Arid Zone Research ›› 2024, Vol. 41 ›› Issue (8): 1395-1404.doi: 10.13866/j.azr.2024.08.13

• Plant Ecology • Previous Articles     Next Articles

Changes in NDVI and its multiscale spatiotemporal responses to precipitation in the Mu Us Desert

SHI Tianyi(), ZHANG Mengmeng(), PU Yang, LIU Shuoyuan   

  1. School of Geographical Sciences, Nanjing University of Information Science & Technology, Nanjing 210044, Jiangsu, China
  • Received:2024-03-28 Revised:2024-05-27 Online:2024-08-15 Published:2024-08-22
  • Contact: ZHANG Mengmeng E-mail:shitianyi0@163.com;mmzhang@nuist.edu.cn

Abstract:

The Mu Us Desert possesses a delicate ecological environment. It is therefore of utmost importance to understand the correlation between sand-fixing vegetation and precipitation to achieve effective ecological restoration and implement the concept of “water-oriented greening” in the desert. This study examined the fluctuation patterns in vegetation within the Mu Us Desert from 2000 to 2018, as well as its reaction to delayed and cumulative precipitation effects. Our findings revealed significant trends in the annual and seasonal average NDVI of the study area from 2000 to 2018 (P<0.01). However, the spatial distribution of these trends exhibited substantial variation. Notably, the region with a significant increase in summer NDVI accounted for 83.2% of the total area, whereas the region with a significant increase in annual NDVI accounted for only 34.15% of the total area. Moreover, the annual and monthly variations in vegetation NDVI showed no significant time lag in response to precipitation, but a significant cumulative effect was observed. Approximately 38.58% of the study region exhibited a cumulative response of NDVI to precipitation lasting between one and two years, which was mostly concentrated in areas with lower annual precipitation and negligible changes in annual NDVI. Finally, the spatial and temporal distribution of the correlation coefficient between seasonal NDVI and cumulative monthly precipitation exhibited pronounced differences. The response time and percentage of NDVI to precipitation varied across seasons, with a range of 2-3 months (19.25%) for spring, 4 months (73.58%) for summer, and either 1 month (27.22%) or 3 months (34.91%) for autumn. This study revealed the absence of significant temporal delays in the vegetation response to precipitation in the Mu Us Desert. Additionally, it revealed that the cumulative effects varied significantly across different spatiotemporal scales. Consequently, the findings of this study serve as a foundation for optimizing ecological restoration programs involving artificial vegetation, as well as implementing the “water-based greening” approach.

Key words: vegetation NDVI, precipitation, time lag and cumulative effects, water-based greening, Mu Us Desert