Strengthening grassland carbon source and sink management to enhance its contribution to regional carbon neutrality

Abstract

Grassland ecosystems are an important part of terrestrial ecosystems. It is of great significance to fully tap the potential of grassland carbon sinks to achieve the goal of carbon neutrality in the region and even worldwide. Previous studies have focused on analyzing the temporal and spatial distributions of grassland carbon sink capacity and lacked a systematic discussion of grassland carbon source/sink management. Taking three grasslands in the Inner Mongolia Autonomous Region of China as an example, this study characterized grassland carbon source/sink capacity through net ecosystem productivity (NEP), combined with a soil respiration model, Sen + MK (Mann-Kendall) trend test method and other methods, revealed the spatiotemporal distribution characteristics of NEP and carbon emissions (CEs) in the study area from 2000 to 2019, and used spatiotemporal and geographical weighted regression (GTWR) model to clarify the potential mechanism of grassland sink increase. Suggestions for grassland carbon source/sink management are also discussed. The study found that the CEs in the study area from 2000 to 2019 could be roughly divided into three stages: slow growth period (2000–2009), rapid growth period (2009–2011) and stable development period (2011–2019). Although grassland carbon sinks could not completely offset regional CEs, grassland ecosystems had a very large carbon sink potential, which could make important contributions to the realization of regional carbon neutrality goals. Grassland carbon sources/sinks were jointly affected by climate change and human activities, and the degree of impact varied from year to year, with the impact of human activities changing more significantly. On this basis, the study puts forward policy recommendations from four aspects: regional priority, dynamic monitoring and management, control of grazing intensity and implementation of ecological compensation, and it proposed a sustainable development pattern of “carbon trading-ecological compensation-grassland sink increase”. The research results have important practical guiding significance for the management of grassland sink increases and regional carbon neutral development strategies in Inner Mongolia under the background of climate change.

Keywords

• Net ecosystem productivity
• Grassland ecosystem
• Carbon neutrality
• Spatiotemporal and geographical weighted regression model
• Arid and semiarid regions