Aims Soil respiration(Rs)is a major process controlling soil carbon loss in forest ecosystems.However,the underlying mechanisms leading to variation in Rs along forest successional gradients are not well understood.In...Aims Soil respiration(Rs)is a major process controlling soil carbon loss in forest ecosystems.However,the underlying mechanisms leading to variation in Rs along forest successional gradients are not well understood.In this study,we investigated the effects of biotic and abiotic factors on Rs along a forest successional gradient in southeast China.Methods We selected 16 plots stratified by forest age,ranging from 20 to 120 years.In each plot,six shallow collars and six deep collars were permanently inserted into the soil.Shallow and deep collars were used to measure Rs and heterotrophic respiration(Rh),respectively.Autotrophic soil respiration(Ra)was estimated as the difference between Rs and Rh.Litter layer respiration(R_(L))was calculated by subtracting soil respiration measured in collars without leaf litter layer(R_(NL))from Rs.Rs was measured every 2 months,and soil temperature(ST)and soil volumetric water content(SVWC)were recorded every hour for 19 months.We calculated daily Rs using an exponential model dependent on ST.Daily Rs was summed to obtain cumulative annual Rs estimates.Structural equation modelling(SEM)was applied to identify the drivers of Rs during forest succession.Important Findings Rs showed significant differences among three successive stages,and it was the highest in the young stage.Ra was higher in the young stage than in the medium stage.Cumulative annual Rs and Ra peaked in the young and old stages,respectively.Cumulative annual Rh and respiration measured from soil organic matter(R_(SOM))decreased,whereas R_(L)increased with forest age.The SEM revealed that cumulative annual Rs was influenced by fine root biomass and SVWC.Our results indicated that the dominant force regulating Rs on a seasonal scale is ST;however,on a successional scale,belowground carbon emerges as the dominant influential factor.展开更多
Aims We investigated the regulation of the water status in three predominant perennial C3 phreatophytes(Alhagi sparsifolia,Populus euphratica,Tamarix ramosissima)at typical sites of their occurrence at the southern fr...Aims We investigated the regulation of the water status in three predominant perennial C3 phreatophytes(Alhagi sparsifolia,Populus euphratica,Tamarix ramosissima)at typical sites of their occurrence at the southern fringe of the hyperarid Taklamakan Desert(north-west China).Methods In the foreland of the river oasis of Qira(Cele),we determined meteorological variables,plant biomass production,plant water potentials(WL)and the water flux through the plants.We calculated the hydraulic conductance on the flow path from the soil to the leaves(kSL)and tested the effects of kSL,WL and the leaf-to-air difference in the partial pressure of water vapour(Dw)on stomatal regulation using regression analyses.Important Findings Despite high values of plant water potential at the point of turgor loss,all plants sustained WL at levels that were high enough to maintain transpiration throughout the growing season.In A.sparsifolia,stomatal resistance(rs;related to leaf area or leaf mass)was most closely correlated with kSL;whereas in P.euphratica,~70%of the variation in rs was explained by Dw.In T.ramosissima,leaf area-related rs was significantly correlated with WL and kSL.The regulation mechanisms are in accordance with the growth patterns and the occurrence of the species in relation to their distance to the ground water.展开更多
Background:Restoration projects have been implemented worldwide to mitigate the adverse effects of the loss and degradation of wetland habitats.Much research has been carried out on the impacts on birds of wetland res...Background:Restoration projects have been implemented worldwide to mitigate the adverse effects of the loss and degradation of wetland habitats.Much research has been carried out on the impacts on birds of wetland restoration and management projects in China. Studies have mainly investigated central or coastal wetlands,while inland wetlands in remote areas have been much less studied. We focused on examining the response of wild birds to wetland restoration in Dianchi Lake,south-west China. Methods: The line transect method was performed at 26 sampling plots.Three of these were in the city,and to acquire all wild bird data 23 plots were located every 2-8 km along the shore of Dianchi Lake, between December 2011 and November 2013.We collected all related bird records by searching the available literature, articles, newspapers and records of birdwatchers to compare species variation before and after implementation of wetland restoration.To measure the relationships between waterbird assemblages and habitat structures, we used canonical correspondence analysis (CCA) to pair the main matrix of bird assemblages with a second matrix of habitat variables. Results: We recorded 182 bird species belonging to 51 families and 17 orders. Of the species, 42 were new records for Kunming City and 20 were new records for Yunnan Province. Ten waterbird species were found to have disappeared from the shore of Dianchi Lake.CCA results indicated that waterbirds could be divided into four categories based on their habitat preference:synanthropic (wintering gulls), special habitat (shorebirds),semi-natural (wintering coots and ducks) and disturbance-tolerant (resident) species.Conclusions:Our study is the first to consider the entire wild bird community throughout the year and discuss the species variation before and after wetland restoration projects launched for Dianchi Lake.Distinct habitat requirements of different waterbird groups were detected in our study,suggesting different types of restoration and management should be impleme展开更多
The active layer is the top layer of permafrost soils that thaws during the summer season due to increased ambient temperatures and solar radiation inputs. This layer is important because almost all biological activit...The active layer is the top layer of permafrost soils that thaws during the summer season due to increased ambient temperatures and solar radiation inputs. This layer is important because almost all biological activity takes place there during the summer. The depth of active layer thaw is influenced by climatic conditions. Vegetation has also been found to have a strong impact on active layer thaw, because it can intercept incoming radiation, thereby insulating the soil from ambient conditions. In order to look at the role of vegetation and climate on active layer thaw, we measured thaw depth and the Normalized Difference Vegetation Index (NDVI; a proxy for aboveground plant biomass) along a latitudinal temperature gradient in arctic Alaska and Canada. At each site several measurements of thaw and NDVIwere taken in areas with high amounts of vegetation and areas with little to no vegetation. Results show that the warmest regions, which had the greatest levels of NDVI, had relatively shallow thaw depths, and the coldest regions, which had the lowest levels of NDVI, also had relatively shallow thaw depths. The intermediate regions, which had moderate levels of NDVIand air temperature, had the greatest depth of thaw. These results indicate that temperature and vegetation interact to control the depth of the active layer across a range of arctic ecosystems. By developing a relationship to explain thaw depth through NDVIand temperature or latitude, the possibility exists to extrapolate thaw depth over large scales via remote sensing applications.展开更多
The paper analyzes the hypothesis that the distribution of dominant plant species and characteristics of plant communities are related to groundwater depth. The results showed that variations of groundwater depth impa...The paper analyzes the hypothesis that the distribution of dominant plant species and characteristics of plant communities are related to groundwater depth. The results showed that variations of groundwater depth impacted distributions and characteristics of dominant plant communities. However, besides groundwater depth, the community composition and species diversity were also influenced by physiognomy of the habitat. Based on the similarity coefficient, the differences between dominant plant communities were significant at different groundwater depths. Compared with other results relating to desert vegetation and groundwater depth, variations of community distribution were similar at the large spatial scale. However, in this extremely arid region, there were significant differences in community type and community succession when compared with other arid regions, especially in relationship to deep groundwater depth. With groundwater depth from deep to shallow, communities transformed with the sequence of Alhagi communities, Tamarix spp. communities, Populus communities, Phragmites communities, and Sophora communities. At groundwater depth of less than 6.0 m, the community type and composition changed, and the species diversity increased. Among these dominant species, Tamarix exhibited the biggest efficiency in resource utilization according to niche breadth, which means it possessed the best adaptability to environmental conditions at the oasis margins.展开更多
The problem of wild elephants, or human-elephant conflict (HEC), influences the daily life of local communities and hinders the conservation of wild elephants.The perception and attitudes of local communities who inha...The problem of wild elephants, or human-elephant conflict (HEC), influences the daily life of local communities and hinders the conservation of wild elephants.The perception and attitudes of local communities who inhabited the frontiers between human activities and wild elephant movement are important to the mitigation of the HEC and conservation of wild elephants. To analyze the perception and attitudes of local communities, the Participatory Rural Appraisal (PRA) was used in the investigation of 423 interviewees from 22 villages in Xishuangbanna from July 2009 to February 2010. The results indicated that local communities had their views on the elephant-related problems. In field survey, we found that 66.5% of interviewees were willing to support, participate in, and assist in the conservation of wild elephants;33.5% of interviewees were opposed or indifferent to such conservation, because their livelihoods and even their lives were endangered by wild elephants. These views and attitudes were influenced by local communities′perception of HEC, education level, gender and self-interest. Therefore, it is necessary to analyze the diverse views among local communities and balance profits and costs in addressing HEC.展开更多
Aims We investigated shifts in community-weighted mean traits(CWm)of 14 leaf functional traits along a secondary successional series in an evergreen broadleaf forest in subtropical southeast China.most of the investig...Aims We investigated shifts in community-weighted mean traits(CWm)of 14 leaf functional traits along a secondary successional series in an evergreen broadleaf forest in subtropical southeast China.most of the investigated traits have been reported to affect litter decomposition in previous studies.We asked whether changes in CWms along secondary succession followed similar patterns for all investigated traits and whether the shifts in CWm indicated a change in resource use strategy along the successional gradient.using community decomposition rates(k-rates)estimated from annual lit-ter production and standing litter biomass,we asked whether the dynamics of litter decomposition were related to changes in leaf functional traits along the successional series.Methods twenty-seven plots were examined for shifts in leaf CWm traits as well as in k-rates along a series of secondary forest succession cov-ered in the framework of the bEF-China project.We investigated whether the changes in CWms followed similar patterns for all traits with ongoing succession.three alternative linear models were used to reveal the general patterns of shifts in CWm trait values.moreover,multiple regression analysis was applied to investigate whether there were causal relationships between the changes in leaf functional traits and the dynamics of litter decomposition along secondary succession.We furthermore assessed which traits had the highest impact on community litter decomposition.Important Findingsshifts in CWm values generally followed logarithmic patterns for all investigated traits,whereas community k-rates remained stable along the successional gradient.In summary,the shifts in CWm values indicate a change in community resource use strategy from high nutrient acquisition to nutrient retention with ongoing succession.stands with higher CWm values of traits related to nutrient acquisition had also higher CWm values of traits related to chemical resistance,whereas stands with higher CWm values of traits related to nutrient retention ex展开更多
Monitoring and minimizing tourist’s water consumption is essential for the sustainable development of mountain destinations in the world. However, available data and a generally accepted protocol on such measurement ...Monitoring and minimizing tourist’s water consumption is essential for the sustainable development of mountain destinations in the world. However, available data and a generally accepted protocol on such measurement are still limited. This study uses water footprint accounting to quantify tourist’s water demand in the Liming valley, a World Heritage site and a rapidly growing tourism destination in Northwest Yunnan, China. Both the water for direct and indirect use is taken into account based on the consumptive behavior of the tourists in the valley. Data were collected through guesthouse monitoring and a tourist survey in the 2005 tourist season. The results indicate that an average tourist leaves behind a footprint of 5.2 m3 on local water resources per day. Food production and waste dilution are the two most important water consumption factors. The results also show tourists consume more water than the local residents on per capita basis. This suggests more commitment is necessary to cope with this stress by individual tourists. Management implications to make water use more sustainable in mountain destinations are derived from this study.展开更多
Aims In forests,the herbaceous understory vegetation plays an important role for ecosystem functioning as it represents a significant component of total aboveground productivity.In addition,the herb layer contributes ...Aims In forests,the herbaceous understory vegetation plays an important role for ecosystem functioning as it represents a significant component of total aboveground productivity.In addition,the herb layer contributes to overall forest species richness and controls tree species regeneration.Vice versa,trees in the overstory control understory herb and shrub growth through competition for resources.Using an experimental forest plantation with manipulated tree richness,we asked to which degree tree species richness and identity affect herb layer composition,richness and productivity and how these relationships across strata change with abiotic environmental conditions and competition intensity.Methods In the context of the Biodiversity-Ecosystem Functioning project in subtropical China(BEF-China),we made use of the integrated BEFmod experiment arranged along a tree species richness gradient at two sites,with additional subplot treatments of phosphorus addition,herb layer weeding and no weeding.We recorded the understory vegetation and determined herb layer biomass production on a total of 201 subplots.Important Findings We found only minor effects of tree layer richness on herb layer species composition and no significant effect on herb layer richness or productivity yet.However,there were strong tree layer identity effects on all response variables,which were partly explained by differences in leaf area index and by a high share of woody species both in total herb layer species richness and biomass.There were strong treatment effects,which were largest in the‘no weeding’treatment but we did not find any treatment×tree layer richness interaction in herb layer responses.Thus,these effects are mainly explained by increased competition intensity within the herb layer in the absence of weeding.Despite the young age of the experiment,the interactions between tree species identity,tree richness and the herb layer did already emerge and can be expected to become stronger with ongoing runtime of the experiment.展开更多
This paper is a compilation of notes on 110 fungal taxa,including one new family,10 new genera,and 76 new species,representing a wide taxonomic and geographic range.The new family,Paradictyoarthriniaceae is introduced...This paper is a compilation of notes on 110 fungal taxa,including one new family,10 new genera,and 76 new species,representing a wide taxonomic and geographic range.The new family,Paradictyoarthriniaceae is introduced based on its distinct lineage in Dothideomycetes and its unique morphology.The family is sister to Biatriosporaceae and Roussoellaceae.The new genera are Allophaeosphaeria(Phaeosphaeriaceae),Amphibambusa(Amphisphaeriaceae),Brunneomycosphaerella(Capnodiales genera incertae cedis),Chaetocapnodium(Capnodiaceae),Flammeascoma(Anteagloniaceae),Multiseptospora(Pleosporales genera incertae cedis),Neogaeumannomyces(Magnaporthaceae),Palmiascoma(Bambusicolaceae),Paralecia(Squamarinaceae)and Sarimanas(Melanommataceae).The newly described species are the Ascomycota Aliquandostipite manochii,Allophaeosphaeria dactylidis,A.muriformia,Alternaria cesenica,Amphibambusa bambusicola,Amphisphaeria sorbi,Annulohypoxylon thailandicum,Atrotorquata spartii,Brunneomycosphaerella laburni,Byssosphaeria musae,Camarosporium aborescentis,C.aureum,C.frutexensis,Chaetocapnodium siamensis,Chaetothyrium agathis,Colletotrichum sedi,Conicomyces pseudotransvaalensis,Cytospora berberidis,C.sibiraeae,Diaporthe thunbergiicola,Diatrype palmicola,Dictyosporium aquaticum,D.meiosporum,D.thailandicum,Didymella cirsii,Dinemasporium nelloi,Flammeascoma bambusae,Kalmusia italica,K.spartii,Keissleriella sparticola,Lauriomyces synnematicus,Leptosphaeria ebuli,Lophiostoma pseudodictyosporium,L.ravennicum,Lophiotrema eburnoides,Montagnula graminicola,Multiseptospora thailandica,Myrothecium macrosporum,Natantispora unipolaris,Neogaeumannomyces bambusicola,Neosetophoma clematidis,N.italica,Oxydothis atypica,Palmiascoma gregariascomum,Paraconiothyrium nelloi,P.thysanolaenae,Paradictyoarthrinium tectonicola,Paralecia pratorum,Paraphaeosphaeria spartii,Pestalotiopsis digitalis,P.dracontomelon,P.italiana,Phaeoisaria pseudoclematidis,Phragmocapnias philippinensis,Pseudocamarosporium cotinae,Pseudocercospora tamarindi,Pseudotrichia rubriostiolata,P.thailandic展开更多
Relict subtropical coniferous forests in China face severe fragmentation,resulting in declining populations,and some are under significant threat from invasive alien species.Despite the crucial importance of understan...Relict subtropical coniferous forests in China face severe fragmentation,resulting in declining populations,and some are under significant threat from invasive alien species.Despite the crucial importance of understanding forest dynamics,knowledge gaps persist,particularly regarding the impact of invasive plants on vulnerable natives like Keteleeria evelyniana.In this study,we investigated the impact of invasive plants on the regeneration of forests dominated by K.evelyniana,a subtropical relict species in southwestern China.For this purpose,we characterized forest dynamics of 160 forest plots featuring K.evelyniana as the primary dominant species and determined whether the presence of invasive plants was correlated with regeneration of K.evelyniana.We identified four distinct forest types in which K.evelyniana was dominant.We found that radial growth of K.evelyniana trees is faster in younger ageclasses today than it was for older trees at the same age.The population structure of K.evelyniana in each forest type exhibited a multimodal age-class distribution.However,three forest types lacked established saplings younger than 10 years old,a situation attributed to the dense coverage of the invasive alien Ageratina adenophora.This invasive species resulted in a reduction of understory species diversity.Additionally,our analysis uncovered a significant negative correlation in phylogenetic relatedness(net relatedness index)between native and invasive alien plant species in eastern Yunnan.This suggests closely related invasive species face heightened competition,hindering successful invasion.Taken together,our findings indicate that successful establishment and habitat restoration of K.evelyniana seedling/saplings require effective measures to control invasive plants.展开更多
Fxcessive forest exploitation significantly contributes to land degradation and the creation of human-made deadwood.Stumps are sometimes ignored in studies on the biodiversity of coarse woody debris.We investigated wh...Fxcessive forest exploitation significantly contributes to land degradation and the creation of human-made deadwood.Stumps are sometimes ignored in studies on the biodiversity of coarse woody debris.We investigated whether the type of stump,i.e.broken stumps(naturally created)and cut stumps(formed during forestry operations)had an impact on the species composition and species diversity as well as due to this fact they can be characterized by plant indicators.The research covered 728 spruce stumps(287 broken and 441 cut stumps)that were inhabited by lichens,liverworts,mosses and vascular plants in mountain forest belt(Karkonosze Mts.,Poland).The following types of microhabitats were included in the research:the upper surface and the lateral surface of a stump with both bark and wood.There are statistically significant compositional differences between the two types of stumps,which was demonstrated by ordination analyses and indicator species analysis.According to the generalized linear models,the probability of occurrence increases in cut stumps in case of liverworts and vascular plants and also along the decomposition stages.The generalized linear mixed-effects model showed that there was a higher species richness of liverworts,mosses and vascular plants on the cut stumps and less drier but the reverse situation was in lichens.The generalized additive models for their cover showed similar trends.Almost all of the taxonomic groups were affected by altitude both in terms of species composition and total cover on the stumps.We concluded that cut stumps are an important type of deadwood for biodiversity and provide a convenient habitat,especially for many lichens and bryophytes.展开更多
Notes on 113 fungal taxa are compiled in this paper,including 11 new genera,89 new species,one new subspecies,three new combinations and seven reference specimens.Awide geographic and taxonomic range of fungal taxa ar...Notes on 113 fungal taxa are compiled in this paper,including 11 new genera,89 new species,one new subspecies,three new combinations and seven reference specimens.Awide geographic and taxonomic range of fungal taxa are detailed.In the Ascomycota the new genera Angustospora(Testudinaceae),Camporesia(Xylariaceae),Clematidis,Crassiparies(Pleosporales genera incertae sedis),Farasanispora,Longiostiolum(Pleosporales genera incertae sedis),Multilocularia(Parabambusicolaceae),Neophaeocryptopus(Dothideaceae),Parameliola(Pleosporales genera incertae sedis),and Towyspora(Lentitheciaceae)are introduced.Newly introduced species are Angustospora nilensis,Aniptodera aquibella,Annulohypoxylon albidiscum,Astrocystis thailandica,Camporesia sambuci,Clematidis italica,Colletotrichum menispermi,C.quinquefoliae,Comoclathris pimpinellae,Crassiparies quadrisporus,Cytospora salicicola,Diatrype thailandica,Dothiorella rhamni,Durotheca macrostroma,Farasanispora avicenniae,Halorosellinia rhizophorae,Humicola koreana,Hypoxylon lilloi,Kirschsteiniothelia tectonae,Lindgomyces okinawaensis,Longiostiolum tectonae,Lophiostoma pseudoarmatisporum,Moelleriella phukhiaoensis,M.pongdueatensis,Mucoharknessia anthoxanthi,Multilocularia bambusae,Multiseptospora thysanolaenae,Neophaeocryptopus cytisi,Ocellularia arachchigei,O.ratnapurensis,Ochronectria thailandica,Ophiocordyceps karstii,Parameliola acaciae,P.dimocarpi,Parastagonospora cumpignensis,Pseudodidymosphaeria phlei,Polyplosphaeria thailandica,Pseudolachnella brevifusiformis,Psiloglonium macrosporum,Rhabdodiscus albodenticulatus,Rosellinia chiangmaiensis,Saccothecium rubi,Seimatosporium pseudocornii,S.pseudorosae,Sigarispora ononidis and Towyspora aestuari.New combinations are provided for Eutiarosporella dactylidis(sexual morph described and illus trated)and Pseudocamarosporium pini.Descriptions,illustrations and/or reference specimens are designated for Aposphaeria corallinolutea,Cryptovalsa ampelina,Dothiorella vidmadera,Ophiocordyceps formosana,Petrakia echinata,Phragmoporthe conformis and Pse展开更多
Bamboo plants are an essential component of tropical ecosystems,yet their vulnerability to climate extremes,such as drought,is poorly understood due to limited knowledge of their hydraulic properties.Cephalostachyum p...Bamboo plants are an essential component of tropical ecosystems,yet their vulnerability to climate extremes,such as drought,is poorly understood due to limited knowledge of their hydraulic properties.Cephalostachyum pergracile,a commonly used tropical bamboo species,exhibited a substantially higher mortality rate than other co-occurring bamboos during a severe drought event in 2019,but the underlying mechanisms remain unclear.This study investigated the leaf and stem hydraulic traits related to drought responses,including leaf-stem embolism resistance(P50leaf;P50stem) estimated using optical and X-ray microtomography methods,leaf pressure-volume and water-releasing curves.Additionally,we investigated the seasonal water potentials,native embolism level(PLC) and xylem water source using stable isotope.We found that C.pergracile exhibited strong resistance to embolism,showing low P50leaf,P50stem,and turgor loss point,despite its rapid leaf water loss.Interestingly,its leaves displayed greater resistance to embolism than its stem,suggesting a lack of effective hydraulic vulnerability segmentation(HVS) to protect the stem from excessive xylem tension.During the dry season,approximately 49% of the water was absorbed from the upper 20-cm-deep soil layer.Consequently,significant diurnal variation in leaf water potentials and an increase in midday PLC from 5.87±2.33% in the wet season to 12.87±4.09%in the dry season were observed.In summary,this study demonstrated that the rapid leaf water loss,high reliance on surface water,and a lack of effective HVS in C.pergracile accelerated water depletion and increased xylem embolism even in the typical dry season,which may explain its high mortality rate during extreme drought events in 2019.展开更多
Aims Along central-Asian rivers in arid regions,lowering of the ground-water level constitutes a major threat to the riparian forests,whose tree layers are dominated by Euphrates poplar(Populus euphratica).Some of the...Aims Along central-Asian rivers in arid regions,lowering of the ground-water level constitutes a major threat to the riparian forests,whose tree layers are dominated by Euphrates poplar(Populus euphratica).Some of these fragile ecosystems are supplied with additional(‘eco-logical’)water for protection and conservation.We investigated interrelationships among groundwater distance,stand structure and above-ground wood production(at the tree and the stand level)in P.euphratica stands along a groundwater gradient(distances of 2.0-12.0 m)that also included a plot supplied with‘ecological water’.Methods We measured the height,diameter at breast height and basal area of poplar trees and determined the annual above-ground wood production for the three most recent years on the basis of tree-ring analyses and allometric regressions at three sites at the upper,mid-dle and lower reaches of the tarim River,Xinjiang,NW china.Important Findingsthe distribution of age classes differed significantly among the plots:in accordance with their life histories,stands growing at a larger distance to the groundwater harboured a larger fraction of old trees(>80 years)and,in most cases,a smaller fraction of young trees(≤20 years).the annual above-ground wood production per ha was highest on a plot with a short groundwater distance(2.0 m;maxi-mum of the 3-year investigation period:3.0 t ha−1 a−1)and lowest,at a plot with a large distance to the water table(6.6 m;minimum:0.23 t ha^(−1)a^(−1)).However,the plot located close to the groundwater(and to the river)at the middle reaches exhibited a relatively large interannual variation in above-ground wood production,which can be attributed to interannual variations in the river discharge.At the middle and the lower reaches,these interannual variations on plots with the most favourable water supply were even more obvious at the tree level.For the fraction of mature trees(60-99 years old),no significant differences in above-ground wood production were found between the plots with 展开更多
Aims studying the ecological significance of highly specialized morpho-logical traits evolved by alpine plants could help us to understand the adaptation and evolution of these plants under severe alpine environ-ment....Aims studying the ecological significance of highly specialized morpho-logical traits evolved by alpine plants could help us to understand the adaptation and evolution of these plants under severe alpine environ-ment.We explored the adaptive significance of woolly and overlap-ping leaves for reproduction in Eriophyton wallichii,a perennial herb native to the subnival belt of the Himalaya-Hengduan mountains.Methods We examined whether the trichomes could influence the leaf wet-tability,temperature and leaf reflectance spectra in the lab.and we investigated the thermal benefits of the woolly and overlapping leaves for flowers and fruits in the field.Pollen viability and seed germination were also examined in the lab to assess whether these leaves enhance reproductive fitness.Important Findingsour results showed that dense trichomes impart good water repel-lency,absorption of solar radiation and accumulation of leaf heat.The woolly and overlapping leaves increased the interior tempera-ture of flowers and fruits to an optimal level on sunny hours,but prevented them from overheating when transient intense solar radi-ation occurs.This kept optimal temperatures in plants’reproduc-tive organs,thus promoting the development of pollen and seed in alpine environment.展开更多
Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we cl...Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.展开更多
基金EU 7th FP Project BACCARA(226299)and the National Basic Research Program of China(2014CB954004).
文摘Aims Soil respiration(Rs)is a major process controlling soil carbon loss in forest ecosystems.However,the underlying mechanisms leading to variation in Rs along forest successional gradients are not well understood.In this study,we investigated the effects of biotic and abiotic factors on Rs along a forest successional gradient in southeast China.Methods We selected 16 plots stratified by forest age,ranging from 20 to 120 years.In each plot,six shallow collars and six deep collars were permanently inserted into the soil.Shallow and deep collars were used to measure Rs and heterotrophic respiration(Rh),respectively.Autotrophic soil respiration(Ra)was estimated as the difference between Rs and Rh.Litter layer respiration(R_(L))was calculated by subtracting soil respiration measured in collars without leaf litter layer(R_(NL))from Rs.Rs was measured every 2 months,and soil temperature(ST)and soil volumetric water content(SVWC)were recorded every hour for 19 months.We calculated daily Rs using an exponential model dependent on ST.Daily Rs was summed to obtain cumulative annual Rs estimates.Structural equation modelling(SEM)was applied to identify the drivers of Rs during forest succession.Important Findings Rs showed significant differences among three successive stages,and it was the highest in the young stage.Ra was higher in the young stage than in the medium stage.Cumulative annual Rs and Ra peaked in the young and old stages,respectively.Cumulative annual Rh and respiration measured from soil organic matter(R_(SOM))decreased,whereas R_(L)increased with forest age.The SEM revealed that cumulative annual Rs was influenced by fine root biomass and SVWC.Our results indicated that the dominant force regulating Rs on a seasonal scale is ST;however,on a successional scale,belowground carbon emerges as the dominant influential factor.
基金European Union INCO-DC(Project No.ERBIC18CT980275).
文摘Aims We investigated the regulation of the water status in three predominant perennial C3 phreatophytes(Alhagi sparsifolia,Populus euphratica,Tamarix ramosissima)at typical sites of their occurrence at the southern fringe of the hyperarid Taklamakan Desert(north-west China).Methods In the foreland of the river oasis of Qira(Cele),we determined meteorological variables,plant biomass production,plant water potentials(WL)and the water flux through the plants.We calculated the hydraulic conductance on the flow path from the soil to the leaves(kSL)and tested the effects of kSL,WL and the leaf-to-air difference in the partial pressure of water vapour(Dw)on stomatal regulation using regression analyses.Important Findings Despite high values of plant water potential at the point of turgor loss,all plants sustained WL at levels that were high enough to maintain transpiration throughout the growing season.In A.sparsifolia,stomatal resistance(rs;related to leaf area or leaf mass)was most closely correlated with kSL;whereas in P.euphratica,~70%of the variation in rs was explained by Dw.In T.ramosissima,leaf area-related rs was significantly correlated with WL and kSL.The regulation mechanisms are in accordance with the growth patterns and the occurrence of the species in relation to their distance to the ground water.
基金The National Natural Science Foundation of China(41471149 and 31060079)
文摘Background:Restoration projects have been implemented worldwide to mitigate the adverse effects of the loss and degradation of wetland habitats.Much research has been carried out on the impacts on birds of wetland restoration and management projects in China. Studies have mainly investigated central or coastal wetlands,while inland wetlands in remote areas have been much less studied. We focused on examining the response of wild birds to wetland restoration in Dianchi Lake,south-west China. Methods: The line transect method was performed at 26 sampling plots.Three of these were in the city,and to acquire all wild bird data 23 plots were located every 2-8 km along the shore of Dianchi Lake, between December 2011 and November 2013.We collected all related bird records by searching the available literature, articles, newspapers and records of birdwatchers to compare species variation before and after implementation of wetland restoration.To measure the relationships between waterbird assemblages and habitat structures, we used canonical correspondence analysis (CCA) to pair the main matrix of bird assemblages with a second matrix of habitat variables. Results: We recorded 182 bird species belonging to 51 families and 17 orders. Of the species, 42 were new records for Kunming City and 20 were new records for Yunnan Province. Ten waterbird species were found to have disappeared from the shore of Dianchi Lake.CCA results indicated that waterbirds could be divided into four categories based on their habitat preference:synanthropic (wintering gulls), special habitat (shorebirds),semi-natural (wintering coots and ducks) and disturbance-tolerant (resident) species.Conclusions:Our study is the first to consider the entire wild bird community throughout the year and discuss the species variation before and after wetland restoration projects launched for Dianchi Lake.Distinct habitat requirements of different waterbird groups were detected in our study,suggesting different types of restoration and management should be impleme
文摘The active layer is the top layer of permafrost soils that thaws during the summer season due to increased ambient temperatures and solar radiation inputs. This layer is important because almost all biological activity takes place there during the summer. The depth of active layer thaw is influenced by climatic conditions. Vegetation has also been found to have a strong impact on active layer thaw, because it can intercept incoming radiation, thereby insulating the soil from ambient conditions. In order to look at the role of vegetation and climate on active layer thaw, we measured thaw depth and the Normalized Difference Vegetation Index (NDVI; a proxy for aboveground plant biomass) along a latitudinal temperature gradient in arctic Alaska and Canada. At each site several measurements of thaw and NDVIwere taken in areas with high amounts of vegetation and areas with little to no vegetation. Results show that the warmest regions, which had the greatest levels of NDVI, had relatively shallow thaw depths, and the coldest regions, which had the lowest levels of NDVI, also had relatively shallow thaw depths. The intermediate regions, which had moderate levels of NDVIand air temperature, had the greatest depth of thaw. These results indicate that temperature and vegetation interact to control the depth of the active layer across a range of arctic ecosystems. By developing a relationship to explain thaw depth through NDVIand temperature or latitude, the possibility exists to extrapolate thaw depth over large scales via remote sensing applications.
基金funded by the National Basic Research Program of China (2009CB421303)the Key Project in Science & Technology Program of Xinjiang Uygur Autonomous Region (200933125)the Science and Technology Ministry Program (2009BAC54B03)
文摘The paper analyzes the hypothesis that the distribution of dominant plant species and characteristics of plant communities are related to groundwater depth. The results showed that variations of groundwater depth impacted distributions and characteristics of dominant plant communities. However, besides groundwater depth, the community composition and species diversity were also influenced by physiognomy of the habitat. Based on the similarity coefficient, the differences between dominant plant communities were significant at different groundwater depths. Compared with other results relating to desert vegetation and groundwater depth, variations of community distribution were similar at the large spatial scale. However, in this extremely arid region, there were significant differences in community type and community succession when compared with other arid regions, especially in relationship to deep groundwater depth. With groundwater depth from deep to shallow, communities transformed with the sequence of Alhagi communities, Tamarix spp. communities, Populus communities, Phragmites communities, and Sophora communities. At groundwater depth of less than 6.0 m, the community type and composition changed, and the species diversity increased. Among these dominant species, Tamarix exhibited the biggest efficiency in resource utilization according to niche breadth, which means it possessed the best adaptability to environmental conditions at the oasis margins.
基金Under the auspices of National Natural Science Foundation of China(No.30870431)
文摘The problem of wild elephants, or human-elephant conflict (HEC), influences the daily life of local communities and hinders the conservation of wild elephants.The perception and attitudes of local communities who inhabited the frontiers between human activities and wild elephant movement are important to the mitigation of the HEC and conservation of wild elephants. To analyze the perception and attitudes of local communities, the Participatory Rural Appraisal (PRA) was used in the investigation of 423 interviewees from 22 villages in Xishuangbanna from July 2009 to February 2010. The results indicated that local communities had their views on the elephant-related problems. In field survey, we found that 66.5% of interviewees were willing to support, participate in, and assist in the conservation of wild elephants;33.5% of interviewees were opposed or indifferent to such conservation, because their livelihoods and even their lives were endangered by wild elephants. These views and attitudes were influenced by local communities′perception of HEC, education level, gender and self-interest. Therefore, it is necessary to analyze the diverse views among local communities and balance profits and costs in addressing HEC.
文摘Aims We investigated shifts in community-weighted mean traits(CWm)of 14 leaf functional traits along a secondary successional series in an evergreen broadleaf forest in subtropical southeast China.most of the investigated traits have been reported to affect litter decomposition in previous studies.We asked whether changes in CWms along secondary succession followed similar patterns for all investigated traits and whether the shifts in CWm indicated a change in resource use strategy along the successional gradient.using community decomposition rates(k-rates)estimated from annual lit-ter production and standing litter biomass,we asked whether the dynamics of litter decomposition were related to changes in leaf functional traits along the successional series.Methods twenty-seven plots were examined for shifts in leaf CWm traits as well as in k-rates along a series of secondary forest succession cov-ered in the framework of the bEF-China project.We investigated whether the changes in CWms followed similar patterns for all traits with ongoing succession.three alternative linear models were used to reveal the general patterns of shifts in CWm trait values.moreover,multiple regression analysis was applied to investigate whether there were causal relationships between the changes in leaf functional traits and the dynamics of litter decomposition along secondary succession.We furthermore assessed which traits had the highest impact on community litter decomposition.Important Findingsshifts in CWm values generally followed logarithmic patterns for all investigated traits,whereas community k-rates remained stable along the successional gradient.In summary,the shifts in CWm values indicate a change in community resource use strategy from high nutrient acquisition to nutrient retention with ongoing succession.stands with higher CWm values of traits related to nutrient acquisition had also higher CWm values of traits related to chemical resistance,whereas stands with higher CWm values of traits related to nutrient retention ex
基金funded by the CEMSIT (Establishment of a Center for Eco-management and Spatial Information Techniques, Yunnan University) project, which is a Chinese-Belgian academic collaboration project under the auspices of the Flemish Interuniversity Council (VLIR)
文摘Monitoring and minimizing tourist’s water consumption is essential for the sustainable development of mountain destinations in the world. However, available data and a generally accepted protocol on such measurement are still limited. This study uses water footprint accounting to quantify tourist’s water demand in the Liming valley, a World Heritage site and a rapidly growing tourism destination in Northwest Yunnan, China. Both the water for direct and indirect use is taken into account based on the consumptive behavior of the tourists in the valley. Data were collected through guesthouse monitoring and a tourist survey in the 2005 tourist season. The results indicate that an average tourist leaves behind a footprint of 5.2 m3 on local water resources per day. Food production and waste dilution are the two most important water consumption factors. The results also show tourists consume more water than the local residents on per capita basis. This suggests more commitment is necessary to cope with this stress by individual tourists. Management implications to make water use more sustainable in mountain destinations are derived from this study.
基金the coordination team of the BEF-China project for their supportthe support of M.S.G.from the German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig funded by the German Research Foundation(FZT 118)+1 种基金the Sino-German Centre for Research Promotion for the participation of M.S.G.in a Summer School in Jingdezhen(GZ 1146)funded by the German Research Foundation(DFG FOR 891/3)with a grant to A.E.(ER 573/1-3).
文摘Aims In forests,the herbaceous understory vegetation plays an important role for ecosystem functioning as it represents a significant component of total aboveground productivity.In addition,the herb layer contributes to overall forest species richness and controls tree species regeneration.Vice versa,trees in the overstory control understory herb and shrub growth through competition for resources.Using an experimental forest plantation with manipulated tree richness,we asked to which degree tree species richness and identity affect herb layer composition,richness and productivity and how these relationships across strata change with abiotic environmental conditions and competition intensity.Methods In the context of the Biodiversity-Ecosystem Functioning project in subtropical China(BEF-China),we made use of the integrated BEFmod experiment arranged along a tree species richness gradient at two sites,with additional subplot treatments of phosphorus addition,herb layer weeding and no weeding.We recorded the understory vegetation and determined herb layer biomass production on a total of 201 subplots.Important Findings We found only minor effects of tree layer richness on herb layer species composition and no significant effect on herb layer richness or productivity yet.However,there were strong tree layer identity effects on all response variables,which were partly explained by differences in leaf area index and by a high share of woody species both in total herb layer species richness and biomass.There were strong treatment effects,which were largest in the‘no weeding’treatment but we did not find any treatment×tree layer richness interaction in herb layer responses.Thus,these effects are mainly explained by increased competition intensity within the herb layer in the absence of weeding.Despite the young age of the experiment,the interactions between tree species identity,tree richness and the herb layer did already emerge and can be expected to become stronger with ongoing runtime of the experiment.
基金The research was supported by 1)Chinese Academy of Sciences(Project No.KSCX2-EW-Z-9).K.Tanaka would like to thank the Japan Society for the Promotion of Science(JSPS,25440199)for financial support.This project was supported by the Distinguished Scientist Fellowship Program(DSFP),King Saud University,Saudi Arabia.This project was also supported by NSTIP strategic technologies program,number(12-BIO2840-02)in the Kingdom of Saudi Arabia.B.Buyck and V.Hofstetter acknowledge the ATM“Emergences”(Dirs.P.Janvier&S.Peigné)from the National museum of natural history,Paris,for financial support related to sequencing as well as travel expenses in Madagascar.Overseas travel of B.Buyck was funded by the ATM research program“Etat et structure phylogénétique de la biodiversitéactuelle et fossile”of the Paris’Museum.(director Ph.Janvier)S.Adamčík acknowledges funding by his national Slovak Project VEGA 02/0075/14.B.D.Shenoy acknowledges funding to visit Mae Fah Luang University,Chiang Rai under Indo-Thailand bilateral programme(THAI-1205).The Lewis family is warmly thanked for their generous hospitality,offering excellent and very agreeable working and field condition.K.Wisitrassameewong and A.Verbeken were financially supported by the joint doctorate program of the“Bijzonder Onderzoeksfonds Gent University”(BOF),Gent University.This research was also financial supported by The Biodiversity and Training Program(BRT R 149009)and Interaction Laboratory(BMIT),National Center for Genetic Engineering and Biotechnology(BIOTEC)Khlong Luang,Pathum Thani 12120,Thailand.Thanks are extended to the Thailand Research Fund grant(BRG 5580009)under the research grant entitled“Taxonomy,Phylogeny and Biochemistry of Thai Basidiomycetes”for financial support.J.Chen and R.L.Zhao would like to thank the National Natural Science Foundation of China(Project ID:31000013,31360014 and 31470152).Uwe Braun,Walter Jaklitsch,Tom May,Marc Stadler and Jo Taylor,are thanks for commenting on some parts of the manuscript.Shaun Pennycook is
文摘This paper is a compilation of notes on 110 fungal taxa,including one new family,10 new genera,and 76 new species,representing a wide taxonomic and geographic range.The new family,Paradictyoarthriniaceae is introduced based on its distinct lineage in Dothideomycetes and its unique morphology.The family is sister to Biatriosporaceae and Roussoellaceae.The new genera are Allophaeosphaeria(Phaeosphaeriaceae),Amphibambusa(Amphisphaeriaceae),Brunneomycosphaerella(Capnodiales genera incertae cedis),Chaetocapnodium(Capnodiaceae),Flammeascoma(Anteagloniaceae),Multiseptospora(Pleosporales genera incertae cedis),Neogaeumannomyces(Magnaporthaceae),Palmiascoma(Bambusicolaceae),Paralecia(Squamarinaceae)and Sarimanas(Melanommataceae).The newly described species are the Ascomycota Aliquandostipite manochii,Allophaeosphaeria dactylidis,A.muriformia,Alternaria cesenica,Amphibambusa bambusicola,Amphisphaeria sorbi,Annulohypoxylon thailandicum,Atrotorquata spartii,Brunneomycosphaerella laburni,Byssosphaeria musae,Camarosporium aborescentis,C.aureum,C.frutexensis,Chaetocapnodium siamensis,Chaetothyrium agathis,Colletotrichum sedi,Conicomyces pseudotransvaalensis,Cytospora berberidis,C.sibiraeae,Diaporthe thunbergiicola,Diatrype palmicola,Dictyosporium aquaticum,D.meiosporum,D.thailandicum,Didymella cirsii,Dinemasporium nelloi,Flammeascoma bambusae,Kalmusia italica,K.spartii,Keissleriella sparticola,Lauriomyces synnematicus,Leptosphaeria ebuli,Lophiostoma pseudodictyosporium,L.ravennicum,Lophiotrema eburnoides,Montagnula graminicola,Multiseptospora thailandica,Myrothecium macrosporum,Natantispora unipolaris,Neogaeumannomyces bambusicola,Neosetophoma clematidis,N.italica,Oxydothis atypica,Palmiascoma gregariascomum,Paraconiothyrium nelloi,P.thysanolaenae,Paradictyoarthrinium tectonicola,Paralecia pratorum,Paraphaeosphaeria spartii,Pestalotiopsis digitalis,P.dracontomelon,P.italiana,Phaeoisaria pseudoclematidis,Phragmocapnias philippinensis,Pseudocamarosporium cotinae,Pseudocercospora tamarindi,Pseudotrichia rubriostiolata,P.thailandic
基金funded by the Major Program for Basic Research Project of Yunnan Province,China,grant number 202101BC070002the Special Foundation for National Science and Technology Basic Resources Investigation of China,grant number 2019FY202300.
文摘Relict subtropical coniferous forests in China face severe fragmentation,resulting in declining populations,and some are under significant threat from invasive alien species.Despite the crucial importance of understanding forest dynamics,knowledge gaps persist,particularly regarding the impact of invasive plants on vulnerable natives like Keteleeria evelyniana.In this study,we investigated the impact of invasive plants on the regeneration of forests dominated by K.evelyniana,a subtropical relict species in southwestern China.For this purpose,we characterized forest dynamics of 160 forest plots featuring K.evelyniana as the primary dominant species and determined whether the presence of invasive plants was correlated with regeneration of K.evelyniana.We identified four distinct forest types in which K.evelyniana was dominant.We found that radial growth of K.evelyniana trees is faster in younger ageclasses today than it was for older trees at the same age.The population structure of K.evelyniana in each forest type exhibited a multimodal age-class distribution.However,three forest types lacked established saplings younger than 10 years old,a situation attributed to the dense coverage of the invasive alien Ageratina adenophora.This invasive species resulted in a reduction of understory species diversity.Additionally,our analysis uncovered a significant negative correlation in phylogenetic relatedness(net relatedness index)between native and invasive alien plant species in eastern Yunnan.This suggests closely related invasive species face heightened competition,hindering successful invasion.Taken together,our findings indicate that successful establishment and habitat restoration of K.evelyniana seedling/saplings require effective measures to control invasive plants.
基金supported by the Statutory Funds of the Institute of Environmental Protection and Engineering of the University of Bielsko-Biala and the Department of Geobotany and Plant Ecologythe University of Lodz,Lodz,Poland。
文摘Fxcessive forest exploitation significantly contributes to land degradation and the creation of human-made deadwood.Stumps are sometimes ignored in studies on the biodiversity of coarse woody debris.We investigated whether the type of stump,i.e.broken stumps(naturally created)and cut stumps(formed during forestry operations)had an impact on the species composition and species diversity as well as due to this fact they can be characterized by plant indicators.The research covered 728 spruce stumps(287 broken and 441 cut stumps)that were inhabited by lichens,liverworts,mosses and vascular plants in mountain forest belt(Karkonosze Mts.,Poland).The following types of microhabitats were included in the research:the upper surface and the lateral surface of a stump with both bark and wood.There are statistically significant compositional differences between the two types of stumps,which was demonstrated by ordination analyses and indicator species analysis.According to the generalized linear models,the probability of occurrence increases in cut stumps in case of liverworts and vascular plants and also along the decomposition stages.The generalized linear mixed-effects model showed that there was a higher species richness of liverworts,mosses and vascular plants on the cut stumps and less drier but the reverse situation was in lichens.The generalized additive models for their cover showed similar trends.Almost all of the taxonomic groups were affected by altitude both in terms of species composition and total cover on the stumps.We concluded that cut stumps are an important type of deadwood for biodiversity and provide a convenient habitat,especially for many lichens and bryophytes.
基金the National Natural Science Foundation of China(No.30770013,No.31500013,No.31000013,No.31360014,No.31470152)the Special Program of Basic Science of the Ministry of Science and Technology(No.2012FY111600)the Technology of and International Cooperation Program of the Ministry of Science and Technology(No.2009DFA31160)of the People’s Republic of China,and the opening funding of State key Laboratory of Mycology,Institute of Microbiology,Chinese Academy of Sciences for funding。
文摘Notes on 113 fungal taxa are compiled in this paper,including 11 new genera,89 new species,one new subspecies,three new combinations and seven reference specimens.Awide geographic and taxonomic range of fungal taxa are detailed.In the Ascomycota the new genera Angustospora(Testudinaceae),Camporesia(Xylariaceae),Clematidis,Crassiparies(Pleosporales genera incertae sedis),Farasanispora,Longiostiolum(Pleosporales genera incertae sedis),Multilocularia(Parabambusicolaceae),Neophaeocryptopus(Dothideaceae),Parameliola(Pleosporales genera incertae sedis),and Towyspora(Lentitheciaceae)are introduced.Newly introduced species are Angustospora nilensis,Aniptodera aquibella,Annulohypoxylon albidiscum,Astrocystis thailandica,Camporesia sambuci,Clematidis italica,Colletotrichum menispermi,C.quinquefoliae,Comoclathris pimpinellae,Crassiparies quadrisporus,Cytospora salicicola,Diatrype thailandica,Dothiorella rhamni,Durotheca macrostroma,Farasanispora avicenniae,Halorosellinia rhizophorae,Humicola koreana,Hypoxylon lilloi,Kirschsteiniothelia tectonae,Lindgomyces okinawaensis,Longiostiolum tectonae,Lophiostoma pseudoarmatisporum,Moelleriella phukhiaoensis,M.pongdueatensis,Mucoharknessia anthoxanthi,Multilocularia bambusae,Multiseptospora thysanolaenae,Neophaeocryptopus cytisi,Ocellularia arachchigei,O.ratnapurensis,Ochronectria thailandica,Ophiocordyceps karstii,Parameliola acaciae,P.dimocarpi,Parastagonospora cumpignensis,Pseudodidymosphaeria phlei,Polyplosphaeria thailandica,Pseudolachnella brevifusiformis,Psiloglonium macrosporum,Rhabdodiscus albodenticulatus,Rosellinia chiangmaiensis,Saccothecium rubi,Seimatosporium pseudocornii,S.pseudorosae,Sigarispora ononidis and Towyspora aestuari.New combinations are provided for Eutiarosporella dactylidis(sexual morph described and illus trated)and Pseudocamarosporium pini.Descriptions,illustrations and/or reference specimens are designated for Aposphaeria corallinolutea,Cryptovalsa ampelina,Dothiorella vidmadera,Ophiocordyceps formosana,Petrakia echinata,Phragmoporthe conformis and Pse
基金supported by the National Natural Science Foundation of China(Nos:32071735,32371576,32350410420,41861144016,and 31570406)CAS‘Light of West China’Program+2 种基金The 14th Five-Year Plan of the Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences(E3ZKFF1K,E3ZKFF2B)Yunnan Provincial Science and Technology Department(2018HB068)Yunnan Revitalization Talents Support Plan(YNWR-QNBJ-2019177).
文摘Bamboo plants are an essential component of tropical ecosystems,yet their vulnerability to climate extremes,such as drought,is poorly understood due to limited knowledge of their hydraulic properties.Cephalostachyum pergracile,a commonly used tropical bamboo species,exhibited a substantially higher mortality rate than other co-occurring bamboos during a severe drought event in 2019,but the underlying mechanisms remain unclear.This study investigated the leaf and stem hydraulic traits related to drought responses,including leaf-stem embolism resistance(P50leaf;P50stem) estimated using optical and X-ray microtomography methods,leaf pressure-volume and water-releasing curves.Additionally,we investigated the seasonal water potentials,native embolism level(PLC) and xylem water source using stable isotope.We found that C.pergracile exhibited strong resistance to embolism,showing low P50leaf,P50stem,and turgor loss point,despite its rapid leaf water loss.Interestingly,its leaves displayed greater resistance to embolism than its stem,suggesting a lack of effective hydraulic vulnerability segmentation(HVS) to protect the stem from excessive xylem tension.During the dry season,approximately 49% of the water was absorbed from the upper 20-cm-deep soil layer.Consequently,significant diurnal variation in leaf water potentials and an increase in midday PLC from 5.87±2.33% in the wet season to 12.87±4.09%in the dry season were observed.In summary,this study demonstrated that the rapid leaf water loss,high reliance on surface water,and a lack of effective HVS in C.pergracile accelerated water depletion and increased xylem embolism even in the typical dry season,which may explain its high mortality rate during extreme drought events in 2019.
基金German Federal Ministry of Education and Research(BMBF),Funding Measure‘Sustainable Land Management’(project number:01LL0918K).
文摘Aims Along central-Asian rivers in arid regions,lowering of the ground-water level constitutes a major threat to the riparian forests,whose tree layers are dominated by Euphrates poplar(Populus euphratica).Some of these fragile ecosystems are supplied with additional(‘eco-logical’)water for protection and conservation.We investigated interrelationships among groundwater distance,stand structure and above-ground wood production(at the tree and the stand level)in P.euphratica stands along a groundwater gradient(distances of 2.0-12.0 m)that also included a plot supplied with‘ecological water’.Methods We measured the height,diameter at breast height and basal area of poplar trees and determined the annual above-ground wood production for the three most recent years on the basis of tree-ring analyses and allometric regressions at three sites at the upper,mid-dle and lower reaches of the tarim River,Xinjiang,NW china.Important Findingsthe distribution of age classes differed significantly among the plots:in accordance with their life histories,stands growing at a larger distance to the groundwater harboured a larger fraction of old trees(>80 years)and,in most cases,a smaller fraction of young trees(≤20 years).the annual above-ground wood production per ha was highest on a plot with a short groundwater distance(2.0 m;maxi-mum of the 3-year investigation period:3.0 t ha−1 a−1)and lowest,at a plot with a large distance to the water table(6.6 m;minimum:0.23 t ha^(−1)a^(−1)).However,the plot located close to the groundwater(and to the river)at the middle reaches exhibited a relatively large interannual variation in above-ground wood production,which can be attributed to interannual variations in the river discharge.At the middle and the lower reaches,these interannual variations on plots with the most favourable water supply were even more obvious at the tree level.For the fraction of mature trees(60-99 years old),no significant differences in above-ground wood production were found between the plots with
基金Natural National Science Foundation of China(U1136601 to H.S.,31360049 to Z.M.L.and 31270005,31470321 to Y.Y.)Strategic Priority Research Program(B)of the Chinese Academy of Science(XDB03030112 to H.S.).
文摘Aims studying the ecological significance of highly specialized morpho-logical traits evolved by alpine plants could help us to understand the adaptation and evolution of these plants under severe alpine environ-ment.We explored the adaptive significance of woolly and overlap-ping leaves for reproduction in Eriophyton wallichii,a perennial herb native to the subnival belt of the Himalaya-Hengduan mountains.Methods We examined whether the trichomes could influence the leaf wet-tability,temperature and leaf reflectance spectra in the lab.and we investigated the thermal benefits of the woolly and overlapping leaves for flowers and fruits in the field.Pollen viability and seed germination were also examined in the lab to assess whether these leaves enhance reproductive fitness.Important Findingsour results showed that dense trichomes impart good water repel-lency,absorption of solar radiation and accumulation of leaf heat.The woolly and overlapping leaves increased the interior tempera-ture of flowers and fruits to an optimal level on sunny hours,but prevented them from overheating when transient intense solar radi-ation occurs.This kept optimal temperatures in plants’reproduc-tive organs,thus promoting the development of pollen and seed in alpine environment.
基金This study received financial support from the Science and Technology Department of Yunnan University,China(2019YNU002)Major Program for Basic Research Project of Yunnan Province,China(202101BC070002)the Special Foundation for National Science and Technology Basic Resources Investigation of China(2019FY202300).
文摘Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.
