Studies On Dominant Populations Dynamics Of Desert Rodent Under Different Disturbance

The dynamic of dominant rodent populations was studied by using mark-recapture methods in Alashan Desert of Inner Mongolia under four different types of disturbance (farmland area, forbidden grazing area, over grazing area and rotational grazing area) from 2005 to 2008. we estimated the dominant rodent populations every month by Jolly-seber model, and analyzed the characteristics of population dynamics, then discussed adaptive response of dominant rodent populations under different types of disturbance. The results showed that:Firstly, under four different types of disturbance, there were obvious differences among dynamics of dominant rodent populations, not only in different types of disturbance in the same year, but also in different years under the same type of disturbance.Secondly, the composition of dominant rodent populations and sub-dominant populations were different under different types of disturbance, little Chinese jird (Meriones meridianus) was the dominant population in farmland area; northern three-toed jerboa (Dipus sagitta) was the dominant population in forbidden grazing area where little Chinese jird and desert hamster (Phodopus roborovskii) both were sub-dominant populations; northern three-toed jerboa was the dominant population in over grazing area where mongolia five toed jerboa (Allactaga sibirica) was sub-dominant population; northern three-toed jerboa was only the dominant population in rotational grazing area.Finally, the month dynamics of dominant rodent populations by Jolly-seber model showed that there were significant differences about adaptability among dominant rodent populations under different disturbance, little Chinese jird had strong adaptability both in farmland area and forbidden grazing area, striped hamster (Cricetulus barabensis) had strong adaptability only in farmland area, mongolia five toed jerboa had larger quantity in grazing area, northern three-toed jerboa and desert hamster both had strong adaptability in forbidden grazing area.