| Dispersal is a research focus of animal ecology because it is very important mechanism that extend animal distribution region, gene exchange and biological revolution. Ecological dispersal refers to the movement of individuals animals from one breeding site to another and it emphasizes process of dispersal and considers distribution and abundance of biology. Plateau zokor(M.baileyi) is a dominant subterranean rodent that plays an important role in the alpine meadow ecosystem.Dispersal of plateau zokor is closely related to their reproductive, habitat selection and damage to grassland. This paper selected distribution area of plateau zokor as sample sites to study dispersal causes, dispersal sex and dispersal time with investigation of plant and soil, capture-recapture, radio tracking, molecular biology and infrared camera monitoring. The purpose is to provide scientific basis for controlling subterranean rodents damage and protecting biodiversity on alpine meadow. The main results were as follows:1. The potential cause of plateau zokor ecological dispersal. Based on the investigation of the zokor population on the sample alpine meadow under different grazing intensities, the rank of decrease range of plateau zokor population in different grazing intensities was ban grazing>medium grazing intensity>light grazing intensity>heavy grazing. The results showed that the zokor departed from the old habitat to another. The soil bulk density, aboveground biomass and grass biomass in ban grazing area were significantly higher than another grazing paddocks(P<0.05),but the forbs biomass in ban grazing paddock was significantly lower than that of another paddocks(P<0.05). The soil compaction in heavy grazing paddock was significantly lower than that of another paddocks(P<0.05). The results indicated that the soil bulk density, aboveground biomass, grass biomass and forbs biomass in ban grazing paddock lead to the zokor population decrease compare to other paddocks.Hereby, the cause of ecological dispersal of plateau zokor were from habitat quality changes. The multivariable regression model(Y=205.36-0.145X1,X1:soilcompaction)revealed the soil compaction was the main factor result in the zokors ecological dispersal.2. Dispersal sex. Used 10 developed microsatellite sites to study the sex-biased dispersal of the zokor, 33 allelic genes in 10 microsatellite sites were found. The polymorphism information content(PIC) was 0.312 and the Fst of genetic differentiation coefficient was 0.016. The mean assignment index of male and female was-1.390±0.786 and 1.086±0.385, respectively. Captured 30 zokors(13 males,17females) first year and recaptured 13 zokors(4 males,9 females) next year, the recapture ratio of males and females was 30.7% and 52.9%, respectively. In addition,the result of radio tracking showed that the lost ratio of male and female was 76.9%and 45.4% in tracked 37 zokors(26 males,11 females). Based on the results above, we believed that plateau zokor existed sex-biased dispersal.3. Dispersal time. Used mark recapture method to catch the zokor in spring and fall next year, the recapture ratio(0%)in fall was lower than that(43.3%)in spring.Besides, the result of radio tracking showed that lost ratio in September(66.6%) was higher than that in spring, and lost ratio was 37.5% in October. We supposed that dispersal time of the zokor was from June to September.4. Dispersal manner. From June to July in sample sites, the zokors walked on aboveground was found by infrared camera monitoring. The number of the zokor walks on aboveground accounted for 13.5% of the total marked samples. Therefore,we supposed that the zokor dispersal by walking on aboveground. |
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