Effects of Three Plantation Coniferous Species on Plant-Soil Feedbacks and Soil Physical and Chemical Properties in Semi-Arid Mountain Ecosystems

Abstract Background: Large-scale afforestation can significantly change ground cover and soil physicochemical properties, especially the soil fertility maintenance and water conservation function of artificial forest is very important in semi-arid mountain ecosystems. To better understand the effects of different tree growth on soil nutrient and soil physicochemical properties following afforestation to determine the best plantation tree species for improving soil fertility and water conservation functions. Methods : This study investigated the soil nutrient contents for three different tree species ( Larix principis-rupprechtii , Picea crassifolia , Pinus tabuliformis ), soils and plant-soil feedbacks, as well as the interaction between soil physicochemical properties. Results : The results revealed that the leaf and litter layer strongly influences soil nutrient availability through biogeochemical processes: P. tabuliformis has higher organic carbon, C:N and C:P in the leaves and litter layer than L. principis-rupprechtii or P. crassifolia , suggesting that higher C:N and C:P hinder litter decomposition. As a result, the L. principis-rupprechtii and P. crassifolia plantation forests significantly improve soil nutrients and clay component than P. tabuliformis plantation forest. Furthermore, the the L. principis-rupprechtii and P. crassifolia plantation forests significantly improved the soil capacity, soil total porosity and capillary porosity, decreased soil bulk density, and enhanced water storage capacity than P. tabuliformis plantation forest. In conclusion, the results of this study show that the strong link between plants and soil is tightly coupled to C:N and C:P, and there had strong correlation between soil particle size distribution and soil physicochemical properties. Conclusions : Therefore, our results recommend planting the L. principis-rupprechtii and P. crassifolia as the preferred tree species to enhance the soil fertility and water conservation functions, especially in semi-arid regions mountain forest ecosystems.