Revisiting the role of China’s protected areas in carbon storage

It is widely expected that conservation efforts within protected areas (PAs) can achieve multiple conservation objectives simultaneously. PAs established primarily for biodiversity conservation also contribute to increasing carbon storage in terrestrial ecosystems. However, there is a lack of quantitative studies on the role of China’s existing PAs in carbon storage protection. We proposed an integrated approach to estimate the carbon density of terrestrial ecosystems in China, based on a modified InVEST model. Through a statistical matching method, we evaluated the effectiveness of PAs in conserving carbon storage during 2020-2050. Under the moderate emission scenario (SSP2-RCP4.5), the average carbon density of PAs was projected to increase to 168.3 Mg C ha-1, a 14.2% rise compared to 2020. In contrast, under the low emission scenario (SSP1-RCP2.6) and high emission scenario (SSP5-RCP8.5), the average carbon density of PAs was projected to decrease by 4.8% and 4.6%, respectively. By 2050, approximately 45%-47% of PAs were expected to be effective in conserving carbon storage, with about 80% of PAs experiencing no change in effectiveness during 2020-2050. Additionally, 34.3%-36.2% of the areas of PAs remained effective, while 1.8%-4.0% were projected to transition from ineffective to effective. PAs effective in conserving carbon storage were predominantly located in humid, mid-to-high-altitude regions. Given the spatial mismatch among existing PAs, priority areas for carbon storage protection and effective areas for carbon storage protection, our findings underscored the necessity of expanding China’s PA system to expand the additional benefits of PAs in conserving carbon storage.