The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms dr...The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms driving population-level variation in phenotypic traits,particularly in relation to migratory adaptations,remain poorly understood.Elevational migration represents an adaptive behavior for mountain birds that offers a unique model to investigate adaptive phenotypes because of the diverse migratory strategies that have been observed within and between species.Flight muscles,as multifunctional organs,exhibit phenotypic variation that aligns with locomotor and thermoregulatory demands.Linking flight muscle phenotypes to migratory strategies can provide insights into inter-and intraspecific variation in migratory adaptations.In this study,we examined spring arrival dates at high-altitude breeding sites for three closely related high-altitude breeding birds in the mountains of Asia:Blue-fronted Redstart(Phoenicurus frontalis),Himalayan Bluetail(Tarsiger rufilatus),and Rufous-gorgeted Flycatcher(Ficedula strophiata).We analyzed relationships between arrival dates and phenotypic traits,including flight muscle physiology,morphology,and internal organ mass,alongside environmental effects on these traits.Our findings indicate that species arriving earlier encountered lower temperatures and exhibited reduced fiber cross-sectional areas coupled with higher fast oxidative glycolytic(FOG)fibers densities.Males displayed pronounced protandry and higher fast glycolytic(FG)fibers densities.Ambient temperature significantly influenced flight muscle phenotypes,highlighting intraspecific variation and the potential plasticity of flight muscle fibers as crucial mechanisms for adapting to migration strategies and environmental conditions.Additionally,this study underscores the potential role of sexual selection in shaping functional phenotypic variation,further advancing our understanding of adaptive strategies in high-altitude migratory birds.展开更多
Deciduous oaks(Quercus spp.)are distributed from subalpine to tropical regions in the northern hemi-sphere and have important roles as carbon sinks and in climate change mitigation.Determining variations in plant func...Deciduous oaks(Quercus spp.)are distributed from subalpine to tropical regions in the northern hemi-sphere and have important roles as carbon sinks and in climate change mitigation.Determining variations in plant functional traits at multiple biological levels and linking them to environmental variables across geographical ranges is important for forecasting range-shifts of broadly-distrib-uted species under climate change.We sampled leaves of five deciduous Quercus spp.covering approximately 20°of latitude(~21°N-41°N)and 20 longitude(~99°E-119°E)across China and measured 12 plant functional traits at different biological levels.The traits varied distinctively,either within each biological level or among different levels driven by climatic and edaphic variables.Traits at the organ level were significantly correlated with those at the cellular and tissue levels,while traits at the whole-plant level only correlated with those at the tissue level.The Quercus species responded to changing environments by regulating stomatal size,leaf thickness and the palisade mesophyll thickness to leaf thickness ratios with contrasting degree of effect to adjust the whole-plant functioning,i.e.,intrinsic water use efficiency(iWUE),carbon supply and nitrogen availability.The results suggest that these deciduous Quercus spp.will maintain vigour by increasing iWUE when subjected to large temperature changes and insufficient moisture,and by accu-mulating leaf non-structural carbohydrates under drought conditions.The findings provide new insights into the inher-ent variation and trait coordination of widely distributed tree species in the context of climate change.展开更多
Seed mineral nutrition is essential for early seedling establishment,and varies under different environmental conditions.However,the intraspecific variation of multi-elements in seeds and the relative effects of clima...Seed mineral nutrition is essential for early seedling establishment,and varies under different environmental conditions.However,the intraspecific variation of multi-elements in seeds and the relative effects of climate and soil on seed elements remain unclear,even though understanding these factors is crucial for predicting plant reproductive responses to global changes.Here,we sampled seeds from Euptelea pleiospermum across 18 populations in China.We quantified the inter-population variation of 12 elements in the seeds and analysed their relationship with soil characteristics and climatic variables.We also explored the relationship of N and P concentrations between seeds and leaves.Results showed that seed elements were highly variable across different populations,with macroelements exhibiting lower variability than most of the microelements.Along the latitudinal gradient,the concentrations of K,Ca,Fe and Al in seeds increased,while the concentrations of C and Mn decreased.The stoichiometry of seed elements did not significantly correlate with latitude.Seed element concentrations were associated with both soil and climatic variables,and the influence of soil conditions on intraspecific variations is comparable to or even greater than climatic factors.However,seed stoichiometry was less related to environmental factors.Seeds had higher P but lower N than leaves,with no correlation between seed elements and leaf elements.Our findings suggest that mountain tree species respond to different local environments by adjusting seed element concentrations while maintaining relatively stable seed stoichiometry.We emphasize that,in addition to climate change,soil conditions should be considered when predicting the influence of environmental changes on the elemental composition of plant reproductive organs.展开更多
Background:The carob tree(Ceratonia siliqua L.)is one of the most iconic tree species of the Mediterranean region,with valuable economic,ecological and cultural value.Carob has been exploited around the Mediterranean ...Background:The carob tree(Ceratonia siliqua L.)is one of the most iconic tree species of the Mediterranean region,with valuable economic,ecological and cultural value.Carob has been exploited around the Mediterranean region since antiquity and has been regarded as an important component of natural habitats and traditional agroecosystems.Several studies have focused on its morphological,biochemical,and genetic diversity.However,less is known about the intraspecific variation of seed traits.In this regard,and as an overall objective,we intend to evaluate the amplitude and the expression of intraspecific variations of carob seed traits at different ecological scales ranging from individual trees to different geographical landscapes.In addition,we investigated how the climate along the study area affects the extent of carob seed variability.Using image analysis techniques,we measured seven traits related to the size and the shape of 1740 seeds collected from 18 populations of spontaneous C.siliqua distributed along a latitudinal transect in Morocco under different bioclimatic conditions.Results:The morphometric analysis of carob seed showed the effectiveness of adopted approach to highlight the amount and the amplitude of intraspecific variation according to geographic and climatic factors.Seed trait analysis revealed high intraspecific variability,explained by differences between and among carob populations and geographic zones.Seed area,perimeter,length,and width showed the largest variability between geographic zones.However,circularity,aspect ratio,and seed roundness showed higher variability at the tree level.Finally,our results show that seed traits vary depending on altitude and climate condition.Conclusions:Revealing the amount and the structure of intraspecific traits variability of carob seed provides interesting insights to understand the mechanisms underlying trees adaptation to various environmental and ecological conditions.Therefore,intraspecific variation of seed traits should be integrated into trait‑based functional ecology to assess plant species responses to environmental changes.展开更多
Aims Key herbivory interaction traits such as plant defensive compounds may differ among populations of a single species due to the spatial variation in herbivore feeding guilds and the strength of the interac-tion.Mo...Aims Key herbivory interaction traits such as plant defensive compounds may differ among populations of a single species due to the spatial variation in herbivore feeding guilds and the strength of the interac-tion.Moreover,the genealogy of population lineages could represent an additional source of variation interacting with the predominant eco-clinal trends.We tested for the existence of genetically based intraspecific variation in chemical defence profiles across the range of the relict tree Prunus lusitanica L.Additionally,we investigated geographical variation in defence inducibility and tested for the exist-ence of a trade-off between qualitative and quantitative defences.Methods We conducted a greenhouse experiment where 210 plants were grown under a common environment,comprising 10 different pop-ulations throughout the distribution range of the species and span-ning three separate regions:iberia,Morocco and Macaronesia.To test for the inducibility of defences,we artificially defoliated plants.Three treatments were established within each population:undam-aged,defoliated and sampled after 2 h,and defoliated and sampled after 72 h.The concentration of cyanogenic glycosides(prunasin)and phenolics was determined in leaf samples for all treatments.Important findings Basal levels of cyanogenics and phenolics significantly differed among populations and regions across the range of P.lusitanica,with this variation having a heritable basis.Cyanogenics(pruna-sin)were significantly higher in ancient Macaronesian populations,while phenolic concentrations were larger in iberia.The higher cyanogenic levels found in Macaronesia could be a consequence of the known stronger herbivory pressure in the islands than in iberia or the likely longer coevolutionary history with herbivores in this region.These findings indicate that the geographical variation of key ecological traits such plant chemical defences can be imprinted by phylogeographical signals,particularly in relict species.Regarding defence inducibility,prunasin increased after simulated herbivory whereas phenolics mostly decreased after defoliation.Variation in defence inducibility across populations and regions was evident,although no consistent patterns related to the variation in herbivore feeding guilds were observed,particularly among regions with and without ungulate browsing pressure.Finally,a trade-off among induced levels of qualitative(prunasin)and quantitative(phenolics)defences was detected in one of the defoliated treatments,likely as a result of a stronger resource limitation in damaged plants.展开更多
Aims Understanding the patterns and drivers of carbon isotope discrimination(13Δ)in C_(3)and C_(4)functional groups is critical for predicting C_(3)/C_(4)vegetation ratio from the isotopic composition of soil organic...Aims Understanding the patterns and drivers of carbon isotope discrimination(13Δ)in C_(3)and C_(4)functional groups is critical for predicting C_(3)/C_(4)vegetation ratio from the isotopic composition of soil organic matter.In this study,we aimed to evaluate how intraspecific variation will modify functional group-level 13Δvalues and the associated prediction of C_(3)/C_(4)vegetation ratio.Methods We investigated 13Δof 726 individual plants(96 species;C_(3)and C_(4)functional groups)and topsoil organic matter in 26 grassland communities along an aridity gradient in northern China.The fraction of C_(4)contribution was calculated with mixing models that considered:(i)both intra-and interspecific effects on the 13Δvalues of C_(3)and C_(4)functional groups;(ii)only interspecific effects;or(iii)none of these effects.Important Findings We found divergent responses of plant 13Δat the intraspecific level to the changes of aridity across the gradient.The 13Δof both C_(3)and C_(4)functional groups was negatively correlated with an aridity index,with higher sensitivity for C_(3)than for C_(4)functional groups.Intraspecific 13Δvariation played a key role in driving the total 13Δvariations of C_(3)plants.Overlooking such intraspecific effect in mixing models led to a greatly increased fraction of C_(4)contribution to soil organic carbon.A correction for the effects of intraspecific variation is therefore essential for correctly inferring C_(3)/C_(4)vegetation ratio in the past.Our findings provide basic information for the reconstruction of past vegetation change from bulk materials in arid and semiarid biomes.展开更多
There has been growing attention to intraspecific variation in trait-based plant ecology. However, studies on these changes across ontogenetic stages and the potential trade-offs with interspecific traits along enviro...There has been growing attention to intraspecific variation in trait-based plant ecology. However, studies on these changes across ontogenetic stages and the potential trade-offs with interspecific traits along environmental gradients are rare. In this study, we measured six wood and bark traits of 1030 trees of six species(Castanopsis nigrescens; C. carlesii; Lithocarpus polystachyus; L. synbalanos; Ormosia glaberrima; O. pachycarpa) from a10-ha plot in a subtropical forest. Mean intraspecific variation in bark thickness and bark percentage to DBH was more than twice that for wood density and bark density.Bark thickness and bark percentage showed a consistent trend with increasing tree size. Small-tree traits were more variable than the same traits in larger trees. Altitude,convexity and soil nutrients explained the majority of the variations in the six traits, while sibling species had similar relationships between traits and environmental variables.Trees with dense wood and thin bark were usually found on steep slopes at lower altitudes. Our findings show intraspecific trait variability has different spatial patterns compared with interspecific variabilities along an environmental gradient.展开更多
Plants deploy various ecological strategies in response to environmental heterogeneity.In many forest ecosystems,plants have been reported to have notable inter-and intra-specific trait variation,as well as clear phyl...Plants deploy various ecological strategies in response to environmental heterogeneity.In many forest ecosystems,plants have been reported to have notable inter-and intra-specific trait variation,as well as clear phylogenetic signals,indicating that these species possess a degree of phenotypic plasticity to cope with habitat variation in the community.Savanna communities,however,grow in an open canopy structure and exhibit little species diversification,likely as a result of strong environmental stress.In this study,we hypothesized that the phylogenetic signals of savanna species would be weak,the intraspecific trait variation(ITV)would be low,and the contribution of intraspecific variation to total trait variance would be reduced,owing to low species richness,multiple stresses and relatively homogenous community structure.To test these hypotheses,we sampled dominant woody species in a dry-hot savanna in southwestern China,focusing on leaf traits related to adaptability of plants to harsh conditions(yearround intense radiation,low soil fertility and seasonal droughts).We found weak phylogenetic signals in leaf traits and low ITV(at both individual and canopy-layer levels).Intraspecific variation(including leaf-,layer-and individual-scales)contributed little to the total trait variance,whereas interspecific variation and variation in leaf phenology explained substantial variance.Our study suggests that intraspecific trait variation is reduced in savanna community.Furthermore,our findings indicate that classifying species by leaf phenology may help better understand how species coexist under similar habitats with strong stresses.展开更多
Seed dispersal is a pivotal process in seed plant life cycle,owing to its effects on seed germination,seedling survival,population recruitment,and diversity maintenance in the entire community(Howe and Smallwood,1982;...Seed dispersal is a pivotal process in seed plant life cycle,owing to its effects on seed germination,seedling survival,population recruitment,and diversity maintenance in the entire community(Howe and Smallwood,1982;Rogers et al.,2021).There are diverse dispersal modes,such as anemochory(wind-driven dispersal),hydrochory(water-mediated dispersal),autochory(self-dispersal),and zoochory,which relies on a diverse array of animals for seed dispersal(Howe and Smallwood,1982).It is widely known that these varying dispersal modes impose selective pressures on many seed and fruit traits,especially the seed size,a key trait which is associated with multiple stages of the life cycle of plants,such as dispersal,germination,and establishment,particularly during early development(Leishman et al.,2000).展开更多
Characterizing trait variation across different ecological scales in plant communities has been viewed as a way to gain insights into the mechanisms driving species coexistence.However,little is known about how change...Characterizing trait variation across different ecological scales in plant communities has been viewed as a way to gain insights into the mechanisms driving species coexistence.However,little is known about how changes in intraspecific and interspecific traits across sites influence species richness and community assembly,especially in understory herbaceous communities.Here we partitioned the variance of four functional traits(maximum height,leaf thickness,leaf area and specific leaf area)across four nested biological scales:individual,species,plot,and elevation to quantify the scale-dependent distributions of understory herbaceous trait variance.We also integrated the comparison of the trait variance ratios to null models to investigate the effects of different ecological processes on community assembly and functional diversity along a 1200-m elevational gradient in Yulong Mountain.We found interspecific trait variation was the main trait variation component for leaf traits,although intraspecific trait variation ranged from 10% to 28% of total variation.In particular,maximum height exhibited high plasticity,and intraspecific variation accounted for 44% of the total variation.Despite the fact that species composition varied across elevation and species richness decreased dramatically along the elevational gradient,there was little variance at our largest(elevation)scale in leaf traits and functional diversity remained constant along the elevational gradient,indicating that traits responded to smaller scale influences.External filtering was only observed at high elevations.However,strong internal filtering was detected along the entire elevational gradient in understory herbaceous communities,possibly due to competition.Our results provide evidence that species coexistence in understory herbaceous communities might be structured by differential niche-assembled processes.This approach ee integrating different biological scales of trait variation ee may provide a better understanding of the mechanisms involved in the structure of communities.展开更多
To reveal the intraspecific evolution of Leptospirillum ferriphilum isolates which thrived in industrial bioleaching ecosystems and acid mine drainages,genome sequences of L.ferriphilum YSK,L.ferriphilum DX and L.ferr...To reveal the intraspecific evolution of Leptospirillum ferriphilum isolates which thrived in industrial bioleaching ecosystems and acid mine drainages,genome sequences of L.ferriphilum YSK,L.ferriphilum DX and L.ferriphilum ZJ were determined to compare with complete genome of L.ferriphilum ML-04.The genome comparisons reveal that extensive intraspecific variation occurs in their genomes,and that the loss and insertion of novel gene blocks of probable phage origin may mostly contribute to heterogeneity of gene content among L.ferriphilum genomes.Surprisingly,a nif gene cluster is identified in L.ferriphilum YSK and L.ferriphilum ZJ genomes.Intensive analysis and further experiments indicate that the nif gene cluster in L.ferriphilum YSK inherits from ancestor rather than lateral gene transfer.Overall,results suggest that the population of L.ferriphilum undergoes frequent genetic recombination,resulting in many closely related genome types in recent evolution.The combinatorial processes profoundly shape their physiologies and provide the basis for adaptation to different niches.展开更多
The population of Saynoceras verrucosum （d＇Orbigny） from the Polish basin （Wawal section, central Poland） shows no significant intraspecific variability. Dimorphism has not been found in this population. Statisti...The population of Saynoceras verrucosum （d＇Orbigny） from the Polish basin （Wawal section, central Poland） shows no significant intraspecific variability. Dimorphism has not been found in this population. Statistical analyses of material from the shallow epicratonic Polish basin and the relatively deep Vocontian basin （southeastern France） indicated two populations. Forms from the Polish basin are somewhat more inflated and smaller than forms from the Vocontian basin.展开更多
Floral trait variation may help pollinators and nectar robbers identify their target plants and,thus,lead to differential selection pressure for defense capability against floral antagonists.However,the effect of flor...Floral trait variation may help pollinators and nectar robbers identify their target plants and,thus,lead to differential selection pressure for defense capability against floral antagonists.However,the effect of floral trait variation among individuals within a population on multi-dimensional plant-animal interactions has been little explored.We investigated floral trait variation,pollination,and nectar robbing among individual plants in a population of the bumble bee-pollinated plant,Caryopteris divaricata,from which flowers are also robbed by bumble bees with varying intensity across individuals.We measured the variation in corolla tube length,nectar volume and sugar concentration among individual plants,and evaluated whether the variation were recognized by pollinators and robbers.We investigated the in-fluence of nectar robbing on legitimate visitation and seed production per fruit.We found that the primary nectar robber(Bombus nobilis)preferred to forage on plants with long-tubed flowers,which produced less nectar and had lower sugar concentration compared to those with shorter corolla tubes.Individuals with shorter corolla tubes had comparatively lower nectar robbing intensity but higher visitation by legitimate visitors(mainly B.picipes)and higher seed production.Nectar robbing signifi-cantly reduced seed production because it decreased pollinator visits.However,neither pollination nor seed production differed between plants with long and short corolla tubes when nectar robbers were excluded.This finding suggests that floral trait variation might not be driven by pollinators.Such variation among individual plants thus allows legitimate visitors and nectar robbers to segregate niches and enhances population defense against nectar robbing in unpredictable conditions.展开更多
The green odorous frog(Odorrana margaretae)has an interesting ring-shaped divergence pattern around the Sichuan Basin and documenting its morphological variations is essential in understanding its evolutionary history...The green odorous frog(Odorrana margaretae)has an interesting ring-shaped divergence pattern around the Sichuan Basin and documenting its morphological variations is essential in understanding its evolutionary history.Using curvilinear models,we detected significant geographical clinal variations in morphological traits,particularly sizes,of female O.margaretae.Males had significantly smaller sizes than females,and also had smaller variation ranges than females.One major trend of morphological variations was clinal:populations from the west tended to have a larger size with wider head and longer posterior limbs than populations from the east.Species history,with an early extended isolation and two subsequent secondary contacts,may explain most of the geographical clinal variations of O.margaretae.Bioclimatic factors may also contribute in explaining the variance of morphology.展开更多
Sexual dimorphism（SD） and geographic variation（GV） are widespread in snakes. Protobothrops mucrosquamatus（Cantor 1839） is one of the most common Asian venomous snakes with a wide geographical distribution. We ex...Sexual dimorphism（SD） and geographic variation（GV） are widespread in snakes. Protobothrops mucrosquamatus（Cantor 1839） is one of the most common Asian venomous snakes with a wide geographical distribution. We examined SD and GV patterns for this species by using multivariate statistical analyses of external morphological characters scored from specimens from the China's Mainland. The result displayed that SD was significant in several external characters in P. mucrosquamatus, and the male P. mucrosquamatus formed two distinct clusters（Hainan Island and China's Mainland）, but the females did not. Based on our present work and the other data, we concluded that no significantly intraspecific differentiation is present within this species.展开更多
Fossil remains of snakes in Quaternary localities are most often represented by vertebrae.Therefore,it is necessary to carry out a comparative study of the vertebrae of modern species in the areas of interest to ident...Fossil remains of snakes in Quaternary localities are most often represented by vertebrae.Therefore,it is necessary to carry out a comparative study of the vertebrae of modern species in the areas of interest to identify fossil materials.In this study,we examined 52 specimens of viperids(7 specimens of Gloydius intermedius,12 specimens of Gloydius ussuriensis,6 specimens of Gloydius halys,4 specimens of Vipera sakhalinensis,16 specimens of Vipera berus,and 7 specimens of Vipera renardi).The features of the trunk,cervical,cloacal and caudal vertebrae of 6 species from 2 genera are described.The vertebrae of the Viperidae are highly similar across species,with variation along the vertebral column.Nevertheless,they can be distinguished if their exact position within the vertebral column is known.The most important diagnostic feature is the shape of the hypapophysis,especially when identifying the cervical vertebrae.Among other morphological features,it is important to consider the shape of the ventral surface of the vertebra,prezygapophyseal and parapophyseal processes,neurapophysis,and zygapophysis.For the epistropheus,the position of the anterior edge of the neurapophysis in relation to the anterior edge of the neural arch is also significant.The caudal vertebrae bear the greatest resemblance.There is a significant overlap between the ratios of different measurements(indices)in different species.However,if an index is out of the overlapping zone,it is possible to identify a vertebra more or less accurately,especially when considering it in conjunction with other indices and morphological characteristics.展开更多
The interspecific variations of plant functional traits can characterize the niche positions of species within communities,while the intraspecific variations can accurately display the species’niche breadth.Revealing...The interspecific variations of plant functional traits can characterize the niche positions of species within communities,while the intraspecific variations can accurately display the species’niche breadth.Revealing relative contributions of intra-and interspecific variations to plant functional community structure is crucial in understanding how the species coexist together,especially in species-diverse ecosystems.To explore how the intra-and interspecific variations of plant functional traits change along the successional pathway in heterogeneous conditions,we established a series of plots and measured main plant functional traits along the natural regeneration in karst forest ecosystems.By quantifying the intra-and interspecific variations of plant functional traits,we found that the changes in intraspecific variations were relatively lower compared to changes in interspecific variations throughout the natural regeneration.Further analysis showed that the community spatial structure contributed more to the intraspecific variations of plant functional traits,while the soil physicochemical properties contributed more to interspecific variations.Our study suggested that tree species might tend to narrow their niche and change the positions to release the niche overlap when faced with heterogeneous habitat conditions.展开更多
A compilation of data on biomass and growth allowed an examination of the intraspecific plasticity in Tha/assia hemprichii which played key roles to develop site-specific growth strategies for this species in Xincun B...A compilation of data on biomass and growth allowed an examination of the intraspecific plasticity in Tha/assia hemprichii which played key roles to develop site-specific growth strategies for this species in Xincun Bay. The results showed the difference in rhizome elongation rates which explained most of the variation of biomass and growth within species. The seagrass T. hempdchii in Xincun Bay adjusted its vertical and horizontal rhizome elongation rates alternatively in response to light level and temperature changes, resulting in the variation of shoot densities and above biomass in return. The vertical and horizontal rhizomes elongated at rates of 2.38 and 24.4 cm yr1 in summer while 1.87 and 29.2 cm yr^-1 in winter respectively. The shoot density ranged from 822 to 941 shoots m^2 with a peak in summer and a trough in winter which was similar to that of biomass. The growth strategy enabled T. hempdchii to minimize the negative effects of desiccation in summer as well as light reduction in winter.展开更多
The concept of foraging niche provides an insight into habitat use and dietary information of animals.Knowing intraspecific variation in foraging niche and trophic level is critical to the understanding of the species...The concept of foraging niche provides an insight into habitat use and dietary information of animals.Knowing intraspecific variation in foraging niche and trophic level is critical to the understanding of the species response to environmental changes during the process of range expansion,as well as the habitat management for conservation of threatened species.Using stable isotopic values of eggshell membranes(δ;C andδ;N),we examined whether there are differences in habitat use,trophic level,foraging niche width between the new and old breeding habitats(plains vs.mountains)of wild Crested Ibis(Nipponia nippon)in the early breeding season.Crested Ibis exhibited high variability in bothδ;C andδ;N values,δ;C andδ;N varied as a function of habitat types.Birds breeding in plains had significantly higherδ;C but lowerδ;N values compared to the birds breeding in mountains.Higherδ;N suggested that individuals in mountains consumed a great proportion of higher trophic level prey species in the early breeding season.Moreover,the isotopic niches were distinctly different in positions and showed small overlap between the two habitat types.The niche width was wider in old habitat than in the expanded new habitat.Our results demonstrated that the wild Crested Ibis had a high intraspecific variation in habitat uses and trophic levels in the early breeding season,and they could be divided into mountain and plain groups based on their different foraging niches.The difference inδ;N and niche width revealed that high trophic level food resources might be insufficient in plains.These findings stressed the importance of protecting foraging grounds in mountains and the necessity of improving foraging grounds in plains during winter and spring.Our study highlights the feasibility of investigating intraspecific variation in foraging ecology of birds through non-invasive isotopes of eggshell membranes.Understanding foraging niche variation gives us an insight into the food resource diversity in local areas and provides important information regarding particular foraging habitats that require protection.展开更多
The taxonomic identification of Quaternary remains requires a comparison of fossil bones with the skeletons of existing taxa based on the morphological criteria. However, the osteology of most modern snake species has...The taxonomic identification of Quaternary remains requires a comparison of fossil bones with the skeletons of existing taxa based on the morphological criteria. However, the osteology of most modern snake species has not yet been studied. This work is aimed at finding differences in the bone morphology of Amur and Dione’s ratsnakes and the criteria for their identification. The variety of bone morphology depends on several parameters. First, these are species differences which determine the systematic position of the animal. Second, it is individual varia bility.Third, these are progressive changes in the vertebrae morphology along the vertebral column from the first vertebra to the last. Fourth, it is age-related variability. 20 skeletonised specimens: 12 specimens of Elaphe dione and 8 specimens of Elaphe schrenckii were used to define diagnostic osteological characters. The bones of the two studied species are very similar and their variability overlaps. However, differences and identification criteria were found for 13 skull bones:nasal, frontal, parietal, supraoccipital, maxilla, quadrate,palatine, pterygoid, ectopterygoid, basiparasphenoid,basioccipital, dentary and the compound bone. In addition, the variability and differences of the cervical,trunk, cloacal, and caudal vertebrae were examined.展开更多
基金financially supported by the National Natural Science Foundation of China (No.32270454)by the Survey of Wildlife Resources in Key Areas of Tibet (ZL202203601)。
文摘The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms driving population-level variation in phenotypic traits,particularly in relation to migratory adaptations,remain poorly understood.Elevational migration represents an adaptive behavior for mountain birds that offers a unique model to investigate adaptive phenotypes because of the diverse migratory strategies that have been observed within and between species.Flight muscles,as multifunctional organs,exhibit phenotypic variation that aligns with locomotor and thermoregulatory demands.Linking flight muscle phenotypes to migratory strategies can provide insights into inter-and intraspecific variation in migratory adaptations.In this study,we examined spring arrival dates at high-altitude breeding sites for three closely related high-altitude breeding birds in the mountains of Asia:Blue-fronted Redstart(Phoenicurus frontalis),Himalayan Bluetail(Tarsiger rufilatus),and Rufous-gorgeted Flycatcher(Ficedula strophiata).We analyzed relationships between arrival dates and phenotypic traits,including flight muscle physiology,morphology,and internal organ mass,alongside environmental effects on these traits.Our findings indicate that species arriving earlier encountered lower temperatures and exhibited reduced fiber cross-sectional areas coupled with higher fast oxidative glycolytic(FOG)fibers densities.Males displayed pronounced protandry and higher fast glycolytic(FG)fibers densities.Ambient temperature significantly influenced flight muscle phenotypes,highlighting intraspecific variation and the potential plasticity of flight muscle fibers as crucial mechanisms for adapting to migration strategies and environmental conditions.Additionally,this study underscores the potential role of sexual selection in shaping functional phenotypic variation,further advancing our understanding of adaptive strategies in high-altitude migratory birds.
基金supported by the Key Area Research and Development Program of Guangdong Province(2022B1111230001)theScience and Technology Foundation of Guangxi Zhuang Autonomous Region(Guike AD23026080)+1 种基金the National Natural Science Founda tion of China(No.42071065)Natural Science Foundation of US(No.2021898).
文摘Deciduous oaks(Quercus spp.)are distributed from subalpine to tropical regions in the northern hemi-sphere and have important roles as carbon sinks and in climate change mitigation.Determining variations in plant functional traits at multiple biological levels and linking them to environmental variables across geographical ranges is important for forecasting range-shifts of broadly-distrib-uted species under climate change.We sampled leaves of five deciduous Quercus spp.covering approximately 20°of latitude(~21°N-41°N)and 20 longitude(~99°E-119°E)across China and measured 12 plant functional traits at different biological levels.The traits varied distinctively,either within each biological level or among different levels driven by climatic and edaphic variables.Traits at the organ level were significantly correlated with those at the cellular and tissue levels,while traits at the whole-plant level only correlated with those at the tissue level.The Quercus species responded to changing environments by regulating stomatal size,leaf thickness and the palisade mesophyll thickness to leaf thickness ratios with contrasting degree of effect to adjust the whole-plant functioning,i.e.,intrinsic water use efficiency(iWUE),carbon supply and nitrogen availability.The results suggest that these deciduous Quercus spp.will maintain vigour by increasing iWUE when subjected to large temperature changes and insufficient moisture,and by accu-mulating leaf non-structural carbohydrates under drought conditions.The findings provide new insights into the inher-ent variation and trait coordination of widely distributed tree species in the context of climate change.
基金National Natural Science Foundation of China(32371653,32001225,and 31770572)State Key Laboratory of Vegetation and Environmental Change(LVEC-2021kf01).
文摘Seed mineral nutrition is essential for early seedling establishment,and varies under different environmental conditions.However,the intraspecific variation of multi-elements in seeds and the relative effects of climate and soil on seed elements remain unclear,even though understanding these factors is crucial for predicting plant reproductive responses to global changes.Here,we sampled seeds from Euptelea pleiospermum across 18 populations in China.We quantified the inter-population variation of 12 elements in the seeds and analysed their relationship with soil characteristics and climatic variables.We also explored the relationship of N and P concentrations between seeds and leaves.Results showed that seed elements were highly variable across different populations,with macroelements exhibiting lower variability than most of the microelements.Along the latitudinal gradient,the concentrations of K,Ca,Fe and Al in seeds increased,while the concentrations of C and Mn decreased.The stoichiometry of seed elements did not significantly correlate with latitude.Seed element concentrations were associated with both soil and climatic variables,and the influence of soil conditions on intraspecific variations is comparable to or even greater than climatic factors.However,seed stoichiometry was less related to environmental factors.Seeds had higher P but lower N than leaves,with no correlation between seed elements and leaf elements.Our findings suggest that mountain tree species respond to different local environments by adjusting seed element concentrations while maintaining relatively stable seed stoichiometry.We emphasize that,in addition to climate change,soil conditions should be considered when predicting the influence of environmental changes on the elemental composition of plant reproductive organs.
基金This study was supported by the Agencia Andaluza de Cooperación Internacional para el Desarrollo(AACID)and the project“Amélioration de la productivitédes cultures forestières d’intérêt socio-économiqueélevédans les zones rurales du nord du Maroc,n°2018004”.
文摘Background:The carob tree(Ceratonia siliqua L.)is one of the most iconic tree species of the Mediterranean region,with valuable economic,ecological and cultural value.Carob has been exploited around the Mediterranean region since antiquity and has been regarded as an important component of natural habitats and traditional agroecosystems.Several studies have focused on its morphological,biochemical,and genetic diversity.However,less is known about the intraspecific variation of seed traits.In this regard,and as an overall objective,we intend to evaluate the amplitude and the expression of intraspecific variations of carob seed traits at different ecological scales ranging from individual trees to different geographical landscapes.In addition,we investigated how the climate along the study area affects the extent of carob seed variability.Using image analysis techniques,we measured seven traits related to the size and the shape of 1740 seeds collected from 18 populations of spontaneous C.siliqua distributed along a latitudinal transect in Morocco under different bioclimatic conditions.Results:The morphometric analysis of carob seed showed the effectiveness of adopted approach to highlight the amount and the amplitude of intraspecific variation according to geographic and climatic factors.Seed trait analysis revealed high intraspecific variability,explained by differences between and among carob populations and geographic zones.Seed area,perimeter,length,and width showed the largest variability between geographic zones.However,circularity,aspect ratio,and seed roundness showed higher variability at the tree level.Finally,our results show that seed traits vary depending on altitude and climate condition.Conclusions:Revealing the amount and the structure of intraspecific traits variability of carob seed provides interesting insights to understand the mechanisms underlying trees adaptation to various environmental and ecological conditions.Therefore,intraspecific variation of seed traits should be integrated into trait‑based functional ecology to assess plant species responses to environmental changes.
文摘Aims Key herbivory interaction traits such as plant defensive compounds may differ among populations of a single species due to the spatial variation in herbivore feeding guilds and the strength of the interac-tion.Moreover,the genealogy of population lineages could represent an additional source of variation interacting with the predominant eco-clinal trends.We tested for the existence of genetically based intraspecific variation in chemical defence profiles across the range of the relict tree Prunus lusitanica L.Additionally,we investigated geographical variation in defence inducibility and tested for the exist-ence of a trade-off between qualitative and quantitative defences.Methods We conducted a greenhouse experiment where 210 plants were grown under a common environment,comprising 10 different pop-ulations throughout the distribution range of the species and span-ning three separate regions:iberia,Morocco and Macaronesia.To test for the inducibility of defences,we artificially defoliated plants.Three treatments were established within each population:undam-aged,defoliated and sampled after 2 h,and defoliated and sampled after 72 h.The concentration of cyanogenic glycosides(prunasin)and phenolics was determined in leaf samples for all treatments.Important findings Basal levels of cyanogenics and phenolics significantly differed among populations and regions across the range of P.lusitanica,with this variation having a heritable basis.Cyanogenics(pruna-sin)were significantly higher in ancient Macaronesian populations,while phenolic concentrations were larger in iberia.The higher cyanogenic levels found in Macaronesia could be a consequence of the known stronger herbivory pressure in the islands than in iberia or the likely longer coevolutionary history with herbivores in this region.These findings indicate that the geographical variation of key ecological traits such plant chemical defences can be imprinted by phylogeographical signals,particularly in relict species.Regarding defence inducibility,prunasin increased after simulated herbivory whereas phenolics mostly decreased after defoliation.Variation in defence inducibility across populations and regions was evident,although no consistent patterns related to the variation in herbivore feeding guilds were observed,particularly among regions with and without ungulate browsing pressure.Finally,a trade-off among induced levels of qualitative(prunasin)and quantitative(phenolics)defences was detected in one of the defoliated treatments,likely as a result of a stronger resource limitation in damaged plants.
基金This work was supported by the National Natural Science Foundation of China(31971465,31822006,31770503,41807108)National Basic Research Program of China(2016YFC0500601,2016YFC0500700)+1 种基金Youth Innovation Promotion Association CAS(201832,2020199)the Key Research Program from CAS(KFZD-SW-305-002).
文摘Aims Understanding the patterns and drivers of carbon isotope discrimination(13Δ)in C_(3)and C_(4)functional groups is critical for predicting C_(3)/C_(4)vegetation ratio from the isotopic composition of soil organic matter.In this study,we aimed to evaluate how intraspecific variation will modify functional group-level 13Δvalues and the associated prediction of C_(3)/C_(4)vegetation ratio.Methods We investigated 13Δof 726 individual plants(96 species;C_(3)and C_(4)functional groups)and topsoil organic matter in 26 grassland communities along an aridity gradient in northern China.The fraction of C_(4)contribution was calculated with mixing models that considered:(i)both intra-and interspecific effects on the 13Δvalues of C_(3)and C_(4)functional groups;(ii)only interspecific effects;or(iii)none of these effects.Important Findings We found divergent responses of plant 13Δat the intraspecific level to the changes of aridity across the gradient.The 13Δof both C_(3)and C_(4)functional groups was negatively correlated with an aridity index,with higher sensitivity for C_(3)than for C_(4)functional groups.Intraspecific 13Δvariation played a key role in driving the total 13Δvariations of C_(3)plants.Overlooking such intraspecific effect in mixing models led to a greatly increased fraction of C_(4)contribution to soil organic carbon.A correction for the effects of intraspecific variation is therefore essential for correctly inferring C_(3)/C_(4)vegetation ratio in the past.Our findings provide basic information for the reconstruction of past vegetation change from bulk materials in arid and semiarid biomes.
基金funded by the National Natural Science Foundation of China(Key Projects 31230013,31361140363)the Zhang-Hongda Science Foundation at Sun Yat-sen University
文摘There has been growing attention to intraspecific variation in trait-based plant ecology. However, studies on these changes across ontogenetic stages and the potential trade-offs with interspecific traits along environmental gradients are rare. In this study, we measured six wood and bark traits of 1030 trees of six species(Castanopsis nigrescens; C. carlesii; Lithocarpus polystachyus; L. synbalanos; Ormosia glaberrima; O. pachycarpa) from a10-ha plot in a subtropical forest. Mean intraspecific variation in bark thickness and bark percentage to DBH was more than twice that for wood density and bark density.Bark thickness and bark percentage showed a consistent trend with increasing tree size. Small-tree traits were more variable than the same traits in larger trees. Altitude,convexity and soil nutrients explained the majority of the variations in the six traits, while sibling species had similar relationships between traits and environmental variables.Trees with dense wood and thin bark were usually found on steep slopes at lower altitudes. Our findings show intraspecific trait variability has different spatial patterns compared with interspecific variabilities along an environmental gradient.
基金the National Natural Science Foundation of China(31870410 and Dimensions US-China:32061123003)the Chinese Academy of Sciences Youth Innovation Promotion Association,the West Light Foundation of the Chinese Academy of Sciences and the Ten Thousand Talents Program of Yunnan(YNWR-QNBJ-2018-309)。
文摘Plants deploy various ecological strategies in response to environmental heterogeneity.In many forest ecosystems,plants have been reported to have notable inter-and intra-specific trait variation,as well as clear phylogenetic signals,indicating that these species possess a degree of phenotypic plasticity to cope with habitat variation in the community.Savanna communities,however,grow in an open canopy structure and exhibit little species diversification,likely as a result of strong environmental stress.In this study,we hypothesized that the phylogenetic signals of savanna species would be weak,the intraspecific trait variation(ITV)would be low,and the contribution of intraspecific variation to total trait variance would be reduced,owing to low species richness,multiple stresses and relatively homogenous community structure.To test these hypotheses,we sampled dominant woody species in a dry-hot savanna in southwestern China,focusing on leaf traits related to adaptability of plants to harsh conditions(yearround intense radiation,low soil fertility and seasonal droughts).We found weak phylogenetic signals in leaf traits and low ITV(at both individual and canopy-layer levels).Intraspecific variation(including leaf-,layer-and individual-scales)contributed little to the total trait variance,whereas interspecific variation and variation in leaf phenology explained substantial variance.Our study suggests that intraspecific trait variation is reduced in savanna community.Furthermore,our findings indicate that classifying species by leaf phenology may help better understand how species coexist under similar habitats with strong stresses.
基金funded by National Natural Science Foundation of China(32171533 and 31971444)Anhui Provincial Natural Science Foundation(2208085J28).
文摘Seed dispersal is a pivotal process in seed plant life cycle,owing to its effects on seed germination,seedling survival,population recruitment,and diversity maintenance in the entire community(Howe and Smallwood,1982;Rogers et al.,2021).There are diverse dispersal modes,such as anemochory(wind-driven dispersal),hydrochory(water-mediated dispersal),autochory(self-dispersal),and zoochory,which relies on a diverse array of animals for seed dispersal(Howe and Smallwood,1982).It is widely known that these varying dispersal modes impose selective pressures on many seed and fruit traits,especially the seed size,a key trait which is associated with multiple stages of the life cycle of plants,such as dispersal,germination,and establishment,particularly during early development(Leishman et al.,2000).
基金supported by the National Key Basic Research Program of China (2014CB954100)the Ministry of Science and Technology of the People's Republic of China (2012FY110800)the Applied Fundamental Research Foundation of Yunnan Province (2014GA003)
文摘Characterizing trait variation across different ecological scales in plant communities has been viewed as a way to gain insights into the mechanisms driving species coexistence.However,little is known about how changes in intraspecific and interspecific traits across sites influence species richness and community assembly,especially in understory herbaceous communities.Here we partitioned the variance of four functional traits(maximum height,leaf thickness,leaf area and specific leaf area)across four nested biological scales:individual,species,plot,and elevation to quantify the scale-dependent distributions of understory herbaceous trait variance.We also integrated the comparison of the trait variance ratios to null models to investigate the effects of different ecological processes on community assembly and functional diversity along a 1200-m elevational gradient in Yulong Mountain.We found interspecific trait variation was the main trait variation component for leaf traits,although intraspecific trait variation ranged from 10% to 28% of total variation.In particular,maximum height exhibited high plasticity,and intraspecific variation accounted for 44% of the total variation.Despite the fact that species composition varied across elevation and species richness decreased dramatically along the elevational gradient,there was little variance at our largest(elevation)scale in leaf traits and functional diversity remained constant along the elevational gradient,indicating that traits responded to smaller scale influences.External filtering was only observed at high elevations.However,strong internal filtering was detected along the entire elevational gradient in understory herbaceous communities,possibly due to competition.Our results provide evidence that species coexistence in understory herbaceous communities might be structured by differential niche-assembled processes.This approach ee integrating different biological scales of trait variation ee may provide a better understanding of the mechanisms involved in the structure of communities.
基金Project(2018YFC1801804)supported by the National Key R&D Program of ChinaProjects(2016JJ3146,2017JJ3160)supported by the Natural Science Foundation of Hunan Province,China。
文摘To reveal the intraspecific evolution of Leptospirillum ferriphilum isolates which thrived in industrial bioleaching ecosystems and acid mine drainages,genome sequences of L.ferriphilum YSK,L.ferriphilum DX and L.ferriphilum ZJ were determined to compare with complete genome of L.ferriphilum ML-04.The genome comparisons reveal that extensive intraspecific variation occurs in their genomes,and that the loss and insertion of novel gene blocks of probable phage origin may mostly contribute to heterogeneity of gene content among L.ferriphilum genomes.Surprisingly,a nif gene cluster is identified in L.ferriphilum YSK and L.ferriphilum ZJ genomes.Intensive analysis and further experiments indicate that the nif gene cluster in L.ferriphilum YSK inherits from ancestor rather than lateral gene transfer.Overall,results suggest that the population of L.ferriphilum undergoes frequent genetic recombination,resulting in many closely related genome types in recent evolution.The combinatorial processes profoundly shape their physiologies and provide the basis for adaptation to different niches.
文摘The population of Saynoceras verrucosum （d＇Orbigny） from the Polish basin （Wawal section, central Poland） shows no significant intraspecific variability. Dimorphism has not been found in this population. Statistical analyses of material from the shallow epicratonic Polish basin and the relatively deep Vocontian basin （southeastern France） indicated two populations. Forms from the Polish basin are somewhat more inflated and smaller than forms from the Vocontian basin.
基金The research was supported by the National Natural Science Foundation of China(No.31970253 and 32270243)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB31010000)+1 种基金AL was also supported by a Ramon y Cajal contract(RYC-2015-19034)from the Spanish Ministry of Science,Innovation and Universities,the Spanish State Research Agency,European Social Funds(ESF invests in your future)and the University of the Balearic Islands,and by the project PRPPID2020-117863RB-I00financed by the Spanish Ministry of Science and Innovation and the Spanish Research Agency(MCIN/AEI/10.13039/501100011033).
文摘Floral trait variation may help pollinators and nectar robbers identify their target plants and,thus,lead to differential selection pressure for defense capability against floral antagonists.However,the effect of floral trait variation among individuals within a population on multi-dimensional plant-animal interactions has been little explored.We investigated floral trait variation,pollination,and nectar robbing among individual plants in a population of the bumble bee-pollinated plant,Caryopteris divaricata,from which flowers are also robbed by bumble bees with varying intensity across individuals.We measured the variation in corolla tube length,nectar volume and sugar concentration among individual plants,and evaluated whether the variation were recognized by pollinators and robbers.We investigated the in-fluence of nectar robbing on legitimate visitation and seed production per fruit.We found that the primary nectar robber(Bombus nobilis)preferred to forage on plants with long-tubed flowers,which produced less nectar and had lower sugar concentration compared to those with shorter corolla tubes.Individuals with shorter corolla tubes had comparatively lower nectar robbing intensity but higher visitation by legitimate visitors(mainly B.picipes)and higher seed production.Nectar robbing signifi-cantly reduced seed production because it decreased pollinator visits.However,neither pollination nor seed production differed between plants with long and short corolla tubes when nectar robbers were excluded.This finding suggests that floral trait variation might not be driven by pollinators.Such variation among individual plants thus allows legitimate visitors and nectar robbers to segregate niches and enhances population defense against nectar robbing in unpredictable conditions.
文摘The green odorous frog(Odorrana margaretae)has an interesting ring-shaped divergence pattern around the Sichuan Basin and documenting its morphological variations is essential in understanding its evolutionary history.Using curvilinear models,we detected significant geographical clinal variations in morphological traits,particularly sizes,of female O.margaretae.Males had significantly smaller sizes than females,and also had smaller variation ranges than females.One major trend of morphological variations was clinal:populations from the west tended to have a larger size with wider head and longer posterior limbs than populations from the east.Species history,with an early extended isolation and two subsequent secondary contacts,may explain most of the geographical clinal variations of O.margaretae.Bioclimatic factors may also contribute in explaining the variance of morphology.
基金funded by the National Natural Science Foundation of China (NSFC31372152)the Scientific Research Fund of Sichuan Provincial Education Department (13TD0027) to Peng Guo
文摘Sexual dimorphism（SD） and geographic variation（GV） are widespread in snakes. Protobothrops mucrosquamatus（Cantor 1839） is one of the most common Asian venomous snakes with a wide geographical distribution. We examined SD and GV patterns for this species by using multivariate statistical analyses of external morphological characters scored from specimens from the China's Mainland. The result displayed that SD was significant in several external characters in P. mucrosquamatus, and the male P. mucrosquamatus formed two distinct clusters（Hainan Island and China's Mainland）, but the females did not. Based on our present work and the other data, we concluded that no significantly intraspecific differentiation is present within this species.
文摘Fossil remains of snakes in Quaternary localities are most often represented by vertebrae.Therefore,it is necessary to carry out a comparative study of the vertebrae of modern species in the areas of interest to identify fossil materials.In this study,we examined 52 specimens of viperids(7 specimens of Gloydius intermedius,12 specimens of Gloydius ussuriensis,6 specimens of Gloydius halys,4 specimens of Vipera sakhalinensis,16 specimens of Vipera berus,and 7 specimens of Vipera renardi).The features of the trunk,cervical,cloacal and caudal vertebrae of 6 species from 2 genera are described.The vertebrae of the Viperidae are highly similar across species,with variation along the vertebral column.Nevertheless,they can be distinguished if their exact position within the vertebral column is known.The most important diagnostic feature is the shape of the hypapophysis,especially when identifying the cervical vertebrae.Among other morphological features,it is important to consider the shape of the ventral surface of the vertebra,prezygapophyseal and parapophyseal processes,neurapophysis,and zygapophysis.For the epistropheus,the position of the anterior edge of the neurapophysis in relation to the anterior edge of the neural arch is also significant.The caudal vertebrae bear the greatest resemblance.There is a significant overlap between the ratios of different measurements(indices)in different species.However,if an index is out of the overlapping zone,it is possible to identify a vertebra more or less accurately,especially when considering it in conjunction with other indices and morphological characteristics.
基金supported by the National Natural Science Foundation of China(Nos.32360380,32360278)the Guizhou Provincial Key Technology R&D Program(General[2023]111)the Basic Research Program in Guizhou Province(ZK[2022]General 098,ZK[2022]General 036,ZK[2022]General 079).
文摘The interspecific variations of plant functional traits can characterize the niche positions of species within communities,while the intraspecific variations can accurately display the species’niche breadth.Revealing relative contributions of intra-and interspecific variations to plant functional community structure is crucial in understanding how the species coexist together,especially in species-diverse ecosystems.To explore how the intra-and interspecific variations of plant functional traits change along the successional pathway in heterogeneous conditions,we established a series of plots and measured main plant functional traits along the natural regeneration in karst forest ecosystems.By quantifying the intra-and interspecific variations of plant functional traits,we found that the changes in intraspecific variations were relatively lower compared to changes in interspecific variations throughout the natural regeneration.Further analysis showed that the community spatial structure contributed more to the intraspecific variations of plant functional traits,while the soil physicochemical properties contributed more to interspecific variations.Our study suggested that tree species might tend to narrow their niche and change the positions to release the niche overlap when faced with heterogeneous habitat conditions.
基金supported by UNEP and Global Environment Foundation (No. UNEP/GEF/SCS/Chi/MoU2c)the Key Innovation Project of Chinese Academy of Science ((No. KSCZ2-SW-132)the National Natural Science Foundation of China (No. 40576052 and No. U0633007)
文摘A compilation of data on biomass and growth allowed an examination of the intraspecific plasticity in Tha/assia hemprichii which played key roles to develop site-specific growth strategies for this species in Xincun Bay. The results showed the difference in rhizome elongation rates which explained most of the variation of biomass and growth within species. The seagrass T. hempdchii in Xincun Bay adjusted its vertical and horizontal rhizome elongation rates alternatively in response to light level and temperature changes, resulting in the variation of shoot densities and above biomass in return. The vertical and horizontal rhizomes elongated at rates of 2.38 and 24.4 cm yr1 in summer while 1.87 and 29.2 cm yr^-1 in winter respectively. The shoot density ranged from 822 to 941 shoots m^2 with a peak in summer and a trough in winter which was similar to that of biomass. The growth strategy enabled T. hempdchii to minimize the negative effects of desiccation in summer as well as light reduction in winter.
基金funded by the National Natural Science Foundation of China(No.31772483,31900371)the Biodiversity Survey,Monitoring and Assessment Project of Ministry of Ecology and Environment,China(No.2019HB2096001006)。
文摘The concept of foraging niche provides an insight into habitat use and dietary information of animals.Knowing intraspecific variation in foraging niche and trophic level is critical to the understanding of the species response to environmental changes during the process of range expansion,as well as the habitat management for conservation of threatened species.Using stable isotopic values of eggshell membranes(δ;C andδ;N),we examined whether there are differences in habitat use,trophic level,foraging niche width between the new and old breeding habitats(plains vs.mountains)of wild Crested Ibis(Nipponia nippon)in the early breeding season.Crested Ibis exhibited high variability in bothδ;C andδ;N values,δ;C andδ;N varied as a function of habitat types.Birds breeding in plains had significantly higherδ;C but lowerδ;N values compared to the birds breeding in mountains.Higherδ;N suggested that individuals in mountains consumed a great proportion of higher trophic level prey species in the early breeding season.Moreover,the isotopic niches were distinctly different in positions and showed small overlap between the two habitat types.The niche width was wider in old habitat than in the expanded new habitat.Our results demonstrated that the wild Crested Ibis had a high intraspecific variation in habitat uses and trophic levels in the early breeding season,and they could be divided into mountain and plain groups based on their different foraging niches.The difference inδ;N and niche width revealed that high trophic level food resources might be insufficient in plains.These findings stressed the importance of protecting foraging grounds in mountains and the necessity of improving foraging grounds in plains during winter and spring.Our study highlights the feasibility of investigating intraspecific variation in foraging ecology of birds through non-invasive isotopes of eggshell membranes.Understanding foraging niche variation gives us an insight into the food resource diversity in local areas and provides important information regarding particular foraging habitats that require protection.
文摘The taxonomic identification of Quaternary remains requires a comparison of fossil bones with the skeletons of existing taxa based on the morphological criteria. However, the osteology of most modern snake species has not yet been studied. This work is aimed at finding differences in the bone morphology of Amur and Dione’s ratsnakes and the criteria for their identification. The variety of bone morphology depends on several parameters. First, these are species differences which determine the systematic position of the animal. Second, it is individual varia bility.Third, these are progressive changes in the vertebrae morphology along the vertebral column from the first vertebra to the last. Fourth, it is age-related variability. 20 skeletonised specimens: 12 specimens of Elaphe dione and 8 specimens of Elaphe schrenckii were used to define diagnostic osteological characters. The bones of the two studied species are very similar and their variability overlaps. However, differences and identification criteria were found for 13 skull bones:nasal, frontal, parietal, supraoccipital, maxilla, quadrate,palatine, pterygoid, ectopterygoid, basiparasphenoid,basioccipital, dentary and the compound bone. In addition, the variability and differences of the cervical,trunk, cloacal, and caudal vertebrae were examined.
