A carregar...
2 resultados
Resultados da pesquisa
A mostrar 1 - 2 de 2
- Land-use change interacts with island biogeography to alter bird community assemblyPublication . Zhao, Yuhao; Mendenhall, Chase D.; Matthews, Thomas J.; Wang, Duorun; Li, Wande; Liu, Xiangxu; Tang, Shupei; Han, Peng; Wei, Guangpeng; Kang, Yi; Wu, Chenxiao; Wang, Rui; Zeng, Di; Frishkoff, Luke O.; Si, XingfengAnthropogenic activities have reshaped biodiversity on islands worldwide. However, it remains unclear how island attributes and land-use change interactively shape multiple facets of island biodiversity through community assembly processes. To answer this, we conducted bird surveys in various land-use types (mainly forest and farmland) using transects on 34 oceanic land-bridge islands in the largest archipelago of China. We found that bird species richness increased with island area and decreased with isolation, regardless of the intensity of land-use change. However, forest-dominated habitats exhibited lower richness than farmland-dominated habitats. Island bird assemblages generally comprised species that share more similar traits or evolutionary histories (i.e. functional and/or phylogenetic clustering) than expected if assemblages were randomly assembled. Contrary to our expectations, we observed that bird assemblages in forest-dominated habitats were more clustered on large and close islands, whereas assemblages in farmland-dominated habitats were more clustered on small islands. These contrasting results indicate that land-use change interacts with island biogeography to alter the community assembly of birds on inhabited islands. Our findings emphasize the importance of incorporating human-modified habitats when examining the community assembly of island biota, and further suggest that agricultural landscapes on large islands may play essential roles in protecting countryside island biodiversity.
- Defaunation erodes the diversity of rodent personality traits in fragmented forestsPublication . Zeng, Di; Matthews, Thomas; Wang, Rui; Zhao, Yuhao; Yan, Chuan; ding, ping; Si, Xingfeng; Bijleveld, AllertABSTRACT: Habitat fragmentation is a primary driver of biodiversity loss globally. One impact of habitat fragmentation is the resultant decline and loss of large and medium mammal populations (also known as defaunation). While the effects of habitat fragmentation and associated defaunation on species diversity are well documented, their impacts on intraspecific diversity are less studied. One understudied source of intraspecific diversity is the animal personality traits within populations. As individuals with contrasting personality traits may disproportionately contribute to ecosystem functions, losing diversity of personality traits could thus impair ecosystem functions, even if some individuals of the species still persist. However, it is still unclear how the diversity of animal personality traits changes in fragmented habitats with severe defaunation. Here, we conducted mammal surveys and comprehensive behavioural assessments of Niviventer confucianus (Chinese white-bellied rat)—the most abundant rodent—on 11 forested islands in Thousand Island Lake, China, a fragmented reservoir island system formed by dam construction. We used Bayesian structural equation modelling and a functional diversity framework considering intraspecific variation to disentangle the direct and indirect effects of habitat fragmentation and defaunation on the functional diversity of N. confucianus personality traits. We found that defaunation directly decreased the functional divergence of N. confucianus personality traits. Decreasing island area indirectly reduced the functional divergence of N. confucianus personality traits through intensifying defaunation. We also found that island area directly increased rodent abundance but simultaneously exerted an indirect negative effect via defaunation. However, we did not find an effect of rodent abundance on the functional divergence, nor any effects of habitat fragmentation and defaunation on the functional richness or functional evenness of N. confucianus personality traits. These results indicate that defaunation may play a key role in mediating the negative effects of habitat fragmentation on animal behavioural diversity. The defaunation-resultant declines of intraspecific behavioural diversity highlight the importance of measuring intraspecific diversity to better understand the ecological consequences of human-driven environmental changes on biodiversity.