Leaf area index（LAI） of Teak（Tectona grandis） and Bamboo（Dendrocalamus strictus） grown in Shoolpaneshwar Wildlife Sanctuary of Narmada District,Gujarat,India was obtained by destructive sampling,photo-grid metho...Leaf area index（LAI） of Teak（Tectona grandis） and Bamboo（Dendrocalamus strictus） grown in Shoolpaneshwar Wildlife Sanctuary of Narmada District,Gujarat,India was obtained by destructive sampling,photo-grid method and by litter trap method.An allometric equation（between leaf area by litter trap method and canopy spread area） was developed for the determination of LAI.Results show that LAI value calculated by the developed allometric equation was similar to that estimated by destructive sampling and photo-grid method,with Root Mean Square Error（RMSE） of 0.90 and 1.15 for Teak,and 0.38 and 0.46 for Bamboo,respectively.There was a perfect match in both the LAI values（estimated and calculated）,indicating the accuracy of the developed equations for both the species.In conclusion,canopy spread is a better and sensitive parameter to estimate leaf area of trees.The developed equations can be used for estimating LAI of Teak and Bamboo in tropics.展开更多
Leaf functional traits are adaptations that enable plants to live under different environmental conditions. This study aims to evaluate the differences in leaf functional traits between red and green leaves of two eve...Leaf functional traits are adaptations that enable plants to live under different environmental conditions. This study aims to evaluate the differences in leaf functional traits between red and green leaves of two evergreen shrubs Photinia × fraseri and Osrnanthus fragrans. Specific areas of red leaves are higher than that of green leaves in both species. Thus, the material investment per unit area and per lamina of red leaves is significantly lower than that of green leaves, implying an utmost effort of red leaves to increase light capture and use efficiency because of their low leafchlorophyll concentration. The higher petiole length of green leaves compared with that of red leaves indicates that adult green leaves may have large fractional biomass allocation to support the lamina structures in capturing light with maximum efficiency and obtaining a high growth rate. The high range of the phenotypic plasticity of leaf size, leaf thickness, single-leaf wet and dry weights, and leaf moisture of green leaves may be beneficial in achieving efficient control of water loss and nutrient deprivation. The high range of phenotypic plasticity of leaf chlorophyll concentration of red leaves may be advantageous in increasing resource （especially light） capture anduse efficiency because this leaf type is juvenile in the growth stage and has low leaf-chlorophyll concentration.展开更多
Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and...Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and their corresponding variability of the invasive tree staghorn sumac Rhus typhina L. with different invasion success, including lower and higher invasion success, in two climatic regions in North China, including a warm temperate region and a cold temperate region. No significant differences were found for leaf functional traits of staghorn sumac across different invasion success. However, the variability of leaf chlorophyll and nitrogen concentrations of staghorn sumac under higher invasion success were approximately 66.023% and 68.615% higher than those under lower invasion success, respectively. The leaf chlorophyll and nitrogen concentrations of staghorn sumac in the warm temperate region were approximately 18.432% and 16.337% higher than those in cold temperate region, respectively. The variability of specific leaf area of staghorn sumac in warm temperate region was approximately 59.802% higher than that in cold temperate region. Accordingly, leaf chlorophyll and N concentrations as well as specific leaf area of staghorn sumac and their corresponding variability may play an essential role in shaping ecological success of studied invader along a climatic gradient.展开更多
Bruguiera sexangula(Lour.)Poir is an exclusive evergreen mangrove species to the Sundarbans of Bangladesh.It grows well in moderate saline zones with full sunlight.This study presents leaf morphological plasticity in ...Bruguiera sexangula(Lour.)Poir is an exclusive evergreen mangrove species to the Sundarbans of Bangladesh.It grows well in moderate saline zones with full sunlight.This study presents leaf morphological plasticity in B.sexangula to saline zones.Leaves were sampled from different saline zones and various morphological traits were measured.The results exposed a wide deviations of leaf size parameters:leaf length varied 6.6–17.3 cm;width 2.7–7.8 cm;upper quarter width 2.2–6.5 cm;down quarter width 2.5–7.3 cm;and petiole length 0.17–1.43 cm.Leaf length was significantly larger in fresh water than in other salinity zones,whereas,leaf width,upper and lower leaf quarters were significantly larger in medium saline zone.Leaf shape parameters showed a large variation among saline zones.Leaf base angle was significantly larger in both medium and strong salinity zones.Tip angle was significantly greater in medium salinity zone.Leaf perimeter was significantly larger in fresh water but leaf area was significantly bigger in medium saline zone.Leaf index and specific leaf area were maximum in moderate saline zone.Plasticity index was the highest in moderate saline for almost all the parameters presented.The ordination(PCA)showed clusters of leaf samples although there were some overlap among them which suggested a salt-stress relationship among salinity zones.The results indicate that B.sexangula had a plasticity strategy on leaf morphological parameters to salinity in the Sundarbans.This study will provide basic information of leaf plasticity of this species among saline zones which will help for site selection of coastal planting and will also provide information for policy makers to take necessary steps for its conservation.展开更多
The greenness （SPAD） of uneven-aged leaves of dominant species in the Castanopsis carlessi forest at different altitude gradients in Lingshishan National Forest Park, Fujian Province, China were measured by using po...The greenness （SPAD） of uneven-aged leaves of dominant species in the Castanopsis carlessi forest at different altitude gradients in Lingshishan National Forest Park, Fujian Province, China were measured by using portable chlorophyll meter SPAD-502. In addition, the correlation between SPAD value and the concentration of chlorophyll and foliar nitrogen was also investigated. Significant variations in SPAD values were found between the uneven-aged leaves of different dominant species and different altitude gradients. Regression analysis showed that SPAD value was significantly correlated with the concentration of chlorophyll and the content of foliar nitrogen, indicating that SPAD value could be indicators for foliar chlorophyll and nitrogen. It is suggested that SPAD meter is a useful tool for forest assessments in decision-making and operational nutrient management programs.展开更多
Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants...Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.展开更多
Riparian vegetation in the lower reaches of Heihe River serves important ecological functions. However, the riparian ecosystems have been constantly deteriorating in the past 30 years simply due to water interception ...Riparian vegetation in the lower reaches of Heihe River serves important ecological functions. However, the riparian ecosystems have been constantly deteriorating in the past 30 years simply due to water interception for oasis agricultural irrigation in the middle reaches of the river. This study pays a particular attention to Populus eu- phratica Oily. forest because it is a dominant component of the riparian ecosystem in the lower reaches of Heihe River where the depth of groundwater table is the controlling factor in sustaining riparian ecosystems. To reveal leaf-related physiological responses of Populus euphratica Oliv. forest to groundwater table variations, we analyzed the relationships between the depth of groundwater table （DG） and three leaf-related parameters, i.e. leaf stomatal density （SD）, specific leaf area （SLA）, and stable carbon isotopic composition （6~SC）. Our results show that the relationship between DG and leaf SD is a bi-mode one shaped by both salt stress and water stress. That is, salt stress appeared in shallow groundwater conditions and water stress happened in deep groundwater conditions, and the thin layer around 2.7 m of DG is a stress-free layer. Leaf SD fluctuated according to the DG variation, first de- creased with increasing DG, then increased at depths ranging 2.7-3.7 m, and after a relatively stable plateau of SD at depths ranging 3.7-5.2 m, decreased again with increasing DG. Our results also show that SLA decreased ex- ponentially with increasing DG and foliar 6130 values are also strongly dependent on DG, further demonstrating that these two parameters are sensitive indicators of water stress. The exponential curve suggests that SLA is more sensitive to DG when groundwater table is shallow and 3 m seems to be a threshold beyond which SLA becomes less sensitive to DG. Foliar 613C becomes more sensitive when the groundwater table is deep and 7 m seems to be a threshold below which the 6130 signature becomes more sensitive to DG. These findings should be helpful in monitoring the growth and development of Populus euphratica Oliv. forests and also in providing protection measures （i.e. DG related） for Heihe River riparian forests.展开更多
Calotropis procera(Aiton)Dryand(Apocynaceae)is a native species in tropical and subtropical Africa and Asia.However,due to its fast growing and drought-tolerant,it has become an invasive species when it was introduced...Calotropis procera(Aiton)Dryand(Apocynaceae)is a native species in tropical and subtropical Africa and Asia.However,due to its fast growing and drought-tolerant,it has become an invasive species when it was introduced into Central and South America,as well as the Caribbean Islands.Currently,C.procera displays a wide distribution in the world.Invasiveness is important,in particular,because many invasive species exert a high reproductive pressure on the invaded communities or are highly productive in their new distributed areas.It has been suggested that a very deep root system and a high capacity to reduce stomatal conductance during water shortage could allow this species to maintain the water status required for a normal function.However,the true mechanism behind the successful distribution of C.procera across wet and dry environments is still unknown.C.procera leaves were collected from 12 natural populations in Brazil,Colombia and Mexico,ranging from wet to dry environments during 2014–2015.Many traits of morphology and anatomy from these distinct morphotypes were evaluated.We found that C.procera leaves had a considerable capacity to adjust their morphological,anatomical and physiological traits to different environments.The magnitude of acclimation responses,i.e.,plasticity,had been hypothesized to reflect the specialized adaptation of plant species to a particular environment.However,allometric models for leaf area(LA)estimation cannot be grouped as a single model.Leaves are narrower and thicker with low amounts of air spaces inside the leaf parenchyma in wet environments,while they are broader and thinner with a small number of palisade cell layers in dry environments.Based on these,we argue that broader and thinner leaves of C.procera dissipate incident energy at the expense of a higher rate of transpiration to survive in environments in which water is the most limiting factor and to compete in favorable wet environments.展开更多
A primary objective of botanical gardens is to conserve threatened plant species from different regions and countries.However,such ex-situ conservation practices for exotic plant species may pose a significant plant i...A primary objective of botanical gardens is to conserve threatened plant species from different regions and countries.However,such ex-situ conservation practices for exotic plant species may pose a significant plant invasion risks.In this study,we predict the naturalization probability of exotic threatened plant species of Cibodas Botanical Garden(CBG) collections based on leaf trait(specific leaf area,SLA) or as a function of invasion risk assessment scoring system(Tropical Weed Risk Assessment Protocol,TWRAP).We found that SLA and TWRAP were positively correlated with naturalization probability.The TWRAP model produced higher predictive probabilities with larger uncertainty compared to SLA model.Parmentiera cereifera and Burretiodendron hsienmu are two species that have highest naturalization probability based on SLA model.Chamaedorea oblongata has the highest naturalization probability based on TWRAP model.From practical and management point of view,we recommend the simultaneous use of SLA-based and TWRAP-based invasive species risk assessment to estimate the naturalization risk of exotic threatened collections of botanical gardens to adjacent mountain forests.Finally,given the important conservation value of threatened exotic collection of botanical garden,we need to be aware with the invasion risks of these species.The threatened condition of a plant species is not only caused by its natural characteristics but also may be caused(in fact mostly confounding with) by external disturbance either natural catastrophic or human related activities.Thus,a threatened species may not necessarily a noninvasive species outside their natural distribution ranges.展开更多
Aims Human activities have dramatically increased nutrient inputs to ecosys-tems,impacting plant community diversity,composition and function-ing.Extensive research has shown that a decrease in species diversity and a...Aims Human activities have dramatically increased nutrient inputs to ecosys-tems,impacting plant community diversity,composition and function-ing.Extensive research has shown that a decrease in species diversity and an increase in productivity are a common phenomenon following fertilization in grasslands ecosystem.The magnitude of the response of species diversity and above-ground net primary productivity(ANPP)to fertilization mainly depends on species traits(mean trait values)and traits variability(plasticity).Our aim of this study was to examine(i)changes of species diversity(species richness and Shannon-Wiener index)and ANPP following fertilization;(ii)which species traits or community-weighted mean(CWM)traits can determine ANPP,as expected from the‘biomass ratio hypothesis’;and(iii)the relative role of intra-specific and inter-specific trait variability in this process following fertilization.Methods We measured ANPP and four key plant functional traits:specific leaf area(SLA),leaf dry matter content(LDMC),mature plant height(MPH)and leaf nitrogen concentration(LNC)for 25 component species along a fertilization gradient in an alpine meadow on the Tibetan Plateau.In addition,trait variation of species was assessed using coefficients of variation(CV),and we calculated the ratio of the CVintra to the CVinter.Important Findings Our results showed that:(i)fertilization significantly reduced species richness and Shannon-Weiner diversity index,but sig-nificantly increased ANPP;(ii)there was a significant positive correlation between ANPP and CWM-SLA and CWM-MPH,yet there was no significant relationship between ANPP and CWM-LNC or CWM-LDMC;(iii)intra-specific variability in SLA and MPH was found to be much greater than inter-specific variability,especially at the higher fertilization levels.We con-cluded that CWM-SLA and CWM-MPH can be used to assess the impacts of species changes on ecosystem functioning,and dominant species can maximize resource use through intra-spe-cific variability in SLA and MPH to compensate for the loss of species following fertilization,therefore maintaining high com-munity productivity.展开更多
Aims To clarify whether variation in leaf traits with climate differs with scale,i.e.across species and within a species,and to detect whether plant functional group affects species-specific response.Methods Leaf dry ...Aims To clarify whether variation in leaf traits with climate differs with scale,i.e.across species and within a species,and to detect whether plant functional group affects species-specific response.Methods Leaf dry matter content(LDMC),specific leaf area(SLA),mass-and area-based leaf N(N_(mass),N_(area))and leaf P concentrations(P_(mass),P_(area))and leaf chlorophyll concentration(SPAD)were measured for 92 woody plant species in two botanical gardens in China.The two gardens share plant species in common but differ in climate.Leaf trait variation between the two gardens was examined via mean comparison at three scales:all species together,species grouped into plant functional groups and within a species.A meta-analysis was performed to summarize the species-specific responses.Important Findings At the scale of all species together,LDMC,SLA,P_(mass) and N_(mass) were significantly lower in the dry-cold habitat than in the wet-warm one,whereas N_(area) and SPAD showed an inverse pattern,indicating a significant environmental effect.The meta-analysis showed that the above-mentioned patterns persisted for SLA,N_(area) and SPAD but not for the other variables at the species-specific scale,indicating that intraspecific variation affects the overall pattern of LDMC,P_(mass) and N_(mass) and P_(area).In terms of species-specific response,posi-tive,negative or nonsignificant patterns were observed among the 92 species.Contrary to our prediction,species-specific responses within a functional group were not statistically more similar than those among functional groups.Our results indicated that leaf trait variation captured climatic difference yet species-specific responses were quite diverse irrespective of plant functional group,providing new insights for interpreting trait variability with climate.展开更多
We re-analyzed two large published databases on leaf traits of plant species from seven different biomes, and determined the scaling relationship between leaf metabolism rate （mass-based photosynthesis capacity, Amas...We re-analyzed two large published databases on leaf traits of plant species from seven different biomes, and determined the scaling relationship between leaf metabolism rate （mass-based photosynthesis capacity, Amass, and mass-based dark respiration, Rdmass） and specific leaf area （SLA） across biomes, using a standardized major axis （SMA） method. Overall pooled data produced a scaling exponent of 1.33 for the relationship between Amass and SLA, significantly larger than 1.0; and 1.04 between Rdmass and SLA. The scaling exponent of the relationship between Amass and SLA ranged between 1.23 （in tropical forest） and 1.66 （in alpine biome）, and it was significantly larger in alpine （1.66） and grass/meadow （1.52） biomes than in tropical forest （1.23） and wetland （1.27）. The exponent of the relationship between Rdmass and SLA, however, was much smaller in wetland （1.05） than in temperate forest （1.29） and tropical rainforest （1.65）. In general, the predicated universal scaling relationship that the mass-based metabolism rate should be proportional to surface area in organisms is not applicable at the leaf-level in plants. Rather, the large slope difference of the relationship between leaf metabolism rate and SLA found among biomes indicates that the strength of the selective forces driving the scaling relationship is different among the biomes. The result basically suggests the importance of increasing SLA to plant carbon gain in stressful environments and to carbon loss in favorable habitats, and therefore has an important implication for survival strategies of plants in different biomes.展开更多
Aims Predicting drought consequences on forests and fruit crop plantings requires improved understanding of drought responses of both leaf and fine-root resource acquisitive traits(specific leaf area—SLA,specific roo...Aims Predicting drought consequences on forests and fruit crop plantings requires improved understanding of drought responses of both leaf and fine-root resource acquisitive traits(specific leaf area—SLA,specific root surface area—SRA and specific root length—SRL).We hypothesize their responses are coordinated towards integrated plant resource conservation under severe drought.Methods We tested the hypothesis with a greenhouse-based drought experiment on saplings of six Prunus hybrids with a priori known contrasting drought sensitivity.Saplings were subjected to either control(100%field capacity)or severe drought stress treatment(33%evapotranspiration of hybrid-specific control plants).Sample collections were carried out at 30 and at 60 days after the start of treatments,for both control and stressed saplings.Important Findings No hybrid showed concurrent significant decrease of SLA and SRA(or SRL)under severe drought.The fine-root traits of the six hybrids showed two major drought-response scenarios,in particular:(i)increased root tissue density(RTD)and decreased average root diameter without significant change of SRL and(ii)increased RTD and decreased SRL without significant change of average root diameter.Drought responses of leaf gas exchange,SRA,SRL and RTD were closely correlated along a gradient towards resource conservation from control to drought-stressed plants in all hybrids,which was orthogonal to another gradient characterized by a hybrid-dependent decrease of SLA.These findings highlight(i)the multi-dimensionality of root-trait drought responses,(ii)the decoupling between leaf economics and leaf hydraulics and(iii)the covariation of leaf and root hydraulics in terms of trait drought responses.The study contributes to identifying the origin of the multi-dimensionality of root-trait drought response at intraspecific scale,and highlights differential drought–response combinations of leaf and fine-root traits among hybrids to survive under severe soil drought stress.展开更多
Aims community assembly links plant traits to particular environmental conditions.Numerous studies have adopted a trait-based approach to understand both community assembly processes and changes in plant functional tr...Aims community assembly links plant traits to particular environmental conditions.Numerous studies have adopted a trait-based approach to understand both community assembly processes and changes in plant functional traits along environmental gradients.In most cases these are long-established,natural or semi-natural environments.However,increasingly human activity has created,and continues to create,a range of new environmental conditions,and under-standing community assembly in these‘novel environments’will be increasingly important.Methods Built in 2006,the three Gorges Dam,largest hydraulic project in china,created a new riparian area of 384 km^(2),with massively al-tered hydrology.this large,newly created ecosystem is an ideal platform for understanding community assembly in a novel environment.We sampled environment variables and plant communities within 103 plots located in both the reservoir riparian zone(RRZ)and adjacent non-flooded and semi-natural upland(Upland)at the three Gorges Reservoir Area.We measured six traits from 168 plant species in order to calculate community-level distribution of trait values.We expected that the altered hydrology in RRZ would have a profound effect on the community assembly process for the local plants.Important Findingsconsistent with previous work on community assembly,the dis-tribution of trait values(range,variance,kurtosis and the standard deviation of the distribution neighbor distances)within all plots was significantly lower than those from random distributions,indicat-ing that both habitat filtering and limiting similarity simultaneously shaped the distributions of traits and the assembly of plant commu-nities.considering the newly created RRZ relative to nearby sites,community assembly was different in two main ways.First,there was a large shift in the mean trait values.compared to Upland commu-nities,plant communities in the RRZ had higher mean specific leaf area(SLA),higher nitrogen per unit leaf mass(Nmass),and lower max-imum height(MH).Second,in the RRZ compared to the Upland,for the percentage of individual plots whose characteristic of trait values was lower than null distributions,the reductions in the community-level range for SLA,Nmass,nitrogen per unit leaf area(Narea)and phos-phorus per unit leaf area(Parea)were much larger,suggesting that the habitat filter in this newly created riparian zone was much stronger compared to longer established semi-natural upland vegetation.this stronger filter,and the restriction to a subset of plants with very similar trait values,has implications for predicting riparian ecosystems’responses to the hydrological alterations and further understanding for human’s effect on plant diversity and plant floras.展开更多
The objective of this paper was to assess the congruency of leaf traits and soil characteristics and to analyze the survival strategies of different plant functional types in response to drought and nutrient-poor envi...The objective of this paper was to assess the congruency of leaf traits and soil characteristics and to analyze the survival strategies of different plant functional types in response to drought and nutrient-poor environ-ments in the southeastern Ke’erqin Sandy Lands in China.Six leaf traits—leaf thickness(TH),density(DN),specific leaf area(SLA),leaf dry weight to fresh weight ratio(DW/FW),leaf N concentration(N mass),and N resorption efficiency(NRE_(mass))-of 42 plant species were investi-gated at four sites.The correlations between leaf traits and soil characteristics-organic C(OC),total N(TN),total P(TP),and soil moisture(SM)-were examined.We found that the six leaf traits across all the 42 species showed large variations and that DW/FW was negatively correlated with OC,TN,TP,and SM(P<0.05),while other leaf traits showed no significant correlations with soil characteristics.To find the dissimilarity to accommodate environment,a hierarchical agglomerative clustering analysis was made of all the species.All the species clustered into three groups except the Scutellaria baicalensis.Species of group III might be most tolerant of an arid environment,and species of group II might avoid nutrient stress in the nutrient-poor environment,while group I was somewhat intermediate.Therefore,species from the different groups may be selected for use in vegetation restoration of different sites based on soil moisture and nutrient conditions.展开更多
Six leaf traits,i.e.,fresh mass(FM),dry mass(DM),leaf dry matter content(DMC),area(AR),specific leaf area(SLA)and thickness(TH)from 23 plant species in the southeastern Keerqin Sandy Lands,China were measured.The resu...Six leaf traits,i.e.,fresh mass(FM),dry mass(DM),leaf dry matter content(DMC),area(AR),specific leaf area(SLA)and thickness(TH)from 23 plant species in the southeastern Keerqin Sandy Lands,China were measured.The results show that leaf traits of herbs were more diversified than those of shrubs and trees and aver-age SLA tended towards a decreasing trend from herbs to shrubs to trees.On the contrary,DMC and DM show an upward trend from herbs to shrubs to trees.No apparent difference was found in TH.Except for DM and TH,there were significant variations in SLA and DMC among three different growth forms.Moreover,a significant correlation was found between SLA and DMC.It is concluded that SLA and DMC could be used to predict species position along a resource use gradient.展开更多
Aims Plant size,environmental conditions and functional traits are important for plant growth;however,it is less clear which combination of these factors is the most effective for predicting tree growth across ontogen...Aims Plant size,environmental conditions and functional traits are important for plant growth;however,it is less clear which combination of these factors is the most effective for predicting tree growth across ontogenetic stages.Methods We selected 65 individuals of an evergreen coniferous species,Pinus koraiensis,with diameters at breast height(DBH)from 0.3 to 100 cm in Northeast China.For each individual,we measured the stem radius growth rate(SRGR,µm/year)for the current year,environmental factors(light,soil nutrient and soil water)and functional traits(leaf,branch and root traits).Important Findings SRGR increased with DBH when the DBH was lower than 58 cm,whereas it decreased with DBH when the DBH was larger than 58 cm.Structural equation modeling analysis suggested that,when the DBH was 0–15 cm,plant size had a direct negative influence on SRGR and an indirect positive influence on SRGR due to the light intensity above the plant.Plant size had direct positive and negative effects when the DBH was 16–58 cm and 59–100 cm,respectively.When the DBH was larger than 15 cm,soil parameters were more important than light intensity for SRGR.The functional traits selected for use in the best model were changed from the specific leaf area and wood density to the root nitrogen concentration with increasing tree size.In summary,plant size,environmental factors and functional traits jointly shaped tree growth,and their relative influence varied with size,suggesting that the resources limiting tree growth may change from light to soil nutrient with increasing tree size.展开更多
Aims Plant functional traits determine how plants respond to environmen-tal factors and influence ecosystem processes.Among them,root traits and analyses of relations between above and below-ground traits in natural c...Aims Plant functional traits determine how plants respond to environmen-tal factors and influence ecosystem processes.Among them,root traits and analyses of relations between above and below-ground traits in natural communities are scarce.Methods we characterized a set of above-and below-ground traits of three dominant shrub species in a semiarid shrub-steppe that had contrasting leaf pheno-logical habits(deciduous,semideciduous and evergreen).We ana-lysed if there was coordination among above-and below-ground resource economics patterns:i.e.patterns of biomass allocation,construction costs and lifespan.Important Findings Above-and below-ground traits and their resource economics relations pointed to species-specific functional strategies to cope with drought and poor soils and to a species ranking of fast to slow whole-plant strategies in terms of resource uptake,biomass con-struction costs and turnover.The deciduous shrub,Proustia cunei-folia,had relatively deep and even distribution of roots,and high proportion of short-lived tissues of low C construction costs:it had high fine to coarse root and high leaf-to-stem biomass ratios,high specific leaf area(SLA),and stems of low wood density.This strat-egy allows Proustia to maximize and coordinate above-and below-ground resources uptake as long as the most limiting factor(water)is available,but at the cost of having relative high plant biomass turnover.The evergreen Porlieria chilensis,instead,displayed a more conservative and slow strategy in terms of resource econom-ics.It had~80%of the roots in the 40 cm topsoil profile,low pro-portion of fine compared with coarse roots and low leaf-to-stem ratios,low SLA and stems of high wood density,i.e.it invested in C costly tissues that,overall,persist longer but probably at the cost of having lower plant resource uptake rates.Traits in the semide-ciduous Adesmia bedwellii were in between these two functional extremes.Our results revealed high functional diversity and above-and below-ground complementarity in resource economics among these three codominant species in the Chilean coastal desert.展开更多
Aims The clustering of plants with similar leaf traits along environmental gradients may arise from adaptation as well as acclimation to het-erogeneous habitat conditions.Determining the forces that shape plant leaf t...Aims The clustering of plants with similar leaf traits along environmental gradients may arise from adaptation as well as acclimation to het-erogeneous habitat conditions.Determining the forces that shape plant leaf traits requires both linking variation in trait morphology with abiotic gradients and linking that trait variation with plant per-formance under varying abiotic conditions.across the spectrum of plant types,shade-tolerant evergreen herbs are relatively low in trait plasticity,compared to deciduous and sun-adapted species.These plants employ stress-tolerant strategies for survival,which coincide with relatively static trait morphologies,slow growth and hence a lower ability to adjust to changing environmental conditions.Methods We investigate how the survival of two ecologically similar under-story evergreen species,Asarum arifolium and Hepatica nobilis,cor-responds with variation in six commonly measured functional traits(leaf area,specific leaf area,plant height,leaf number,leaf length and shoot mass)along natural and experimental abiotic gradients.We examine temporal(the period 2007-9)and spatial(100 km)variations in these traits after(i)translocating 576 plants across a span from the southerm Appalachian Mountains in NC,USA,to the Piedmont,GA,USA,which includes north-and south-facing slope habitats and(ii)the experimental manipulation of diffuse light and soil moisture.Important findings We find that when translocated into a novel habitats,with novel environmental conditions that often are more extreme than the source habitat,both species appear capable of considerable mor-phological acclimation and generally converge to similar trait values.Hepatica nobilis does not exhibit mean trait values particu-larly different from those of A.arifolium,but it demonstrates much greater phenotypic plasticity.These results indicate that relatively conservative plant species nonetheless acclimate and survive across heterogeneous environmental conditions.展开更多
We conducted 30-and 60-d greenhouse experiments to compare functional traits of Bromus tectorum(invasive annual grass) and four perennial bunchgrasses under well-watered or drought conditions.Even under drought, B. te...We conducted 30-and 60-d greenhouse experiments to compare functional traits of Bromus tectorum(invasive annual grass) and four perennial bunchgrasses under well-watered or drought conditions.Even under drought, B. tectorum experienced significantly less stress(i.e., higher xylem pressure potential and greater shoot water content, water use per day and water-use efficiency) and biomass production than the perennial grasses after 30 d. However, after 60 d, its superiority was reduced under infrequent watering. Differences among perennial grasses were more pronounced for physiological traits under infrequent watering and for morphological traits under frequent watering. Elymus multisetus(fastgrowing species) had a higher transpiration rate, lower leaf temperature, and lower water-use efficiency than the other grasses after 30 d. In contrast, Pseudoroegneria spicata(slow-growing) had lower xylem pressure potential and higher leaf temperature than all other grasses under infrequent watering. Under frequent watering, shoot dry mass and specific leaf area of B. tectorum was matched by Elymus wawawaiensis(moderate-growing species). Our results indicate that multiple-species plantings or seedings are necessary to foster greater weed resistance against B. tectorum. We also emphasize that when choosing plant material for restoration, performance during both pulse(resource-rich) and inter-pulse(resource-poor) periods should be considered.展开更多
基金supported by ISRO-SAC,Ahmeda-bad,and DST,New Delhi through SSS programme (Project No SR/S4/ES-21/Baroda window P2)
文摘Leaf area index（LAI） of Teak（Tectona grandis） and Bamboo（Dendrocalamus strictus） grown in Shoolpaneshwar Wildlife Sanctuary of Narmada District,Gujarat,India was obtained by destructive sampling,photo-grid method and by litter trap method.An allometric equation（between leaf area by litter trap method and canopy spread area） was developed for the determination of LAI.Results show that LAI value calculated by the developed allometric equation was similar to that estimated by destructive sampling and photo-grid method,with Root Mean Square Error（RMSE） of 0.90 and 1.15 for Teak,and 0.38 and 0.46 for Bamboo,respectively.There was a perfect match in both the LAI values（estimated and calculated）,indicating the accuracy of the developed equations for both the species.In conclusion,canopy spread is a better and sensitive parameter to estimate leaf area of trees.The developed equations can be used for estimating LAI of Teak and Bamboo in tropics.
基金financially supported by the National Natural Science Foundation of China(31300343)Natural Science Foundation of Jiangsu Province,China(BK20130500)Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment
文摘Leaf functional traits are adaptations that enable plants to live under different environmental conditions. This study aims to evaluate the differences in leaf functional traits between red and green leaves of two evergreen shrubs Photinia × fraseri and Osrnanthus fragrans. Specific areas of red leaves are higher than that of green leaves in both species. Thus, the material investment per unit area and per lamina of red leaves is significantly lower than that of green leaves, implying an utmost effort of red leaves to increase light capture and use efficiency because of their low leafchlorophyll concentration. The higher petiole length of green leaves compared with that of red leaves indicates that adult green leaves may have large fractional biomass allocation to support the lamina structures in capturing light with maximum efficiency and obtaining a high growth rate. The high range of the phenotypic plasticity of leaf size, leaf thickness, single-leaf wet and dry weights, and leaf moisture of green leaves may be beneficial in achieving efficient control of water loss and nutrient deprivation. The high range of phenotypic plasticity of leaf chlorophyll concentration of red leaves may be advantageous in increasing resource （especially light） capture anduse efficiency because this leaf type is juvenile in the growth stage and has low leaf-chlorophyll concentration.
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject(Y20160023)supported by Open Science Research Fund of State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,China+1 种基金Project supported by Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment
文摘Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and their corresponding variability of the invasive tree staghorn sumac Rhus typhina L. with different invasion success, including lower and higher invasion success, in two climatic regions in North China, including a warm temperate region and a cold temperate region. No significant differences were found for leaf functional traits of staghorn sumac across different invasion success. However, the variability of leaf chlorophyll and nitrogen concentrations of staghorn sumac under higher invasion success were approximately 66.023% and 68.615% higher than those under lower invasion success, respectively. The leaf chlorophyll and nitrogen concentrations of staghorn sumac in the warm temperate region were approximately 18.432% and 16.337% higher than those in cold temperate region, respectively. The variability of specific leaf area of staghorn sumac in warm temperate region was approximately 59.802% higher than that in cold temperate region. Accordingly, leaf chlorophyll and N concentrations as well as specific leaf area of staghorn sumac and their corresponding variability may play an essential role in shaping ecological success of studied invader along a climatic gradient.
基金supported by JSPS RONPAKU Program FY2018,Japan(R11810)Bangladesh University Grants Commission(UGC/SciTech/Agri(Crop-47)-26/2017/4915)。
文摘Bruguiera sexangula(Lour.)Poir is an exclusive evergreen mangrove species to the Sundarbans of Bangladesh.It grows well in moderate saline zones with full sunlight.This study presents leaf morphological plasticity in B.sexangula to saline zones.Leaves were sampled from different saline zones and various morphological traits were measured.The results exposed a wide deviations of leaf size parameters:leaf length varied 6.6–17.3 cm;width 2.7–7.8 cm;upper quarter width 2.2–6.5 cm;down quarter width 2.5–7.3 cm;and petiole length 0.17–1.43 cm.Leaf length was significantly larger in fresh water than in other salinity zones,whereas,leaf width,upper and lower leaf quarters were significantly larger in medium saline zone.Leaf shape parameters showed a large variation among saline zones.Leaf base angle was significantly larger in both medium and strong salinity zones.Tip angle was significantly greater in medium salinity zone.Leaf perimeter was significantly larger in fresh water but leaf area was significantly bigger in medium saline zone.Leaf index and specific leaf area were maximum in moderate saline zone.Plasticity index was the highest in moderate saline for almost all the parameters presented.The ordination(PCA)showed clusters of leaf samples although there were some overlap among them which suggested a salt-stress relationship among salinity zones.The results indicate that B.sexangula had a plasticity strategy on leaf morphological parameters to salinity in the Sundarbans.This study will provide basic information of leaf plasticity of this species among saline zones which will help for site selection of coastal planting and will also provide information for policy makers to take necessary steps for its conservation.
基金supported by National Natural Science Foundation of China (No: 30671664)
文摘The greenness （SPAD） of uneven-aged leaves of dominant species in the Castanopsis carlessi forest at different altitude gradients in Lingshishan National Forest Park, Fujian Province, China were measured by using portable chlorophyll meter SPAD-502. In addition, the correlation between SPAD value and the concentration of chlorophyll and foliar nitrogen was also investigated. Significant variations in SPAD values were found between the uneven-aged leaves of different dominant species and different altitude gradients. Regression analysis showed that SPAD value was significantly correlated with the concentration of chlorophyll and the content of foliar nitrogen, indicating that SPAD value could be indicators for foliar chlorophyll and nitrogen. It is suggested that SPAD meter is a useful tool for forest assessments in decision-making and operational nutrient management programs.
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,ChinaProject(12JDG086)supported by Research Foundation for Advanced Talents of Jiangsu University,China
文摘Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.
基金financially supported by the National Natural Science Foundation of China (91025015, 30770387)
文摘Riparian vegetation in the lower reaches of Heihe River serves important ecological functions. However, the riparian ecosystems have been constantly deteriorating in the past 30 years simply due to water interception for oasis agricultural irrigation in the middle reaches of the river. This study pays a particular attention to Populus eu- phratica Oily. forest because it is a dominant component of the riparian ecosystem in the lower reaches of Heihe River where the depth of groundwater table is the controlling factor in sustaining riparian ecosystems. To reveal leaf-related physiological responses of Populus euphratica Oliv. forest to groundwater table variations, we analyzed the relationships between the depth of groundwater table （DG） and three leaf-related parameters, i.e. leaf stomatal density （SD）, specific leaf area （SLA）, and stable carbon isotopic composition （6~SC）. Our results show that the relationship between DG and leaf SD is a bi-mode one shaped by both salt stress and water stress. That is, salt stress appeared in shallow groundwater conditions and water stress happened in deep groundwater conditions, and the thin layer around 2.7 m of DG is a stress-free layer. Leaf SD fluctuated according to the DG variation, first de- creased with increasing DG, then increased at depths ranging 2.7-3.7 m, and after a relatively stable plateau of SD at depths ranging 3.7-5.2 m, decreased again with increasing DG. Our results also show that SLA decreased ex- ponentially with increasing DG and foliar 6130 values are also strongly dependent on DG, further demonstrating that these two parameters are sensitive indicators of water stress. The exponential curve suggests that SLA is more sensitive to DG when groundwater table is shallow and 3 m seems to be a threshold beyond which SLA becomes less sensitive to DG. Foliar 613C becomes more sensitive when the groundwater table is deep and 7 m seems to be a threshold below which the 6130 signature becomes more sensitive to DG. These findings should be helpful in monitoring the growth and development of Populus euphratica Oliv. forests and also in providing protection measures （i.e. DG related） for Heihe River riparian forests.
基金funded by the National Council for Scientific and Technological Development (CNPq470476/2011-7)+1 种基金the Foundation for Science and Technology of Pernambuco, Brazil (APQ-0077-5.01/09, DCR-0034-2.03/13)the scholarship granted to the first author
文摘Calotropis procera(Aiton)Dryand(Apocynaceae)is a native species in tropical and subtropical Africa and Asia.However,due to its fast growing and drought-tolerant,it has become an invasive species when it was introduced into Central and South America,as well as the Caribbean Islands.Currently,C.procera displays a wide distribution in the world.Invasiveness is important,in particular,because many invasive species exert a high reproductive pressure on the invaded communities or are highly productive in their new distributed areas.It has been suggested that a very deep root system and a high capacity to reduce stomatal conductance during water shortage could allow this species to maintain the water status required for a normal function.However,the true mechanism behind the successful distribution of C.procera across wet and dry environments is still unknown.C.procera leaves were collected from 12 natural populations in Brazil,Colombia and Mexico,ranging from wet to dry environments during 2014–2015.Many traits of morphology and anatomy from these distinct morphotypes were evaluated.We found that C.procera leaves had a considerable capacity to adjust their morphological,anatomical and physiological traits to different environments.The magnitude of acclimation responses,i.e.,plasticity,had been hypothesized to reflect the specialized adaptation of plant species to a particular environment.However,allometric models for leaf area(LA)estimation cannot be grouped as a single model.Leaves are narrower and thicker with low amounts of air spaces inside the leaf parenchyma in wet environments,while they are broader and thinner with a small number of palisade cell layers in dry environments.Based on these,we argue that broader and thinner leaves of C.procera dissipate incident energy at the expense of a higher rate of transpiration to survive in environments in which water is the most limiting factor and to compete in favorable wet environments.
基金supported by "Program Prioritas Bidang Kebun Raya Cibodas 2019".
文摘A primary objective of botanical gardens is to conserve threatened plant species from different regions and countries.However,such ex-situ conservation practices for exotic plant species may pose a significant plant invasion risks.In this study,we predict the naturalization probability of exotic threatened plant species of Cibodas Botanical Garden(CBG) collections based on leaf trait(specific leaf area,SLA) or as a function of invasion risk assessment scoring system(Tropical Weed Risk Assessment Protocol,TWRAP).We found that SLA and TWRAP were positively correlated with naturalization probability.The TWRAP model produced higher predictive probabilities with larger uncertainty compared to SLA model.Parmentiera cereifera and Burretiodendron hsienmu are two species that have highest naturalization probability based on SLA model.Chamaedorea oblongata has the highest naturalization probability based on TWRAP model.From practical and management point of view,we recommend the simultaneous use of SLA-based and TWRAP-based invasive species risk assessment to estimate the naturalization risk of exotic threatened collections of botanical gardens to adjacent mountain forests.Finally,given the important conservation value of threatened exotic collection of botanical garden,we need to be aware with the invasion risks of these species.The threatened condition of a plant species is not only caused by its natural characteristics but also may be caused(in fact mostly confounding with) by external disturbance either natural catastrophic or human related activities.Thus,a threatened species may not necessarily a noninvasive species outside their natural distribution ranges.
基金This study was supported by Natural Science Foundation of China(41230852)Key Program of Chinese Academy of Sciences(KJZD-EW-TZ-G10)+3 种基金Northwest A&F University(Z109021107,Z109021307,QN2013070)West Light Foundation of Chinese Academy of Sciences(K318021305)Natural Science Foundation of Shaanxi Province(2016JQ3008)the China Scholarship Council.
文摘Aims Human activities have dramatically increased nutrient inputs to ecosys-tems,impacting plant community diversity,composition and function-ing.Extensive research has shown that a decrease in species diversity and an increase in productivity are a common phenomenon following fertilization in grasslands ecosystem.The magnitude of the response of species diversity and above-ground net primary productivity(ANPP)to fertilization mainly depends on species traits(mean trait values)and traits variability(plasticity).Our aim of this study was to examine(i)changes of species diversity(species richness and Shannon-Wiener index)and ANPP following fertilization;(ii)which species traits or community-weighted mean(CWM)traits can determine ANPP,as expected from the‘biomass ratio hypothesis’;and(iii)the relative role of intra-specific and inter-specific trait variability in this process following fertilization.Methods We measured ANPP and four key plant functional traits:specific leaf area(SLA),leaf dry matter content(LDMC),mature plant height(MPH)and leaf nitrogen concentration(LNC)for 25 component species along a fertilization gradient in an alpine meadow on the Tibetan Plateau.In addition,trait variation of species was assessed using coefficients of variation(CV),and we calculated the ratio of the CVintra to the CVinter.Important Findings Our results showed that:(i)fertilization significantly reduced species richness and Shannon-Weiner diversity index,but sig-nificantly increased ANPP;(ii)there was a significant positive correlation between ANPP and CWM-SLA and CWM-MPH,yet there was no significant relationship between ANPP and CWM-LNC or CWM-LDMC;(iii)intra-specific variability in SLA and MPH was found to be much greater than inter-specific variability,especially at the higher fertilization levels.We con-cluded that CWM-SLA and CWM-MPH can be used to assess the impacts of species changes on ecosystem functioning,and dominant species can maximize resource use through intra-spe-cific variability in SLA and MPH to compensate for the loss of species following fertilization,therefore maintaining high com-munity productivity.
基金Chinese National Basic Research Program(2014CB954201)National Natural Science Foundation of China(30870398).
文摘Aims To clarify whether variation in leaf traits with climate differs with scale,i.e.across species and within a species,and to detect whether plant functional group affects species-specific response.Methods Leaf dry matter content(LDMC),specific leaf area(SLA),mass-and area-based leaf N(N_(mass),N_(area))and leaf P concentrations(P_(mass),P_(area))and leaf chlorophyll concentration(SPAD)were measured for 92 woody plant species in two botanical gardens in China.The two gardens share plant species in common but differ in climate.Leaf trait variation between the two gardens was examined via mean comparison at three scales:all species together,species grouped into plant functional groups and within a species.A meta-analysis was performed to summarize the species-specific responses.Important Findings At the scale of all species together,LDMC,SLA,P_(mass) and N_(mass) were significantly lower in the dry-cold habitat than in the wet-warm one,whereas N_(area) and SPAD showed an inverse pattern,indicating a significant environmental effect.The meta-analysis showed that the above-mentioned patterns persisted for SLA,N_(area) and SPAD but not for the other variables at the species-specific scale,indicating that intraspecific variation affects the overall pattern of LDMC,P_(mass) and N_(mass) and P_(area).In terms of species-specific response,posi-tive,negative or nonsignificant patterns were observed among the 92 species.Contrary to our prediction,species-specific responses within a functional group were not statistically more similar than those among functional groups.Our results indicated that leaf trait variation captured climatic difference yet species-specific responses were quite diverse irrespective of plant functional group,providing new insights for interpreting trait variability with climate.
基金the National Natural Science Foundation of China (30670333)the Program for New Century Excellent Talents in University to Shucun Sun.
文摘We re-analyzed two large published databases on leaf traits of plant species from seven different biomes, and determined the scaling relationship between leaf metabolism rate （mass-based photosynthesis capacity, Amass, and mass-based dark respiration, Rdmass） and specific leaf area （SLA） across biomes, using a standardized major axis （SMA） method. Overall pooled data produced a scaling exponent of 1.33 for the relationship between Amass and SLA, significantly larger than 1.0; and 1.04 between Rdmass and SLA. The scaling exponent of the relationship between Amass and SLA ranged between 1.23 （in tropical forest） and 1.66 （in alpine biome）, and it was significantly larger in alpine （1.66） and grass/meadow （1.52） biomes than in tropical forest （1.23） and wetland （1.27）. The exponent of the relationship between Rdmass and SLA, however, was much smaller in wetland （1.05） than in temperate forest （1.29） and tropical rainforest （1.65）. In general, the predicated universal scaling relationship that the mass-based metabolism rate should be proportional to surface area in organisms is not applicable at the leaf-level in plants. Rather, the large slope difference of the relationship between leaf metabolism rate and SLA found among biomes indicates that the strength of the selective forces driving the scaling relationship is different among the biomes. The result basically suggests the importance of increasing SLA to plant carbon gain in stressful environments and to carbon loss in favorable habitats, and therefore has an important implication for survival strategies of plants in different biomes.
基金supported by the Australian almond industry through Horticulture Innovation Australia Limited(Hort Innovation)using the almond industry research and development levy and funds from the Australian Government(AL13009)In-kind funding support from The Commonwealth Scientific and Industrial Research Organisation(CSIRO)is also gratefully acknowledged.
文摘Aims Predicting drought consequences on forests and fruit crop plantings requires improved understanding of drought responses of both leaf and fine-root resource acquisitive traits(specific leaf area—SLA,specific root surface area—SRA and specific root length—SRL).We hypothesize their responses are coordinated towards integrated plant resource conservation under severe drought.Methods We tested the hypothesis with a greenhouse-based drought experiment on saplings of six Prunus hybrids with a priori known contrasting drought sensitivity.Saplings were subjected to either control(100%field capacity)or severe drought stress treatment(33%evapotranspiration of hybrid-specific control plants).Sample collections were carried out at 30 and at 60 days after the start of treatments,for both control and stressed saplings.Important Findings No hybrid showed concurrent significant decrease of SLA and SRA(or SRL)under severe drought.The fine-root traits of the six hybrids showed two major drought-response scenarios,in particular:(i)increased root tissue density(RTD)and decreased average root diameter without significant change of SRL and(ii)increased RTD and decreased SRL without significant change of average root diameter.Drought responses of leaf gas exchange,SRA,SRL and RTD were closely correlated along a gradient towards resource conservation from control to drought-stressed plants in all hybrids,which was orthogonal to another gradient characterized by a hybrid-dependent decrease of SLA.These findings highlight(i)the multi-dimensionality of root-trait drought responses,(ii)the decoupling between leaf economics and leaf hydraulics and(iii)the covariation of leaf and root hydraulics in terms of trait drought responses.The study contributes to identifying the origin of the multi-dimensionality of root-trait drought response at intraspecific scale,and highlights differential drought–response combinations of leaf and fine-root traits among hybrids to survive under severe soil drought stress.
文摘Aims community assembly links plant traits to particular environmental conditions.Numerous studies have adopted a trait-based approach to understand both community assembly processes and changes in plant functional traits along environmental gradients.In most cases these are long-established,natural or semi-natural environments.However,increasingly human activity has created,and continues to create,a range of new environmental conditions,and under-standing community assembly in these‘novel environments’will be increasingly important.Methods Built in 2006,the three Gorges Dam,largest hydraulic project in china,created a new riparian area of 384 km^(2),with massively al-tered hydrology.this large,newly created ecosystem is an ideal platform for understanding community assembly in a novel environment.We sampled environment variables and plant communities within 103 plots located in both the reservoir riparian zone(RRZ)and adjacent non-flooded and semi-natural upland(Upland)at the three Gorges Reservoir Area.We measured six traits from 168 plant species in order to calculate community-level distribution of trait values.We expected that the altered hydrology in RRZ would have a profound effect on the community assembly process for the local plants.Important Findingsconsistent with previous work on community assembly,the dis-tribution of trait values(range,variance,kurtosis and the standard deviation of the distribution neighbor distances)within all plots was significantly lower than those from random distributions,indicat-ing that both habitat filtering and limiting similarity simultaneously shaped the distributions of traits and the assembly of plant commu-nities.considering the newly created RRZ relative to nearby sites,community assembly was different in two main ways.First,there was a large shift in the mean trait values.compared to Upland commu-nities,plant communities in the RRZ had higher mean specific leaf area(SLA),higher nitrogen per unit leaf mass(Nmass),and lower max-imum height(MH).Second,in the RRZ compared to the Upland,for the percentage of individual plots whose characteristic of trait values was lower than null distributions,the reductions in the community-level range for SLA,Nmass,nitrogen per unit leaf area(Narea)and phos-phorus per unit leaf area(Parea)were much larger,suggesting that the habitat filter in this newly created riparian zone was much stronger compared to longer established semi-natural upland vegetation.this stronger filter,and the restriction to a subset of plants with very similar trait values,has implications for predicting riparian ecosystems’responses to the hydrological alterations and further understanding for human’s effect on plant diversity and plant floras.
基金This work was supported by grants from the National Key Technologies R&D Program of China(Nos.2006BAD26B0201-1 and 2006BAC01A12)the National Natural Science Foundation of China(grant No.30872011)+1 种基金the National Key Basic Research Program of China(No.2007CB106803)D.Pepper acknowledges grant support from the Australia-China Special Fund for Scientific&Technological Cooperation(CH060165).
文摘The objective of this paper was to assess the congruency of leaf traits and soil characteristics and to analyze the survival strategies of different plant functional types in response to drought and nutrient-poor environ-ments in the southeastern Ke’erqin Sandy Lands in China.Six leaf traits—leaf thickness(TH),density(DN),specific leaf area(SLA),leaf dry weight to fresh weight ratio(DW/FW),leaf N concentration(N mass),and N resorption efficiency(NRE_(mass))-of 42 plant species were investi-gated at four sites.The correlations between leaf traits and soil characteristics-organic C(OC),total N(TN),total P(TP),and soil moisture(SM)-were examined.We found that the six leaf traits across all the 42 species showed large variations and that DW/FW was negatively correlated with OC,TN,TP,and SM(P<0.05),while other leaf traits showed no significant correlations with soil characteristics.To find the dissimilarity to accommodate environment,a hierarchical agglomerative clustering analysis was made of all the species.All the species clustered into three groups except the Scutellaria baicalensis.Species of group III might be most tolerant of an arid environment,and species of group II might avoid nutrient stress in the nutrient-poor environment,while group I was somewhat intermediate.Therefore,species from the different groups may be selected for use in vegetation restoration of different sites based on soil moisture and nutrient conditions.
基金This work was supported by grants from the National Science&Technology Supporting Program of China(No.2006BAD26B0201-1,No.2006BAC01A12)the National Natural Science Foundation of China(No.30471377)Korea Science and Engineering Foundation.We acknowledge Zhanyuan Yu,Bin Deng,Dongzhou Deng for their helps in sampling,and Heming Lin,Guiyan Ai for chemical analysis of samples。
文摘Six leaf traits,i.e.,fresh mass(FM),dry mass(DM),leaf dry matter content(DMC),area(AR),specific leaf area(SLA)and thickness(TH)from 23 plant species in the southeastern Keerqin Sandy Lands,China were measured.The results show that leaf traits of herbs were more diversified than those of shrubs and trees and aver-age SLA tended towards a decreasing trend from herbs to shrubs to trees.On the contrary,DMC and DM show an upward trend from herbs to shrubs to trees.No apparent difference was found in TH.Except for DM and TH,there were significant variations in SLA and DMC among three different growth forms.Moreover,a significant correlation was found between SLA and DMC.It is concluded that SLA and DMC could be used to predict species position along a resource use gradient.
基金by the National Natural Science Foundation of China(31971636,31870399)Yong Elite Scientists Sponsorship Program by CAST(2018QNRC001).
文摘Aims Plant size,environmental conditions and functional traits are important for plant growth;however,it is less clear which combination of these factors is the most effective for predicting tree growth across ontogenetic stages.Methods We selected 65 individuals of an evergreen coniferous species,Pinus koraiensis,with diameters at breast height(DBH)from 0.3 to 100 cm in Northeast China.For each individual,we measured the stem radius growth rate(SRGR,µm/year)for the current year,environmental factors(light,soil nutrient and soil water)and functional traits(leaf,branch and root traits).Important Findings SRGR increased with DBH when the DBH was lower than 58 cm,whereas it decreased with DBH when the DBH was larger than 58 cm.Structural equation modeling analysis suggested that,when the DBH was 0–15 cm,plant size had a direct negative influence on SRGR and an indirect positive influence on SRGR due to the light intensity above the plant.Plant size had direct positive and negative effects when the DBH was 16–58 cm and 59–100 cm,respectively.When the DBH was larger than 15 cm,soil parameters were more important than light intensity for SRGR.The functional traits selected for use in the best model were changed from the specific leaf area and wood density to the root nitrogen concentration with increasing tree size.In summary,plant size,environmental factors and functional traits jointly shaped tree growth,and their relative influence varied with size,suggesting that the resources limiting tree growth may change from light to soil nutrient with increasing tree size.
基金C.A.was granted with a postdoctoral fellowship from the Institute of Ecology and Biodiversity with the financial support of contract(ICM P05-002)This study was funded by Fondo Nacional de Desarrollo Científico y Tecnológico(1110228).
文摘Aims Plant functional traits determine how plants respond to environmen-tal factors and influence ecosystem processes.Among them,root traits and analyses of relations between above and below-ground traits in natural communities are scarce.Methods we characterized a set of above-and below-ground traits of three dominant shrub species in a semiarid shrub-steppe that had contrasting leaf pheno-logical habits(deciduous,semideciduous and evergreen).We ana-lysed if there was coordination among above-and below-ground resource economics patterns:i.e.patterns of biomass allocation,construction costs and lifespan.Important Findings Above-and below-ground traits and their resource economics relations pointed to species-specific functional strategies to cope with drought and poor soils and to a species ranking of fast to slow whole-plant strategies in terms of resource uptake,biomass con-struction costs and turnover.The deciduous shrub,Proustia cunei-folia,had relatively deep and even distribution of roots,and high proportion of short-lived tissues of low C construction costs:it had high fine to coarse root and high leaf-to-stem biomass ratios,high specific leaf area(SLA),and stems of low wood density.This strat-egy allows Proustia to maximize and coordinate above-and below-ground resources uptake as long as the most limiting factor(water)is available,but at the cost of having relative high plant biomass turnover.The evergreen Porlieria chilensis,instead,displayed a more conservative and slow strategy in terms of resource econom-ics.It had~80%of the roots in the 40 cm topsoil profile,low pro-portion of fine compared with coarse roots and low leaf-to-stem ratios,low SLA and stems of high wood density,i.e.it invested in C costly tissues that,overall,persist longer but probably at the cost of having lower plant resource uptake rates.Traits in the semide-ciduous Adesmia bedwellii were in between these two functional extremes.Our results revealed high functional diversity and above-and below-ground complementarity in resource economics among these three codominant species in the Chilean coastal desert.
基金National Science Foundation(DEB-0235371 to H.Ronald Pulliam)the Coweeta LTER programme(DEB-9632854 and DEB-0218001).
文摘Aims The clustering of plants with similar leaf traits along environmental gradients may arise from adaptation as well as acclimation to het-erogeneous habitat conditions.Determining the forces that shape plant leaf traits requires both linking variation in trait morphology with abiotic gradients and linking that trait variation with plant per-formance under varying abiotic conditions.across the spectrum of plant types,shade-tolerant evergreen herbs are relatively low in trait plasticity,compared to deciduous and sun-adapted species.These plants employ stress-tolerant strategies for survival,which coincide with relatively static trait morphologies,slow growth and hence a lower ability to adjust to changing environmental conditions.Methods We investigate how the survival of two ecologically similar under-story evergreen species,Asarum arifolium and Hepatica nobilis,cor-responds with variation in six commonly measured functional traits(leaf area,specific leaf area,plant height,leaf number,leaf length and shoot mass)along natural and experimental abiotic gradients.We examine temporal(the period 2007-9)and spatial(100 km)variations in these traits after(i)translocating 576 plants across a span from the southerm Appalachian Mountains in NC,USA,to the Piedmont,GA,USA,which includes north-and south-facing slope habitats and(ii)the experimental manipulation of diffuse light and soil moisture.Important findings We find that when translocated into a novel habitats,with novel environmental conditions that often are more extreme than the source habitat,both species appear capable of considerable mor-phological acclimation and generally converge to similar trait values.Hepatica nobilis does not exhibit mean trait values particu-larly different from those of A.arifolium,but it demonstrates much greater phenotypic plasticity.These results indicate that relatively conservative plant species nonetheless acclimate and survive across heterogeneous environmental conditions.
文摘We conducted 30-and 60-d greenhouse experiments to compare functional traits of Bromus tectorum(invasive annual grass) and four perennial bunchgrasses under well-watered or drought conditions.Even under drought, B. tectorum experienced significantly less stress(i.e., higher xylem pressure potential and greater shoot water content, water use per day and water-use efficiency) and biomass production than the perennial grasses after 30 d. However, after 60 d, its superiority was reduced under infrequent watering. Differences among perennial grasses were more pronounced for physiological traits under infrequent watering and for morphological traits under frequent watering. Elymus multisetus(fastgrowing species) had a higher transpiration rate, lower leaf temperature, and lower water-use efficiency than the other grasses after 30 d. In contrast, Pseudoroegneria spicata(slow-growing) had lower xylem pressure potential and higher leaf temperature than all other grasses under infrequent watering. Under frequent watering, shoot dry mass and specific leaf area of B. tectorum was matched by Elymus wawawaiensis(moderate-growing species). Our results indicate that multiple-species plantings or seedings are necessary to foster greater weed resistance against B. tectorum. We also emphasize that when choosing plant material for restoration, performance during both pulse(resource-rich) and inter-pulse(resource-poor) periods should be considered.
