Abstract: The effects of multiscale catchment landscape features on soil physical and chemical properties of riparian zone along the secondorder tributaries of Liuxi River in Guangzhou City were analyzed. The objective of this study was to explore and identify the main factors that influence soil properties at different spatial scales and to provide scientific data for riparian zone management and restoration. The results showed that along the longitudinal direction of the riparian zone, topographic index, land slope, land elevation and landuse type were the governing factors on the spatial heterogeneity of soil water content, soil textures and pH. Along the transversal direction, the distance of a landscape from riverside and the vegetation coverage were the main factors affecting the spatial heterogeneity of soil dissolved organic carbon, nitrate nitrogen (NO₃^--N) and bulk density. Along the vertical profile of the riparian zone, the intensity of human disturbance on soil, the root system distribution in soil profile and the groundwater tables were the major factors affecting the spatial heterogeneity of soil organic carbon, TN and NH₄⁺-N in the riparian zone.

Key words: Grain for Green Program (GPP), net carbon sequestration, carbon leakage, carbon cost, greenhouse gas.