Publications

Yi, KP; Zhao, XM; Zheng, ZJ; Zhao, D; Zeng, Y (2023). Trends of greening and browning in terrestrial vegetation in China from 2000 to 2020. ECOLOGICAL INDICATORS, 154, 110587.

Abstract
Terrestrial vegetation condition is altering generally as a result of climate change and anthropogenic activity during the past few decades. To reveal the impact of long-term climate factors and artificial protection on multiple vegetation types, it is crucial to understand the spatial distribution of vegetation greening and browning and the effect of national ecological restoration programs. In this study, we established a persistent vegetation change index (P-value) to characterize greening (restoration) and browning (degradation) in China in 2000-2020. Firstly, we generated annual time-series normalized difference vegetation index (NDVI) data from MODIS product by averaging the monthly maximum NDVI values for each year. Secondly, we calculated the Pvalue to investigate the continuous change in vegetation state by incremental time interval. Finally, patterns and trends of greening and browning in forests, shrublands, and grasslands were quantified and mapped at pixel and sample point levels. The findings of our study revealed that Chinese wild vegetated lands greened up by -3.4 x 104 km2 (25%) and turned brown in -1.6 x 104 km2 (11%) between 2000 and 2020. Net greening was detected in all biomes, most conspicuously in several ecological program regions in northern China. The NDVI time-series data in 31% of field plots showed a consistent result, 11% of field plots showed a browning trend, and 58% of field plots showed a stable state. These results indicated a synergistic effect on forests, shrublands, and grasslands, but with regional variations attributed to differences in precipitation abundance, the implementation of positive ecological programs by the government and negative human activities. Additionally, these findings provide valuable insight into large-scale terrestrial vegetation transitions and have practical applications for decision-making and policy development in the assessment and restoration of ecosystems aimed at reducing carbon emissions, mitigating climate change, preserving biodiversity, and conserving water resources in China.

DOI:
10.1016/j.ecolind.2023.110587

ISSN:
1872-7034