Carbon Sequestration Potential of Himalayan Cypress Stands of Kumaun Central Himalaya, India

Abstract

Forests play a substantial role in sequestering carbon and regulating the global carbon balance. Himalayan Cypress (Cupressus torulosa D. Don) from an ecological and economic stand point is a least explored evergreen conifer of Central Himalaya that often forms either pure stands or sometimes association with other tree species. However, very little information is known about the carbon sequestration potential of these Cypress stands. Therefore, the main objective of this study was to quantify carbon stocks and carbon sequestration potential of six Cypress stands distributed along the altitudinal gradients of 1600–2500 m asl in Kumaon Central Himalaya. A total of 120 circular plots of 5.65 m radius were laid systematically in six Cypress stands with 20 sample plots in each. Soil physical and chemical properties were also assessed. Results revealed that total tree density and basal area in cypress stand ranged from 440–1050 individuals ha-1 and 30.84–60.79 m2 ha-1, respectively. The total carbon stock ranged between 151–285 Mg C ha-1, respectively. Carbon sequestration rate across stands fluctuated between 2.42 and 4.87 Mg C ha-1 yr-1. Soil organic carbon (SOC), total nitrogen (TN) and available potassium (K) levels were higher in high altitude stands. Soil organic carbon (SOC) stock (for soil depth 0-60 cm) ranged from 155.58–398.80 Mg ha-1. Altitude and soil physico-chemical factors showed no significant (p>0.05) impact on carbon stocks of Cypress stands. Overall, the carbon reserves in the soil across stands were 9-57% higher than those in the trees' biomass. These estimates indicate that the value of cypress forests lies not only in their ability to sequester biomass carbon but primarily in their extensive soil carbon reserves. This study provides useful background for future research to assess the trend of carbon sequestration in Cypress stands.