نتایج جستجو برای: richness
تعداد نتایج: 20745 فیلتر نتایج به سال:
Understanding the spatial patterns in species richness gets new implication for biodiversity conservation in the context of climate change and intensified human intervention. Here, we created a database of the geographical distribution of 30,519 vascular plant species and 565 mammal species from 2,376 counties across China and disentangled the determinants that explain species richness patterns...
The relationships between species richness and driving factors might vary with taxa and spatial scale. For this study we used plant species data of eight groups from nature reserves in China, namely pteridophytes, gymnosperms, angiosperms, vascular plants, Chinese endemic species, rare and endangered plants, woody plants, and herbaceous plants, and eight putative environmental predictors to exp...
While we frequently observe that increasing species richness within a trophic level can increase the rates of predation or herbivory on lower trophic levels, the general impacts of prey diversity on consumption rates by their predators or herbivores remains unclear. Here we report the results of two field experiments that examined how subcanopy sessile species richness affects rates of consumpt...
Allen H. Hurlbert* and Ethan P. White Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA *Correspondence: E-mail: [email protected] Present address: Ethan P. White, Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322, USA Abstract Species richness patterns are characterized either by overlaying species range maps or by compiling geographical...
It is well established that species richness of primary producers and primary consumers can enhance efficiency of resource uptake and biomass production of respective trophic levels. At the level of secondary consumers (predators), however, conclusions about the functional role of biodiversity have been mixed. We take advantage of a recent surge of published experiments (totaling 46 since 2005)...
We report on the species richness patterns of epigaeic beetles (Coleoptera: Carabidae and Staphylinidae) along a subtropical elevational gradient of Balang Mountain, southwestern China. We tested the roles of environmental factors (e.g. temperature, area and litter cover) and direct biotic interactions (e.g. foods and antagonists) that shape elevational diversity gradients. Beetles were sampled...
Pollinating insect populations, essential for maintaining wild plant diversity and agricultural productivity, rely on (semi)natural habitats. An increasing human population is encroaching upon and deteriorating pollinator habitats. Thus the population persistence of pollinating insects and their associated ecosystem services may depend upon on man-made novel habitats; however, their importance ...
Genetic diversity within key species can play an important role in the functioning of entire communities. However, the extent to which different dimensions of diversity (e.g., the number of genotypes vs. the extent of genetic differentiation among those genotypes) best predicts functioning is unknown and may yield clues into the different mechanisms underlying diversity effects. We explicitly t...
Allelic richness (number of alleles) is a measure of genetic diversity indicative of a population's long-term potential for adaptability and persistence. It is used less commonly than heterozygosity as a genetic diversity measure, partially because it is more mathematically difficult to take into account the stochastic process of genetic drift for allelic richness. This paper presents a stochas...
A promising shortcut for quantifying species patterns is to use genera and families as surrogates of species. At large spatial scales, concurrence between patterns of richness, rarity, and composition of species and higher taxa is generally high. Only a few researchers, however, have examined this relationship at the local scale, which is frequently the relevant scale in land-use conflicts. We ...
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