Abstract: | Cultivation on grassland ecosystem, as one of the greatest disturbance, is well studied. Grassland cultivation, especially in desert region, often results in habitat fragmentation, and subsequently affects plant and animal communities. Under intensive disturbance, the responses of rodent species with different bionomic strategies to environmental change could play a key role in determining structure of their communities. Alashan, has a continental climate with cold and dry winters and extremely warm summers, is a classic desert region in China. In this region, rodents dominate local fauna. Cultivation, happened in last 60 years, destroyed the original vegetation and changed animal habitats in Alashan desert. However, few literatures on Chinese western desert have focused on the impacts of cultivation on rodents. A study was conducted from 2006 to 2011 at cultivated and non-cultivated sites to investigate effect of cultivation on rodent community diversity, community structure with different bionomic strategies, and their population abundance in Alashan, Inner Mongolia, China. We expected that rodents with r strategy will dominate in cultivated site, while the K strategists will dominate in non-cultivated site. Rodent communities monitoring using live trapping method showed that cultivation significantly decreased Shannon-Wiener index and Simpson index, but did not affect Pielou evenness index. In the cultivated site, species richness and population abundance of rodents with r strategy were higher than those of K strategy. In non-cultivated site, rodent population abundance was lower for rodent with r strategy than the rodent with K strategy. Abundance-biomass comparison (ABC curve) and W statistic were used to detect dynamic of species abundance and biomass for rodents with different bionomic strategies. ABC curve analysis showed that cumulative dominance of species abundance was higher cumulative dominance of species biomass in cultivated site. These results suggested that cultivation had a negative impact on the rodent community diversity, and severely disturbed rodent community, therefore, excluded or decreased rodents with K strategy. Our results supported hypothesis that rodents with r strategy will be dominant in communities in cultivated site. Cultivation exclusion will benefit to support more diverse and stable rodent community. |