Prioritizing Tree-Based Systems for Optimizing Carbon Sink in the Indian Sub-Himalayan Region

Abstract

Land use of the sub-Himalayan region is not that intensive like the intensively land-managed region of Punjab, India. Land resources of the sub-Himalayas must be managed effectively for sustainable development by preparing carbon inventories and data banks. Such macro-level studies have not been conducted yet in the present study area, and thus were conducted to suggest sustainable land use management options. To achieve the present study’s desired goal, 33 tree-based land uses were identified from forested and agricultural landscapes of the sub-humid tropical region of West Bengal, India. Stratified random nested quadrat sampling was adopted for the study. The SOC, biomass, and carbon accumulation significantly differed. Mixed forests had the highest soil primary nutrients and carbon stock. Positive correlations were observed between SOC, total standing biomass, litter production, and ecosystem carbon. The sequence of land uses based on carbon stock was mixed-species forest > sole tree species stands in a forest landscape > tea plantations > homegardens. This baseline information can be used for developing prediction models for future interventions towards sustainable land management. The study, however, could not estimate the carbon fluxes in and out of the systems due to the absence of detailed land use land-cover databases.

Variation in Tree Density, Biomass and Carbon Stock with Altitude under the Large Cardamom-based Traditional Agroforestry System of Darjeeling

“…The SOC stock increased by 27.69 %, 18.76 % and 51.64 % from low-to mid-, mid-to high-and low-to high-altitude class, respectively. Overall, SOC stock up to 60 cm soil depth quantified was 84.62 Mg ha -1 in the range of 66.92-101.48 Mg ha -1 in the present study is within the range of 8.9 to 851.9 Mg C ha -1 estimated for agroforestry systems, plantations, and forests Simon et al, 2018;Rai et al, 2021;Chettri et al, 2023;Dey et al, 2023). However, SOC stock significantly increased with increasing altitude (r = 0.699 ** ) due to slower decomposition rates similarly reported from Sikkimese large cardamom agroforestry systems (Lepcha and Devi, 2020), homegardens of Darjeeling Himalayas (Sarkar, 2020) and other different land-uses elsewhere (Ramesh et al, 2015;Chaudhary et al, 2016).…”

“…Ecosystem carbon stock under large cardamom traditional agroforestry systems estimated was higher than the stock estimated for traditional homegardens, farm forestry and plantation forests (Mulatu, 2019;Tamang et al, 2021;Chettri et al, 2023;Dey et al, 2023).…”

“…Consequently, the vegetation heterogeneity of these under-canopy forest-based large cardamom traditional agroforestry systems is conserved which leads to higher carbon net gain and high ecosystem carbon balance while, making the system more permanent, stable, resilient and productive than any other land use systems in an agricultural landscape (Mulatu, 2019;Rai et al, 2021;Tamang et al, 2021;Chettri et al, 2023;Dey et al, 2023). This traditional practice of forest-based under-canopy large cardamom cultivation can be an efficient adaptation option at Darjeeling Himalayas to mitigate climate change locally and regionally besides the provision of livelihood and ecological benefits to the locals (Lepcha and Devi, 2020;Vineeta et al, 2023).…”