Multiple abiotic and biotic drivers of soil water storage capacity in temperate forests recovering from disturbances

Abstract Background and aims Soil water storage capacity acts as a vital forest function to intercept rainfall and retain water for plant growth processes. However, whether or how plant functional trait diversity and composition regulate soil water storage capacity remains poorly understood. Methods Structural equation modeling (SEM) was used to detect the direct and indirect effects of multiple biotic (i.e., functional trait composition and functional diversity) and abiotic (topography and soil organic carbon) factors on soil water storage capacity, i.e., in terms of soil capillary water storage content (CW), soil non-capillary water storage content (NCW), and soil saturated water storage content (TSW), in temperate forests recovering from different logging disturbance intensity levels. Results The community-weighted mean of specific leaf area (CWMSLA) increased CW but decreased NCW directly, whereas improved NCW and TSW indirectly via soil organic carbon. Disturbance influenced soil water storage capacity mainly in indirect ways via promoting CWMSLA and soil organic carbon. Elevation increased NCW and TSW but decreased CW directly, and it also had indirect effects on soil water storage capacity via decreasing CWMSLA and soil organic carbon. Moreover, soil organic carbon influenced NCW and TSW directly or mediated the effects of elevation, disturbance, and CWMSLA on soil water storage capacity. Conclusions The quick return on investments trait of CWMSLA shows a positive effect on soil water storage capacity (CW and TSW), supporting the mass ratio mechanism in temperate forests recovering from disturbances. Soil organic carbon also presents additional importance to soil water storage capacity.