关键词: 沙地, Shuttleworth-Wallace模型, 蒸散发, 蒸散拆分, 干旱, 降水

Abstract: Plant-soil feedback plays an important role in explaining the change of community composition and in predicting the community dynamics, and thus becomes a hot point in the field of community ecology and restoration ecology. In the present study, we selected four common species,Leymus chinensis,Stipa grandis,Stipa krylovii and Agropyron cristatumfrom a community in the Inner Mongolia Steppe, and examined the plant-soil feedback with a two phase method. In the first phase, we planted those four species in monoculture and compared the soil differenceamong different monocultures. The soil was then named as S-the initial of the Latin name of a plant species, i.e., S-Lc, S-Sg, S-Sk, S-Ac, respectively. In the second phase, we examined the plant-soil feedback effects on the subsequent plants at both species and community levels. There were significant differences among species treatments in soil C∶N ratio, soil available phosphorus content and soil pH value (P<0.05). The plant-soil feedback effects were species specific.L. chinensisandA. cristatum showed the best performance for all five variables observed (tiller number, plant height, aboveground biomass, belowground biomass and totalbiomass) in the S-Sk, S. kryloviishowed the best performance for all five variables observed in S-Lc,S. grandis showed the largest tiller number and greatest plant height in S-Ac, and the largest amount of biomass in S-Lc. There were significant negative feedbacks for S. grandis andS. krylovii, neutral feedback forA. cristatum, and neutral to weak positive feedback forL. chinensis as indicated by the feedback effect value. The net pairwise feedback values among the fourspecies were negative, and the values between S. kryloviiandL. chinenses, and between S. krylovii andA. cristatum were significantly less than zero, indicating the probability of coexistence for these pair wised species. These results would help to predict the effects of plant community composition change on soil properties and the performance of subsequent plants and interspecific relationships among common species in the Inner Mongolia Steppe.

Key words: evapotranspiration, partitioning of evapotranspiration, Shuttleworth-Wallace model, drought, precipitation, sand