SOIL ORGANIC CARBON DISTRIBUTION IN THE SEMI-ARID HIMALAYA AND THE POTENTIAL EFFECTS OF CLIMATE CHANGE ON REGIONAL CARBON STORAGE

Soil organic carbon in an environment affects soil fertility and agricultural production, and organic C storage can also mitigate increasing atmospheric CO₂ concentrations. However, soil organic C storage is dependent on climatic conditions, especially temperature and precipitation, and changes in these parameters associated with climate change can act as feedback mechanisms to atmospheric CO₂ concentrations. The objective of this study is to evaluate the effect of changing precipitation on soil organic carbon abundance in northern India. Previous work has shown that soils in the humid sub-tropical Himalayas in the Ganges River headwaters have very high organic matter contents, similar to levels found in high-latitude peat soils. A significant precipitation gradient has previously been established for portions of the Ladakh range of Northern India, revealing a difference in annual precipitation in northern and southern ranges spanning from 200-1,000mm/yr. It is possible that a soil organic carbon gradient also exists as a result of this large precipitation and assumed vegetation discrepancy, and we hypothesize that regions with lower mean annual precipitation will have lower overall soil organic carbon. A comparison of soils in the northern and southern semi-arid ranges of Ladakh will be conducted to clarify the relationship between climate and organic C stock. Samples will be collected from the Kulu Himalaya, Lahul Himalaya, and Zanskar to be analyzed upon return. By examining the distribution of soil organic carbon stock, the potential effects of warming and changing precipitation on C storage in this region can be predicted.