Tree diversity, carbon sequestration and production potential of Oryza sativa L. in traditional agroforestry systems of Garhwal Himalaya, India.

Agroforestry is an alternative land use practice that holds promise for societal benefits and the attainment of ecosystem sustainability. The objectives of this study were to evaluate the tree diversity, carbon sequestration, soil carbon pool, oxygen production and rice productivity under traditional agroforestry systems at different elevations in the Garhwal Himalayan region of India. Tree diversity, carbon sequestration and oxygen production were quantified by field measurements (using 0.04 ha quadrats) and subsequent calculations. Rice productivity was assessed using grain yield, straw yield and biological yield, while soil properties were analyzed in the laboratory using standard methods. Results of the study showed that tree diversity was higher at the 1200–1600 m elevation and had a maximum Shannon Diversity Index (1.29) and Simpson Diversity Index (0.69). The 1600–2000 m elevation stored more carbon (34.43 Mg ha⁻¹) and total oxygen production (91.79 Mg ha⁻¹). Among the agroforestry trees, Quercus leucotrichophora, Melia azedarach and Prunus cerasoides showed the highest carbon storage and total oxygen production. Elevation and soil depth were found to affect the soil properties. The agroforestry systems had higher soil organic carbon and lower bulk density than sole cropping systems. Compared to the agroforestry system, the monoculture produced more rice (Oryza sativa). The study shows that traditional agroforestry is a valuable tool for carbon sequestration and soil improvement, albeit with potential compromises in crop productivity. It emphasises the need for tailored management approaches to harness the ecological and environmental benefits of agroforestry in the Himalayas. This study draws attention to the potential of traditional agroforestry in the Garhwal Himalaya for carbon sequestration, climate change mitigation and soil quality improvement which provides a reference for striking a balance between the ecological advantages of agroforestry and the socio-economic considerations of local communities. However, it also underlines the importance of considering trade-offs between environmental benefits and crop yields when implementing such agroforestry systems. Highlights: • Elevation plays an important role for tree diversity, net carbon sequestration and net oxygen production in Himalaya. • Compared to sole cropping system, agroforestry systems had higher soil pH and soil organic carbon, along with lower bulk density. • Production was high in sole cropping system while agroforestry had ecological benefits like carbon storage and soil improvement. [ABSTRACT FROM AUTHOR]