Reply on RC2

Abstract

Vegetation, water, and carbon dioxide have complex interactions on carbon mitigation in vegetation-water ecosystems. As one of the major global change drivers of carbon sequestration, water disturbance is a fundamental but poorly discussed topic to date. The riparian zone is a representative highly dynamic vegetation-water carbon capture system. Unfortunately, its global carbon offset functionality is remarkably underestimated. This study examines the daily CO2 perturbations in the riparian zone with two-year in-situ observations along the Lijiang River. We show that the riparian zone transformed from a carbon source to carbon sink after recovery from flooding. Consequently, a quantitative global riparian carbon offset model is proposed. Based on the intensity of flooding submergence and post-flooding vegetation coverage, ~0.11Gt·year-1 CO2 is captured following flooding, and 0.53 Gt·year-1 more CO2 is captured due to flooding, which is equivalent to 9.1 % of the global forest carbon sequestration. This finding shed new light on the quantitative modelling of the riparian carbon cycle under flooding disturbance, underlining the importance of the proper restoration of riparian systems to achieve global carbon offset.