Small mammal community succession on the beach of Dongting Lake, China after the Three Gorges Project

Abstract

Although the Three Gorges Project (TGP) may have affected the population structure and distribution of plant and animal communities, few studies have analyzed the effect of this project on small mammal communities. Therefore, the present paper compares the small mammal communities inhabiting the beaches of Dongting Lake using field investigations spanning a 20-year period, both before and after the TGP was implemented. Snap traps were used throughout the census. The results indicate that the TGP caused major changes to the structure of the small mammal community at a lake downstream of the dam. First, species abundance on the beaches increased after the project commenced. The striped field mouse (Apodemus agrarius) and the Norway rat (Rattus norvegicus), which rarely inhabited the beach before the TGP, became abundant (with marked population growth) once water was impounded by the Three Gorges Reservoir. Second, dominant species concentration indices exhibited a stepwise decline, indicating that the community structure changed from a single dominant species to a more diverse species mix after TGP implementation. Third, the regulation of water discharge release by the TGP might have caused an increase in the species diversity of the animal community on the beaches. A significant difference in diversity indices was obtained before and after the TGP operation. Similarity indices also indicate a gradual increase in species numbers. Hence, a long-term project should be established to monitor the population fluctuations of the Yangtze vole (Microtus fortis), the striped field mouse and the Norway rat to safeguard against population outbreaks (similar to the Yangtze vole outbreak in 2007), which could cause crop damage to adjacent farmland, in addition to documenting the succession process of the small mammal community inhabiting the beaches of Dongting Lake.

Spatial distribution drivers of Amur leopard density in northeast China

“…Reliable spatial distribution estimates of population density are crucial to population conservation and habitat management of elusive endangered species (Sollmann et al, 2013;Li and Wang, 2013;Zimmermann et al, 2013;Zhang et al, 2014). Camera trapping is an effective, non-invasive technique for wildlife surveys and is currently a popular tool for estimating population sizes of elusive, rare species (Karanth, 1995).…”

The Effect of Three Gorge Project on the Small Mammals in Yangtze River of China

“…Therefore, the manipulation of flow regulation by the TGR might also influence the small mammal communities inhabiting the beaches of rivers and lakes in the middle reaches of the Yangtze River, downstream of the TGR. To date, a few small mammal studies have been conducted, with a focus on the small mammals inhabiting the beach areas in the Dongting Lake region and the Poyang Lake region [35,[51][52][53][54][55].…”

“…Historical data for Dongting Lake showed that, before the TGP, extensive flooding in summer made the lake beaches unstable habitats for small mammal populations, other than M. fortis [54], with studies suggesting that the lake beach represented suitable living and breeding habitat for the vole living [56,57]. It was predicted that the regulation of water flow by the TGR might reduce water levels in fall and increase the amount of time that M. fortis had access to its preferred beach habitats, which would, consequently, result in larger vole populations and greater damage to surrounding crops [51,52].…”

Successive sheep grazing reduces population density of Brandt’s voles in steppe grassland by altering food resources: a large manipulative experiment

“…As human populations grow, anthropogenic disturbances are imposing increasing threats to biodiversity and ecosystem functioning (Dirzo et al 2014;Zhang et al 2014). Livestock grazing has been recognized as one of the oldest and most geographically expansive forms of terrestrial anthropogenic activities Pielke et al 2011), and has significantly shaped grassland ecosystems through both direct and indirect effects (Golluscio et al 2009).…”