1. Plateau zokors, Myospalax fontanierii, are the only subterranean herbivores on the Tibetan plateau of China. Although the population biology of plateau zokors has been studied for many years, the interactions between zokors and plants, especially for the maintenance and structure of ecological communities, have been poorly recognized. In the past, plateau zokors have been traditionally viewed as pests, competitors with cattle, and agents of soil erosion, thus eradication programmes have been carried out by local governments and farmers. Zokors are also widely and heavily exploited for their use in traditional Chinese medicine. 2. Like other fossorial animals, such as pocket gophers Geomys spp. and prairie dogs Cynomys spp. in similar ecosystems, zokors may act to increase local environmental heterogeneity at the landscape level, aid in the formation, aeration and mixing of soil, and enhance infiltration of water into the soil thus curtailing erosion. The changes that zokors cause in the physical environment, vegetation and soil clearly affect the herbivore food web. Equally, plateau zokors also provide a significant food source for many avian and mammalian predators on the plateau. Zokor control leading to depletion of prey and secondary poisoning may therefore present problems for populations of numerous other animals. 3. We highlight the important role plateau zokors play in the Tibetan plateau ecosystem. Plateau zokors should be managed in concert with other comprehensive rangeland treatments to ensure the ecological equilibrium and preservation of native biodiversity, as well as the long‐term sustainable use of pastureland by domestic livestock.

No abstract

No abstract

J. 2005. Regulation of root vole population dynamics by food supply and predation: a two-factor experiment. Á/ Oikos 109: 387 Á/395. This paper reports the effects of food supply, predation and the interaction between them on the population dynamics of root voles, Microtus oeconomus, by adopting factorial experiments in field enclosures. This two-factor experiment proved the general hypothesis that food supply and predation had independent and additive effects on population dynamics of root voles. The experimental results proved the following predictions: (1) predation reduced population density and recruitment significantly; (2) food supply increased population density; (3) predation and food supply influenced spacing behavior of root voles separately and additively: Exposure to predation reduced long movements of root voles between trapping sessions; additional food supply reduced aggression level and home range size of root voles. Less movement of individuals that exposed to predators possibly reduced their opportunity of obtaining food and lessened population survival rate, which led population density to decrease. Smaller home range and lower aggression level could make higher population density tolerable. The interactive effect of predation and food on home range size was highly significant (P 0/0.0082B/0.01). The interactive effect of food and predation on dispersal rate was significant (P B/0.01). From the experimental results, we conclude that the external factors (predation, food supply) were more effective than internal factors (spacing behavior) in determining population density of root voles Á/ under the most favorable external conditions ( (/P, '/F treatment), the mean density and mean recruitment of root vole population was the highest; under the most unfavorable external conditions ('/P, (/F treatment), the mean density and mean recruitment of root vole population was the lowest.

No abstract