Relationships Between Rodent Communities And Environmental Factors In Different Disturbance Habitats In Alashan Desert

The rodent communities were sampled by a trap-day method in four different disturbance habitats in April, July and October (spring, summer, autumn) from2009to2011in Alashan desert.The habitats were farmland,rotational-grazing, over-grazing and prohibited-grazing areas, and the relationships between rodent communities and plant factors were analyzed by Redundancy Analysis (RDA). The results showed that:(1) Rodent community diversity indices (H) between different disturbance habitats were significant difference (P<0.05) in three seasons. The highest diversity index of rodent community was found in rotational-grazing area (H=1.42) and the lowest one was in the over-grazing area (H=0.91) in spring; in the same way, the highest index was found in farmland area (H=1.45) and the lowest one was in the prohibited-grazing area (H=1.06) in summer; the highest index was found in over-grazing area (H=1.23) and the lowest one was in the prohibited-grazing area (H=0.65) in autumn.(2) The rodent community diversity indices (H) with different inter-annual changes in different disturbance habitats.The rodent community diversity indices are2010>2011>2009in farmland area;The rodent community diversity indices are2011>2010>2009in rotational-grazing and over-grazing areas;The rodent community diversity indices are2009>2011>2009in prohibited-grazing area.(3) With the seasonal variation characteristics and annual variation characteristics,habitat quality appear obvious differences between different habitat disturbance.Seasonal variation characteristics are mainly from height and density of the shrub; height,coverage, density and biomass of the herbaceous; the hardness of the soil at the level of0～5cm,5～10cm,10～15cm and15～20cm are significant differences between four different disturbance habitats.Annual variation characteristics mainly height, the height of the shrub, cover, density and biomass of herbaceous, the hardness of the soil at the level of0～5cm,5～10cm,10-15cm and15-20cm are significant differences between four different disturbance habitats.(4) The RDA with forward selection showed that variations of rodent community were significantly related to coverage of suffruticosa plant and density of herbaceous plant in spring and summer,density and coverage of herbaceous plant in autumn.(5) The RDA with forward selection showed that variations of rodent communities were significantly related to density and coverage of herbaceous plant in autumn.We suggest that coverage and density of plant are the most important factors influencing the structures of rodent communities in Alashan desert.