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1.
The range of resources that a species uses (i.e. its niche breadth) might determine the geographical area it can occupy, but consensus on whether a niche breadth–range size relationship generally exists among species has been slow to emerge. The validity of this hypothesis is a key question in ecology in that it proposes a mechanism for commonness and rarity, and if true, may help predict species' vulnerability to extinction. We identified 64 studies that measured niche breadth and range size, and we used a meta‐analytic approach to test for the presence of a niche breadth–range size relationship. We found a significant positive relationship between range size and environmental tolerance breadth (= 0.49), habitat breadth (= 0.45), and diet breadth (= 0.28). The overall positive effect persisted even when incorporating sampling effects. Despite significant variability in the strength of the relationship among studies, the general positive relationship suggests that specialist species might be disproportionately vulnerable to habitat loss and climate change due to synergistic effects of a narrow niche and small range size. An understanding of the ecological and evolutionary mechanisms that drive and cause deviations from this niche breadth–range size pattern is an important future research goal.  相似文献   

2.
The regional occupancy and local abundance of species are affected by various species traits, but their relative effects are poorly understood. We studied the relationships between species traits and occupancy (i.e., proportion of sites occupied) or abundance (i.e., mean local abundance at occupied sites) of stream invertebrates using small‐grained data (i.e., local stream sites) across a large spatial extent (i.e., three drainage basins). We found a significant, yet rather weak, linear relationship between occupancy and abundance. However, occupancy was strongly related to niche position (NP), but it showed a weaker relationship with niche breadth (NB). Abundance was at best weakly related to these explanatory niche‐based variables. Biological traits, including feeding modes, habit traits, dispersal modes and body size classes, were generally less important in accounting for variation in occupancy and abundance. Our findings showed that the regional occupancy of stream invertebrate species is mostly related to niche characteristics, in particular, NP. However, the effects of NB on occupancy were affected by the measure itself. We conclude that niche characteristics determine the regional occupancy of species at relatively large spatial extents, suggesting that species distributions are determined by environmental variation among sites.  相似文献   

3.
Aim  Range size and niche breadth have been found to be positively related to abundance in many plant and animal groups. We tested these two relationships for the tree species flora of Central Europe; that is, for all 25 species that have their distribution centre in this region.
Location  Eurasia, with a focus on Central Europe.
Methods  We devised an abundance and niche variable classification system to transform the existing literature data into a semi-quantitative assessment of abundance and niche breadth (in terms of soil chemical and physical variables, and temperature) for each of the 25 tree species. Regression analyses between abundance, range size and niche breadth were conducted for the entire species sample and for subsets of species defined by their ecology or phylogeny.
Results  The relationship between abundance in the distribution centre and range size was weak for the Central European tree species. However, significant abundance–range size relationships were found for phylogenetically or ecologically more homogenous species groups (for example for trees of the order Rosales and for mid-successional tree species). Realized niche breadth was positively related to range size in the case of temperature, but not for soil-related variables. No relationship existed between niche breadth and abundance in the distribution centre.
Main conclusions  We hypothesize that the weak relationship between abundance and range size is primarily a consequence of substantial ecological and phylogenetic heterogeneity within this rather species-poor assemblage. The positive relationship between realized temperature niche breadth and range size emphasizes the strong influence of climatic variables on plant distribution patterns over continental or global scales.  相似文献   

4.
Determinants of local abundance and range size in forest vascular plants   总被引:2,自引:0,他引:2  
Aim For a large set of forest herbs we tested: (1) whether there is a positive relationship between local abundance and geographical range size; (2) whether abundance or range size are affected by the niche breadths of species or niche availability; and (3) whether these are affected by the species life‐history traits. Location Northwestern Germany. Methods We measured abundance as mean density in 22 base‐rich deciduous forests and recorded range size as area of occupancy on four different spatial scales (local to national). Niche breadth was expressed in terms of habitat specificity (specialists, generalists) and of the ability to grow across a broad range of soil pH. The species’ pH niche position was used as a measure of the importance of habitat availability. As life‐history traits we used diaspore mass and number, plant height, seed longevity, lifespan/clonality, pollination mode, dispersal capability and flowering time. Results There were mainly no positive relationships between the abundance of species and their range size, as tested across species and across phylogenetically independent contrasts. Forest specialists were generally distributed less widely than generalists, but habitat specificity was not related to local abundance. Species with a broader pH niche breadth were more common, but the positive relationships between niche breadth and abundance or range size disappeared when accounting for sample size effects. Clonal species with few and heavy diaspores were most abundant, as well as early‐flowering species and those lacking dispersal structures. Local and regional range size were determined largely by habitat availability, while national range was positively affected by plant height and diaspore mass. Main conclusions Different processes determine the local density of species and their range size. Abundance within habitat patches appears to be related mainly to the species life histories, especially to their capacity for extensive clonal reproduction, whereas range size appears to be determined strongly by the availability of suitable habitat.  相似文献   

5.
The relationship between species’ niche breadth (i.e. the range of environmental conditions under which a species can persist) and range size (i.e. the extent of its spatial distribution) has mostly been tested within geographically restricted areas but rarely at the global extent. Here, we not only tested the relationship between range size (derived from species’ distribution data) and niche breadth (derived from species’ distribution and co‐occurrence data) of 1255 plant species at the regional extent of the European Alps, but also at the global extent and across both spatial scales for a subset of 180 species. Using correlation analyses, linear models and variation partitioning, we found that species’ realized niche breadth estimated at the regional level is a weak predictor of species’ global niche breadth and range size. Against our expectations, distribution‐derived niche breadth was a better predictor for species’ range size than the co‐occurrence‐based estimate, which should, theoretically, account for more than the climatically determined niche dimensions. Our findings highlight that studies focusing on the niche breadth vs range size relationship must explicitly consider spatial mismatches that might have confounded and diminished previously reported relationships.  相似文献   

6.
Most species of Australian desert lizards are uncommon. Possible causes of rarity are examined, including body size as measured by snout–vent length (SVL), fecundity, number of sites occupied, habitat niche breadth, microhabitat niche breadth, dietary niche breadth, and average total niche overlap with other species. Rare species tend to be larger with lower fecundities than abundant species and they occur at fewer sites. Many, but not all, uncommon species are specialists, either in habitat, microhabitat, or diet. The niche breadth hypothesis, which states that abundant species should be generalists whereas specialized species should be rare, is tested, but rejected as a general explanation for rarity. Some uncommon species exhibit high overlap with other species suggesting that they may experience diffuse competition. However, no single cause of rarity can be identified, but rather each species has its own idiosyncratic reasons for being uncommon. Multivariate analyses show distinct ecological differences between abundant and uncommon species.  相似文献   

7.

Aim

The breadth of ecological niches and dispersal abilities have long been discussed as important determinants of species' range sizes. However, studies directly comparing the relative effects of both factors are rare, taxonomically biased and revealed inconsistent results.

Location

Europe.

Time Period

Cenozoic.

Major Taxa

Butterflies, Lepidoptera.

Methods

We relate climate, diet and habitat niche breadth and two indicators of dispersal ability, wingspan and a dispersal tendency index, to the global range size of 369 European-centred butterfly species. The relative effects of these five predictors and their variation across the butterfly phylogeny were assessed by means of phylogenetic generalized least squares models and phylogenetically weighted regressions respectively.

Results

Climate niche breadth was the most important single predictor, followed by habitat and diet niche breadth, while dispersal tendency and wingspan showed no relation to species' range size. All predictors together explained 59% of the variation in butterfly range size. However, the effects of each predictor varied considerably across families and genera.

Main Conclusions

Range sizes of European-centred butterflies are strongly correlated with ecological niche breadth but apparently independent of dispersal ability. The magnitude of range size–niche breadth relationships is not stationary across the phylogeny and is often negatively correlated across the different dimensions of the ecological niche. This variation limits the generalizability of range size–trait relationships across broad taxonomic groups.  相似文献   

8.
Macroclimatic niches are indirect and potentially inadequate predictors of the realized environmental conditions that many species experience. Consequently, analyses of niche evolution based on macroclimatic data alone may incompletely represent the evolutionary dynamics of species niches. Yet, understanding how an organisms’ climatic (Grinnellian) niche responds to changing macroclimatic conditions is of vital importance for predicting their potential response to global change. In this study, we integrate microclimatic and macroclimatic data across 26 species of plethodontid salamanders to portray the relationship between microclimatic niche evolution in response to changing macroclimate. We demonstrate stronger phylogenetic signal in microclimatic niche variables than at the macroclimatic scale. Even so, we find that the microclimatic niche tracks climatic changes at the macroscale, but with a phylogenetic lag at million-year timescales. We hypothesize that behavioral tracking of the microclimatic niche over space and phenology generates the lag: salamanders preferentially select microclimates similar to their ancestral conditions rather than adapting with changes in physiology. We demonstrate that macroclimatic variables are weak predictors of niche evolution and that incorporating spatial scale into analyses of niche evolution is critical for predicting responses to climate change.  相似文献   

9.
The analysis of a local community of forest passerines (13 species) using phylogenetic contrasts shows a correlation between body size of bird species and mean prey size, minimum prey size, maximum prey size and the size range of dietary items. This suggests that larger birds drop small prey taxa from their prey list, because of the difficulty of capturing very small prey, for energetic reasons or because of microhabitat usage. We find some support for the third hypothesis. Dietary niche breadth calculated across prey taxa is not related to body size. Dietary niche breadth, however, is correlated with size-corrected measurements of the bill and locomotor apparatus. Long and slender bills increase the dietary niche breadth. Thus subtle differences constrain foraging and the techniques of extracting certain prey taxa form crevices. Dietary niche breadth and foraging diversity are positively correlated with population density: at least locally dietary generalists occur at higher breeding densities than specialists.  相似文献   

10.
Divergent evolution between Western Rock Nuthatch Sitta neumayer and Eastern Rock Nuthatch Sitta tephronota is widely recognized as the original case study of character displacement. However, in their contact zone in the Zagros Mountains, Iran, the morphological differences important for niche segregation between the two species remain unknown. We investigated microhabitat use and morphological adaptations of the two species, predicting that morphological adaptations to different habitats in these two nuthatches have led to spatial segregation. Seventy‐seven birds were captured and measured in the contact zone and allopatric zone in Iran. Twenty‐two primary variables related to flight apparatus, functional foot apparatus and feeding apparatus were measured and 11 ratios of primary variables were calculated as secondary variables due to their importance in habitat use. We also measured environmental variables related to geological features, mineral substrates and vegetation cover at a random sample of 100 of the locations where a nuthatch was observed. Results of morphometric and habitat analyses indicated that, in addition to trophic niche segregation, the two nuthatch species also differ in their microhabitat use and show differences in morphological features accordingly. In many case studies of character displacement, much more interest has been focused on the morphological differences in feeding apparatus than on those relating to habitat use. We suggest that future studies of character displacement should pay more attention to spatial niche segregation between sympatric species rather than trophic niche segregation.  相似文献   

11.
Distribution, abundance and niche breadth of birds: scale matters   总被引:1,自引:0,他引:1  
We used local habitat niche breadth, local abundance and body size of non-passerine afrotropical birds in Tsavo East National Park (Kenya) to predict species distributional ranges in Kenya and across Africa. Univariate analysis revealed a significant positive correlation between local abundance and distribution only on the scale of Kenya. Performing a multiple regression analysis, local abundance, local habitat niche breadth and body size explained a significant part of the variance in bird distribution, again only on the Kenyan scale. From these results, we speculate that on continental scales distributions may be more influenced by macroclimatic conditions and historical factors, whereas distributions on regional scales are predominantly influenced by ecological factors.  相似文献   

12.

Aim

Species geographical range sizes play a crucial role in determining species vulnerability to extinction. Although several mechanisms affect range sizes, the number of biotic interactions and species climatic tolerance are often thought to play discernible roles, defining two dimensions of the Hutchinsonian niche. Yet, the relative importance of the trophic and the climatic niche for determining species range sizes is largely unknown.

Location

Central and northern Europe.

Time period

Present.

Major taxa studied

Gall-inducing sawflies and their parasitoids.

Methods

We use data documenting the spatial distributions and biotic interactions of 96 herbivore species, and their 125 parasitoids, across Europe and analyse the relationship between species range size and the climatic and trophic dimensions of the niche. We then compare the observed relationships with null expectations based on species occupancy to understand whether the relationships observed are an inevitable consequence of species range size or if they contain information about the importance of each dimension of the niche on species range size.

Results

We find that both niche dimensions are positively correlated with species range size, with larger ranges being associated with wider climatic tolerances and larger numbers of interactions. However, diet breadth appears to more strongly limit species range size. Species with larger ranges have more interactions locally and they are also able to interact with a larger diversity of species across sites (i.e. higher β-diversity), resulting in a larger number of interactions at continental scales.

Main conclusions

We show for the first time how different aspects of species diet niches are related to their range size. Our study offers new insight into the importance of biotic interactions in determining species spatial distributions, which is critical for improving understanding and predictions of species vulnerability to extinction under the current rates of global environmental change.  相似文献   

13.
唐家河自然保护区小哺乳动物空间生态位初步研究   总被引:3,自引:0,他引:3  
1989年4~11月,采用去除取样法,对四川省唐家河自然保护区内小哺乳动物的空间生态位宽度和重叠度进行了研究。共安置ll000铗日,捕获小哺乳动物14种846只。根据香农一威纳多样性指数公式以及Cowell和Futuyma公式分别计算了各小哺乳动物种群的空间生态位宽度和空间生态位重叠指数。在14种小哺乳动物中,社鼠的空间生态位宽度指数最大(1.00),大足鼠、川I西长尾朐、川朐和灰麝朐的最小,均为0。14种小哺乳动物空间生态位重叠指数最大为1,最小为0,其中大足鼠与川西长尾朐及灰麝朐、针毛鼠与川朐的空间生态位彼此完全重叠;藏鼠兔与针毛鼠、大足鼠、洮洲绒鼠、川西长尾朐、川朐以及灰麝朐的空间生态位完全分离。空间生态位完全重叠的种类,是通过选择不同的食物以及不同的微生境来避免过度竞争。回归分析显示,小哺乳动物种群的空间生态位宽度指数与它们利用空间资源的平均值呈显著的正相关(r=0.8285,P〈0.05)。空间生态位宽度指数的季节变化表明,社鼠种群分布没有明显的季节差异,中华姬鼠和安氏白腹鼠每年可能有一个数量高峰期,高山姬鼠一年则可能有两个数量高峰。  相似文献   

14.
Insights into the causal mechanisms that limit species distributions are likely to improve our ability to anticipate species range shifts in response to climate change. For species with complex life histories, a mechanistic understanding of how climate affects different lifecycle stages may be crucial for making accurate forecasts. Here, we use mechanistic niche modeling (NicheMapR) to derive “proximate” (mechanistic) variables for tadpole, juvenile, and adult Rana temporaria. We modeled the hydroperiod, and maximum and minimum temperatures of shallow (30 cm) ponds, as well as activity windows for juveniles and adults. We then used those (“proximate”) variables in correlative ecological niche models (Maxent) to assess their role in limiting the species’ current distribution, and to investigate the potential effects of climate change on R. temporaria across Europe. We further compared the results with a model based on commonly used macroclimatic (“distal”) layers (i.e., bioclimatic layers from WorldClim). The maximum temperature of the warmest month (a macroclimatic variable) and maximum pond temperatures (a mechanistic variable) were the most important range‐limiting factors, and maximum temperature thresholds were consistent with the observed upper thermal limit of R. temporaria tadpoles. We found that range shift forecasts in central Europe are far more pessimistic when using distal macroclimatic variables, compared to projections based on proximate mechanistic variables. However, both approaches predicted extensive decreases in climatic suitability in southern Europe, which harbors a significant fraction of the species’ genetic diversity. We show how mechanistic modeling provides ways to depict gridded layers that directly reflect the microenvironments experienced by organisms at continental scales, and to reconstruct those predictors without extrapolation under novel future conditions. Furthermore, incorporating those predictors in correlative ecological niche models can help shed light on range‐limiting processes, and can have substantial impacts on predictions of climate‐induced range shifts.  相似文献   

15.
浙江江山公益林物种种间关系及CCA排序   总被引:3,自引:0,他引:3  
利用浙江省江山市80个公益林固定小班监测数据,基于生态位理论、种间联结、CCA排序方法对研究区内群落优势种种间关系及其与环境的关系进行研究。结果表明:江山市公益林群落中杉木、檵木、紫萁分别在乔木、灌木、草本层中占优势地位;石栎与青冈、隔药柃与山苍子、蕨与海金沙的生态位重叠指数值分别在乔、灌、草本层中最大;而CCA协变量矩阵偏典范对应分析说明物种分布主要受海拔、坡度、坡向(光照强度)以及腐殖质厚度的影响,总体上可以对89.44%的环境因子进行解释。并且还表明,生态位宽度较大的物种其生态位重叠值较大,并在CCA排序图物种集中区分布。反之,生态位重叠较小,在CCA排序图中将偏离物种集中区;除此之外,在CCA排序图上,物种间的距离与其生态位重叠值的大小及种间联结均有密切的关联,若未存在显著的联结性,随物种间的生态位重叠值越高,其在CCA排序上的距离越近,若存在显著联结性,则正相关缩小距离,负相关拉大距离。  相似文献   

16.
17.
1 Relationships between microhabitat variables (altitude, inclination, topographic position, drainage, canopy height) and the distribution and abundance of palms and palm-like plants in 50 ha of old-growth terra firme rain forest in the Yasuní National Park, lowland Amazonian Ecuador, were examined using 118 20 × 20 m plots laid out in a stratified random design.
2 If microhabitat niche differentiation is important for maintaining the species richness of the community, then (i) the distribution of the palms will be strongly influenced by microhabitat heterogeneity and (ii) palms of similar growth form will show antagonistic microhabitat relationships.
3 Mantel and cluster analyses showed that palm species distributions were strongly structured by topography. The main difference in species composition was between plots in the bottomland and plots on the upper slopes and hill tops.
4 Logistic and logit analyses showed that 20 of the 31 palm and palm-like taxa analysed had distributions that were significantly related to the microhabitat variables measured, mainly to topography but also to drainage and canopy height.
5 Spatial autocorrelation in the overall community structure was not explained by the microhabitat variables. Analyses of distributions or abundances of single species showed neighbourhood effects for seven taxa.
6 Antagonistic patterns of microhabitat preferences were recognizable among some species pairs of small palms, medium-sized palms and palm-like plants, but not among canopy palms.
7 It is concluded that microhabitat specialization is an important factor in maintaining the diversity of this palm community, while mass effects might also be important.  相似文献   

18.
Historically, macroecology and microecology have diverged with regard to the niche concept. A better understanding of functioning ecological systems, however, depends on an integrative approach to this concept at different spatial scales. A mixed approach, merging macro‐ and microscale by validating ecological niche modeling (ENM) with the results of in situ experiments and environmental data collection was used to understand if areas identified by ENM as highly suitable for adult palms are also adequate for seedling establishment. Syagrus weddelliana's (Arecaceae) distribution range falls within the Atlantic Rain Forest, and more specifically Serra dos Órgãos region (Rio de Janeiro state), southeastern Brazil. The following steps were performed: (a) ENM to delimit the area of occurrence of S. weddelliana and locate experimental areas; (b) a seed sowing experiment in areas with presence or absence of the species in areas of high or low environmental suitability at 36 experimental stations; and (c) characterization of each microhabitat which was related back to the macroscale results of ENM. Evidence of biotic and abiotic limitations was found for S. weddelliana distribution. Areas of higher suitability had lower seed predation rates and, consequently, higher seed germination rates. On the other hand, areas with low environmental suitability at the macroscale were divided into two types: areas with microhabitat similar to that of areas with high environmental suitability that had some germination despite high predation and areas with different environmental conditions that had no germination and high predation rates. Seedlings and adults had different abiotic requirements. Microhabitat conditions were more important for the initial establishment of S. weddelliana than macroclimatic variables. This finding demonstrates that macro‐ and microecological information works in a complementary way to a better understanding of the distribution of S. weddelliana.  相似文献   

19.
昆承湖优势种鱼类时空-营养生态位   总被引:1,自引:0,他引:1  
陈亚东  任泷  徐跑  凡迎春  徐东坡 《生态学报》2023,43(4):1655-1663
为了解昆承湖优势种鱼类资源利用情况,首先利用生态位方法计算了时间、空间及营养三个资源维度的生态位宽度及重叠值,然后根据时空-营养生态位宽度值将优势种鱼类划分为广位种、中位种和窄位种,最后讨论了生态位宽度及重叠的可能原因。结果显示:刀鲚Coilia nasus、蒙古鲌Chanodichthys mongolicus、似鱎Toxabramis swinhonis、似鳊Pseudobrama simoni、鳙Hypophthalmichthys nobilis、鲢Hypophthalmichthys molitrix、花鱼骨Hemibarbus maculatus、似刺鳊鮈Paracanthobrama guichenoti、大鳍鱊Acheilognathus macropterus和鲫Carassius auratus为优势种。在时间维度:鲢的生态位宽度最大,似鳊的最小;生态位重叠具有显著意义的有24对,占总的53.33%。在空间维度,似刺鳊鮈最大,鲢最小;生态位重叠具有显著意义的有36对,占总的80%。在营养维度,最大的为鲫,最小的为花鱼骨;生态位重叠具有显著意义的有8对,占17.78%...  相似文献   

20.
烟台近海浮游动物优势种空间生态位研究   总被引:2,自引:0,他引:2  
根据2018年春、夏季烟台近海海域的调查资料,以浮游动物优势种(类)为研究对象,运用Levins公式和Pianka指数分析了浮游动物优势种(类)的生态位宽度和生态位重叠程度,采用冗余分析(RDA)研究了影响浮游动物优势种(类)空间生态位分化的主要因素。研究结果表明,浮游幼虫和桡足类是烟台近海浮游动物群落结构的主要组成群体,春、夏季浮游动物优势种(类)更替率为73.33%。依据烟台近海浮游动物优势种(类)的生态位宽度值,可将其划分为广生态位、中生态位和窄生态位三大类群,广生态位种类为浮游动物优势种(类)的主要构成群体,春季代表种类有短角长腹剑水蚤(Oithona brevicornis)、拟长腹剑水蚤(Oithona similis)等,夏季代表种类有小拟哲水蚤(Paracalanus parvus)、克式纺锤水蚤(Acartia clausi)等。生态位重叠指数与物种分布的环境位点的重合情况密切相关,广生态位种类之间的生态位重叠程度要高于窄生态位种类与其他种类之间的生态位重叠程度。RDA分析表明,春季影响浮游动物优势种(类)空间生态位分化的主要因素为海水温度、盐度和无机氮(DIN),夏...  相似文献   

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