Fate of Carbon Stocks of Indian Vegetation

Abstract: Carbon use efficiency (CUE), defined as the ratio of the net (NPP) to gross primary productivity (GPP), is a valuable metric to examine the extent of atmospheric carbon sequestered by vegetation into biomass. Evaluating CUE is essential for policymakers to devise future carbon sequestration policies and identify hotspots of carbon storage loss. Indian ecosystems face pronounced weather variability across the year. However, the role of weather variability, spatial patterns, temporal dynamics, and resilience to hydroclimatic perturbations of CUE in Indian terrestrial ecosystems remains poorly understood, particularly at sub-annual scales. The lack of sub-annual NPP datasets hinders remote sensing-based sub-annual CUE assessments, but this study derived an 8-day scale NPP dataset through an empirical formulation performed on moderate resolution imaging spectroradiometer (MODIS) products. This study assesses CUE dynamics for India across its six homogeneous meteorological regions (HMRs) and the major biomes of each HMR, including croplands, forests, and grasslands, through a fine-scale remote sensing approach for 2000-2021. The results show pronounced variability of CUE across spatiotemporal scales governed by the water availability-temperature interplay. Distinct patterns were observed among the biomes, depending on the HMRs dictated by the land management practices of the regions. The study also derived sustainability maps of carbon stocks for India from the trend-persistence interplay of CUE, revealing alarming concerns across most HMRs. A severe loss of resilience of carbon stocks was observed, primarily driven by increased precipitation, and warming among meteorological drivers and soil and atmospheric drying among aridity drivers. Overall, this study highlights the critical role of CUE in assessing the carbon sequestration potential of Indian ecosystems and the need for a better understanding of the factors that influence it to develop effective carbon sequestration policies.

Date/Time
Date(s) - 23/03/2023
5:00 pm - 6:00 pm