Effects Of Burrowing Behavior Of Animals On Plant Community Structure And Soil Nutrient In An Alpine Grassland

Plateau zokor(Eospalax Fontanierii),plateau pika(Ochotona curzoniae)and ant(Camponotus)are typical small soil-dwelling animals in the alpine grassland ecosystem on the Qinghai-Tibet Plateau.Their burrowing,feeding and excretion activities often develop alpine meadows into discrete mosaics of vegetated areas and bare soil areas.Soil nutrients and water infiltration were positively affected and could contribute to the heterogeneity of aboveground landscape when the population number and density of soil animals living in caves(nests)are in an appropriate range,but negatively affect was found in excessive disturbance.However,most of studies mainly considered one small animal caver,which leads to insufficient recognition on how small soil-dwelling animals cavers affect plant community structure and soil nutrient characteristics.Therefore,we focused on the three small soil-dwelling animals’(plateau zokor,plateau pika and ant)burrowing-induced microtopography on plant community structure and soil nutrient of alpine grassland.We aimed to detect how small soil-dwelling animals cavers affect plant community structure and soil physicochemical properties as well as examining similarities and differences between soil animal burrowing-induced microtopography and the adjacent native grassland.We found some novel results and concluded the following points:1.Plant height,coverage,diversity,aboveground and underground biomass as well as plant community structure were substantial decreased by the establishment of burrows of plateau zokor and plateau pika.The plateau zokor rather than plateau pika burrowing behavior caused significantly increase in soil organic carbon,total nitrogen and nitrate nitrogen contents.2.The ant mound caused a shift of plant communities from sedge-dominated species to grass-dominated in alpine grasslands.Compared with the control plots,the height,aboveground and underground biomass of plants in ant mounds were significantly increased,but the vegetation coverage,evenness and biodiversity indices were dramatically decreased.In addition,soil nutrient was significantly increased in ant mounds except soil total phosphorus.3.Relative interaction index(RII)suggested that plant diversity was strongly inhibited,whereas soil nutrient was significantly promoted by small soil-dwelling animals cavers.Compared with others two kinds of burrowing animals,the nest-building behavior of ant showed an absolute advantage on soil nutrients content.