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Despite constituting important ecosystem of Kashmir Himalaya and being sensitive to climate change, data on soil organic carbon (SOC) in grasslands remain scarce. Present study was conducted in 20 grasslands that represent pasture and non-pasture types, with an aim to record SOC stocks at 5 sampling depths (0–10; 10–20; 20–30; 30–40 and 40–50cm), study its variation along altitude and elucidate how environmental factors affect this variation. SOC stocks exhibited high variability and ranged between 28.85 and 94.76 Mg C ha−1, with mean value of 54.52 Mg C ha−1, which was stored as 30.63, 22.98, 21.06, 14.89, and 10.41%, respectively at five depths. Differences in SOC stocks between pasture and non-pasture types were minor, with average stocks appearing slightly higher for pasture (59.69 ± 15.43 Mg C ha−1) than non-pasture (56.32 ± 17.01 Mg C ha−1). However non-pasture type had higher stocks particularly in upper soil layers. SOC exhibited negative relationship with soil depth and bulk density while increasing relationship with altitude, species richness and aboveground live and dead biomass was observed. On depth gradient, altitude affected subsurface (10–20cm) soils more distinctly than surface (0–10 cm) soils. Besides contributing baseline data, comparison of SOC provides possibility to determine management effects on SOC storage and consequently C sequestration. [ABSTRACT FROM AUTHOR]

• Agroforestry forms an explicit part of the hill farming systems. • Mostly all the dominant agroforestry systems were prevalent in the study area. • Silvopastoral and agrohortosilviculture have the highest CO 2 mitigation potential. • Along elevation, the highest total carbon stock was recorded in Zone III. The estimation of carbon stock in agroforestry is crucial for curbing the global climate crisis. In this study, biomass production and carbon storage potential of the prevalent agroforestry systems along an altitudinal gradient in the Chamba district of Himachal Pradesh was carried out during 2019–2021. Agroforestry practices were categorized into eight land use systems viz., agrisilviculture, agrihorticulture, agrosilvohorticulture, agrohortisilviculture, hortiagriculture, silvopastoral, pastoralsilviculture and hortipastoral systems and were divided into four altitudinal ranges viz., <1000 m above sea level (m asl; Z-I), 1000–1500 m asl (Z-II), 1500–2500 m asl (Z-III) and > 2500 m asl (Z-IV). Results revealed that biomass production and total carbon storage (vegetation + soil) were significantly affected by the land use type along the altitudinal gradient. Among the different agroforestry systems, maximum aboveground biomass (47.48 Mg ha−1) and belowground biomass (12.20 Mg ha−1) were recorded for agrohortisilviculture. Biomass production was positively correlated with altitudes and increased with an increase in altitudes. Soil carbon density was the maximum (35.77 Mg ha−1) under silvopastoral showing a decreasing trend along the altitudinal gradient. The total carbon storage potential was observed the maximum (59.76 Mg ha−1) under silvopastoral system followed by agrohortisilvicuture > agrosilvohorticulture > agrisilviculture > pastoralsilviculture > hortiagriculture > hortipastoral > agrihorticulture. Along the elevation gradient, total carbon stock ranged from 43.99 to 51.13 Mg ha−1 with the maximum carbon stock corresponding to Z-III and the minimum for Z-IV. This study offers a useful approach for selecting different land use systems and vegetation patterns to maximize thecarbon stocks in a cost-effective manner, which will further help to mitigate global warming issues in other fragile Himalayan catchments. [ABSTRACT FROM AUTHOR]

• The soil stoichiometric ratios (C:N:P) were invariant in lower Himalaya. • The studied region has low C:N ratio indicating prospect for N 2 O emission. • Abies species have a higher C sequestration potential and carbon credit. • The findings are helpful to understand nutrient dynamics in forest. Understating of forest functioning is crucial for ensuring the sustainable flow of forest ecosystem services. Climate regulation service of a forest ecosystem can be ensured through emission reduction by increasing carbon sequestration in forests. However, understanding about the functioning of forests for carbon sequestration is constrained due to lack of information on nutrient stocks and stoichiometry of soils of forests of India. Present study focuses to examine the stoichiometry of major nutrients; nitrogen (N), phosphorus (P), carbon (C) of forest soil to understand the dynamics of the forests of Uttarakhand, India. The study also attempted to supplement the information about the soil carbon sequestration potential of important tree species of the forest. Soil samples were collected randomly for the evaluation of physico-chemical characteristics and stoichiometry of forest soil at four altitudinal ranges i.e., <1000, 1000–1500, 1500–2000, and >2000 m a.s.l in the Himalayan region of Uttarakhand, India. The analysis shows that total nitrogen, total phosphorous, and soil organic carbon contents in forest soil were 0.35 ± 0.11%, 0.10 ± 0.04% and 3.36 ± 0.84%, respectively, which increases with altitude. The stoichiometric ratios viz., C:N:P, N:P, C:N, and C:P, and N:P were reported of 51.6:5.4:1, 4.30 ± 2.39, 9.60 ± 1.48, and 41.94 ± 23.35, respectively which were invariant with altitude. The low C:N ratio may be attributed to either increase in the nitrous oxide (N 2 O) emissions with an increase in nitrogen, or low in carbon stock leading to decrease in carbon dioxide (CO 2) and methane (CH 4) emissions. Moreover, the soil C sequestration potential in the forest tree species follow the order of Abies pindrow > Cedrus deodara > Quercus leucotrichophora > Pinus roxburghii. The information of the study would facilitate for broadening the understanding about the soil properties and stoichiometry of forest ecosystem and would provide an aid to forest management besides contributing to the mitigations strategies of the forests. [ABSTRACT FROM AUTHOR]

• Productivity parameters of Cedrus deodara forests decreases with altitude. • Biomass and soil carbon of Cedrus deodara forests decreases with altitude. • Litterfall production also decreased with altitude. Carbon inventories are urgently needed for understanding climate dynamics and implementing climate mitigation strategies, but such data is scarce in for forest ecosystem of Himalaya. Therefore, the present study focuses to supplement the existing information by estimating carbon stocks in temperate forests dominated by Cedrus deodara along the altitudinal gradients in the Central Himalaya. Three altitudes i.e., lower (1750 m), middle (1900 m) and upper (2050 m) of the stand was considered to understand and estimate biomass and soil carbon storage potential of the forests based on the standard protocol. The results showed that the soil carbon stock (SOC) decreased significantly with increasing soil depths and altitudes. Litterfall production in the forests varied adversely with altitude. Above and below-ground biomass carbon stock also decreased along with altitude. The study observed that the total carbon stock (soil, trees and forest floor) of the Cedrus deodara forest in different altitudes was 395.4 t ha−1 (lower altitude), 321.6 t ha−1 (middle altitude) and 282.5 t ha−1 (upper altitude). The estimates of the Cedrus forests would provide guidelines for estimating carbon for forest-based mitigation activities in the Himalayan region. [ABSTRACT FROM AUTHOR]