Holocene peat record from the Chandra valley, NW Himalayas, India

Abstract

Unprecedented atmospheric carbon dioxide (CO2) rise leading to irreversible changes to the Planet earth including change in Indian monsoon pattern and intensity. Additionally, the Indian monsoon largely controls terrestrial process and ecosystems. Terrestrial ecosystems such as forest and lake plays significant role in regulating atmospheric CO2 as well. To understand the future of these ecosystem and how their potential to capture atmospheric CO2 will be affected, we must understand past history of these terrestrial ecosystems. To do so, we examine the Chandratal Lake, which is situated in the Northwestern Himalaya at the confluence of the Indian Summer Monsoon and the Westerlies, provides a chance to reconstruct climate change during the last ~10,000 cal yrs BP. The high resolution Holocene paleomonsoon and carbon sequestration records from the region are very limited. Here, we reconstructed the carbon isotope (13C) and Total organic carbon (TOC) record from the peat bog sediment sequence for the Holocene period. Our results demonstrated decline in TOC ~9,200 cal yrs BP cold event, during the warm period of Holocene Climate Optimum during ~6342- 5820 cal yrs BP TOC increased. An increase in TOC was observed between 3000-4000 yrs. During, the Little Ice Age event of ~1301- 1610 cal yrs BP, a decrease in TOC was observed. These finding were also supported by concurrent opposite trends of δ13C. This study suggests a strong correlation between Indian summer monsoon strength and carbon sequestration potential of Chandratal lake. We further infer that the Indian monsoon will be instrumental in regulating terrestrial ecosystems and their potential in long term carbon storage.