemistry. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Pre-dispersal strategies by Quercus schottkyana to mitigate the effects of weevil infestation of acorns.

    Science.gov (United States)

    Xia, Ke; Harrower, William L; Turkington, Roy; Tan, Hong-Yu; Zhou, Zhe-Kun

    2016-11-22

    We investigated how pre-dispersal strategies may mitigate the effects of weevil infestation of acorns in a population of Quercus schottkyana, a dominant oak in Asian evergreen broad-leaved forests, and assess if weevil infestation contributes to low seedling recruitment. We counted the number of acorns produced, daily from the end of August to mid-late November for 9 years from 2006-2014. We also recorded the rate of acorn infestation by weevils and acorn germination rates of weekly collections. Annual acorn production was variable, but particularly low in 2011 and 2013. There was no trade-off between acorn production and acorn dry mass. However, acorns produced later in the season were significantly heavier. For most years: (i) the rate of weevil infestation was negatively density dependent (a greater proportion of acorns died with increased acorn density), (ii) the percentage germination of acorns was positively density dependent (proportionately more acorns germinated with increased density), and (iii) as the season progressed, the percentage of infested acorns declined while germination rates increased. Finally, (iv) maximum acorn production, percentage infestation and percentage germination were asynchronous. Although pre-dispersal mortality is important it is unlikely to be the primary factor leading to low recruitment of oak seedlings.

  17. POLLINATION ECOLOGY OF TARENNA ASIATICA (L. KUNTZ EX. K. SCHUM. (RUBIACEAE, A KEYSTONE EVERGREEN SHRUB SPECIES IN THE EASTERN GHATS FOREST - ANDHRA PRADESH, INDIA

    Directory of Open Access Journals (Sweden)

    A. Jacob Solomon Raju

    2016-03-01

    Full Text Available Tarenna asiatica flowers throughout the year with profuse flowering during december-april. the flowers are hermaphroditic, self- and cross-compatible, protandrous, nectariferous and entomophilous. the mating system is facultatively xenogamous with highest fruit set in xenogamy. The protandry facilitates autonomous selfing. Bees and butterflies effect both self- and cross-pollinations. Fruits mature within a short period and the fallen seeds germinate following monsoon rains in June-July. a dearth of floral resources exists during december-april period; T. asiatica with profuse flowering during this period plays a key role to provide pollen and nectar for the probing flower foragers and hence is considered to be a keystone species in the eastern Ghats forest

  18. POLLINATION ECOLOGY OF TARENNA ASIATICA (L.) KUNTZ EX. K. SCHUM. (RUBIACEAE), A KEYSTONE EVERGREEN SHRUB SPECIES IN THE EASTERN GHATS FOREST - ANDHRA PRADESH, INDIA

    OpenAIRE

    A. Jacob Solomon Raju; M. Mallikarjuna Rao

    2016-01-01

    Tarenna asiatica flowers throughout the year with profuse flowering during december-april. the flowers are hermaphroditic, self- and cross-compatible, protandrous, nectariferous and entomophilous. the mating system is facultatively xenogamous with highest fruit set in xenogamy. The protandry facilitates autonomous selfing. Bees and butterflies effect both self- and cross-pollinations. Fruits mature within a short period and the fallen seeds germinate following monsoon rains in June-July. a de...

  19. Expeditious Quantification of Lignocellulolytic Enzymes from Indigenous Wood Rot and Litter Degrading Fungi from Tropical Dry Evergreen Forests of Tamil Nadu

    Directory of Open Access Journals (Sweden)

    Jenefar Sudarson

    2014-01-01

    Full Text Available In this study thirty wood rotting and litter degrading basidiomycetes were screened for the production of lignocellulolytic enzymes such as, laccase, peroxidase, and cellulase using rapid micro quantification assay. Out of the 30 indigenous isolates Trametes gibbosa was identified to be a potential lignocellulolytic enzyme producer, producing a maximum amount of cellulase (299.66±1.59 IU/L and laccase (257.94±1.79 U/L. Moreover, it is the second leading producer of peroxidase enzyme (170.19±1.98 U/L. Tricholomopsis sp. a wood rot basidiomycete was found to be the leading lignin decomposer with maximum peroxidase activity (287.84±2 U/L and second maximum laccase activity (250.19±1.83 U/L. However, its cellulolytic potential was found to be moderate (100.04±1.13 U/L. A higher level of lignocellulolytic enzymes was recorded in wood rotting basidiomycetes, whereas very low levels of lignolytic enzymes were found in litter inhabiting basidiomycetes. However, their cellulolytic potential was found to be moderate.

  20. Carbon cycling at a temperate evergreen forest: a comparison of three ecosystem-model data assimilation systems at Howland, ME (Invited)

    Science.gov (United States)

    Moore, D. J.; Richardson, A. D.; Ricciuto, D. M.; Hollinger, D.

    2009-12-01

    At an expanding number of research sites, the eddy covariance method and automated respiration chambers provide near continuous measurements of different C fluxes, and ancillary ecological measurements (e.g., biomass inventories) provide valuable information on C pools. Starting in 1996 at the spruce-dominated Howland Forest AmeriFlux site, eddy covariance measurements of net ecosystem exchange and evapo-transpiration, chamber measurements of soil respiration, as well as periodic measurements of leaf area index, litterfall, soil respiration, and standing biomass have been quantified. We conducted a multi-model data assimilation experiment, using the available data to constrain the parameters of three ecosystem models; the Simplified Photosynthesis and Evapo-transpiration (SIPNET) model, the Data Assimilation Linked Ecosystem Carbon (DALEC) model and the Local Terrestrial Ecosystem Carbon model (LOTEC). Data and associated uncertainties from 1997 through 2000 were used to optimize model parameters using a modified Metropolis algorithm, a Monte-Carlo Markov Chain technique and the Ensemble Kalman Filter. We compare the strengths and weaknesses of three ecosystem models in extracting process level information from different data streams in isolation and in combination by comparing predictions to measurements of carbon fluxes and pools made from 2001 through 2004. When all data were used in the parameterization all models reproduced the daily carbon fluxes well (R2 = 0.85-0.9; RMS error 0.8) however the magnitude of the observations was sometimes very poorly estimated (slope = 0.3 - 14). While the LOTEC model reproduced the data more effectively than the other models for most data streams, there was little improvement in the predictions whether all data or just eddy flux data was used in the parameterization. Because of differences in the implementation of the cost function, when constrained using all available data improved predictions from the DALEC model but not from the SIPNET model. Conditioning these two models using eddy covariance data in isolation improved estimates of short term variation; however, this was in part driven by unrealistic behaviour in Carbon pools. When all data streams were combined (assuming equal weighting of LAI, eddy covariance measurements, soil efflux and litterfall), longer term processes were constrained, reducing uncertainty in model predictions and carbon cycling over inter-annual time scales remains challenging.

  1. Identifying the best season for mapping evergreen swamp and mangrove species using leaf-level spectra in an estuarine system in KwaZulu-Natal, South Africa

    CSIR Research Space (South Africa)

    Van Deventer, Heidi

    2014-10-01

    Full Text Available Swamp and mangrove forests are some of the most threatened forest types in the world. In Africa, these forests are essential in providing food, construction material and medicine to people. These forest types have not sufficiently been mapped...

  2. On the difference in the net ecosystem exchange of CO2 between deciduous and evergreen forests in the southeastern United States.

    Science.gov (United States)

    Novick, Kimberly A; Oishi, A Christopher; Ward, Eric J; Siqueira, Mario B S; Juang, Jehn-Yih; Stoy, Paul C

    2015-02-01

    The southeastern United States is experiencing a rapid regional increase in the ratio of pine to deciduous forest ecosystems at the same time it is experiencing changes in climate. This study is focused on exploring how these shifts will affect the carbon sink capacity of southeastern US forests, which we show here are among the strongest carbon sinks in the continental United States. Using eight-year-long eddy covariance records collected above a hardwood deciduous forest (HW) and a pine plantation (PP) co-located in North Carolina, USA, we show that the net ecosystem exchange of CO2 (NEE) was more variable in PP, contributing to variability in the difference in NEE between the two sites (ΔNEE) at a range of timescales, including the interannual timescale. Because the variability in evapotranspiration (ET) was nearly identical across the two sites over a range of timescales, the factors that determined the variability in ΔNEE were dominated by those that tend to decouple NEE from ET. One such factor was water use efficiency, which changed dramatically in response to drought and also tended to increase monotonically in nondrought years (P temperate climates. Additional variability in the fluxes at long-time scales may be attributable to slowly evolving factors, including canopy structure and increases in dormant season air temperature. Taken together, study results suggest that the carbon sink in the southeastern United States may become more variable in the future, owing to a predicted increase in drought frequency and an increase in the fractional cover of southern pines. © 2014 John Wiley & Sons Ltd.

  3. Ecological Importance of Small-Diameter Trees to the Structure, Diversity and Biomass of a Tropical Evergreen Forest at Rabi, Gabon.

    Directory of Open Access Journals (Sweden)

    Hervé R Memiaghe

    Full Text Available Tropical forests have long been recognized for their biodiversity and ecosystem services. Despite their importance, tropical forests, and particularly those of central Africa, remain understudied. Until recently, most forest inventories in Central Africa have focused on trees ≥10 cm in diameter, even though several studies have shown that small-diameter tree population may be important to demographic rates and nutrient cycling. To determine the ecological importance of small-diameter trees in central African forests, we used data from a 25-ha permanent plot that we established in the rainforest of Gabon to study the diversity and dynamics of these forests. Within the plot, we censused 175,830 trees ≥1 cm dbh from 54 families, 192 genera, and 345 species. Average tree density was 7,026 trees/ha, basal area 31.64 m2/ha, and above-ground biomass 369.40 Mg/ha. Fabaceae, Ebenaceae and Euphorbiaceae were the most important families by basal area, density and above-ground biomass. Small-diameter trees (1 cm ≥ dbh <10 cm comprised 93.7% of the total tree population, 16.5% of basal area, and 4.8% of the above-ground biomass. They also had diversity 18% higher at family level, 34% higher at genus level, and 42% higher at species level than trees ≥10 cm dbh. Although the relative contribution of small-diameter trees to biomass was comparable to other forests globally, their contribution to forest density, and diversity was disproportionately higher. The high levels of diversity within small-diameter classes may give these forests high levels of structural resilience to anthropogenic/natural disturbance and a changing climate.

  4. Critical zone co-evolution: evidence that weathering and consequent seasonal rock moisture storage leads to a mixed forest canopy of conifer and evergreen broadleaf trees

    Science.gov (United States)

    Oshun, J.; Dietrich, W. E.; Dawson, T. E.; Rempe, D. M.; Fung, I. Y.

    2014-12-01

    Despite recent studies demonstrating the importance of rock moisture as a source of water to vegetation, much remains unknown regarding species-specific and seasonal patterns of water uptake in a Mediterranean climate. Here, we use stable isotopes of water (d18O, dD) to define the isotope composition of water throughout the subsurface critical zone of Rivendell, within the Eel River Critical Zone Observatory. We find that a structured heterogeneity of water isotope composition exists in which bulk saprolite is chronically more negative than bulk soil, and tightly held moisture is more negative than the mobile water that recharges the saturated zone and generates runoff. These moisture reservoirs provide a blueprint from which to measure the seasonal uptake patterns of different species collocated on the site. Douglas-firs use unsaturated saprolite and weathered bedrock moisture (i. e. rock moisture) throughout the year. Contrastingly, hardwood species (madrone, live oak, tanoak) modify their source water depending on which moisture is energetically favorable. Hardwoods use freely mobile water in the wet season, and rely on unsaturated zone soil moisture in the dry season. When soil water tension decreases on the drier south-facing slope, hardwood species use saprolite moisture. Although adjacent hardwoods and Douglas-firs partition water based on matric pull on the north side, there is competition for saprolite moisture in late summer on the south side. These results reveal the eco-hydrological importance of moisture derived from weathered bedrock, and show that the hardwoods have a competitive advantage under the drier conditions predicted in many climate models. Finally, the data emphasize that isotope measurements of all subsurface reservoirs and potential water sources are necessary for a complete and accurate characterization of the eco-hydrological processes within the critical zone.

  5. A comparison of carbon sequestration potential and photosynthetic efficiency in evergreen and deciduous oaks growing in contrasting environments in the Southwest UK

    OpenAIRE

    Carne, Demelza Jane

    2013-01-01

    Global climate change is predicted to alter the weather patterns around the world, as climatic zones shift, forest carbon sequestration projects (e.g. the UK woodland carbon code) need to take into account the specific requirements of planted species. In the UK, oaks are an important charismatic group of trees favoured in recent planting programmes. The English oak (Quercus robur L.), has poor water conservation, but is a major component of natural forests in lowland UK. On the other hand, Ho...

  6. Gas exchange recovery following natural drought is rapid unless limited by loss of leaf hydraulic conductance: evidence from an evergreen woodland.

    Science.gov (United States)

    Skelton, Robert P; Brodribb, Timothy J; McAdam, Scott A M; Mitchell, Patrick J

    2017-09-01

    Drought can cause major damage to plant communities, but species damage thresholds and postdrought recovery of forest productivity are not yet predictable. We used an El Niño drought event as a natural experiment to test whether postdrought recovery of gas exchange could be predicted by properties of the water transport system, or if metabolism, primarily high abscisic acid concentration, might delay recovery. We monitored detailed physiological responses, including shoot sapflow, leaf gas exchange, leaf water potential and foliar abscisic acid (ABA), during drought and through the subsequent rehydration period for a sample of eight canopy and understory species. Severe drought caused major declines in leaf water potential, elevated foliar ABA concentrations and reduced stomatal conductance and assimilation rates in our eight sample species. Leaf water potential surpassed levels associated with incipient loss of leaf hydraulic conductance in four species. Following heavy rainfall gas exchange in all species, except those trees predicted to have suffered hydraulic impairment, recovered to prestressed rates within 1 d. Recovery of plant gas exchange was rapid and could be predicted by the hydraulic safety margin, providing strong support for leaf vulnerability to water deficit as an index of damage under natural drought conditions. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  7. Do seasonal profiles of foliar pigments improve species discrimination of evergreen coastal tree species in KwaZulu- Natal, South Africa?

    CSIR Research Space (South Africa)

    Van Deventer, Heidi

    2013-04-01

    Full Text Available pigments, as well as improve species discrimination. This study investigated the potential of seasonal pigment profiles (for foliar carotenoid and total chlorophyll) in improving species discrimination for trees using leaf spectral data. Our aims were to (i...

  8. Morpho-anatomical, physiological and biochemical adjustments in response to root zone salinity stress and high solar radiation in two Mediterranean evergreen shrubs, Myrtus communis and Pistacia lentiscus.

    Science.gov (United States)

    Tattini, Massimiliano; Remorini, Damiano; Pinelli, Patrizia; Agati, Giovanni; Saracini, Erica; Traversi, Maria Laura; Massai, Rossano

    2006-01-01

    Salt- and light-induced changes in morpho-anatomical, physiological and biochemical traits were analysed in Myrtus communis and Pistacia lentiscus with a view to explaining their ecological distribution in the Mediterranean basin. In plants exposed to 20 or 100% solar radiation and supplied with 0 or 200 mm NaCl, measurements were conducted for ionic and water relations and photosynthetic performance, leaf morpho-anatomical and optical properties and tissue-specific accumulation of tannins and flavonoids. Net carbon gain and photosystem II (PSII) efficiency decreased less in P. lentiscus than in M. communis when exposed to salinity stress, the former having a superior ability to use Na(+) and Cl(-) for osmotic adjustment. Morpho-anatomical traits also allowed P. lentiscus to protect sensitive targets in the leaf from the combined action of salinity stress and high solar radiation to a greater degree than M. communis. Salt and light-induced increases in carbon allocated to polyphenols, particularly to flavonoids, were greater in M. communis than in P. lentiscus, and appeared to be related to leaf oxidative damage. Our data may conclusively explain the negligible distribution of M. communis in open Mediterranean areas suffering from salinity stress, and suggest a key antioxidant function of flavonoids in response to different stressful conditions.

  9. Responses to changes in Ca2+ supply in two Mediterranean evergreens, Phillyrea latifolia and Pistacia lentiscus, during salinity stress and subsequent relief.

    Science.gov (United States)

    Tattini, Massimiliano; Traversi, Maria Laura

    2008-10-01

    Changes in root-zone Ca(2+) concentration affect a plant's performance under high salinity, an issue poorly investigated for Mediterranean xerophytes, which may suffer from transient root-zone salinity stress in calcareous soils. It was hypothesized that high-Ca(2+) supply may affect differentially the response to salinity stress of species differing in their strategy of Na(+) allocation at organ level. Phillyrea latifolia and Pistacia lentiscus, which have been reported to greatly differ for Na(+) uptake and transport rates to the leaves, were studied. Methods In plants exposed to 0 mM or 200 mM NaCl and supplied with 2.0 mM or 8.0 mM Ca(2+), under 100 % solar irradiance, measurements were conducted of (a) gas exchange, PSII photochemistry and plant growth; (b) water and ionic relations; (c) the activity of superoxide dismutase and the lipid peroxidation; and (d) the concentration of individual polyphenols. Gas exchange and plant growth were also estimated during a period of relief from salinity stress. Key Results The performance of Pistacia lentiscus decreased to a significantly smaller degree than that of Phillyrea latifolia because of high salinity. Ameliorative effects of high-Ca(2+) supply were more evident in Phillyrea latifolia than in Pistacia lentiscus. High-Ca(2+) reduced steeply the Na(+) transport to the leaves in salt-treated Phillyrea latifolia, and allowed a faster recovery of gas exchange and growth rates as compared with low-Ca(2+) plants, during the period of relief from salinity. Salt-induced biochemical adjustments, mostly devoted to counter salt-induced oxidative damage, were greater in Phillyrea latifolia than in Pistacia lentiscus. An increased Ca(2+) : Na(+) ratio may be of greater benefit for Phillyrea latifolia than for Pistacia lentiscus, as in the former, adaptive mechanisms to high root-zone salinity are primarily devoted to restrict the accumulation of potentially toxic ions in sensitive shoot organs.

  10. Live above- and belowground biomass of a Mozambican evergreen forest: a comparison of estimates based on regression equations and biomass expansion factors

    Directory of Open Access Journals (Sweden)

    Tarquinio Mateus Magalhães

    2015-10-01

    Full Text Available Background Biomass regression equations are claimed to yield the most accurate biomass estimates than biomass expansion factors (BEFs. Yet, national and regional biomass estimates are generally calculated based on BEFs, especially when using national forest inventory data. Comparison of regression equations based and BEF-based biomass estimates are scarce. Thus, this study was intended to compare these two commonly used methods for estimating tree and forest biomass with regard to errors and biases. Methods The data were collected in 2012 and 2014. In 2012, a two-phase sampling design was used to fit tree component biomass regression models and determine tree BEFs. In 2014, additional trees were felled outside sampling plots to estimate the biases associated with regression equation based and BEF-based biomass estimates; those estimates were then compared in terms of the following sources of error: plot selection and variability, biomass model, model parameter estimates, and residual variability around model prediction. Results The regression equation based below-, aboveground and whole tree biomass stocks were, approximately, 7.7, 8.5 and 8.3 % larger than the BEF-based ones. For the whole tree biomass stock, the percentage of the total error attributed to first phase (random plot selection and variability was 90 and 88 % for regression- and BEF-based estimates, respectively, being the remaining attributed to biomass models (regression and BEF models, respectively. The percent bias of regression equation based and BEF-based biomass estimates for the whole tree biomass stock were −2.7 and 5.4 %, respectively. The errors due to model parameter estimates, those due to residual variability around model prediction, and the percentage of the total error attributed to biomass model were larger for BEF models (than for regression models, except for stem and stem wood components. Conclusions The regression equation based biomass stocks were found to be slightly larger, associated with relatively smaller errors and least biased than the BEF-based ones. For stem and stem wood, the percentages of their total errors (as total variance attributed to BEF model were considerably smaller than those attributed to biomass regression equations.

  11. Ecological Importance of Small-Diameter Trees to the Structure, Diversity and Biomass of a Tropical Evergreen Forest at Rabi, Gabon.

    Science.gov (United States)

    Memiaghe, Hervé R; Lutz, James A; Korte, Lisa; Alonso, Alfonso; Kenfack, David

    2016-01-01

    Tropical forests have long been recognized for their biodiversity and ecosystem services. Despite their importance, tropical forests, and particularly those of central Africa, remain understudied. Until recently, most forest inventories in Central Africa have focused on trees ≥10 cm in diameter, even though several studies have shown that small-diameter tree population may be important to demographic rates and nutrient cycling. To determine the ecological importance of small-diameter trees in central African forests, we used data from a 25-ha permanent plot that we established in the rainforest of Gabon to study the diversity and dynamics of these forests. Within the plot, we censused 175,830 trees ≥1 cm dbh from 54 families, 192 genera, and 345 species. Average tree density was 7,026 trees/ha, basal area 31.64 m2/ha, and above-ground biomass 369.40 Mg/ha. Fabaceae, Ebenaceae and Euphorbiaceae were the most important families by basal area, density and above-ground biomass. Small-diameter trees (1 cm ≥ dbh tree population, 16.5% of basal area, and 4.8% of the above-ground biomass. They also had diversity 18% higher at family level, 34% higher at genus level, and 42% higher at species level than trees ≥10 cm dbh. Although the relative contribution of small-diameter trees to biomass was comparable to other forests globally, their contribution to forest density, and diversity was disproportionately higher. The high levels of diversity within small-diameter classes may give these forests high levels of structural resilience to anthropogenic/natural disturbance and a changing climate.

  12. Bird communities following high-severity fire: Response to single and repeat fires in a mixed-evergreen forest, Oregon, USA

    Science.gov (United States)

    Joseph B. Fontaine; Daniel C. Donato; W. Douglas Robinson; Beverly E. Law; J. Boone Kauffman

    2009-01-01

    Fire is a widespread natural disturbance agent in most conifer-dominated forests. In light of climate change and the effects of fire exclusion, single and repeated high-severity (stand-replacement) fires have become prominent land management issues. We studied bird communities using point counting in the Klamath-Siskiyou ecoregion of Oregon, USA at various points in...

  13. Modeling the impact of drought on canopy carbon and water fluxes for a subtropical evergreen coniferous plantation in southern China through parameter optimization using an ensemble Kalman filter

    Directory of Open Access Journals (Sweden)

    W. Ju

    2010-03-01

    Full Text Available Soil and atmospheric water deficits have significant influences on CO2 and energy exchanges between the atmosphere and terrestrial ecosystems. Model parameterization significantly affects the ability of a model to simulate carbon, water, and energy fluxes. In this study, an ensemble Kalman filter (EnKF and observations of gross primary productivity (GPP and latent heat (LE fluxes were used to optimize model parameters significantly affecting the calculation of these fluxes for a subtropical coniferous plantation in southeastern China. The optimized parameters include the maximum carboxylation rate (Vcmax, the slope in the modified Ball-Berry model (M and the coefficient determining the sensitivity of stomatal conductance to atmospheric water vapor deficit (D0. Optimized Vcmax and M showed larger variations than D0. Seasonal variations of Vcmax and M were more pronounced than the variations between the two years. Vcmax and M were associated with soil water content (SWC. During dry periods, SWC at the 20 cm depth explained 61% and 64% of variations of Vcmax and M, respectively. EnKF parameter optimization improved the simulations of GPP, LE and SH, mainly during dry periods. After parameter optimization using EnKF, the variations of GPP, LE and SH explained by the model increased by 1% to 4% at half-hourly steps and by 3% to 5% at daily time steps. Further efforts are needed to differentiate the real causes of parameter variations and improve the ability of models to describe the change of stomatal conductance with net photosynthesis rate and the sensitivity of photosynthesis capacity to soil water stress under different environmental conditions.

  14. On the difference in the net ecosystem exchange of CO2 between deciduous and evergreen forests in the southeastern United States

    Science.gov (United States)

    Kimberly A. Novick; A. Christopher Oishi; Eric J. Ward; Mario B.S. Siqueira; Jehn-Yih Juang; Paul C. Stoy

    2015-01-01

    The southeastern United States is experiencing a rapid regional increase in the ratio of pine to deciduous forest ecosystems at the same time it is experiencing changes in climate. This study is focused on exploring how these shifts will affect the carbon sink capacity of southeastern US forests, which we show here are among the strongest carbon sinks in the...

  15. Temperature Sensitivity and Basal Rate of Soil Respiration and Their Determinants in Temperate Forests of North China: e81793

    National Research Council Canada - National Science Library

    Zhiyong Zhou; Chao Guo; He Meng

    2013-01-01

    .... R10 and Q10 were calculated using an exponential function with measured soil respiration and soil temperature for 11 mixed conifer-broadleaved forest stands and nine broadleaved forest stands at a catchment scale...

  16. Temperature sensitivity and basal rate of soil respiration and their determinants in temperate forests of North China

    National Research Council Canada - National Science Library

    Zhou, Zhiyong; Guo, Chao; Meng, He

    2013-01-01

    .... R10 and Q10 were calculated using an exponential function with measured soil respiration and soil temperature for 11 mixed conifer-broadleaved forest stands and nine broadleaved forest stands at a catchment scale...

  17. How the environment, canopy structure and canopy physiological functioning influence carbon, water and energy fluxes of a temperate broad-leaved deciduous forest -- an assessment with the biophysical model CANOAK

    Energy Technology Data Exchange (ETDEWEB)

    Baldocchi, D. D.; Gu, L. [Univ. of California-Berkeley, Dept. of Environmental Science, Berkeley, CA (United States); Wilson, K. B. [NOAA. Atmospheric Turbulence and Diffusion Divison, Oak Ridge, TN (United States)

    2002-11-01

    The interaction of the environment, canopy structure and its physiological functioning in controlling and driving the exchange of carbon dioxide and water vapour between a temperate forest and the atmosphere are described. The modulation of carbon dioxide and water vapour by temporal and spatial variations in canopy structure and physiological functioning is reviewed. This review is followed by quantification of the effects of leaf dimension and thickness, vertical variations in leaf area and photosynthetic capacity, leaf clumping, leaf inclination angle stomatal conductance and weather on the annual sums of carbon dioxide and water vapour and sensible heat exchange, using the biophysical model CANOAK. The paper also attempts to estimate the amount of detail required in a model to reliably predict fluxes of carbon dioxide and water vapour. A closer coupling between detailed biophysical models like CANOAK, with modules that compute the dynamics of canopy structure is envisaged. 105 refs., 10 tabs., 3 figs.

  18. Relationship between the decomposition process of coarse woody debris and fungal community structure as detected by high-throughput sequencing in a deciduous broad-leaved forest in Japan.

    Science.gov (United States)

    Yamashita, Satoshi; Masuya, Hayato; Abe, Shin; Masaki, Takashi; Okabe, Kimiko

    2015-01-01

    We examined the relationship between the community structure of wood-decaying fungi, detected by high-throughput sequencing, and the decomposition rate using 13 years of data from a forest dynamics plot. For molecular analysis and wood density measurements, drill dust samples were collected from logs and stumps of Fagus and Quercus in the plot. Regression using a negative exponential model between wood density and time since death revealed that the decomposition rate of Fagus was greater than that of Quercus. The residual between the expected value obtained from the regression curve and the observed wood density was used as a decomposition rate index. Principal component analysis showed that the fungal community compositions of both Fagus and Quercus changed with time since death. Principal component analysis axis scores were used as an index of fungal community composition. A structural equation model for each wood genus was used to assess the effect of fungal community structure traits on the decomposition rate and how the fungal community structure was determined by the traits of coarse woody debris. Results of the structural equation model suggested that the decomposition rate of Fagus was affected by two fungal community composition components: one that was affected by time since death and another that was not affected by the traits of coarse woody debris. In contrast, the decomposition rate of Quercus was not affected by coarse woody debris traits or fungal community structure. These findings suggest that, in the case of Fagus coarse woody debris, the fungal community structure is related to the decomposition process of its host substrate. Because fungal community structure is affected partly by the decay stage and wood density of its substrate, these factors influence each other. Further research on interactive effects is needed to improve our understanding of the relationship between fungal community structure and the woody debris decomposition process.

  19. Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

    Directory of Open Access Journals (Sweden)

    M. Zhang

    2010-02-01

    Full Text Available Clouds can significantly affect carbon exchange process between forest ecosystems and the atmosphere by influencing the quantity and quality of solar radiation received by ecosystem's surface and other environmental factors. In this study, we analyzed the effects of cloudiness on net ecosystem exchange of carbon dioxide (NEE in a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS and a subtropical evergreen broad-leaved forest at Dinghushan (DHS, based on the flux data obtained during June–August from 2003 to 2006. The results showed that the response of NEE of forest ecosystems to photosynthetically active radiation (PAR differed under clear skies and cloudy skies. Compared with clear skies, the light-saturated maximum photosynthetic rate (Pec,max at CBS under cloudy skies during mid-growing season (from June to August increased by 34%, 25%, 4% and 11% in 2003, 2004, 2005 and 2006, respectively. In contrast, Pec,max of the forest ecosystem at DHS was higher under clear skies than under cloudy skies from 2004 to 2006. When the clearness index (kt ranged between 0.4 and 0.6, the NEE reached its maximum at both CBS and DHS. However, the NEE decreased more dramatically at CBS than at DHS when kt exceeded 0.6. The results indicate that cloudy sky conditions are beneficial to net carbon uptake in the temperate forest ecosystem and the subtropical forest ecosystem. Under clear skies, vapor pressure deficit (VPD and air temperature increased due to strong light. These environmental conditions led to greater decrease in gross ecosystem photosynthesis (GEP and greater increase in ecosystem respiration (Re at CBS than at DHS. As a result, clear sky conditions caused more reduction of NEE in the temperate forest ecosystem than in the subtropical forest ecosystem. The response of NEE of different forest ecosystems to the changes in

  20. Net ecosystem carbon exchange of a dry temperate eucalypt forest

    Science.gov (United States)

    Hinko-Najera, Nina; Isaac, Peter; Beringer, Jason; van Gorsel, Eva; Ewenz, Cacilia; McHugh, Ian; Exbrayat, Jean-François; Livesley, Stephen J.; Arndt, Stefan K.

    2017-08-01

    Forest ecosystems play a crucial role in the global carbon cycle by sequestering a considerable fraction of anthropogenic CO2, thereby contributing to climate change mitigation. However, there is a gap in our understanding about the carbon dynamics of eucalypt (broadleaf evergreen) forests in temperate climates, which might differ from temperate evergreen coniferous or deciduous broadleaved forests given their fundamental differences in physiology, phenology and growth dynamics. To address this gap we undertook a 3-year study (2010-2012) of eddy covariance measurements in a dry temperate eucalypt forest in southeastern Australia. We determined the annual net carbon balance and investigated the temporal (seasonal and inter-annual) variability in and environmental controls of net ecosystem carbon exchange (NEE), gross primary productivity (GPP) and ecosystem respiration (ER). The forest was a large and constant carbon sink throughout the study period, even in winter, with an overall mean NEE of -1234 ± 109 (SE) g C m-2 yr-1. Estimated annual ER was similar for 2010 and 2011 but decreased in 2012 ranging from 1603 to 1346 g C m-2 yr-1, whereas GPP showed no significant inter-annual variability, with a mean annual estimate of 2728 ± 39 g C m-2 yr-1. All ecosystem carbon fluxes had a pronounced seasonality, with GPP being greatest during spring and summer and ER being highest during summer, whereas peaks in NEE occurred in early spring and again in summer. High NEE in spring was likely caused by a delayed increase in ER due to low temperatures. A strong seasonal pattern in environmental controls of daytime and night-time NEE was revealed. Daytime NEE was equally explained by incoming solar radiation and air temperature, whereas air temperature was the main environmental driver of night-time NEE. The forest experienced unusual above-average annual rainfall during the first 2 years of this 3-year period so that soil water content remained relatively high and the forest

  1. Evaluating the performance of land surface model ORCHIDEE-CAN v1.0 on water and energy flux estimation with a single- and multi-layer energy budget scheme

    Science.gov (United States)

    Chen, Yiying; Ryder, James; Bastrikov, Vladislav; McGrath, Matthew J.; Naudts, Kim; Otto, Juliane; Ottlé, Catherine; Peylin, Philippe; Polcher, Jan; Valade, Aude; Black, Andrew; Elbers, Jan A.; Moors, Eddy; Foken, Thomas; van Gorsel, Eva; Haverd, Vanessa; Heinesch, Bernard; Tiedemann, Frank; Knohl, Alexander; Launiainen, Samuli; Loustau, Denis; Ogée, Jérôme; Vessala, Timo; Luyssaert, Sebastiaan

    2016-09-01

    Canopy structure is one of the most important vegetation characteristics for land-atmosphere interactions, as it determines the energy and scalar exchanges between the land surface and the overlying air mass. In this study we evaluated the performance of a newly developed multi-layer energy budget in the ORCHIDEE-CAN v1.0 land surface model (Organising Carbon and Hydrology In Dynamic Ecosystems - CANopy), which simulates canopy structure and can be coupled to an atmospheric model using an implicit coupling procedure. We aim to provide a set of acceptable parameter values for a range of forest types. Top-canopy and sub-canopy flux observations from eight sites were collected in order to conduct this evaluation. The sites crossed climate zones from temperate to boreal and the vegetation types included deciduous, evergreen broad-leaved and evergreen needle-leaved forest with a maximum leaf area index (LAI; all-sided) ranging from 3.5 to 7.0. The parametrization approach proposed in this study was based on three selected physical processes - namely the diffusion, advection, and turbulent mixing within the canopy. Short-term sub-canopy observations and long-term surface fluxes were used to calibrate the parameters in the sub-canopy radiation, turbulence, and resistance modules with an automatic tuning process. The multi-layer model was found to capture the dynamics of sub-canopy turbulence, temperature, and energy fluxes. The performance of the new multi-layer model was further compared against the existing single-layer model. Although the multi-layer model simulation results showed few or no improvements to both the nighttime energy balance and energy partitioning during winter compared with a single-layer model simulation, the increased model complexity does provide a more detailed description of the canopy micrometeorology of various forest types. The multi-layer model links to potential future environmental and ecological studies such as the assessment of in

  2. Growth synchrony between leaves and stems during twig development differs among plant functional types of subtropical rainforest woody species.

    Science.gov (United States)

    Meng, Fengqun; Zhang, Guangfu; Li, Xincheng; Niklas, Karl J; Sun, Shucun

    2015-06-01

    During the development of woody twigs, the growth in leaf may or may not be proportional to the growth in stem. The presence or absence of a synchronicity between these two phenologies may reflect differences in life history adaptive strategies concerning carbon gain. We hypothesized that sun-adapted species are more likely to be less synchronous between growths in total leaf area (TLA) and stem length compared with shade-adapted species, with a bias in growth in stem length, and that shade-adapted species are more likely to be more synchronous between increases in individual leaf area (ILA) (leaf size) and leaf number (LN) during twig development compared with sun-adapted species, giving priority to growth of leaf size. We tested these two hypotheses by recording the phenologies of leaf emergence, leaf expansion and stem elongation during twig development for 19 evergreen woody species (including five shade-adapted understory species, six sun-adapted understory species and eight sun-adapted canopy species) in a subtropical evergreen broad-leaved forest in eastern China. We constructed indices to characterize the synchronicity between TLA and stem length (αLS) and between leaf size and leaf number (αSN) and we derived the α values from logistic functions taking the general form of A = A(max)/[1 + exp(β - αB)] (where A is the TLA or average ILA, B is the corresponding stem length or LN at a specific time, and A(max) is the maximum TLA or the maximum ILA of a twig; the higher the numerical value of α, the less synchronous the corresponding phenologies). Consistent with our hypotheses, sun-adapted species were higher both in α(LS) and α(SN), showing less synchronous patterns in the growths of TLA vs stem length and leaf size vs LN during twig development. Moreover, α(LS) and α(SN) were significantly positively correlated with relative growth rates of LN and leaf size across species, as indicated by both analyses of ordinary regression and

  3. Net ecosystem carbon exchange of a dry temperate eucalypt forest

    Directory of Open Access Journals (Sweden)

    N. Hinko-Najera

    2017-08-01

    Full Text Available Forest ecosystems play a crucial role in the global carbon cycle by sequestering a considerable fraction of anthropogenic CO2, thereby contributing to climate change mitigation. However, there is a gap in our understanding about the carbon dynamics of eucalypt (broadleaf evergreen forests in temperate climates, which might differ from temperate evergreen coniferous or deciduous broadleaved forests given their fundamental differences in physiology, phenology and growth dynamics. To address this gap we undertook a 3-year study (2010–2012 of eddy covariance measurements in a dry temperate eucalypt forest in southeastern Australia. We determined the annual net carbon balance and investigated the temporal (seasonal and inter-annual variability in and environmental controls of net ecosystem carbon exchange (NEE, gross primary productivity (GPP and ecosystem respiration (ER. The forest was a large and constant carbon sink throughout the study period, even in winter, with an overall mean NEE of −1234 ± 109 (SE g C m−2 yr−1. Estimated annual ER was similar for 2010 and 2011 but decreased in 2012 ranging from 1603 to 1346 g C m−2 yr−1, whereas GPP showed no significant inter-annual variability, with a mean annual estimate of 2728 ± 39 g C m−2 yr−1. All ecosystem carbon fluxes had a pronounced seasonality, with GPP being greatest during spring and summer and ER being highest during summer, whereas peaks in NEE occurred in early spring and again in summer. High NEE in spring was likely caused by a delayed increase in ER due to low temperatures. A strong seasonal pattern in environmental controls of daytime and night-time NEE was revealed. Daytime NEE was equally explained by incoming solar radiation and air temperature, whereas air temperature was the main environmental driver of night-time NEE. The forest experienced unusual above-average annual rainfall during the first 2 years of this 3-year period so

  4. Potential and limitations of using digital repeat photography to track structural and physiological phenology in Mediterranean tree-grass ecosystems

    Science.gov (United States)

    Luo, Yunpeng; EI-Madany, Tarek; Filippa, Gianluca; Carrara, Arnaud; Cremonese, Edoardo; Galvagno, Marta; Hammer, Tiana; Pérez-Priego, Oscar; Reichstein, Markus; Martín Isabel, Pilar; González Cascón, Rosario; Migliavacca, Mirco

    2017-04-01

    Tree-Grass ecosystems are global widely distributed (16-35% of the land surface). However, its phenology (especially in water-limited areas) has not yet been well characterized and modeled. By using commercial digital cameras, continuous and relatively vast phenology data becomes available, which provides a good opportunity to monitor and develop a robust method used to extract the important phenological events (phenophases). Here we aimed to assess the usability of digital repeat photography for three Tree-Grass Mediterranean ecosystems over two different growing seasons (Majadas del Tietar, Spain) to extract critical phenophases for grass and evergreen broadleaved trees (autumn regreening of grass- Start of growing season; resprouting of tree leaves; senescence of grass - End of growing season), assess their uncertainty, and to correlate them with physiological phenology (i.e. phenology of ecosystem scale fluxes such as Gross Primary Productivity, GPP). We extracted green chromatic coordinates (GCC) and camera based normalized difference vegetation index (Camera-NDVI) from an infrared enabled digital camera using the "Phenopix" R package. Then we developed a novel method to retrieve important phenophases from GCC and Camera-NDVI from various region of interests (ROIs) of the imagery (tree areas, grass, and both - ecosystem) as well as from GPP, which was derived from Eddy Covariance tower in the same experimental site. The results show that, at ecosystem level, phenophases derived from GCC and Camera-NDVI are strongly correlated (R2 = 0.979). Remarkably, we observed that at the end of growing season phenophases derived from GCC were systematically advanced (ca. 8 days) than phenophase from Camera-NDVI. By using the radiative transfer model Soil Canopy Observation Photochemistry and Energy (SCOPE) we demonstrated that this delay is related to the different sensitivity of GCC and NDVI to the fraction of green/dry grass in the canopy, resulting in a systematic

  5. Challenges to Sierra Nevada forests and their local communities: An observational and modeling perspective

    Science.gov (United States)

    Schmidt, Cynthia L.

    management, not the three identified land-use tools. San Diego County, the county that has experienced the most devastating fires, had the highest percentage of residential developments with both clustering and buffering. The third chapter focuses on future forest conditions. I used a Dynamic Global Vegetation Model (DGVM) to assess future vegetation dynamics and productivity under changing climate and atmospheric CO2 concentrations in the Sierra Nevada. Model results suggest that Temperate Broadleaved Evergreen Plant Functional Types (PFTs) will move upslope and eastward, replacing Temperate Needleleaved PFTs. Boreal Needleleaved Evergreen PFTs, found primarily at higher elevations, will decline dramatically as temperatures continue to increase. Gross Primary Productivity (GPP) will increase as atmospheric CO2 concentration increases, due primarily to the increase in the more productive broadleaved PFTs. Forest ecosystems play an important role in maintaining climate stability at the regional and global scales as a vital carbon sink, so understanding the role of disturbance and climate change will be vital to both scientists and policy makers in the future.

  6. Spatial and seasonal variation in amino compounds in the xylem sap of a mistletoe (Viscum album) and its hosts (Populus spp. and Abies alba).

    Science.gov (United States)

    Escher, Peter; Eiblmeier, Monika; Hetzger, Ilka; Rennenberg, Heinz

    2004-06-01

    In a field study, the composition and concentrations of amino compounds in the xylem sap of the mistletoe, Viscum album L., and in the xylem sap of two host species, an evergreen conifer (Abies alba Mill.) and a deciduous broad-leaved tree (Populus x euramericana), were analyzed. The xylem sap of both hosts and mistletoe contained large, but similar amounts of total organic nitrogen in low molecular weight amino compounds (TONLW). Nevertheless, individual amino compounds accumulated in the xylem sap of mistletoe relative to the host xylem sap, indicating selective uptake. In the xylem sap of Populus, major amino compounds (asparagine (Asn) and glutamine (Gln)) and the bulk parameters, TONLW and proteinogenic amino acids, showed significant seasonal variation. In Abies and in mistletoe on either host, variation of amino compounds in xylem sap was largely explained by inter-annual differences, not by seasonal variation. In both hosts, TONLW in the xylem sap was dominated by Gln. There was a steady decrease in relative abundance of Gln from the host xylem sap to the mistletoe xylem sap and to the stems and leaves of mistletoe. Simultaneously, the abundance of arginine (Arg) increased. Arginine was the predominant amino compound in the stems and leaves of mistletoe, occurring at concentrations previously observed only in leaves of trees exposed to excess nitrogen. We conclude that Gln (2 mol N mol(-1)) delivered by the host xylem sap is converted, in mistletoe, to Arg (4 mol N mol(-1)) and that the organic carbon liberated from Gln contributes significantly to the parasite's heterotrophic carbon gain. Statistical analyses of the data support this conclusion. Accumulation of Arg in mistletoe is an indication of excess N supply as a result of the uptake of amino compounds from the host xylem sap and a lack of phloem uploading.

  7. Dioecious plants are more precocious than cosexual plants: A comparative study of relative sizes at the onset of sexual reproduction in woody species.

    Science.gov (United States)

    Ohya, Itsuki; Nanami, Satoshi; Itoh, Akira

    2017-08-01

    The reproductive capacities of dioecious plant species may be limited by severe pollen limitation and narrow seed shadows for the two reasons. First, they are unable to self-pollinate, and seed production occurs only with pollinator movement from males to females. Second, only 50% of the individuals in populations contribute to seed production. Despite these handicaps, dioecious plants maintain their populations in plant communities with cooccurring cosexual plants, and no substantial difference in population growth rates has been found between dioecious and cosexual plants. Hence, dioecious plants are thought to mitigate these disadvantages by adopting ecological traits, such as insect pollination, animal-dispersed fleshy fruits, and precocious flowering. We studied the relationship between flowering and plant size in 30 woody species with different sex expressions, leaf habits, fruit types, and maximum plant sizes. The study site was located in an evergreen broad-leaved forest on the island of Honshu, Japan. A phylogenetic linear regression model showed that dioecious species tended to mature at smaller sizes than did cosexual taxa. At the population level, given equal plant densities and reproductive efforts, the precocity of dioecious plants could serve as one of the factors that mitigate the limitations of pollen and seed-shadow handicaps by increasing the density of reproductive individuals in the population. At the individual level, smaller size of onset of flowering may play a role in enhancing reproductive success over a lifetime by increasing reproductive opportunities. We discussed the possible effect of the relationship between precocity and some ecological traits of dioecious plants, such as small flowers pollinated by unspecialized insects, fleshy fruit dispersed by animals, and their preferential occurrence in the tropics and in island habitats. The universality of precocity among dioecious plants should be investigated in diverse plant communities

  8. Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994)

    Energy Technology Data Exchange (ETDEWEB)

    Raich, J.W.

    2003-09-15

    We used a climate-driven regression model to develop spatially resolved estimates of soil-CO{sub 2} emissions from the terrestrial land surface for each month from January 1980 to December 1994, to evaluate the effects of interannual variations in climate on global soil-to-atmosphere CO{sub 2} fluxes. The mean annual global soil-CO{sub 2} flux over this 15-y period was estimated to be 80.4 (range 79.3-81.8) Pg C. Monthly variations in global soil-CO{sub 2} emissions followed closely the mean temperature cycle of the Northern Hemisphere. Globally, soil-CO{sub 2} emissions reached their minima in February and peaked in July and August. Tropical and subtropical evergreen broad-leaved forests contributed more soil-derived CO{sub 2} to the atmosphere than did any other vegetation type ({approx}30% of the total) and exhibited a biannual cycle in their emissions. Soil-CO{sub 2} emissions in other biomes exhibited a single annual cycle that paralleled the seasonal temperature cycle. Interannual variability in estimated global soil-CO{sub 2} production is substantially less than is variability in net carbon uptake by plants (i.e., net primary productivity). Thus, soils appear to buffer atmospheric CO{sub 2} concentrations against far more dramatic seasonal and interannual differences in plant growth. Within seasonally dry biomes (savannas, bushlands, and deserts), interannual variability in soil-CO{sub 2} emissions correlated significantly with interannual differences in precipitation. At the global scale, however, annual soil-CO{sub 2} fluxes correlated with mean annual temperature, with a slope of 3.3 PgCY{sup -1} per degree Celsius. Although the distribution of precipitation influences seasonal and spatial patterns of soil-CO{sub 2} emissions, global warming is likely to stimulate CO{sub 2} emissions from soils.

  9. Soil respiration and organic carbon dynamics with grassland conversions to woodlands in temperate china.

    Directory of Open Access Journals (Sweden)

    Wei Wang

    Full Text Available Soils are the largest terrestrial carbon store and soil respiration is the second-largest flux in ecosystem carbon cycling. Across China's temperate region, climatic changes and human activities have frequently caused the transformation of grasslands to woodlands. However, the effect of this transition on soil respiration and soil organic carbon (SOC dynamics remains uncertain in this area. In this study, we measured in situ soil respiration and SOC storage over a two-year period (Jan. 2007-Dec. 2008 from five characteristic vegetation types in a forest-steppe ecotone of temperate China, including grassland (GR, shrubland (SH, as well as in evergreen coniferous (EC, deciduous coniferous (DC and deciduous broadleaved forest (DB, to evaluate the changes of soil respiration and SOC storage with grassland conversions to diverse types of woodlands. Annual soil respiration increased by 3%, 6%, 14%, and 22% after the conversion from GR to EC, SH, DC, and DB, respectively. The variation in soil respiration among different vegetation types could be well explained by SOC and soil total nitrogen content. Despite higher soil respiration in woodlands, SOC storage and residence time increased in the upper 20 cm of soil. Our results suggest that the differences in soil environmental conditions, especially soil substrate availability, influenced the level of annual soil respiration produced by different vegetation types. Moreover, shifts from grassland to woody plant dominance resulted in increased SOC storage. Given the widespread increase in woody plant abundance caused by climate change and large-scale afforestation programs, the soils are expected to accumulate and store increased amounts of organic carbon in temperate areas of China.

  10. Holocene fire activity and vegetation response in South-Eastern Iberia

    Science.gov (United States)

    Gil-Romera, Graciela; Carrión, José S.; Pausas, Juli G.; Sevilla-Callejo, Miguel; Lamb, Henry F.; Fernández, Santiago; Burjachs, Francesc

    2010-05-01

    Since fire has been recognized as an essential disturbance in Mediterranean landscapes, the study of long-term fire ecology has developed rapidly. We have reconstructed a sequence of vegetation dynamics and fire changes across south-eastern Iberia by coupling records of climate, fire, vegetation and human activities. We calculated fire activity anomalies (FAAs) in relation to 3 ka cal BP for 10-8 ka cal BP, 6 ka cal BP, 4 ka cal BP and the present. For most of the Early to the Mid-Holocene uneven, but low fire events were the main vegetation driver at high altitudes where broadleaved and coniferous trees presented a highly dynamic post-fire response. At mid-altitudes in the mainland Segura Mountains, fire activity remained relatively stable, at similar levels to recent times. We hypothesize that coastal areas, both mountains and lowlands, were more fire-prone landscapes as biomass was more likely to have accumulated than in the inland regions, triggering regular fire events. The wet and warm phase towards the Mid-Holocene (between ca 8 and 6 ka cal BP) affected the whole region and promoted the spread of mesophytic forest co-existing with Pinus, as FAAs appear strongly negative at 6 ka cal BP, with a less important role of fire. Mid and Late Holocene landscapes were shaped by an increasing aridity trend and the rise of human occupation, especially in the coastal mountains where forest disappeared from ca 2 ka cal BP. Mediterranean-type vegetation (evergreen oaks and Pinus pinaster- halepensis types) showed the fastest post-fire vegetation dynamics over time.

  11. De Novo Sequencing and Comparative Analysis of Schima superba Seedlings to Explore the Response to Drought Stress.

    Directory of Open Access Journals (Sweden)

    Bao-Cai Han

    Full Text Available Schima superba is an important dominant species in subtropical evergreen broadleaved forests of China, and plays a vital role in community structure and dynamics. However, the survival rate of its seedlings in the field is low, and water shortage could be a factor that limits its regeneration. In order to better understand the response of its seedlings to drought stress on a functional genomics scale, RNA-seq technology was utilized in this study to perform a large-scale transcriptome sequencing of the S. superba seedlings under drought stress. More than 320 million clean reads were generated and 72218 unique transcripts were obtained through de novo assembly. These unigenes were further annotated by blasting with different public databases and a total of 53300 unique transcripts were annotated. A total of 31586 simple sequence repeat (SSR loci were presented. Through gene expression profiling analysis between drought treatment and control, 11038 genes were found to be significantly enriched in drought-stressed seedlings. Based on these differentially expressed genes (DEGs, Gene Ontology (GO terms enrichment and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG enrichment analysis indicated that drought stress caused a number of changes in the types of sugars, enzymes, secondary mechanisms, and light responses, and induced some potential physical protection mechanisms. In addition, the expression patterns of 18 transcripts induced by drought, as determined by quantitative real-time PCR, were consistent with their transcript abundance changes, as identified by RNA-seq. This transcriptome study provides a rapid method for understanding the response of S. superba seedlings to drought stress and provides a number of gene sequences available for further functional genomics studies.

  12. A comparison of fungal endophytic community diversity in tree leaves of rural and urban temperate forests of Kanto district, eastern Japan.

    Science.gov (United States)

    Matsumura, Emi; Fukuda, Kenji

    2013-03-01

    To clarify the effects of forest fragmentation and a change in tree species composition following urbanization on endophytic fungal communities, we isolated fungal endophytes from the foliage of nine tree species in suburban (Kashiwa City, Chiba) and rural (Mt. Wagakuni, Ibaraki; Mt. Takao, Tokyo) forests and compared the fungal communities between sites and host tree species. Host specificity was evaluated using the index of host specificity (Si), and the number of isolated species, total isolation frequency, and the diversity index were calculated. From just one to several host-specific species were recognized in all host tree species at all sites. The total isolation frequency of all fungal species on Quercus myrsinaefolia, Quercus serrata, and Chamaecyparis obtusa and the total isolation frequency of host-specific species on Q. myrsinaefolia, Q. serrata, and Eurya japonica were significantly lower in Kashiwa than in the rural forests. The similarity indices (nonmetric multidimensional scaling (NMS) and CMH) of endophytic communities among different tree species were higher in Kashiwa, as many tree species shared the same fungal species in the suburban forest. Endophytic fungi with a broad host range were grouped into four clusters suggesting their preference for conifer/broadleaves and evergreen/deciduous trees. Forest fragmentation and isolation by urbanization have been shown to cause the decline of host-specific fungal species and a decrease in β diversity of endophytic communities, i.e., endophytic communities associated with tree leaves in suburban forests were found to be depauperate. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  13. Leaf Caloric Value from Tropical to Cold-Temperate Forests: Latitudinal Patterns and Linkage to Productivity.

    Science.gov (United States)

    Song, Guangyan; Hou, Jihua; Li, Ying; Zhang, Jiahui; He, Nianpeng

    2016-01-01

    Leaf caloric value (LCV) reflects the capacity of a leaf to fix and accumulate solar energy through photosynthesis. We systematically investigated the LCV of 745 plant species in 9 forests, representing a range of tropical to cold-temperate forests along the 4700-km North-South Transect of Eastern China. The goals were to explore the latitudinal patterns of LCV at the levels of species, plant functional group, and community and to establish the relationship between LCV and gross primary productivity (GPP). Our results showed that LCV for all species ranged from 12.85 to 22.15 KJ g-1 with an average of 18.46 KJ g-1. Plant functional groups had a significant influence on LCV, with trees > shrubs > herbs, conifers > broadleaved trees, and evergreens > deciduous trees. The different values of LCV represented the long-term evolution and adaptation of plant species to different environments. Unexpectedly, no apparent latitudinal trends of LCV at community level were observed, although LCV at the species level clearly decreased with increasing latitude. Use efficiency of LCV (CUE, gC KJ-1), defined as the ratio of GPP to total LCV at the community level, varied quadratic with latitude and was lower in the middle latitudes. Climate (temperature and precipitation) may explain 52.9% of the variation in spatial patterns of CUE, which was positively correlated with aridity. Our findings are the first large-scale report of the latitudinal patterns of LCV in forests at the species, plant functional group, and community levels and provide new insights into the relationship between LCV and ecosystem functions in forest communities.

  14. Leaf Caloric Value from Tropical to Cold-Temperate Forests: Latitudinal Patterns and Linkage to Productivity.

    Directory of Open Access Journals (Sweden)

    Guangyan Song

    Full Text Available Leaf caloric value (LCV reflects the capacity of a leaf to fix and accumulate solar energy through photosynthesis. We systematically investigated the LCV of 745 plant species in 9 forests, representing a range of tropical to cold-temperate forests along the 4700-km North-South Transect of Eastern China. The goals were to explore the latitudinal patterns of LCV at the levels of species, plant functional group, and community and to establish the relationship between LCV and gross primary productivity (GPP. Our results showed that LCV for all species ranged from 12.85 to 22.15 KJ g-1 with an average of 18.46 KJ g-1. Plant functional groups had a significant influence on LCV, with trees > shrubs > herbs, conifers > broadleaved trees, and evergreens > deciduous trees. The different values of LCV represented the long-term evolution and adaptation of plant species to different environments. Unexpectedly, no apparent latitudinal trends of LCV at community level were observed, although LCV at the species level clearly decreased with increasing latitude. Use efficiency of LCV (CUE, gC KJ-1, defined as the ratio of GPP to total LCV at the community level, varied quadratic with latitude and was lower in the middle latitudes. Climate (temperature and precipitation may explain 52.9% of the variation in spatial patterns of CUE, which was positively correlated with aridity. Our findings are the first large-scale report of the latitudinal patterns of LCV in forests at the species, plant functional group, and community levels and provide new insights into the relationship between LCV and ecosystem functions in forest communities.

  15. Wild mushroom food custom associated with Japanese red pine forest in a small town in southwestern Japan

    OpenAIRE

    TANESAKA, Eiji

    2005-01-01

    [抄録] 西南日本に位置する小さな町, 奈良県平群町, において野生きのこ食習慣を調べた.常緑広葉樹が混生する落莫広葉樹林が二次林として優占し, 集落の周囲には竹林とアカマツ林が形成されている.ここでは, 200種以上のきのこ類が発生するが, 伝統的に9種のきのこしか採集・消費されてこなかった.これら9種のきのこはアカマツと共生する菌根菌に限られた.広葉樹林に発生する他のきのこ類は, たとえ商業的な栽培菌として知られた菌, あるいは特に東北日本で一般的に利用される菌であっても収穫されない.本研究は住民, アカマツ林, および菌根菌の緊密な関係を明らかにし, この関係は西南日本に典型的な野生きのこ食習慣を表現した. [Abstract] A wild mushroom food custom was investigated in the small town of Heguri, Nara Prefecture, southwestern Japan. Deciduous trees mixed with evergreen broadleaved tr...

  16. Rapidly growing tropical trees mobilize remarkable amounts of nitrogen, in ways that differ surprisingly among species.

    Science.gov (United States)

    Russell, Ann E; Raich, James W

    2012-06-26

    Fast-growing forests such as tropical secondary forests can accumulate large amounts of carbon (C), and thereby play an important role in the atmospheric CO(2) balance. Because nitrogen (N) cycling is inextricably linked with C cycling, the question becomes: Where does the N come from to match high rates of C accumulation? In unique experimental 16-y-old plantations established in abandoned pasture in lowland Costa Rica, we used a mass-balance approach to quantify N accumulation in vegetation, identify sources of N, and evaluate differences among tree species in N cycling. The replicated design contained four broad-leaved evergreen tree species growing under similar environmental conditions. Nitrogen uptake was rapid, reaching 409 (± 30) kg · ha(-1) · y(-1), double the rate reported from a Puerto Rican forest and greater than four times that observed at Hubbard Brook Forest (New Hampshire, USA). Nitrogen amassed in vegetation was 874 (± 176) kg · ha(-1), whereas net losses of soil N (0-100 cm) varied from 217 (±146) to 3,354 (± 915) kg · ha(-1) (P = 0.018) over 16 y. Soil C:N, δ(13)C values, and N budgets indicated that soil was the main source of biomass N. In Vochysia guatemalensis, however, N fixation contributed >60 kg · ha(-1) · y(-1). All species apparently promoted soil N turnover, such that the soil N mean residence time was 32-54 y, an order of magnitude lower than the global mean. High rates of N uptake were associated with substantial N losses in three of the species, in which an average of 1.6 g N was lost for every gram of N accumulated in biomass.

  17. [Impacts of Land Use Changes on Soil Light Fraction and Particulate Organic Carbon and Nitrogen in Jinyun Mountain].

    Science.gov (United States)

    Lei, Li-guo; Jiang, Chang-sheng; Hao, Qing-ju

    2015-07-01

    Four land types including the subtropical evergreen broad-leaved forest, sloping farmland, orchard and abandoned land were selected to collect soil samples from 0 to 60 cm depth at the same altitude of sunny slope in the Jinyun Mountain in this study. Soil light fraction organic carbon and nitrogen ( LFOC and LFON), and particulate organic carbon and nitrogen (POC and PON) were determined and the distribution ratios and C/N ratios were calculated. The results showed that the contents of LFOC and LFON decreased significantly by 71. 42% and 38. 46% after the forest was changed into sloping farmland (P 0. 05), while the contents of LFOC and LFON increased significantly by 3. 77 and 1. 38 times after the sloping farmland was changed into abandoned land (P organic carbon and nitrogen accumulation; on the contrary, sloping farmland was easy to lose soil labile carbon and nitrogen. The LFOC and LFON distribution ratios were significantly reduced by 31. 20% and 30. 08%, respectively after the forest was changed into the sloping farmland, and increased by 18. 74% and 20. 33% respectively after the forest was changed into the orchard. Nevertheless, the distribution ratios of LFOC and LFON were changed little by converting the forest into the sloping farmland and orchard. The distribution ratios of LFOC, LFON, POC and PON all increased significantly after the farmland was abandoned (P organic carbon and nitrogen was enhanced after forest reclamation, while reduced after the sloping farmland was abandoned. The ratios of carbon to nitrogen in soil organic matter, light fraction organic matter and particulate organic matter were in the order of abandoned land (12. 93) > forest (8. 53) > orchard (7. 52) > sloping farmland (4. 40), abandoned land (16. 32) > forest (14. 29) > orchard (11. 32) > sloping farmland (7. 60), abandoned land (23. 41) > sloping farmland (13. 85 ) > forest (10. 30) > orchard (9. 64), which indicated that the degree of organic nitrogen mineralization was

  18. Soil respiration and organic carbon dynamics with grassland conversions to woodlands in temperate china.

    Science.gov (United States)

    Wang, Wei; Zeng, Wenjing; Chen, Weile; Zeng, Hui; Fang, Jingyun

    2013-01-01

    Soils are the largest terrestrial carbon store and soil respiration is the second-largest flux in ecosystem carbon cycling. Across China's temperate region, climatic changes and human activities have frequently caused the transformation of grasslands to woodlands. However, the effect of this transition on soil respiration and soil organic carbon (SOC) dynamics remains uncertain in this area. In this study, we measured in situ soil respiration and SOC storage over a two-year period (Jan. 2007-Dec. 2008) from five characteristic vegetation types in a forest-steppe ecotone of temperate China, including grassland (GR), shrubland (SH), as well as in evergreen coniferous (EC), deciduous coniferous (DC) and deciduous broadleaved forest (DB), to evaluate the changes of soil respiration and SOC storage with grassland conversions to diverse types of woodlands. Annual soil respiration increased by 3%, 6%, 14%, and 22% after the conversion from GR to EC, SH, DC, and DB, respectively. The variation in soil respiration among different vegetation types could be well explained by SOC and soil total nitrogen content. Despite higher soil respiration in woodlands, SOC storage and residence time increased in the upper 20 cm of soil. Our results suggest that the differences in soil environmental conditions, especially soil substrate availability, influenced the level of annual soil respiration produced by different vegetation types. Moreover, shifts from grassland to woody plant dominance resulted in increased SOC storage. Given the widespread increase in woody plant abundance caused by climate change and large-scale afforestation programs, the soils are expected to accumulate and store increased amounts of organic carbon in temperate areas of China.

  19. Contribution to growth and increment analysis on the Italian CONECOFOR Level II Network

    Directory of Open Access Journals (Sweden)

    Emilio AMORINI

    2002-09-01

    Full Text Available The paper deals with the "Estimation of growth and yield" included in the National Programme on Intensive Monitoring of Forest Ecosystems CONECOFOR Aims of the paper are: i to outline the composition and design of Level II PMPs network, also examining the structural characteristics of forest stands; ii to describe the contents of mensurational surveys carried out in winter 1996/97 and 1999/00; iii to analyse the growth rates in progress at each PMP using selected descriptors. Stand origin (11 high forests and 13 stored coppices and transitory crops and the number of forest types tested are focused as the main discriminants of the PMPs network. This composition, together with irregular forestry practice, results in a number of consequences (prevailing age classes, tree densities and related stand structures, growth patterns which cause a high in-and-between variability of all growth parameters. For the purposes of this analysis, the network of the plots was divided into three main sets: broadleaved high forest (i.e. beech stands, 6 PMPs; coniferous forest (i.e. Norway spruce stands, 5 PMPs; coppice forest (i.e. deciduous and evergreen oaks, beech and hardbeam stands, 13 PMPs. The measurement of basic growth variables (dbh and tree height was used to describe the tree populations in each PMP; the calculation of basal area, mean and top dbh, mean and top height, provided the reference dataset at each inventory. The assessment of social class according to Kraft gave information on vertical stand structure and made it possible to analyse growth according to tree layers. Data comparison provided increments in the interval 1997-2000. The occurrence of natural mortality and ingrowth was also assessed to take into account their combined effect on tree population dynamics. No trend was found, due to limited data availability, but it was possible to have a detailed overview of the stand situation and growth rates in PMPs.

  20. Seasonal patterns of carbon allocation to respiratory pools in 60-yr-old deciduous (Fagus sylvatica) and evergreen (Picea abies) trees assessed via whole-tree stable carbon isotope labeling.

    Science.gov (United States)

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

    2011-07-01

    • The CO(2) efflux of adult trees is supplied by recent photosynthates and carbon (C) stores. The extent to which these C pools contribute to growth and maintenance respiration (R(G) and R(M), respectively) remains obscure. • Recent photosynthates of adult beech (Fagus sylvatica) and spruce (Picea abies) trees were labeled by exposing whole-tree canopies to (13) C-depleted CO(2). Label was applied three times during the year (in spring, early summer and late summer) and changes in the stable C isotope composition (δ(13) C) of trunk and coarse-root CO(2) efflux were quantified. • Seasonal patterns in C translocation rate (CTR) and fractional contribution of label to CO(2) efflux (F(Label-Max)) were found. CTR was fastest during early summer. In beech, F(Label-Max) was lowest in spring and peaked in trunks during late summer (0.6 ± 0.1, mean ± SE), whereas no trend was observed in coarse roots. No seasonal dynamics in F(Label-Max) were found in spruce. • During spring, the R(G) of beech trunks was largely supplied by C stores. Recent photosynthates supplied growth in early summer and refilled C stores in late summer. In spruce, CO(2) efflux was constantly supplied by a mixture of stored (c. 75%) and recent (c. 25%) C. The hypothesis that R(G) is exclusively supplied by recent photosynthates was rejected for both species. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  1. Phenolic profile within the fine-root branching orders of an evergreen species highlights a disconnect in root tissue quality predicted by elemental- and molecular-level carbon composition.

    Science.gov (United States)

    Wang, Jun-Jian; Tharayil, Nishanth; Chow, Alex T; Suseela, Vidya; Zeng, Hui

    2015-06-01

    Fine roots constitute a significant source of plant productivity and litter turnover across terrestrial ecosystems, but less is known about the quantitative and qualitative profile of phenolic compounds within the fine-root architecture, which could regulate the potential contribution of plant roots to the soil organic matter pool. To understand the linkage between traditional macro-elemental and morphological traits of roots and their molecular-level carbon chemistry, we analyzed seasonal variations in monomeric yields of the free, bound, and lignin phenols in fine roots (distal five orders) and leaves of Ardisia quinquegona. Fine roots contained two-fold higher concentrations of bound phenols and three-fold higher concentrations of lignin phenols than leaves. Within fine roots, the concentrations of free and bound phenols decreased with increasing root order, and seasonal variation in the phenolic profile was more evident in lower order than in higher order roots. The morphological and macro-elemental root traits were decoupled from the quantity, composition and tissue association of phenolic compounds, revealing the potential inability of these traditional parameters to capture the molecular identity of phenolic carbon within the fine-root architecture and between fine roots and leaves. Our results highlight the molecular-level heterogeneity in phenolic carbon composition within the fine-root architecture, and imply that traits that capture the molecular identity of the root construct might better predict the decomposition dynamics within fine-root orders. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  2. 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

    Deeper winter snow is hypothesized to favor shrub growth and may partly explain the shrub expansion observed in many parts of the arctic during the last decades, potentially triggering biophysical feedbacks including regional warming and permafrost thawing. We experimentally tested the effects...

  3. Comparison of Reflectance Measurements Acquired with a Contact Probe and an Integration Sphere: Implications for the Spectral Properties of Vegetation at a Leaf Level

    Czech Academy of Sciences Publication Activity Database

    Potúčková, M.; Červená, L.; Kupková, L.; Lhotáková, Z.; Lukeš, Petr; Hanuš, Jan; Novotný, Jan; Albrechtová, J.

    2016-01-01

    Roč. 16, č. 11 (2016), č. článku 1801. ISSN 1424-8220 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : broadleaved leaf * broadleaved plants * conifers * contact probe * integration sphere * needle * spectroradiometer * spectroscopy Subject RIV: EH - Ecology, Behaviour Impact factor: 2.677, year: 2016

  4. Investigation of the effective factors on rate of stemflow for tree ...

    African Journals Online (AJOL)

    The objective of this study was (i) to compare the amount of stemflow in deciduous broadleaved trees (with and without leaves) in accordance with different growth seasons and (ii) to compare the rate of stemflow in coniferous and broadleaved trees in according to the canopy cover area. Stemflow was measured on 20 ...

  5. 76 FR 53673 - Combined Notice of Filings #1

    Science.gov (United States)

    2011-08-29

    ... Company, Constellation Power Source Generation Inc., CER Generation II, LLC, Safe Harbor Water Power.... Applicants: Evergreen Wind Power III, LLC, Evergreen Wind Power V, LLC, Stetson Wind II, LLC. Description: First Wind Holdings, LLC submits Notification of Non- material Change in Status by Evergreen Wind Power...

  6. Satellite- and pollen-based quantitative woody cover reconstructions for northern Asia: Verification and application to late-Quaternary pollen data

    Science.gov (United States)

    Tarasov, Pavel; Williams, John W.; Andreev, Andrei; Nakagawa, Takeshi; Bezrukova, Elena; Herzschuh, Ulrike; Igarashi, Yaeko; Müller, Stefanie; Werner, Kirstin; Zheng, Zhuo

    2007-12-01

    Accurate reconstruction of late-Quaternary vegetation cover is necessary for better understanding of past vegetation dynamics, the role of vegetation feedbacks in glacial-interglacial climate variations, and for validating vegetation and climate models. In this paper over 1700 surface-pollen spectra from the former Soviet Union, Mongolia, northern China, and northern Japan together with data from the Advanced Very High Resolution Radiometer (AVHRR) were used to calibrate modern-analogue method for quantitatively reconstructing past woody cover from fossil pollen data. The AVHRR-based estimates of woody cover percentages within a 21 × 21 km window around pollen sampling sites were attributed to the respective modern pollen spectra. Reconstructions of modern woody cover using the pollen data and best-modern-analogues (BMA) method matched well to the original AVHRR-based estimates, for both total woody cover ( r2 = 0.77) and its fractions, including broad-leaved ( r2 = 0.66), needle-leaved ( r2 = 0.79), deciduous ( r2 = 0.60) and evergreen ( r2 = 0.76) woody cover. Discrepancies in the pollen-AVHRR cross-validation may be caused by long-distance transport of arboreal pollen, patchy forest distributions, underrepresentation of Larix and Populus in pollen records, and errors in the AVHRR classification. The generally strong correlations encourage application of the modern-analogue approach for reconstructing late-Quaternary variations in vegetation cover from northern Asian fossil pollen records. At the last glacial maximum (LGM: ˜ 21,000 cal yr BP), areas presently occupied by boreal forest were much more open, suggesting a reduction in total woody cover to below 20% at most modern forest sites. Pollen records from northern and central Siberia suggest a rather quick spread of tree and shrub vegetation after 15,000 cal yr BP, presumably in response to increased summer insolation. Woody cover histories are spatially variable in the modern forest-steppe, where tree

  7. [Effects of Different Land Uses on Soil Active Organic Carbon and Nitrogen Fractions in Jinyun Mountain].

    Science.gov (United States)

    Qi, Xin; Jiang, Chang-sheng; Hao, Qing-ju; Li, Jian-lin

    2015-10-01

    In this paper, we take Jinyun Mountain where located in Beibei district of Chongqing as the research object and explore the effect of different ways of land use on soil active organic carbon, nitrogen components by collecting the soil samples from 0 to 60 cm depth in subtropical evergreen broad-leaved forest (hereinafter referred to as the forest), abandoned land, orchard, farmland and measuring the content of MBC, MBN, DOC and DON. The research results show that the contents of soil MBC, MBN, DOC, DON are reduced with the increase of soil depth in four types of land using soils. Variance analysis of the single factor shows that four kinds of land uses have no significant difference in the contents of MBC, MBN and DON, but the DOC content of the abandoned land is significantly higher than that of other three kinds. It shows that the different ways of land use have no obvious effects on soil MBC, MBN and DON but the abandonment of slope cropland can significantly increase the content of soil DOC. There is no significant difference among the distribution ratio of MBN, DOC, DON in forest, abandoned land, orchard and farmland within the soil from 0 to 60 cm, but the distribution ratio of slope MBC is significantly higher than that of other three kinds. It means farmland soil organic carbon has a higher biological activity, this could due to the application of green manure, farmland manure and other organic fertilizers. Under different land utilizations, DOC/DON is the highest, MBC/MBN is the second, and SOC/TN is the lowest. It means the biological solidification of dissolved organic matter is the strongest, and the mineralization of soil organic matter is the most obvious. Under the four kinds of land uses, there are the lowest ratios in SOC/TN, MBC/MBN and DOC/DON in the farmland. And all the ratios are less than 20, which suggest that the mineralization of farmland soil organic matter is stronger and it's easy to cause the loss of soil carbon.

  8. [Effects of Land Use Type on Soil Microbial Biomass Carbon and Nitrogen in Water-Stable Aggregates in Jinyun Mountain].

    Science.gov (United States)

    Li, Zeng-quan; Jiang, Chang-sheng; Hao, Qing-ju

    2015-11-01

    In this study, four land use types including subtropical evergreen broad-leaved forest (abbreviation: forest), sloping farmland, orchard and abandoned land were selected to collect soil samples from 0 to 60 cm depth at the same altitude in Jinyun Mountain. Four sizes of large macroaggregates (> 2 mm), small macroaggregates (0.25-2 mm), microaggregates (0.053-0.25 mm) and silt + clay (land use types on MBC and MBN in soil aggregates. The results showed that the contents of MBC and MBN in all aggregates in the four land use types decreased with the increasing soil depth. Except large macroaggregetes, the contents of MBC and MBN in the other three soil aggregates decreased when the forest was reclamated into orchard and sloping farmland. MBC and MBN contents in large macroaggregates, small macroaggregates and microaggregates all increased when the sloping farmland was abandoned. The storages of organic carbon and nitrogen in soil depth of 0-60 cm in the four proportions were calculated by the equivalent soil mass method. The results revealed that MBC storages in the other three sizes except silt + clay were higher in the forest than those in orchard and sloping land. And MBC storages in the all aggregates were higher in the abandoned land than those in the sloping land. MBN storages in small macroaggregates and microaggregates were higher in the forest than those in orchard and sloping land. And MBN storages in the other three aggregates except silt + clay were higher in the abandoned land than those in the sloping land. Generally speaking, the storages of MBC in soil aggregates of forest and abandoned land were higher than in orchard and sloping land, MBN storage in soil aggregates of forest was nearly equal to the storage in orchard. However, the storages of MBN in soil aggregates of forest and abandoned land were higher than those in sloping land. The results showed that the reclamation of the forest resulted in the loss of MBC and MBN in soil aggregates of sloping

  9. Biomass Inventory Using Small Footprint Lidar: Preliminary Results in Two Maryland Counties

    Science.gov (United States)

    Suárez, J.; Nelson, R. F.; Pinto, N.; Rosette, J.; Dubayah, R.; Fatoyinbo, T. E.; Cook, B. D.

    2011-12-01

    The Carbon Monitoring System (CMS) project started in September 2010 with a mandate from the U.S. Congress to NASA (NASA, 2010). The primary goal of the project is the estimation of above-ground biomass stocks and carbon fluxes, the appraisal of error budgets and the delivery of cartographic products and other geo-referenced information for selected locations at a scale that is ecologically meaningful and relevant for forest management. The project is incrementally planning to marry carbon monitoring efforts firstly at both local and federal scale and then globally. As part of the local component of this effort, small footprint LiDAR data from archive have been analysed for two counties in Maryland. LiDAR metrics, such as the percentile distribution of heights and density deciles, were generated for each National Land Cover Database (NLCD) pixel at 30 m resolution. Field data for validation and training of models consisted of variable plot sizes with BAF 10, 20 and 30. Training of models was based on a previous stratification of woodland types into evergreen, broadleaves, mixed, wetlands and non-wooded areas. The biomass models were derived by means of empirical fits between ground-measured biomass and the LiDAR metrics generated for each stratum. The results showed coefficients of determination ranging above 0.70 for all the strata with the exception of mixed woodlands (0.48). The distribution of the residuals showed a bias for plots with largest biomass levels measured in the field, due to the unintended inclusion of boundary trees. The final results were converted into a 30m raster map showing the spatial distribution of biomass in Mg ha-1. Further research within the CMS initiative will concentrate on further validation and error analysis in addition to replicating this methodology in other monitoring areas in order to ensure this methodology is consistent and widely applicable. REFERENCE NASA, 2010. NASA Carbon Monitoring System Initiative. Available online at

  10. Palynology and the Ecology of the New Zealand Conifers

    Directory of Open Access Journals (Sweden)

    Matt S. McGlone

    2017-11-01

    Full Text Available The New Zealand conifers (20 species of trees and shrubs in the Araucariaceae, Podocarpaceae, and Cupressaceae are often regarded as ancient Gondwanan elements, but mostly originated much later. Often thought of as tall trees of humid, warm forests, they are present throughout in alpine shrublands, tree lines, bogs, swamps, and in dry, frost-prone regions. The tall conifers rarely form purely coniferous forest and mostly occur as an emergent stratum above evergreen angiosperm trees. During Maori settlement in the thirteenth century, fire-sensitive trees succumbed rapidly, most of the drier forests being lost. As these were also the more conifer-rich forests, ecological research has been skewed toward conifer dynamics of forests wetter and cooler than the pre-human norm. Conifers are well represented in the pollen record and we here we review their late Quaternary history in the light of what is known about their current ecology with the intention of countering this bias. During glacial episodes, all trees were scarce south of c. 40° S, and extensive conifer-dominant forest was confined to the northern third of the North Island. Drought- and cold-resistant Halocarpus bidwillii and Phyllocladus alpinus formed widespread scrub in the south. During the deglacial, beginning 18,000 years ago, tall conifers underwent explosive spread to dominate the forest biomass throughout. Conifer dominance lessened in favor of angiosperms in the wetter western lowland forests over the Holocene but the dryland eastern forests persisted largely unchanged until settlement. Mid to late Holocene climate change favored the more rapidly growing Nothofagaceae which replaced the previous conifer-angiosperm low forest or shrubland in tree line ecotones and montane areas. The key to this dynamic conifer history appears to be their bimodal ability to withstand stress, and dominate on poor soils and in cool, dry regions but, in wetter, warmer locations, to slowly grow thorough

  11. Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China

    Science.gov (United States)

    Tian, Di; Li, Peng; Fang, Wenjing; Xu, Jun; Luo, Yongkai; Yan, Zhengbing; Zhu, Biao; Wang, Jingjing; Xu, Xiaoniu; Fang, Jingyun

    2017-07-01

    Reactive nitrogen (N) increase in the biosphere has been a noteworthy aspect of global change, producing considerable ecological effects on the functioning and dynamics of the terrestrial ecosystems. A number of observational studies have explored responses of plants to experimentally simulated N enrichment in boreal and temperate forests. Here we investigate how the dominant trees and different understory plants respond to experimental N enrichment in a subtropical forest in China. We conducted a 3.4-year N fertilization experiment in an old-aged subtropical evergreen broad-leaved forest in eastern China with three treatment levels applied to nine 20 m × 20 m plots and replicated in three blocks. We divided the plants into trees, saplings, shrubs (including tree seedlings), and ground-cover plants (ferns) according to the growth forms, and then measured the absolute and relative basal area increments of trees and saplings and the aboveground biomass of understory shrubs and ferns. We further grouped individuals of the dominant tree species, Castanopsis eyrei, into three size classes to investigate their respective growth responses to the N fertilization. Our results showed that the plot-averaged absolute and relative growth rates of basal area and aboveground biomass of trees were not affected by N fertilization. Across the individuals of C. eyrei, the small trees with a DBH (diameter at breast height) of 5-10 cm declined by 66.4 and 59.5 %, respectively, in N50 (50 kg N ha-1 yr-1) and N100 fertilized plots (100 kg N ha-1 yr-1), while the growth of median and large trees with a DBH of > 10 cm did not significantly change with the N fertilization. The growth rate of small trees, saplings, and the aboveground biomass of understory shrubs and ground-cover ferns decreased significantly in the N-fertilized plots. Our findings suggested that N might not be a limiting nutrient in this mature subtropical forest, and that the limitation of other nutrients in the forest

  12. Conservation and ecofriendly utilization of wetlands associated with the Three Gorges Reservoir.

    Science.gov (United States)

    Willison, J H Martin; Li, Ruoxi; Yuan, Xingzhong

    2013-10-01

    The Three Gorges Dam on the Yangtze River in China has created a major reservoir in which the water level fluctuates annually by about 30 m, generating a drawdown zone of up to 350 km(2) in summer. Since construction of the dam, there has been scientific and public interest in how to use the drawdown zone resources in environmentally sustainable ways. To this end, and with government support, an international conference was held in Chongqing Municipality (China) in October 2011 on the subject of conservation and ecofriendly utilization of wetlands in the Three Gorges Reservoir. The conference proceedings were subsequently published in the Journal of Chongqing Normal University. The proceedings reports are reviewed here in the context of other relevant literature. The proceedings included papers on ecology, ecodesign and ecological engineering, erosion control, plant production and carbon sequestration, phytoremediation of pollution, hydrosystem management, and others. Several of the reports derive from experimental work conducted at a research field station on the Three Gorges Reservoir situated in Kaixian County, Chongqing Municipality. Plant communities in the drawdown zone are declining in diversity and evolving. Experimental plantings of flood-tolerant edible hydrophytes in a dike-pond system reveal their potential to provide economic returns for farmers, and flooding-tolerant trees, such as cypresses, also show promising results for stabilizing soils in the drawdown zone. Flood-tolerant natural plant communities vary strongly with depth and their composition provides useful indicators for revegetation strategies. In the region surrounding the reservoir, remnant natural broad-leaved evergreen forests are most effective in sequestering carbon, and within the drawdown zone, carbon is mostly stored below ground. There is strong interest in the potential of aquatic plants for removal of pollutants, notably N and P, from the reservoir water by means of floating beds

  13. High resolution taxonomic study of the late Eocene (~34 Ma) Florissant palynoflora, Colorado, USA

    Science.gov (United States)

    Bouchal, J. M.

    2012-04-01

    The Florissant Fossil Beds National Monument is located in Teller County in central Colorado, at approximate latitude 38°54'N and longitude 105°13'. The lithologies of the Florissant Formation consist of coarse-grained arkosic and volcanoclastic sandstones and conglomerates, finer shale, and tuffaceus mudstone and siltstone. It is divided into six units, mostly of lacustrine and fluvial origin with volcanic sediments interfingering and topping the strata. Volcanic units have been dated using the 40Ar/39Ar single-crystal method, giving an absolute age of ca. 34 Ma for the upper fossiliferous sedimentary unit. This pinpoints the formation of the Florissant sediments at the end of the Eocene, providing fruitful insight into the changing palaeoecosystem of the region at the dawn of the Oligocene. The formation is very well known for its rich fossil insect fauna and well preserved plant macrofossils found in the shale units, and the silicified tree stumps occurring in the lower mudstone unit. The sample used for this study originates from the upper shale unit, the fifth unit from the base of the formation. Previous studies on the plant macrofossils, mesofossils and the palynoflora have shown that during the late Eocene the surroundings of Florissant palaeo-lake were covered by diverse mixed broad-leaved evergreen/deciduous and needle-leafed forests. Until now pollen from the Florissant Formation has mostly been described according to conventional morphological nomenclature, using light microscopy (LM) only. In this study the same individual pollen grains are investigated using both LM and scanning electron microscopy (SEM), by means of single grain technique. This provides best exploitable results concerning a more detailed resolution regarding taxonomy and more accurate identifications. The main goal of this study is to compile a well resolved taxonomic species list based on the palynoflora, to clarify the generic and species diversity of selected families (e

  14. Surface Energy Exchange in a Tropical Montane Cloud Forest Environment: Flux Partitioning, and Seasonal and Land Cover-Related Variations

    Science.gov (United States)

    Holwerda, F.; Alvarado-Barrientos, M. S.; González-Martínez, T.

    2015-12-01

    Relationships between seasonal climate, land cover and surface energy exchange in tropical montane cloud forest (TMCF) environments are poorly understood. Yet, understanding these linkages is essential to evaluating the impacts of land use and climate change on the functioning of these unique ecosystems. In central Veracruz, Mexico, TMCF occurs between 1100 and 2500 m asl. The canopy of this forest consists of a mix of deciduous and broadleaved-evergreen tree species, the former of which shed their leaves for a short period during the dry season. The aim of this study was to quantify the surface energy balance, and seasonal variations therein, for TMCF, as well as for shaded coffee (CO) and sugarcane (SU), two important land uses that have replaced TMCF at lower elevations. Sensible (H) and latent heat (LE) fluxes were measured using eddy covariance and sap flow methods. Other measurements included: micrometeorological variables, soil heat flux, soil moisture and vegetation characteristics. Partitioning of available energy (A) into H and LE showed important seasonal changes as well as differences among land covers. During the wet-season month of July, average midday Bowen ratios for sunny days were lowest and least variable among land covers: 0.5 in TMCF and SU versus 0.7 in CO. However, because of higher A, along with lower Bowen ratio with respect to CO, LE over TMCF was ca. 20% higher compared to CO and SU. During the late dry-season months of March and April, average midday Bowen ratios for sunny days were generally much higher and more variable among land covers. The higher Bowen ratios indicated a reduction of LE under the drier conditions prevailing (low soil moisture and high VPD), something rarely observed in TMCFs. Moreover, because some trees were still partially leafless in March, LE over TMCF was about half that over CO and SU, suggesting an important effect of phenology on energy exchange of this TMCF. Observed differences between seasons and land

  15. Controle de mono e dicotiledôneas na cultura de soja em pós-emergência, através da combinação de mefluidide e bentazon Control of grasses and broadleaves in soybean crop with mefluidide and bentazon tankmix

    Directory of Open Access Journals (Sweden)

    E.M. Paulo

    1982-06-01

    Full Text Available O presente trabalho buscou uma alternativa de solução para o problema através da mistura, no tanque, dos agroquímicos mefluidide e bentazon, aplicada apó s a emergência total da cultura e das plantas infestantes. As doses dos componentes usados no experimento em kg/ha, foram, para o mefluidide, 0,000 - 0,144 - 0,288 e 0,480 e, para o bentazon, 0,000 - 0576 - 0,864 e 1,152 combinadas entre si. O delineamento estatístico foi o de blocos ao acaso. No momento da aplicação a soja iniciava o seu terceiro trifólio e as principais plantas daninhas presentes no experimento, carurú (Amaranthus spp, carrapicho-de-carneiro (Acanthospermum hispidum DC, guanxuma (Sida spp, quenopólio (Chenopodium album L. , da classe das dicotiledôneas, e capim-marmelada (Brachiaria plantaginea (Link Hitcl, capimpé-de-galinha (Eleusine indica (L. Gaertm, da classe das monocotiledôneas, estavam em diferentes estádios de desenvolvimento. Os resultados obtidos confirmaram a ação definida dos componentes na calda, mefluidide, sobre o grupo das monocotiledôneas e bentazon sobre o grupo das dicotiledôneas. Misturados, entretanto, a adição de um melhorou a atividade do outro sobre o grupo de plantas que controla. Sintomas fitotóxicos somente foram observados nos tratamentos com mefluidide solitário. Os tratamentos, quanto à produção, não diferiram estatisticamente da testemunha capinada. No controle total das plantas infestantes as misturas não di fe riram estatis ticamente entre si. A extensão numérica no controle de dicotiledôneas, bem como a interação estatística entre os compostos indica a existência de ação sinérgica da mistura.The tankmix of mefluidide and bentazon offers a possibility for solution of the mixed weed population in soybean crop. The mefluidide rates applied in the experiment were 0.000 - 0.144 - 0.288 - 0.480 kg i.a./ha, and for bentazon 0.000 - 0.576 - 0.864 - 1.152 isolated or mixed in a randomized blocks design experiment. At spraying time soybean were at the leaves stage and the predominant weeds were Amaranthus sp., Acanthospermum hispidum, Sida sp., Chenopodium album, Brachiaria plantaginea, Digitaria sanguinalis, Eleusine indica. The tankmixed spray showed a wide herbicide activity, more effective than the control of any of the herbicides applied alone due to a sinergistic action.

  16. Hanford Reach - Snively Basin Rye Field Rehabilitation 2013

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The project as described for the FY 2013 grant was to continue the control treatments of cereal rye, as well as of selected invasive broadleaves, to continue and...

  17. NPP Grassland: Nylsvley, South Africa, 1974-1989, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains five data files in text format (.txt). Three files contain biomass dynamics data for a broad-leaved savanna located in the 800-hectare...

  18. A critical transition in leaf evolution facilitated the Cretaceous angiosperm revolution

    NARCIS (Netherlands)

    Boer, H.J. de; Eppinga, M.B.; Wassen, M.J.; Dekker, S.C.

    2012-01-01

    The revolutionary rise of broad-leaved (flowering) angiosperm plant species during the Cretaceous initiated a global ecological transformation towards modern biodiversity. Still, the mechanisms involved in this angiosperm radiation remain enigmatic. Here we show that the period of rapid

  19. 集合フェロモン剤を利用した昆虫病原性糸状菌感染装置のチャバネアオカメムシに対する効果

    National Research Council Canada - National Science Library

    堤, 隆文; 手柴, 真弓; 山中, 正博; 大平, 喜男; 樋口, 俊男

    2003-01-01

    .... Broad-leaved trees were used for the inoculum stations. Five or 10 lures containing synthesized aggregation pheromone and 20 non-woven fabric sheets containing the entomopathogenic fungus Beauveria bassiana E-9102 were attached to each tree...

  20. The interspecific relationships between plants, cicadellids, and dryinids (Hemiptera: Cicadellidae - Hymenoptera: Dryinidae):

    OpenAIRE

    Alma, Alberto; Arzone, Alessandra; Giordano, Valeria

    2002-01-01

    The relationships between 14 species of broadleaved trees, 29 species of cicadellids, 9 species of dryinids, and 1 species of a diapriid hyperparasitoid were examined in several areas of the western Piedmont (Northern Italy)

  1. [Niche comparison of dominant entomopathogenic fungi in three forest ecosystems].

    Science.gov (United States)

    Chen, Ming-Jun; Huang, Bo; Li, Zeng-Zhi

    2011-05-01

    An investigation was made on the quantitative composition, niche width, and niche overlap of dominant entomopathogenic fungi in three different forest ecosystems, i.e., natural broad-leaved forest, natural secondary broad-leaved forest, and pure Masson' s pine plantation. In the three forest ecosystems, Beauveria bassiana was the first dominant species in natural secondary broad-leaved forest, the second in pure Masson's pine plantation, and the third in natural broad-leaved forest. B. bassiana had the broadest temporal niche width and nutritional niche width, whereas the dominant species Isaria cateinannulata, L. farinose, and I. tenuipes had much smaller niche widths. Meanwhile, B. bassiana had larger temporal niche overlaps but smaller nutritional niche overlaps with other dominant entomopathogenic fungi. It was suggested that in the three forest ecosystems, B. bassiana had the longest occurrence duration, widest host range, and strongest environmental adaptability.

  2. Forest vegetation in view of some scenarios of climate change in Italy

    National Research Council Canada - National Science Library

    Pignatti G

    2011-01-01

    ... °C in 2080, current temperature values for the main forest species will change greatly, creating favorable preconditions for an increased presence of broadleaved deciduous species in mountain altitudes...

  3. Wind Speed Response of Sap Flow in Five Subtropical Trees Based on Wind Tunnel Experiments

    OpenAIRE

    Laplace, Sophie; Kume, Tomonori; Chu, Chia-Ren; Komatsu, Hikaru

    2013-01-01

    Aims: We evaluated the responses of tree sap flow to wind speeds in coniferous and broad-leaved plants under steady and unsteady wind conditions. Study Design: We performed sap flow and micro-meteorological measurements on two conifers, Chamaecyparis obtusa var. formosana and Araucaria cunninghamii, and three broadleaved species, Swietenia mahagoni, Michelia formosana and Plumeria acutifolia in a wind tunnel. Place and Duration of Study: Civil Engineering Department, National Central Universi...

  4. The Effects of Disturbance and Climate on Carbon Storage and the Exchanges of CO2 Water Vapor and Energy Exchange of Evergreen Coniferous Forests in the Pacific Northwest: Integration of Eddy Flux, Plant and Soil Measurements at a Cluster of Supersites. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Law, Beverly E.; Thomas, Christoph K.

    2011-09-20

    This is the final technical report containing a summary of all findings with regard to the following objectives of the project: (1) To quantify and understand the effects of wildfire on carbon storage and the exchanges of energy, CO2, and water vapor in a chronosequence of ponderosa pine (disturbance gradient); (2) To investigate the effects of seasonal and interannual variation in climate on carbon storage and the exchanges of energy, CO2, and water vapor in mature conifer forests in two climate zones: mesic 40-yr old Douglas-fir and semi-arid 60-yr old ponderosa pine (climate gradient); (3) To reduce uncertainty in estimates of CO2 feedbacks to the atmosphere by providing an improved model formulation for existing biosphere-atmosphere models; and (4) To provide high quality data for AmeriFlux and the NACP on micrometeorology, meteorology, and biology of these systems. Objective (1): A study integrating satellite remote sensing, AmeriFlux data, and field surveys in a simulation modeling framework estimated that the pyrogenic carbon emissions, tree mortality, and net carbon exchange associated with four large wildfires that burned ~50,000 hectares in 2002-2003 were equivalent to 2.4% of Oregon statewide anthropogenic carbon emissions over the same two-year period. Most emissions were from the combustion of the forest floor and understory vegetation, and only about 1% of live tree mass was combusted on average. Objective (2): A study of multi-year flux records across a chronosequence of ponderosa pine forests yielded that the net carbon uptake is over three times greater at a mature pine forest compared with young pine. The larger leaf area and wetter and cooler soils of the mature forest mainly caused this effect. A study analyzing seven years of carbon and water dynamics showed that interannual and seasonal variability of net carbon exchange was primarily related to variability in growing season length, which was a linear function of plant-available soil moisture in spring and early summer. A multi-year drought (2001-2003) led to a significant reduction of net ecosystem exchange due to carry-over effects in soil moisture and carbohydrate reserves in plant-tissue. In the same forest, the interannual variability in the rate carbon is lost from the soil and forest floor is considerable and related to the variability in tree growth as much as it is to variability in soil climatic conditions. Objective (3): Flux data from the mature ponderosa pine site support a physical basis for filtering nighttime data with friction velocity above the canopy. An analysis of wind fields and heat transport in the subcanopy at the mesic 40-year old Douglas site yielded that the non-linear structure and behavior of spatial temperature gradients and the flow field require enhanced sensor networks to estimate advective fluxes in the subcanopy of forest to close the surface energy balance in forests. Reliable estimates for flux uncertainties are needed to improve model validation and data assimilation in process-based carbon models, inverse modeling studies and model-data synthesis, where the uncertainties may be as important as the fluxes themselves. An analysis of the time scale dependence of the random and flux sampling error yielded that the additional flux obtained by increasing the perturbation timescale beyond about 10 minutes is dominated by random sampling error, and therefore little confidence can be placed in its value. Artificial correlation between gross ecosystem productivity (GEP) and ecosystem respiration (Re) is a consequence of flux partitioning of eddy covariance flux data when GEP is computed as the difference between NEE and computed daytime Re (e.g. using nighttime Re extrapolated into daytime using soil or air temperatures). Tower-data must be adequately spatially averaged before comparison to gridded model output as the time variability of both is inherently different. The eddy-covariance data collected at the mature ponderosa pine site and the mesic Douglas fir site were used to develop and evaluate a new method to extract the signal of ecosystem respiration directly from daytime net ecosystem exchange. This approach may help reducing uncertainty in carbon budgets by providing direct measurements of ecosystem respiration during daylight conditions by replacing modeled estimates. Objective (4): We submitted our flux and biological and ancillary data to the AmeriFlux web site and to Fluxnet. This includes atmospheric carbon, water, and heat fluxes, soil fluxes, NPP, carbon stocks, LAI, and disturbance history. Fluxnet is updating the original La Thuile files and will include the more recent years of data. They will be using a new approach to compute GPP, following discussions within the network about the need to improve GPP methodology

  5. 7 CFR 457.162 - Nursery crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ... industry for the area as compatible with the nursery plant production practices and weather conditions in...) Deciduous Shrubs; (6) Broad-leaf Evergreen Shrubs; (7) Coniferous Evergreen Shrubs; (8) Small Fruits; (9... established; (g) Are grown in an appropriate medium; (h) Are not grown for sale as Christmas trees; (i) Are...

  6. Phenotypic plasticity of leaf length to an environmental gradient in ...

    African Journals Online (AJOL)

    USER

    2010-12-06

    Dec 6, 2010 ... species is distributed in three main ecological zones (Wet. Evergreen, Moist Evergreen and Moist semi-deciduous forest zones) (Figure 1), with isolated patches of popu- lations in riverine habitats in dry semi-deciduous forest zones. Due to the heterogeneous nature of K. ivorensis habitat, it can therefore be ...

  7. Species composition, Plant Community structure and Natural ...

    African Journals Online (AJOL)

    Belete forest is one of the very few remnant moist evergreen montane forests in Ethiopia. The objective of this work was to study the vegetation structure, composition and Natural regeneration status of Belete moist evergreen montane forest. To investigate the plant community structure, composition and regeneration status ...

  8. Influencia de las especies del dosel en la disponibilidad de recursos y regeneración avanzada en un bosque templado lluvioso del sur de Chile Influence of overstorey species identity on resource availability and variation in composition of advanced regeneration in a temperate rainforest in southern Chile

    Directory of Open Access Journals (Sweden)

    ALFREDO SALDAÑA

    2003-12-01

    advanced regeneration was studied in a temperate rain forest in southern Chile. The forest over storey was dominated by the broadleaved evergreens Laureliopsis philippiana, Aextoxicon punctatum, Eucryphia cordifolia and Nothofagus dombeyi. Availabilities of diffuse light, nitrogen, phosphorous and calcium were measured under these four over storey species, as was nutrient content of leaf litter. Advanced regeneration was sampled in plots beneath each over storey species, and results analyzed by ordination. There were significant differences in light transmission, nutritional content of leaf litter and availability of N-NO3 and P beneath the four species. Nevertheless, all nutrients showed low availability due to low mineralization and high immobilization. Ordination results indicate that the composition of advanced regeneration under N. dombeyi and L. philippiana differed from the composition of regeneration under A. punctatum or E. cordifolia. The ordination suggested that light level explained a large proportion of compositional variation. We propose that species regenerating in the understory differed more in shade tolerance than in nutritional requirements, being the light the most limiting resource in the under story

  9. Decontamination Trials for the Bed-Log Cultivation of Mushroom in Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, Kahori; Arai, Shio; Hirano, Yurika; Yoshida, Hirohisa [Graduate School of Urban Environmental Science, Tokyo Metropolitan University, Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Ogawa, Hideki [Graduate School of Urban Environmental Science, Tokyo Metropolitan University, Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Fukushima Prefectural Forestry Research Centre, Nishi-Shimasaka, Asaka, Koriyama, Fukushima 963-0112 (Japan); Ito, Hirohisa; Kumata, Atsushi [Fukushima Prefectural Forestry Research Centre, Nishi-Shimasaka, Asaka, Koriyama, Fukushima 963-0112 (Japan); Murayama, Kazunari [Macoho Co. Ltd., Nagaoka, Niigata (Japan); Suzuki, Kin-ichi [Abukuma Cooperative for Best Use of Broad-leaved Trees (Japan)

    2014-07-01

    Radioactive nuclear dispersed in environment from Fukushima Dai-ichi Nuclear Power Plant (FNP) Accident-contaminated forests in Fukushima Prefecture, especially in Abukuma mountainous region located 10 to 20 Km west from FNP. Broad-leaved trees such as Quercus serrata, chestnut tree, oak, chinquapin tree, Japanese beech are widely planting in Abukuma area. Many prefectures in Japan depends on supply of bed-log from Fukushima prefecture, especially Abukuma area. North part of Abukuma mountain area has highly contaminated by radioactive nuclear, however, the contamination level in the south part of Abkuma area was about ten times lower than the north part. The outside (bark, leaves and twigs) of broad-leaved trees was highly contaminated above 10,000 Bq/kg in Iidate and Kawamata villages located the north part of Abkuma ears, 35 to 40 km from FNP. On the other hand, the contamination level of the outside of broad-leaved trees in the south part of Abukuma ears was 100-500 Bq/kg and the contamination of the inside tree was lower than 10 Bq/kg. For the bed-log cultivation of mushrooms using broad-leaved trees, two methods were used in Japan. The mushrooms incubated broad-leaved trees (90 cm of length and 15 cm of diameter) were setting in the lack on the ground in forest from winter to autumn. This method was mainly used for the cultivation of shiitake mushroom (Lentinus edodes). The second method was used for Maitake (Grifola frondosa) cultivation. The mushroom incubated broad-leaved trees (20 cm of length and 20 cm of diameter) were setting in the ground holes and covered by soil (2 cm) and litters. The maitake (Grifola frondosa) mushrooms harvesting October 2013 at Iidate, the evaluation area, contained 120 Bq/kg, even though the soil on the broad-leaved trees contained more than 20,000 Bq/kg. The outside contamination of broad-leaved trees supplied from the south part of Abkuma ears were washed by the wet blasting. 80 % of radiocesium on the bark was efficiently

  10. From the investigations on Armillaria root rot occurrence in young Scots pine stands in Zielonka Forest District

    Directory of Open Access Journals (Sweden)

    Wojciech Szewczyk

    2013-12-01

    Full Text Available Armillaria root rot, one of the most dangerous diseases in our forests, is caused in Poland mainly by Armillaria ostoyae, especially severe in young Scots pine stands, established after broadleaved stands or with participation of broadleaved species. In Forest District Zielonka young stands are severly affected by Armillaria root rot. Only one species, A.ostoyae, was found in the young (8-14 yrs Scots pine stands, despite the presence of other Armillaria species in the district. The pathogen's frequent occurrence may be due, inter alia, to favouring environmental factors.

  11. Multiple recruitment limitation causes arrested succession in Mediterranean Cork Oak systems

    NARCIS (Netherlands)

    Acácio, V.C.; Holmgren, M.; Jansen, P.A.; Schrotter, O.

    2007-01-01

    Lack of tree regeneration and persistency of species-poor shrublands represent a growing problem across Mediterranean evergreen oak forests. What constrains forest regeneration is poorly understood, and restoration attempts have been largely unsuccessful. We assessed the contribution of four

  12. Multiple recruitment limitation causes arrested succession in mediterranean cork oak systems

    NARCIS (Netherlands)

    Acacio, Vanda; Holmgren, Milena; Jansen, Patrick A.; Schrotter, Ondrej

    2007-01-01

    Lack of tree regeneration and persistency of species-poor shrublands represent a growing problem across Mediterranean evergreen oak forests. What constrains forest regeneration is poorly understood, and restoration attempts have been largely unsuccessful. We assessed the contribution of four

  13. NPP Tropical Forest: Magdalena Valley, Colombia, 1970-1971

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Biomass, litterfall, and nutrient content of above-ground vegetation and soil for a tropical seasonal evergreen forest at Magdalena Valley, Columbia,...

  14. ASSESSMENT OF MODIS LAI (W4) IN LOBLOLLY PINE (P. TAEDA) FOREST TYPE, APPOMATTOX, VIRGINIA

    Science.gov (United States)

    The United States Environmental Protection Agency initiated MODIS MODI5A2LAI validation research (2002) in the evergreen needle leaf biome, as defined in the MOD12 classification, in a regional study located in the southeastern United States.

  15. Pop / Margus Kiis

    Index Scriptorium Estoniae

    Kiis, Margus

    2007-01-01

    Uutest heliplaatidest Krää "Läti lugu", Talk Talk "Natural History", Dikta "Haunting For Happiness", Processory", The Used "Berth", Seventeen Evergreen "Life Embarrasses Me on Planet Earth", Jesu "Conqueror", Electrelane "No Shouts, No Calls", "The Sleeping Moustache"

  16. Fulltext PDF

    Indian Academy of Sciences (India)

    Admin

    branched evergreen tree. Young branches are covered with short rusty hairs. Leaves are simple, ovate-lanceolate and strongly three- nerved with minute glands underneath. Flowers are unisexual, male and female flowers occurring on differ-.

  17. Phytochemical Analysis of Danae Racemosa L. Moench Leaves

    National Research Council Canada - National Science Library

    Fatemeh Fathiazad; Sanaz Hamedeyazdan

    2015-01-01

      Danae racemosa (L.) Moench (Ruscus racemosa L., Asparagaceae) is an erect, muchbranched evergreen shrub, native in the mountains from Syria to Iran, commonly used for its decorative green foliage in fresh flower arrangements...

  18. 78 FR 63474 - Notice of Agreements Filed

    Science.gov (United States)

    2013-10-24

    ...: Evergreen Line Joint Service Agreement and Hanjin Shipping Co. Ltd. Filing Party: Paul M. Keane, Esq.; Cichanowicz, Callan, Keane, Vengrow and Textor, LLP; 61 Broadway, Suite 3000; New York, NY 10006. Synopsis...

  19. 75 FR 78245 - Notice of Agreements Filed

    Science.gov (United States)

    2010-12-15

    ...: Evergreen Line Joint Service Agreement and A.P. Moller- Maersk A/S. Filing Party: Paul M. Keane, Esq.; Cichanowicz, Callan, Keane, Vengrow & Textor, LLP; 61 Broadway, Suite 3000, New York, NY 10006- 2802. Synopsis...

  20. Effects of forest certification on the ecological condition of Mediterranean streams

    National Research Council Canada - National Science Library

    Dias, Filipe S; Bugalho, Miguel N; Rodríguez‐González, Patricia M; Albuquerque, António; Cerdeira, J. Orestes; Strecker, Angela

    2015-01-01

    .... Here, we assess the effects of Forest Stewardship Council ( FSC ) certification, one of the largest certification schemes in the world, on the ecological condition of streams crossing Mediterranean evergreen oak woodlands...

  1. EnviroAtlas - Acres of crops that have no nearby pollinator habitat for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset is a summary of crop acres without nearby pollinator habitat. Pollination habitat here is defined as trees (fruit, nut, deciduous, and evergreen). Crops...

  2. Pterocarpus officinalis Jacq. Bloodwood Legumeminosae, Legume Family, lotoideae, Pea Subfamily

    Science.gov (United States)

    Peter L. Weaver

    1997-01-01

    Pterocarpus officinalis Jacq., called palo de pollo in Puerto Rico, bloodwood in Guyana and Panama, and by numerous other names throughout its extensive range, is an evergreen tree that reaches 40m in height

  3. Salinity Differentially Affects Growth and Ecophysiology of Two Mastic Tree (Pistacia lentiscus L.) Accessions

    National Research Council Canada - National Science Library

    Cristiano, Giuseppe; Camposeo, Salvatore; Fracchiolla, Mariano; Vivaldi, Gaetano; De Lucia, Barbara; Cazzato, Eugenio

    2016-01-01

    Pistacia lentiscus (Anacardiaceae; mastic tree) is an evergreen sclerophyll species, largely distributed in dry areas of the Mediterranean basin and well-adapted to severe conditions of drought in very unfertile soils...

  4. Host Specificity of Argopistes tsekooni (Coleoptera: Chrysomelidae), a Potential Biological Control Agent of Chinese Privet

    Science.gov (United States)

    Yan Zhuo Zhang; James Hanula; Jiang Hua Sun

    2008-01-01

    Chinese privet, Ligustrum sinense Lour., is a perennial semi-evergreen shrub that is aserious invasive weed in the United States. Classical biological control offers the best hope forcontrolling it in an economic, effective, and persistent way. Host...

  5. Rediscovery of Syzygium kanarense (Talbot Raizada (Myrtaceae - an endemic species of the Western Ghats, India

    Directory of Open Access Journals (Sweden)

    H.S. Shenoy

    2015-01-01

    Full Text Available Syzygium kanarense - a rare and critically endangered species of the Western Ghats has been rediscovered after a gap of 47 years from the evergreen forests of the North Kanara District, Karnataka-India. 

  6. 78 FR 51726 - Notice of Agreements Filed

    Science.gov (United States)

    2013-08-21

    ... ( www.fmc.gov ) or by contacting the Office of Agreements at (202) 523-5793 or [email protected]fmc.gov... Corporation; Evergreen Marine Corporation (Taiwan), Ltd.; Hamburg- S d KG; Hanjin Shipping Co., Ltd.; Hapag...

  7. Vitex altissima L.f of verbenaceae is a large tree of dry deciduous ...

    Indian Academy of Sciences (India)

    evergreen forests with spreading crown and greyish brown scaly bark (tree in the picture is a young specimen). Leaves are compound with three or five leaflets. Flowers are numerous on branched inflorescence, small and white, tinged with blue.

  8. Horizontal, but not vertical canopy structure is related to stand functional diversity in a subtropical slope forest

    NARCIS (Netherlands)

    Lang, A.C.; Härdtle, W.; Bruelheide, H.; Kröber, W.; Schröter, M.; Wehrden, von H.; Oheimb, von G.

    2012-01-01

    The aim of this study was to analyse the relation of horizontal and vertical canopy structure to tree functional diversity of a highly diverse subtropical broad-leaved slope forest, stratified for different successional stages. This is of particular interest because many key ecosystem processes and

  9. Aerides phongii (Orchidaceae), a new species from Southern Vietnam

    OpenAIRE

    L. V. Averyanov; Loc, P. K.; C. X. Canh

    2015-01-01

    The paper provides illustrated description of a new orchid species, Aerides phongii, discovered in heavily disturbed primary seasonal tropical broad-leaved woodland of southern Vietnam. Terete subulate leaves and verruculose lip with large verrucose calli on the lip disc define isolated taxonomic position of the species. Discovered plant is assessed preliminarily as critically endangered species.

  10. Vegetation composition and soil nutrients status from polyculture to ...

    African Journals Online (AJOL)

    The study was conducted on status of nutrients in three major types of forests namely, broad-leaved, mixed pine and pine forests in Meghalaya, considering altitude and seasonality as variables. The findings revealed that the change in micro-environmental conditions as influenced by attitude and seasonality has marked ...

  11. Colour and shape analysis techniques for weed detection in cereal fields

    DEFF Research Database (Denmark)

    Pérez, A.J; López, F; Benlloch, J.V.

    2000-01-01

    Information on weed distribution within the field is necessary to implement spatially variable herbicide application. This paper deals with the development of near-ground image capture and processing techniques in order to detect broad-leaved weeds in cereal crops under actual field conditions. T...

  12. Termites of the Savanna ecosystem project study area, Nylsvley

    CSIR Research Space (South Africa)

    Ferrar, P

    1982-09-01

    Full Text Available on their biology are given. Most of the species occur in the flatter areas of Burkea savanna; three are restricted to open land near the turfvlei" Tfie broad-leaved woodland of Maroelakop lacks two species but has two others restricted. Acacia patches (including...

  13. Is Tree Species Diversity or Species Identity the More Important Driver of Soil Carbon Stocks, C/N Ratio, and pH?

    DEFF Research Database (Denmark)

    Dawud, Seid Muhie; Raulund-Rasmussen, Karsten; Domisch, Timo

    2016-01-01

    We explored tree species diversity effects on soil C stock, C/N ratio, and pH as compared with effects of tree species identity. We sampled forest floors and mineral soil (0–40 cm) in a diversity gradient of 1–5 tree species composed of conifers and broadleaves in Białowieża Forest, Poland...

  14. SELECTIVE FORAGING ON WOODY SPECIES BY THE BEAVER CASTOR FIBER, AND ITS IMPACT ON A RIPARIAN WILLOW FOREST

    NARCIS (Netherlands)

    NOLET, BA; HOEKSTRA, A; OTTENHEIM, MM

    1994-01-01

    Beavers were re-introduced in the Biesbosch, The Netherlands, a wood dominated by willows Salix spp. Conservationists expected that herbivory by beavers would enhance succession to a mixed broad-leaved forest. Willows formed the staple food of the beavers, but they removed only 1.4% of the standing

  15. Relationships of S-Band Radar Backscatter and Forest Aboveground Biomass in Different Forest Types

    Directory of Open Access Journals (Sweden)

    Ramesh K. Ningthoujam

    2017-11-01

    Full Text Available Synthetic Aperture Radar (SAR signals respond to the interactions of microwaves with vegetation canopy scatterers that collectively characterise forest structure. The sensitivity of S-band (7.5–15 cm backscatter to the different forest types (broadleaved, needleleaved with varying aboveground biomass (AGB across temperate (mixed, needleleaved and tropical (broadleaved, woody savanna, secondary forests is less well understood. In this study, Michigan Microwave Canopy Scattering (MIMICS-I radiative transfer model simulations showed strong volume scattering returns from S-band SAR for broadleaved canopies caused by ground/trunk interactions. A general relationship between AirSAR S-band measurements and MIMICS-I simulated radar backscatter with forest AGB up to nearly 100 t/ha in broadleaved forest in the UK was found. Simulated S-band backscatter-biomass relationships suggest increasing backscatter sensitivity to forest biomass with a saturation level close to 100 t/ha and errors between 37 t/ha and 44 t/ha for HV and VV polarisations for tropical ecosystems. In the near future, satellite SAR-derived forest biomass from P-band BIOMASS mission and L-band ALOS-2 PALSAR-2 in combination with S-band UK NovaSAR-S and the joint NASA-ISRO NISAR sensors will provide better quantification of large-scale forest AGB at varying sensitivity levels across primary and secondary forests and woody savannas.

  16. Management and conservation of migratory landbirds overwintering in the neotropics

    Science.gov (United States)

    Daniel R. Petit; James F. Lynch; Richard L. Hutto; John G. Blake; Robert B. Waide

    1993-01-01

    Loss of tropical broadleaved forests and concurrent population declines of long-distance migratory birds in temperate breeding areas have been closely linked in both scientific and popular literature; however, little evidence of a causal association currently exists. We review the current land use situation in the neotropics, the projected outcome of deforestation...

  17. Recente vondsten van breedbladige fonteinkruiden (Groenlandia en Potamogeton spec.) in de provincie Noord-Brabant

    NARCIS (Netherlands)

    Linden, van der J.; Poelmans, W.

    1993-01-01

    Since 1987 the distribution of many plant species in the central and eastern parts of the province Noord-Brabant has been mapped for country use planning by the Provincial Authorities. Distribution maps (with a 5 x 5 km² grid) of the Potamogeton (broad-leaved pondweed) species, which are important

  18. Temperature and rainfall strongly drive temporal growth variation in Asian tropical forest trees

    NARCIS (Netherlands)

    Vlam, M.; Baker, P.J.; Bunyavejchewin, S.; Zuidema, P.A.

    2014-01-01

    Climate change effects on growth rates of tropical trees may lead to alterations in carbon cycling of carbon-rich tropical forests. However, climate sensitivity of broad-leaved lowland tropical trees is poorly understood. Dendrochronology (tree-ring analysis) provides a powerful tool to study the

  19. Host range of the exotic brown marmorated stink bug, Halyomorpha halys, (Hemiptera: Pentatomidae), implications for future distribution

    Science.gov (United States)

    Gary Bernon; Karen M. Bernhard; Anne L. Nielsen; James F. Stimmel; E. Richard Hoebeke; Maureen E. Carter

    2007-01-01

    Halyomorpha halys, (Hemiptera: Pentatomidae), is a pest in eastern Asia on soybeans and woody plants, including broadleaved trees and fruit trees. A population was discovered in Allentown, PA in 2001. H. halys is also a nuisance pest as it overwinters in homes and other buildings. Based on earlier reports to the Lehigh County...

  20. Regeneration of mixed deciduous forest in a Dutch forest-heathland, following a reduction of ungulate densities

    NARCIS (Netherlands)

    Kuiters, A.T.; Slim, P.A.

    2002-01-01

    The conversion of single-species coniferous forest stands into mixed stands by promoting the natural regeneration of indigenous broadleaved tree species was studied in a forest-heathland on the Veluwe, in the central part of the Netherlands. Red deer (Cervus elaphus), roe deer (Capreolus capreolus)

  1. Natural and near natural tropical forest values

    Science.gov (United States)

    Daniel H. Henning

    2011-01-01

    This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

  2. Disentangling the effects of land-use change, climate and CO2 on projected future European habitat types

    NARCIS (Netherlands)

    Lehsten, V; Sykes, M.T.; Scott, A.V.; Tzanopoulis, A.; Kallimanis, A.; Verburg, P.H.; Schulp, C.J.E.; Potts, S.G.; Vogiatzakis, I.

    2015-01-01

    Aim: To project the potential European distribution of seven broad habitat categories (needle-leaved, broad-leaved, mixed and mediterranean forest, urban, grassland and cropland) in order to assess effects of land use, climate change and increase in CO2 on predicted habitat changes up to

  3. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    The amount of interception depends on the type of vegetation cover (coniferous or broadleaved), leaf area index, age of ... The morphology of the vegetation can influence the quantity and distribution of water .... Alizadeh A (2007) Applied hydrology, Ferdowsi University of Mashhad. Ghods Razavi Publications, 800 pp.

  4. Zur soziologie und Synoekologie der Buchen- und Buchenmischwaelder der nordwestdeutschen Mittelgebirge

    NARCIS (Netherlands)

    Diemont, W.H.

    1938-01-01

    The beech (Fagus sylvatica L.) occurs in Europe in pure and mixed mesophile, deciduous, dominantly broad-leaved forests belonging to the phytosociological order of the Fagetalia silvaticae. This order includes the true beech forests united into the Fagion alliance and is

  5. Simulation of regional temperature change effect of land cover change in agroforestry ecotone of Nenjiang River Basin in China

    Science.gov (United States)

    Liu, Tingxiang; Zhang, Shuwen; Yu, Lingxue; Bu, Kun; Yang, Jiuchun; Chang, Liping

    2017-05-01

    The Northeast China is one of typical regions experiencing intensive human activities within short time worldwide. Particularly, as the significant changes of agriculture land and forest, typical characteristics of pattern and process of agroforestry ecotone change formed in recent decades. The intensive land use change of agroforestry ecotone has made significant change for regional land cover, which had significant impact on the regional climate system elements and the interactions among them. This paper took agroforestry ecotone of Nenjiang River Basin in China as study region and simulated temperature change based on land cover change from 1950s to 1978 and from 1978 to 2010. The analysis of temperature difference sensitivity to land cover change based on Weather Research and Forecasting (WRF) model showed that the land cover change from 1950s to 1978 induced warming effect over all the study area, including the change of grassland to agriculture land, grassland to deciduous broad-leaved forest, and deciduous broad-leaved forest to shrub land. The land cover change from 1978 to 2010 induced cooling effect over all the study area, including the change of deciduous broad-leaved forest to agriculture land, grassland to agriculture land, shrub land to agriculture land, and deciduous broad-leaved forest to grassland. In addition, the warming and cooling effect of land cover change was more significant in the region scale than specific land cover change area.

  6. Non-carbon benefits for effective implementation of REDD+

    African Journals Online (AJOL)

    EJIRO

    Shannon diversity indices and carbon stock, (iv) identify the most important forest non-carbon benefits obtained by the local ..... Other trees that are grouped under broadleaved tree species include Apodytes dimidiate, Celtis ... dominance and, hence, important value indices of woody species as well as their carbon stock, ...

  7. San Francisco Vessel Traffic Service/Maritime Community Interrelationship.

    Science.gov (United States)

    1983-03-01

    Mediterranean/Pacific Line East Asiatic Company, Inc. Empress Lineas Maritimas Argentinas, S.A. Evergreen Line Evergreen Marine corp. Flota Mercante...play a direct polit . , We will state no preference among contest, al role. Sierra Club executive director Michael d theories but ill report...in American politics . He has trans- movement to electoral politics ." formed hundreds of thousands of formerly placid Americans into political

  8. Crispin: capital requirements and reinsurance protect against insolvency.

    Science.gov (United States)

    Crispin, C

    2001-12-01

    Charles Crispin is president of Evergreen Re, a managed care consulting firm with expertise in the reinsurance industry. Before Joining Evergreen Re, Crispin served as a consultant to the managed care industry. He is a member of the American Association of Integrated Delivery Systems, Glen Allen, Virginia, and the Provider Excess Loss Association, Princeton, New Jersey. Crispin recently talked with HFM about risk-based capital requirements for health plans and the Impact these solvency guidelines could have on healthcare providers.

  9. A Machine Learning and Cross-Validation Approach for the Discrimination of Vegetation Physiognomic Types Using Satellite Based Multispectral and Multitemporal Data

    OpenAIRE

    Ram C. Sharma; Keitarou Hara; Hidetake Hirayama

    2017-01-01

    This paper presents the performance and evaluation of a number of machine learning classifiers for the discrimination between the vegetation physiognomic classes using the satellite based time-series of the surface reflectance data. Discrimination of six vegetation physiognomic classes, Evergreen Coniferous Forest, Evergreen Broadleaf Forest, Deciduous Coniferous Forest, Deciduous Broadleaf Forest, Shrubs, and Herbs, was dealt with in the research. Rich-feature data were prepared from time-se...

  10. [Species-abundance distribution patterns along succession series of Phyllostachys glauca forest in a limestone mountain].

    Science.gov (United States)

    Shi, Jian-min; Fan, Cheng-fang; Liu, Yang; Yang, Qing-pei; Fang, Kai; Fan, Fang-li; Yang, Guang-yao

    2015-12-01

    To detect the ecological process of the succession series of Phyllostachys glauca forest in a limestone mountain, five niche models, i.e., broken stick model (BSM), niche preemption model (NPM), dominance preemption model (DPM), random assortment model (RAM) and overlap- ping niche model (ONM) were employed to describe the species-abundance distribution patterns (SDPs) of 15 samples. χ² test and Akaike information criterion (AIC) were used to test the fitting effects of the five models. The results showed that the optimal SDP models for P. glauca forest, bamboo-broadleaved mixed forest and broadleaved forest were DPM (χ² = 35.86, AIC = -69.77), NPM (χ² = 1.60, AIC = -94.68) and NPM (χ² = 0.35, AIC = -364.61), respectively. BSM also well fitted the SDP of bamboo-broadleaved mixed forest and broad-leaved forest, while it was unsuitable to describe the SDP of P. glauca forest. The fittings of RAM and ONM in the three forest types were all rejected by the χ² test and AIC. With the development of community succession from P. glauca forest to broadleaved forest, the species richness and evenness increased, and the optimal SDP model changed from DPM to NPM. It was inferred that the change of ecological process from habitat filtration to interspecific competition was the main driving force of the forest succession. The results also indicated that the application of multiple SDP models and test methods would be beneficial to select the best model and deeply understand the ecological process of community succession.

  11. Water cycle observations in forest watersheds of Cambodia

    Science.gov (United States)

    Shimizu, A.; Tamai, K.; Kabeya, N.; Shimizu, T.; Iida, S. I.

    2015-12-01

    The Lower Mekong River flows through Cambodia, where forests cover ~60% of the country and are believed to have a marked effect on the water cycle. These tropical seasonal forests in the Cambodian flat lands are very precious in the Indochinese Peninsula as few forests of this type remain. However, few hydrological observations have been conducted in these areas. In Cambodia, deciduous and evergreen forests make up 42% and 33% of the total forest area, respectively. We established experimental watersheds both in deciduous and evergreen forests containing meteorological observation towers in Cambodia and collected various observational data since 2003 (O'Krieng, deciduous forest watershed including a 30-m-high observation tower, 2,245 km2; Stung Chinit, evergreen forest watershed including a 60-m-high observation tower, 3,700 km2 including three small watersheds). The basic data from these sites included various kinds of information related to the composition of vegetation, soil characteristics, etc. Hydrologic data was collected and linked to the above data; the main hydrologic research results follow. The water budget for each watershed was determined using an observational rainfall and runoff dataset. The evapotranspiration rate in an evergreen forest was obtained using various observational methods including the Bowen energy-balance ratio and the bandpass eddy covariance method. The annual evapotranspiration of evergreen forests, estimated using the Bowen energy-balance ratio method and water balance, was about 1100-1200 mm, corresponding to 70-80% of annual rainfall. While considering the importance of the presence of evergreen forest, we conducted sap flow measurements to analyze the transpiration process that maintains water uptake through root systems that reach to depths exceeding 8 m. Characteristics of the evaporation from the forest floor that form an important element of the evaporation system were estimated in both evergreen and deciduous forests.

  12. Interrupting Chagas disease transmission in Venezuela A interrupção da transmissão da doença de Chagas na Venezuela

    Directory of Open Access Journals (Sweden)

    Alberto ACHÉ

    2001-02-01

    Full Text Available The interruption of vectorial transmission of Chagas disease in Venezuela is attributed to the combined effects of ongoing entomoepidemiological surveillance, ongoing house spraying with residual insecticides and the concurrent building and modification of rural houses in endemic areas during almost five decades. The original endemic areas which totaled 750,000 km², have been reduced to 365,000 km². During 1958-1968, initial entomological evaluations carried out showed that the house infestation index ranged between 60-80%, the house infection index at 8-11% and a house density index of 30-50 triatomine bugs per house. By 1990-98, these indexes were further reduced to 1.6-4.0%, 0.01-0.6% and 3-4 bugs per house respectively. The overall rural population seroprevalence has declined from 44.5% (95% C.I.: 43.4-45.3% to 9.2% (95% C.I.: 9.0-9.4% for successive grouped periods from 1958 to 1998. The annual blood donor prevalence is firmly established below 1%. The population at risk of infection has been estimated to be less than four million. Given that prevalence rates are stable and appropriate for public health programmes, consideration has been given to potential biases that may distort results such as: a geographical differences in illness or longevity of patients; b variations in levels of ascertainment; c variations in diagnostic criteria; and d variations in population structure, mainly due to appreciable population migration. The endemic areas with continuous transmission are now mainly confined to piedmonts, as well as patchy foci in higher mountainous ranges, where the exclusive vector is Rhodnius prolixus. There is also an unstable area, of which landscapes are made up of grasslands with scattered broad-leaved evergreen trees and costal plains, where transmission is very low and occasional outbreaks are reported.A interrupção da transmissão da doença de Chagas é atribuida aos efeitos conjuntos da vigilância soroepidemiol

  13. Exploring variation in leaf mass per area (LMA) from leaf to cell: an anatomical analysis of 26 woody species.

    Science.gov (United States)

    Villar, Rafael; Ruiz-Robleto, Jeannete; Ubera, José Luis; Poorter, Hendrik

    2013-10-01

    Plant species differ widely in the leaf biomass invested per unit area (LMA). LMA can be explained by variation in leaf thickness and/or density, both of which are influenced by anatomical tissue composition. The aim of this study is to quantify the anatomical characteristics that underlie variation in LMA in a range of woody species. • Twenty-six woody species, forming 13 species pairs with a deciduous and evergreen species from the same genus or family, were grown in a glasshouse. The youngest full-grown leaves were analyzed for LMA and morpho-anatomical characteristics at leaf, tissue, and cell level. • Considered over all species studied, leaf thickness and density were equally important to explain the variation in LMA, but the class difference between deciduous and evergreen species was mainly determined by thickness, whereas variation within each group was largely due to density. Evergreens had thicker leaves, predominantly caused by a larger volume of mesophyll and air spaces, whereas the higher leaf density within each group was due to a lower proportion of epidermis and air spaces, and overall smaller cells. • The anatomical basis for variation in LMA in woody species depends on the contrast made. Higher LMA in evergreens is mainly due to a greater leaf thickness, caused by a larger volume of mesophyll and air spaces. Within deciduous species and evergreens, higher LMA is caused by a higher density, due to higher volumetric fractions of mesophyll and lower fractions of air spaces and epidermis.

  14. Western equatorial African forest-savanna mosaics: a legacy of late Holocene climatic change?

    Directory of Open Access Journals (Sweden)

    A. Ngomanda

    2009-10-01

    Full Text Available Past vegetation and climate changes reconstructed using two pollen records from Lakes Maridor and Nguène, located in the coastal savannas and inland rainforest of Gabon, respectively, provide new insights into the environmental history of western equatorial African rainforests during the last 4500 cal yr BP. These pollen records indicate that the coastal savannas of western equatorial Africa did not exist during the mid-Holocene and instead the region was covered by evergreen rainforests. From ca. 4000 cal yr BP a progressive decline of inland evergreen rainforest, accompanied by the expansion of semi-deciduous rainforest, occurred synchronously with grassland colonisation in the coastal region of Gabon. The contraction of moist evergreen rainforest and the establishment of coastal savannas in Gabon suggest decreasing humidity from ca. 4000 cal yr BP. The marked reduction in evergreen rainforest and subsequent savanna expansion was followed from 2700 cal yr BP by the colonization of secondary forests dominated by the palm, Elaeis guineensis, and the shrub, Alchornea cordifolia (Euphorbiaceae. A return to wetter climatic conditions from about 1400 cal yr BP led to the renewed spread of evergreen rainforest inland, whereas a forest-savanna mosaic still persists in the coastal region. There is no evidence to suggest that the major environmental changes observed were driven by human impact.

  15. Western equatorial African forest-savanna mosaics: a legacy of late Holocene climatic change?

    Science.gov (United States)

    Ngomanda, A.; Chepstow-Lusty, A.; Makaya, M.; Favier, C.; Schevin, P.; Maley, J.; Fontugne, M.; Oslisly, R.; Jolly, D.

    2009-10-01

    Past vegetation and climate changes reconstructed using two pollen records from Lakes Maridor and Nguène, located in the coastal savannas and inland rainforest of Gabon, respectively, provide new insights into the environmental history of western equatorial African rainforests during the last 4500 cal yr BP. These pollen records indicate that the coastal savannas of western equatorial Africa did not exist during the mid-Holocene and instead the region was covered by evergreen rainforests. From ca. 4000 cal yr BP a progressive decline of inland evergreen rainforest, accompanied by the expansion of semi-deciduous rainforest, occurred synchronously with grassland colonisation in the coastal region of Gabon. The contraction of moist evergreen rainforest and the establishment of coastal savannas in Gabon suggest decreasing humidity from ca. 4000 cal yr BP. The marked reduction in evergreen rainforest and subsequent savanna expansion was followed from 2700 cal yr BP by the colonization of secondary forests dominated by the palm, Elaeis guineensis, and the shrub, Alchornea cordifolia (Euphorbiaceae). A return to wetter climatic conditions from about 1400 cal yr BP led to the renewed spread of evergreen rainforest inland, whereas a forest-savanna mosaic still persists in the coastal region. There is no evidence to suggest that the major environmental changes observed were driven by human impact.

  16. Molecular phylogeny based on mitochondrial genes and evolution of host plant use in the long-horned beetle tribe Lamiini (Coleoptera: Cerambycidae) in Japan.

    Science.gov (United States)

    Toki, W; Kubota, K

    2010-08-01

    The molecular phylogeny of the long-horned beetle tribe Lamiini Mulsant (Coleoptera: Cerambycidae) in Japan (12 genera, 25 species, 3 additional subspecies) was determined based on mitochondrial 16S rRNA and cytochrome oxydase subunit I. The monophyly of the tribe Lamiini was supported, whereas that of the genus Acalolepta Pascoe was unclear. Evolution of host plant use in Lamiini was estimated using the molecular phylogeny. For adult and larval host plant kind-and-condition, the most ancestral state was for weakened to dead broad-leaved trees, whereas derived states favored conifers, healthy broad-leaved trees, and herbs. For adult and larval host range, the most ancestral state was polyphagy, whereas oligophagy and monophagy were derived. Evolution of hosts' idiosyncrasy and that of the insects' host range were related in many lineages. Our results partly support the hypothesis that habitation in living trees requires dietary specialization in phytophagous insects.

  17. Using niche-based modelling to assess the impact of climate change on tree functional diversity in Europe

    DEFF Research Database (Denmark)

    Thuiller, Wilfried; Lavorel, Sandra; Sykes, Martin T.

    2006-01-01

    role in the future of different European regions. Temperate areas were projected to lose both species richness and functional diversity due to the loss of broadleaved deciduous trees. These were projected to migrate to boreal forests, thereby increasing their species richness and functional diversity....... Atlantic areas provided an intermediate case, with a predicted reduction in the numbers of species and occasional predicted gains in functional diversity. This resulted from a loss in species within the broadleaved deciduous FT, but overall maintenance of the group. Our results illustrate the fact...... that both species-specific predictions and functional patterns should be examined separately in order to assess the impacts of climate change on biodiversity and gain insights into future ecosystem functioning....

  18. Declining of forests - biotic and abiotic stress

    Directory of Open Access Journals (Sweden)

    Radulović Zlatan

    2014-01-01

    Full Text Available During the last several years, a significant decline of different forests in Serbia was recorded. The decline is more widespread in conifer stands, but occurence of decline was recorded in broadleaved forest stands as well. These declines are the result of abiotic, biotic and anthropogenic factors. According to the studies performed so far in Serbia, the predisposing factor were droughts during the 2012 and 2013 vegetation periods that caused physiological weakness of the trees. Among the biotic factors, the most important are fungi (mainly root rot, but rot fungi, and needle diseases and insects (bark beetles in conifer species and defoliators in broadleaved species. [Projekat Ministarstva nauke Republike Srbije, br. TR 37008 i br. TR 31070

  19. Analyzing the hydrological impact of afforestation and tree species in two catchments with contrasting soil properties using the spatially distributed model MIKE SHE SWET

    DEFF Research Database (Denmark)

    Sonnenborg, Torben Obel; Christiansen, Jesper Riis; Pang, Bo

    2017-01-01

    afforestation or forest conversion impacts the water resource at the catchment scale. We hypothesize that the groundwater formation and streamflow is increased when water consuming conifers are replaced with the less consumptive broadleaf tree species. To test this a distributed hydrological model...... (conifer/broadleaf) and agricultural crops (grass, maize, wheat and barley) in different areal combinations. Initially, the SWET component was calibrated against plot scale field data from two forest sites to obtain vegetation parameter estimates for conifers and broadleaves. Subsequently, the catchment...... models were run for 10 years with predefined land use scenarios. MIKE SHE SWET simulated canopy interception and throughfall for conifers and broadleaf forests satisfactorily. The catchment simulations showed that replacing current conifer forests with broadleaves, resulted in a significant increase...

  20. Multiple metrics of diversity have different effects on temperate forest functioning over succession.

    OpenAIRE

    Yuan, Zuoqiang; Wang, Shaopeng; Gazol, Antonio; Mellard, Jarad Pope; Lin, Fei; Ye, Ji; Hao, Zhanqing; Wang, Xugao; Loreau, Michel

    2016-01-01

    Biodiversity can be measured by taxonomic, phylogenetic, and functional diversity. How ecosystem functioning depends on these measures of diversity can vary from site to site and depends on successional stage. Here, we measured taxonomic, phylogenetic, and functional diversity, and examined their relationship with biomass in two successional stages of the broad-leaved Korean pine forest in northeastern China. Functional diversity was calculated from six plant traits, and aboveground biomass (...

  1. Availability and toxicity of pendimethalin to aquatic microorganisms

    OpenAIRE

    Bražėnaitė, Janina; Šakalienė, Ona

    2006-01-01

    The characterization of bioavailability and toxicity of pesticides is necessary for the assessment of environmental risk caused by these chemicals. Pendimethalin is a dinitroaniline herbicide used for selective control of most annual grasses and many annual broad-leaved weeds in several crops. The technical formulation of this herbicide, Stomp 330, has been approved in Lithuania and is applied to winter rye, barley, maize, winter wheat, as well as to some vegetable crops. The objective of thi...

  2. Výskyt RNA elementů u rodu Armillaria

    OpenAIRE

    Dvořák, Jiří

    2008-01-01

    Mycoviruses are widespread among the fungi. Most mycoviruses reported have dsRNA genomes. The first mycovirus was found in the edible mushroom Agaricus bisporus. Mycoviruses do not have an extracellular phase of their life cycle and are transmitted only by intracellular routes. Many mycoviruses reveal no apparent effect on their hosts. The genus Armillaria represents economically important edible fungal pathogens causing root rot in conifers and broadleaves trees. From this viewpoint, genus A...

  3. Saugus River and Tributaries Flood Damage Reduction Study; Lynn, Malden, Revere and Saugus, Massachusetts. Section 2. Final Environmental Impact Statement and Final Environmental Impact Report

    Science.gov (United States)

    1989-12-01

    toxins, interspecific competition and allelopathy (the suppression of growth of one plant species by another due to the release of toxic substances...integrated assemblages of narrow-leaved cattail (IUh angustifolia), broad-leaved cattail (Toha latifolia) and the hybrid blue cattail (Jxpjha gja), and...X Atlantic Herring Clu ep harenlgusharng X X X Alewife (a) Alo seudoharenus X x X Blueback Herring (a) Alosa aestivalis X X X American Shad (a) Alosa

  4. Final Environmental Assessment for Land Exchange at Dyess Air Force Base, Taylor County, Texas

    Science.gov (United States)

    2011-10-01

    areas (zones) for the AICUZ program. These runway classes are not to be confused with aircraft approach categories and aircraft wingspan in other...status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual’s... insects for feeding; species composition less important than presence of adequate broad-leaved shrubs, foliage to ground level, and required

  5. Satellite Derived Forest Phenology and Its Relation with Nephropathia Epidemica in Belgium

    OpenAIRE

    José Miguel Barrios; Verstraeten, Willem W.; Piet Maes; Jan Clement; Jean-Marie Aerts; Sara Amirpour Haredasht; Julie Wambacq; Katrien Lagrou; Geneviève Ducoffre; Marc Van Ranst; Daniel Berckmans; Pol Coppin

    2010-01-01

    The connection between nephropathia epidemica (NE) and vegetation dynamics has been emphasized in recent studies. Changing climate has been suggested as a triggering factor of recently observed epidemiologic peaks in reported NE cases. We have investigated whether there is a connection between the NE occurrence pattern in Belgium and specific trends in remotely sensed phenology parameters of broad-leaved forests. The analysis of time series of the MODIS Enhanced Vegetation Index revealed that...

  6. Cluster analysis in primary roundwood production of 25 countries of European Union

    OpenAIRE

    Panagiotis P. Koulelis

    2009-01-01

    Main objective of this research is the effects of the political and economic enlargement of Europe in the market of wood products, especially for primary production of conifers and broadleaves round timber. The research consists in the application of the hierarchical cluster analysis to classify the 25 member countries, based on the roundwood coniferous and non-coniferous production during the period 1992-2002. Valuable conclusions came out regarding the market changes due to the participatio...

  7. Influence de la structure du peuplement forestier sur la distribution de l'éclairement sous couvert. Cas d'une forêt hétérogène feuillue sur plateau calcaire.

    OpenAIRE

    Piboule, Alexandre

    2005-01-01

    Light models simulate the distribution of understory lighting from a characterisation of crowns geometry. Our goal was to reduce the quantity of data required. We measured the data set necessary to a light model (tRAYci) in a heterogeneous broadleaved stand. We established relationships between the variables characteristic of the crown and the diameter of the trees at 1.30 m. We developed an algorithm taking competition between crowns for space occupation into account, given only the species ...

  8. Sweet chestnut cultures in the Southern Alps – conservation and regional development. eco.mont (Journal on Protected Mountain Areas Research)|eco.mont Vol. 2 No. 1 2 1|

    OpenAIRE

    Bender, Oliver

    2010-01-01

    Sweet chestnut cultures are a major component of the vegetation in many large protected areas of the Southern Alps. Since Roman times, vast areas of Southern and Western Europe have been covered by groves and coppices of sweet chestnut trees (Castanea sativa MILL.). Having replaced the original broadleaved forest, they used to play a vital role in traditional agriculture. Chestnut cultivation was even more important in terms of producing a substitute for cereals (bread) than for the productio...

  9. Laboratory study on the interaction between herbicide MCPA and two different soils

    OpenAIRE

    Hiller, Edgar; Dubovský, Dávid; Bartal', Mikuláš; Zemanová, Lenka; Khun, Miloslav

    2006-01-01

    Acidic herbicide MCPA (4-chloro-2-methylphenoxyacetic acid) is applied to post-emergence control of annual and perennial broad-leaved weeds, mostly in cereals. This study was undertaken with two soils of different properties sampled from two soil horizons to determine the extent of degradation, sorption and desorption of MCPA. These processes are the most important to evaluate the fate of the herbicide in soil and its potential to leach from soil into groundwater. Two soils were used: a calca...

  10. SOILS UNDER BEECH IN THE KODRY HILLS

    Directory of Open Access Journals (Sweden)

    A. Ursu

    2008-10-01

    Full Text Available In the Kodry Hills, small areas of virgin beech forests stands are preserved. These beech groves are developed on specific intrazonal lithomorphic soils. The mineralogical composition of substrate impedes the development of eluvial−illuvial processes and leaching of carbonates typical of the zonal soils that form under broad-leaved forests. The soils under study belong to the group of rendzic soils and can be referred to as marly rendzinas (or pseudorendzinas.

  11. Assessing the after-effects of changes in the river flow regime due to different hydrotechnical constructions upon floodplain ecosystems

    OpenAIRE

    Kouzmina, J.V.; Treshkin, S.Y.; Avetjan, S.A.; Henrichfreise, A.

    2005-01-01

    The complex environmental research (hydrology, vegetation, soils and ground water) has been carried out in nature reserves, located on the Danube banks within the zone of broad-leaved forests in Germany. Under comparison were terrestrial ecosystems along the regulated and natural rivers. It was established that the weirs, dams with low head of water and small artificial reservoirs affects upon the vegetation and soils of floodplains to be manifested some decades later. A comprehensive analysi...

  12. Tissue culture of trees. [Contains glossary

    Energy Technology Data Exchange (ETDEWEB)

    Dodds, J.H. (ed.)

    1983-01-01

    The book is designed for students and research scientists. Apart from an introduction and conclusions by the editor, there are 9 chapters by various authors covering: the tissue culture of conifers, broadleaves, coconut, date and oil palm, ornamental trees, temperate fruit trees, and citrus; the influence of physical factors on xylem differentation in vitro; the use of protoplast technology; and tissue culture conservation. A short glossary is provided.

  13. Wall-to-Wall Tree Type Mapping from Countrywide Airborne Remote Sensing Surveys

    OpenAIRE

    Lars T. Waser; Christian Ginzler; Nataliia Rehush

    2017-01-01

    Although wall-to-wall, accurate, and up-to-date forest composition maps at the stand level are a fundamental input for many applications, ranging from global environmental issues to local forest management planning, countrywide mapping approaches on the tree type level remain rare. This paper presents and validates an innovative remote sensing based approach for a countrywide mapping of broadleaved and coniferous trees in Switzerland with a spatial resolution of 3 m. The classification approa...

  14. Cocos sahnii Kaul: a Cocos nucifera L.-like fruit from the Early Eocene rainforest of Rajasthan, western India.

    Science.gov (United States)

    Shukla, Anumeha; Mehrotra, Rakesh C; Guleria, Jaswant S

    2012-09-01

    Cocos sahnii Kaul, a fossil palm fruit, is validated and described from the Fuller's earth deposits of Kapurdi village of Rajasthan considered as Early Eocene in age. The fossil best resembles the genus Cocos, particularly Cocos nucifera L., which is now a common coastal element thriving in highly moist conditions. The recovery of this coconut-like fruit, along with earlier described evergreen taxa from the same formation, suggests the existence of typical tropical, warm and humid coastal conditions during the depositional period. The present arid to semi-arid climatic conditions occurring in Rajasthan indicate drastic climate change in the region during the Cenozoic. The possible time for the onset of aridity in the region which caused the total eradication of semi-evergreen to evergreen forests is discussed, as well as the palaeobiogeography of coconuts.

  15. Insect herbivory, plant defense, and early Cenozoic climate change.

    Science.gov (United States)

    Wilf, P; Labandeira, C C; Johnson, K R; Coley, P D; Cutter, A D

    2001-05-22

    Insect damage on fossil leaves from the Central Rocky Mountains, United States, documents the response of herbivores to changing regional climates and vegetation during the late Paleocene (humid, warm temperate to subtropical, predominantly deciduous), early Eocene (humid subtropical, mixed deciduous and evergreen), and middle Eocene (seasonally dry, subtropical, mixed deciduous and thick-leaved evergreen). During all three time periods, greater herbivory occurred on taxa considered to have short rather than long leaf life spans, consistent with studies in living forests that demonstrate the insect resistance of long-lived, thick leaves. Variance in herbivory frequency and diversity was highest during the middle Eocene, indicating the increased representation of two distinct herbivory syndromes: one for taxa with deciduous, palatable foliage, and the other for hosts with evergreen, thick-textured, small leaves characterized by elevated insect resistance. Leaf galling, which is negatively correlated with moisture today, apparently increased during the middle Eocene, whereas leaf mining decreased.

  16. Vegetation and climate dynamics of southern Chile during the past 50,000 years: results of ODP Site 1233 pollen analysis

    Science.gov (United States)

    Heusser, Linda; Heusser, Cal; Pisias, Nicklas

    2006-03-01

    High-resolution pollen data from ODP Site 1233 (41°0.005S, 74°26.992W, 838 m water depth) provide a continuous, chronostratigraphically controlled ˜50,000-yr record of regional changes in vegetation from temperate South America. Deposited ˜38 km west of the transition from northern, summer-green, lowland forest to southern evergreen rain forest, the 135 m core documents the comparatively brief Holocene development of thermophilous vegetation (Lowland Deciduous Beech Forest and Valdivian Evergreen Forest), and the expansion of glacial, subantarctic vegetation (North Patagonian Evergreen Forest-Subantarctic Parkland) during Marine Isotope State (MIS) 2 and 3. Systematic variability in these terrestrial climate proxies that reflect latitudinal movement of the southern westerlies is mirrored in co-eval ocean conditions inferred from radiolaria census data and in Antarctic climate records.

  17. The response of macroinvertebrates to artificially enhanced detritus levels in plantation streams

    Science.gov (United States)

    Pretty, J. L.; Dobson, M.

    The leaves and wood from vegetation surrounding headwater streams constitute a major food source for aquatic invertebrates, providing they are retained upon the streambed and not transported downstream. This study investigated the response of aquatic invertebrates to artificially increased detritus retention, in an effort to reproduce the naturally occurring build up of dead organic matter associated with streams in old-growth forest. The background detrital standing stock in streams in Kielder Forest (Northumberland, UK) was low, approximately 32 gm-2. Two streams flowing through dense conifer plantation and one in open broadleaved woodland were manipulated by the addition of logs over a 10 m stream reach. After several months, log addition significantly enhanced detrital standing stocks in both conifer and broadleaved streams. Total invertebrate abundance, taxon richness and the numbers of certain numerically dominant families were significantly higher in experimental than reference reaches in both conifer and broadleaved streams. This response was most marked for detritivores, whilst non-detritivore groups often showed no response to the manipulation. Whilst in the short term the responses to enhanced retention may reflect a redistribution of the local fauna, it is argued that over a longer time-scale, a genuine increase in invertebrate density and diversity could occur. Allowing old-growth forest to develop in planted valley bottoms may be a viable management option for conservation. If established alongside streams, it would ensure continuous input of woody material and the fauna may benefit from the resulting increase in detritus retention.

  18. Using historical ecology to reassess the conservation status of coniferous forests in Central Europe.

    Science.gov (United States)

    Szabó, Péter; Kuneš, Petr; Svobodová-Svitavská, Helena; Švarcová, Markéta Gabriela; Křížová, Lucie; Suchánková, Silvie; Müllerová, Jana; Hédl, Radim

    2017-02-01

    Forests cover approximately one-third of Central Europe. Oak (Quercus) and European beech (Fagus sylvatica) are considered the natural dominants at low and middle elevations, respectively. Many coniferous forests (especially of Picea abies) occur primarily at midelevations, but these are thought to have resulted from forestry plantations planted over the past 200 years. Nature conservation and forestry policy seek to promote broadleaved trees over conifers. However, there are discrepancies between conservation guidelines (included in Natura 2000) and historical and palaeoecological data with regard to the distribution of conifers. Our aim was to bring new evidence to the debate on the conservation of conifers versus broadleaved trees at midelevations in Central Europe. We created a vegetation and land-cover model based on pollen data for a highland area of 11,300 km 2 in the Czech Republic and assessed tree species composition in the forests before the onset of modern forestry based on 18th-century archival sources. Conifers dominated the study region throughout the entire Holocene (approximately 40-60% of the area). Broadleaved trees were present in a much smaller area than envisaged by current ideas of natural vegetation. Rather than casting doubt on the principles of Central European nature conservation in general, our results highlight the necessity of detailed regional investigations and the importance of historical data in challenging established notions on the natural distribution of tree species. © 2016 Society for Conservation Biology.

  19. The relationship between soil properties, enzyme activity and land use

    Directory of Open Access Journals (Sweden)

    Błońska Ewa

    2017-03-01

    Full Text Available The aim of this study was to assess the effects of different types of land use (forest, tillage and pasture on soil properties, especially enzyme activity. Our investigation was carried out on 53 research plots with 11 plots in broadleaved forest stands, 12 plots in mixed broadleaved stands, 10 plots in mixed coniferous stands, 9 plots on tillage and 11 plots on pasture. The soil samples were collected from a depth of 0–15 cm after removing the organic horizon. Contents of organic carbon and nitrogen, pH and soil texture were investigated. Furthermore, dehydrogenase and urease activity were determined. Significant differences in the enzyme activity between forest and agricultural soils were observed, thus demonstrating that enzyme activity is influenced by the organic matter content of the soil. The highest enzyme activity was recorded in the forest soil within broadleaved stands, whilst the lowest activity was found in tillage soil, because tillage soil contained significantly less organic matter. High enzymatic activity of pasture soils is the combined result of vegetation type and the lack of plowing.

  20. [Characteristics of soil seed banks in logging gaps of forests at different succession stages in Changbai Mountains].

    Science.gov (United States)

    Zhang, Zhi-Ting; Song, Xin-Zhang; Xiao, Wen-Fa; Gao, Bao-Jia; Guo, Zhong-Ling

    2009-06-01

    An investigation was made on the soil seed banks in the logging gaps of Populus davidiana--Betula platyphylla secondary forest, secondary broad-leaved forest, and broad-leaved Korean pine mixed forest at their different succession stages in Changbai Mountains. Among the test forests, secondary broad-leaved forest had the highest individual density (652 ind x m(-2)) in its soil seed bank. With the succession of forest community, the diversity and uniformity of soil seed bank increased, but the dominance decreased. The seed density of climax species such as Pinus koraiensis, Abies nephrolepis, and Acer mono increased, whereas that of Maackia amurensis and Fraxinus mandshurica decreased. Moreover, the similarity in species composition between soil seed bank and the seedlings within logging gaps became higher. The individual density and similarity between soil seed bank and the seedlings in non-logging gaps were similar to those in logging gaps. All of these indicated that soil seed bank provided rich seed resources for forest recovery and succession, and the influence of soil seed bank on seedlings regeneration increased with the succession.

  1. Persistent and pervasive compositional shifts of western boreal forest plots in Canada.

    Science.gov (United States)

    Searle, Eric B; Chen, Han Y H

    2017-02-01

    Species compositional shifts have important consequences to biodiversity and ecosystem function and services to humanity. In boreal forests, compositional shifts from late-successional conifers to early-successional conifers and deciduous broadleaves have been postulated based on increased fire frequency associated with climate change truncating stand age-dependent succession. However, little is known about how climate change has affected forest composition in the background between successive catastrophic fires in boreal forests. Using 1797 permanent sample plots from western boreal forests of Canada measured from 1958 to 2013, we show that after accounting for stand age-dependent succession, the relative abundances of early-successional deciduous broadleaves and early-successional conifers have increased at the expense of late-successional conifers with climate change. These background compositional shifts are persistent temporally, consistent across all forest stand ages and pervasive spatially across the region. Rising atmospheric CO2 promoted early-successional conifers and deciduous broadleaves, and warming increased early-successional conifers at the expense of late-successional conifers, but compositional shifts were not associated with climate moisture index. Our results emphasize the importance of climate change on background compositional shifts in the boreal forest and suggest further compositional shifts as rising CO2 and warming will continue in the 21st century. © 2016 John Wiley & Sons Ltd.

  2. Deposition velocities to Sorbus aria, Acer campestre, Populus deltoides x trichocarpa 'Beaupre', Pinus nigra and x Cupressocyparis leylandii for coarse, fine and ultra-fine particles in the urban environment

    Energy Technology Data Exchange (ETDEWEB)

    Freer-Smith, P.H.; Beckett, K.P.; Taylor, Gail

    2005-01-01

    Trees are effective in the capture of particles from urban air to the extent that they can significantly improve urban air quality. As a result of their aerodynamic properties conifers, with their smaller leaves and more complex shoot structures, have been shown to capture larger amounts of particle matter than broadleaved trees. This study focuses on the effects of particle size on the deposition velocity of particles (Vg) to five urban tree species (coniferous and broadleaved) measured at two field sites, one urban and polluted and a second more rural. The larger uptake to conifers is confirmed, and for broadleaves and conifers Vg values are shown to be greater for ultra-fine particles (Dp<1.0 {mu}m) than for fine and coarse particles. This is important since finer particles are more likely to be deposited deep in the alveoli of the human lung causing adverse health effects. The finer particle fraction is also shown to be transported further from the emission source; in this study a busy urban road. In further sets of data the aqueous soluble and insoluble fractions of the ultra-fines were separated, indicating that aqueous insoluble particles made up only a small proportion of the ultra-fines. Much of the ultra-fine fraction is present as aerosol. Chemical analysis of the aqueous soluble fractions of coarse, fine and ultra-fine particles showed the importance of nitrates, chloride and phosphates in all three size categories at the polluted and more rural location.

  3. Deposition velocities to Sorbus aria, Acer campestre, Populus deltoides X trichocarpa 'Beaupré', Pinus nigra and X Cupressocyparis leylandii for coarse, fine and ultra-fine particles in the urban environment.

    Science.gov (United States)

    Freer-Smith, P H; Beckett, K P; Taylor, Gail

    2005-01-01

    Trees are effective in the capture of particles from urban air to the extent that they can significantly improve urban air quality. As a result of their aerodynamic properties conifers, with their smaller leaves and more complex shoot structures, have been shown to capture larger amounts of particle matter than broadleaved trees. This study focuses on the effects of particle size on the deposition velocity of particles (Vg) to five urban tree species (coniferous and broadleaved) measured at two field sites, one urban and polluted and a second more rural. The larger uptake to conifers is confirmed, and for broadleaves and conifers Vg values are shown to be greater for ultra-fine particles (Dp < 1.0 microm) than for fine and coarse particles. This is important since finer particles are more likely to be deposited deep in the alveoli of the human lung causing adverse health effects. The finer particle fraction is also shown to be transported further from the emission source; in this study a busy urban road. In further sets of data the aqueous soluble and insoluble fractions of the ultra-fines were separated, indicating that aqueous insoluble particles made up only a small proportion of the ultra-fines. Much of the ultra-fine fraction is present as aerosol. Chemical analysis of the aqueous soluble fractions of coarse, fine and ultra-fine particles showed the importance of nitrates, chloride and phosphates in all three size categories at the polluted and more rural location.

  4. Evolutionarily stable strategy of carbon and nitrogen investments in forest leaves and its application in vegetation dynamic modeling

    Science.gov (United States)

    Weng, E.; Farrior, C.; Dybzinski, R.; Pacala, S. W.

    2015-12-01

    Leaf mass per area (LMA) and leaf lifespan (LL) are two highly correlated plant traits that are key to plant physiological and ecological properties. Usually, low LMA means short LL, high nitrogen (N) content per unit mass, and fast turnover rates of nutrients; high LMA leads to long LL, low N content, and slow turnover rates. Deciduous trees with low LMA and short lifespan leaves have low carbon cost but high nitrogen demand; and evergreen trees, with high LMA and long lifespan leaves, have high carbon cost but low nitrogen demand. These relationships lead to: 1) evergreen trees have higher leaf area index than deciduous trees; 2) evergreen trees' carbon use efficiency is lower than the deciduous trees' because of their thick leaves and therefore high maintenance respiration; 3) the advantage of evergreens trees brought by their extra leaves over deciduous trees diminishes with increase N in ecosystem. These facts determine who will win when trees compete with each other in a N-limited ecosystem. In this study, we formulate a mathematical model according to the relationships between LMA, LL, leaf nitrogen, and leaf building and maintenance cost, where LMA is the fundamental variable determining the other three. We analyze the evolutionarily stable strategies (ESSs) of LMA with this mathematical model by examining the benefits of carbon and nitrogen investments to leaves in ecosystems with different N. The model shows the ESS converges to low LMA at high N and high LMA at low N. At intermediate N, there are two ESSs at low and high ends of LMA, respectively. The ESS also leads to low forest productivity by outcompeting the possible high productive strategies. We design a simulation scheme in an individual-based competition model (LM3-PPA) to simulate forest dynamics as results of the competition between deciduous and evergreen trees in three different biomes, which are temperate deciduous forest, deciduous-evergreen mixed forest, and boreal evergreen forest. The

  5. Phase and amplitude of ecosystem carbon release and uptake potentials as derived from FLUXNET measurements

    DEFF Research Database (Denmark)

    Falge, E.; Tenhunen, J.; Baldocchi, D.

    2002-01-01

    boreal and temperate. deciduous and coniferous forests, Mediterranean evergreen systems, rainforest, native and managed temperate grasslands, tundra, and C-3 and C-4 crops. Generalization of seasonal patterns are useful for identifying functional vegetation types for global dynamic vegetation models...... in four classes: (1) boreal and high altitude conifers and grasslands: (2) temperate deciduous and temperate conifers; (3) tundra and crops; (4) evergreen Mediterranean and tropical forest,,, Similar results are found for maximum daytime uptake (F-min) and the integral net carbon flux, but temperate...... deciduous forests fall into class 1. For forests, seasonal amplitudes of F-max and F-min increased in the order tropical

  6. Easing Gently into OpenSRF, Part 1

    Directory of Open Access Journals (Sweden)

    Dan Scott

    2010-06-01

    Full Text Available The Open Service Request Framework (or OpenSRF, pronounced "open surf" is an inter-application message passing architecture built on XMPP (aka "jabber". The Evergreen open source library system is built on an OpenSRF architecture to support loosely coupled individual components communicating over an OpenSRF messaging bus. This article introduces OpenSRF, demonstrates how to build OpenSRF services through simple code examples, explains the technical foundations on which OpenSRF is built, and evaluates OpenSRF's value in the context of Evergreen. Part 1 of a 2 part article in this issue.

  7. Easing Gently into OpenSRF, Part 2

    Directory of Open Access Journals (Sweden)

    Dan Scott

    2010-06-01

    Full Text Available The Open Service Request Framework (or OpenSRF, pronounced "open surf" is an inter-application message passing architecture built on XMPP (aka "jabber". The Evergreen open source library system is built on an OpenSRF architecture to support loosely coupled individual components communicating over an OpenSRF messaging bus. This article introduces OpenSRF, demonstrates how to build OpenSRF services through simple code examples, explains the technical foundations on which OpenSRF is built, and evaluates OpenSRF's value in the context of Evergreen. Part 2 of a 2 part article in this issue.

  8. Temperature sensitivity and basal rate of soil respiration and their determinants in temperate forests of North China.

    Directory of Open Access Journals (Sweden)

    Zhiyong Zhou

    Full Text Available The basal respiration rate at 10°C (R10 and the temperature sensitivity of soil respiration (Q10 are two premier parameters in predicting the instantaneous rate of soil respiration at a given temperature. However, the mechanisms underlying the spatial variations in R10 and Q10 are not quite clear. R10 and Q10 were calculated using an exponential function with measured soil respiration and soil temperature for 11 mixed conifer-broadleaved forest stands and nine broadleaved forest stands at a catchment scale. The mean values of R10 were 1.83 µmol CO2 m(-2 s(-1 and 2.01 µmol CO2 m(-2 s(-1, the mean values of Q10 were 3.40 and 3.79, respectively, for mixed and broadleaved forest types. Forest type did not influence the two model parameters, but determinants of R10 and Q10 varied between the two forest types. In mixed forest stands, R10 decreased greatly with the ratio of coniferous to broadleaved tree species; whereas it sharply increased with the soil temperature range and the variations in soil organic carbon (SOC, and soil total nitrogen (TN. Q10 was positively correlated with the spatial variances of herb-layer carbon stock and soil bulk density, and negatively with soil C/N ratio. In broadleaved forest stands, R10 was markedly affected by basal area and the variations in shrub carbon stock and soil phosphorus (P content; the value of Q10 largely depended on soil pH and the variations of SOC and TN. 51% of variations in both R10 and Q10 can be accounted for jointly by five biophysical variables, of which the variation in soil bulk density played an overwhelming role in determining the amplitude of variations in soil basal respiration rates in temperate forests. Overall, it was concluded that soil respiration of temperate forests was largely dependent on soil physical properties when temperature kept quite low.

  9. Cold in the common garden: comparative low-temperature tolerance of boreal and temperate conifer foliage

    Science.gov (United States)

    G. Richard Strimbeck; Trygve D. Kjellsen; Paul G. Schaberg; Paula F. Murakami

    2007-01-01

    Because they maintain green foliage throughout the winter season, evergreen conifers may face special physiological challenges in a warming world. We assessed the midwinter low-temperature (LT) tolerance of foliage from eight temperate and boreal species in each of the genera Abies, Picea, and Pinus growing in an arboretum in...

  10. Does water stress, nutrient limitation, or H-toxicity explain the differential stature among Heath Forest types in Central Kalimantan, Indonesia?

    NARCIS (Netherlands)

    Vernimmen, R.R.E.; Bruijnzeel, L.A.; Proctor, J.; Verhoef, H.A.; Klomp, N.

    2013-01-01

    To investigate the causes of the reduced stature of heath forest compared to lowland evergreen rain forest (LERF), the quantity and quality of small litterfall (LF), the standing crop of litter on the forest floor (LSC), and the annual rates of litter decay were determined over a period of 12 months

  11. Mapping resistance to Phytophthora cinnamomi in chestnut (Castanea sp.)

    Science.gov (United States)

    Bode A. Olukolu; C. Dana Nelson; Albert G. Abbott

    2012-01-01

    Phytophthora cinnamomi (Phytophthora crown and root rot, or ink disease) is now known to infect several hundred plant species in the world and is especially linked to the widespread death of mature chestnut (Castanea) and evergreen oak (Quercus ilex L.) trees in southeast United States. With an expanding...

  12. Molecular diversity among Turkish oaks ( QUERCUS ) using random ...

    African Journals Online (AJOL)

    Here, three species of evergreen oaks known as Quercus coccifera, Quercus ilex and Quercus aucheri were studied in all area located and made the comparison within and among species studied using ten RAPD markers. As a result; it can be stated that the presence of the three species in Ilex section is clear. Furthermore ...

  13. Genetic structure of Notholithocarpus densiflorus(Fagaceae) from the species to the local scale: A review of our knowledge for conservation and replanting

    Science.gov (United States)

    Richard S Dodd; Alejandro Nettel; Jessica W. Wright; Zara. Afzal-Rafii

    2013-01-01

    Tanoak, Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S. H. Oh (Fagaceae), is an important component of mixed-evergreen forests and woodlands in coastal California and Oregon, with incursions into the Sierra Nevada and the Klamath Ranges. Sudden Oak Death (SOD) is causing severe dieback and mortality in tanoak and could...

  14. Comprehensive national database of tree effects on air quality and human health in the United States

    Science.gov (United States)

    Satoshi Hirabayashi; David J. Nowak

    2016-01-01

    Trees remove air pollutants through dry deposition processes depending upon forest structure, meteorology, and air quality that vary across space and time. Employing nationally available forest, weather, air pollution and human population data for 2010, computer simulations were performed for deciduous and evergreen trees with varying leaf area index for rural and...

  15. 21 CFR 184.1343 - Locust (carob) bean gum.

    Science.gov (United States)

    2010-04-01

    ...) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia siliqua (Linne), a leguminous evergreen tree, with lesser quantities of seed coat and germ. (b) The...(o)(28) of this chapter. Beverages and beverage bases, nonalcoholic, § 170.3(n)(3) of this chapter...

  16. Flowering Trees

    Indian Academy of Sciences (India)

    Cerbera manghasL. (SEA MANGO) of Apocynaceae is a medium-sized evergreen coastal tree with milky latex. The bark is grey-brown, thick and rough. Leaves are leathery, long-veined, alternate and usually crowded at the end of branches. Flowers are in terminal compact clusters and are mildly scented, large (3–.

  17. Saraca asoca (Roxb.) de Wilde Syn. Saraca indica L. (English ...

    Indian Academy of Sciences (India)

    Saraca asoca (Roxb.) de Wilde Syn. Saraca indica L. (English: Ashoka; Hindi: Asok) ofCaesalpilliaceae is a medium sized extremely ornamental evergreen tree with numerous spreading and drooping branches, compound leaves and orange-yellow flowers in clusters. Fruits are black, leathery pods with compressed seeds.

  18. Effects of Ben 10 on Kids in the Age-Group 5 to 8 Years

    Science.gov (United States)

    Sandhu, Devendar

    2014-01-01

    "The problem with our society is that our values aren't in the right place. There's an awful lot of bleeding and naked bodies on prime-time networks, but not nearly enough cable television on public programming." --Bauvard, Evergreens Are Prudish Technology has expanded the availability of information through various routes, such as,…

  19. Forest ecosystem changes from annual methane source to sink depending on late summer water balance

    Science.gov (United States)

    Julie K. Shoemaker; Trevor F. Keenan; David Y. Hollinger; Andrew D. Richardson

    2014-01-01

    Forests dominate the global carbon cycle, but their role in methane (CH4) biogeochemistry remains uncertain. We analyzed whole-ecosystem CH4 fluxes from 2 years, obtained over a lowland evergreen forest in Maine, USA. Gross primary productivity provided the strongest correlation with the CH4 flux in...

  20. Homesick vulture moves into retirement village

    African Journals Online (AJOL)

    2007-03-01

    Mar 1, 2007 ... Residents of Pietermaritzburg's. Evergreen Retirement Village had a bit of a turn recently when a rare and homesick vulture took up residence in a pine tree in their garden. Believing it to be a harbinger of bad news, one resident apparently turned to another and said,. “We had better do a head count to see.