Human activities significantly impact China’s net primary production variation from 2001 to 2020

Abstract

Formulating ecological restoration strategies requires accurately quantifying how climate and anthropogenic factors influence net primary production (NPP). A Carnegie-Ames-Stanford approach (CASA) model was applied to estimate China’s terrestrial NPP from 2001 to 2020. We adopted a random forest (RF) method to identify the main driving forces for NPP change in China. Total NPP in China increased noticeably with a 24.91 Tg C/yr rate, as shown in our results. The significantly increased NPP was mainly attributed to human activities (64.29 ± 0.17%), chiefly due to human management and ecological projects (afforestation or other) fostered vegetation growth. The primary drivers of NPP variation varied in different geographic regions. Climate dominated the NPP dynamic in north China (52.38 ± 0.91%), where the main factor that restricted the increase of NPP was precipitation. Human activities strongly impacted the NPP variation in the remaining regions. Human management measures increased NPP in northwest and southwest China. In the northeast, east, and south-central China, the NPP change resulted from land use change, primarily grassland, cropland, and forest change. Collectively, our study expands the understanding of the driving forces of NPP change, informing different strategies for achieving ecological restoration and carbon neutrality.

Quantitative Assessment of the Impact of the Three-North Shelter Forest Program on Vegetation Net Primary Productivity over the Past Two Decades and Its Environmental Benefits in China

“…In recent years, societal policies such as ecological engineering have played an increasingly significant role in influencing terrestrial vegetation [30]. Cai et al (2023) employed the RF method to identify the primary drivers of changes in NPP in China, attributing them mainly to human activities, particularly afforestation and other ecological engineering endeavors [31]. Wenwen Li et al (2023) discovered that implementing ecological projects such as the Grain for Green Program had a significant role in the recent increase in NPP [32].…”