Biomass production and carbon storage potential of agroforestry land use systems in high hills of north-western Himalaya: an approach towards natural based climatic solution

The expansion of agroforestry has immense potential in mitigating and curbing regional and/or global climate change. In the present study, agroforestry systems, viz., agrihorticulture (AH), agrisilviculture (AS), and agrihortisilviculture (AHS), were explored for biomass production and carbon density in vegetation as well as in soil in two different climatic conditions, viz., high hills, dry temperate (C-1) and high hills, dry and cold temperate (C-2). The results revealed that production of above-ground biomass (AGB) and below-ground biomass (BGB) were found to be maximum in AS followed by AHS and minimum under AH systems. A similar trend was also observed for litter biomass production. Moreover, the maximum soil organic carbon (SOC; 1.26%) was recorded in the AHS system and minimum (1.14%) in AS system whereas vegetation carbon density displayed its maximum value (63.09 t ha(-1)) in AS system, followed by AHS (56.20 t ha(-1)) and AH system (40.85 t ha(-1)). Litter carbon density and total carbon density (vegetation + soil) followed the trend: AS similar to AHS > AH. Unlike agroforestry systems, climatic conditions failed to exert any significant influence on different biomass components. However, the SOC and total carbon increased with a change in climatic conditions from C-1 to C-2 but declined with an increase in soil depth. Contrary to leaf litter and soil organic carbon for which a reverse trend was observed for climatic conditions. Overall, the study establish that the various agroforestry land use systems had a substantial impact on the capacity for biomass production and carbon storage; however, the influence of climatic conditions was confined to soil and total C density. Thus, agroforestry in temperate regions could be considered one of the potential natural-based climate solutions.