Relative contribution of plant traits and soil properties to the functioning of a temperate forest ecosystem in the Indian Himalayas

Abstract Plant-soil interactions are a major determinant of changes in forest ecosystem processes and functioning. We conducted a trait-based study to quantify the contribution of plant traits and soil properties to above- and below-ground ecosystem properties in temperate forest in the Indian Himalayas. Nine plant traits (leaf area, specific leaf area, leaf water content, leaf dry matter content, leaf carbon (C), nitrogen (N), phosphorus (P), leaf C/N, and leaf N/P) and eight soil properties (pH, moisture, available N, P, potassium (K), total C, N, P) were selected for determination of their contribution to major ecosystem processes (above-ground biomass C, soil organic C, soil microbial C, soil microbial N, soil microbial P, and soil respiration) in temperate forest. Among the plant traits leaf C, N, P, and leaf N/P ratio proved to be the main contributors to above-ground biomass, explaining 20–27% of variation. Leaf N, P, and leaf N/P were the main contributors to below-ground soil organic C, soil microbial C, soil microbial N, soil microbial P, and soil respiration (explaining 33% of variation). Together, the soil properties, pH, available P, total N and C explained 60% of variation in above-ground biomass, while pH and total C explained 56% of variation in soil organic C. Other soil properties (available P, total C and N) also explained much of the variation in soil microbial C (52%) and soil microbial N (67%), while soil pH explained some of variation in soil microbial N (14%). Available P, total N, and pH explained soil microbial P (81%), while soil respiration was only explained by soil total C (70%). Thus, leaf traits and soil characteristics significantly explaining variations in above- and below-ground ecosystem processes and functioning in temperate forest in the Indian Himalayas. Consequently, tree species for afforestation, restoration, and commercial forestry should be carefully selected, as they can influence the climate change mitigation potential of forest in terms of C stocks in biomass and soils.