Monika Rawat, Kusum Arunachalam, Ayyandar Arunachalam, Juha M. Alatalo, Ujjwal Kumar, Barbara Simon, Levente Hufnagel, Erika Micheli, Rajiv Pandey

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 biomass C, N, and P, and soil respiration) in temperate forest. Among the plant traits studied, 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 biomass C, N, and 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 biomass C (52%) and N (67%), while soil pH explained some of variation in soil microbial biomass N (14%). Available P, total N, and pH explained soil microbial biomass P (81%), while soil respiration was only explained by soil total C (70%). Thus
leaf traits and soil characteristics make a significant contribution to 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.