Arid Zone Research ›› 2023, Vol. 40 ›› Issue (12): 1982-1995.doi: 10.13866/j.azr.2023.12.11

• Plant Ecology • Previous Articles     Next Articles

Impact of climatic factors and human activities on the net primary productivity of the vegetation in the Pisha sandstone area

WANG Yi’en1,2(),RAO Liangyi1,2()   

  1. 1. College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
    2. Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
  • Received:2023-05-30 Revised:2023-08-04 Online:2023-12-15 Published:2023-12-18

Abstract:

As a highly serious soil and water loss area in the Loess Plateau, vegetation growth plays an important role in controlling soil erosion and maintaining ecological balance. This study calculated the net primary productivity of vegetation NPP and 18 extreme climate indices in the Pisha sandstone area from 2001 to 2021 based on the CASA model and Rclimdex 1.0, respectively. Trend analysis, correlation analysis, random forest importance ranking, and residual analysis were used to study the spatial-temporal variation of NPP and its response to climate factors in the Pisha sandstone area. The relative contributions of climate factors and human activities to the NPP in the Pisha sandstone area were also calculated. The results showed that (1) NPP variation in all regions of the Pisha sandstone area from 2001 to 2021 had a significant increasing trend, but in the future, 82.5% of the NPP in the Pisha sandstone area will change to a decreasing trend. (2) On the annual scale, NPP correlated positively with average annual temperature, total annual precipitation, and extreme heavy precipitation index and correlated negatively with cold night days TN10P and diurnal temperature range DTR. On the seasonal scale, the increase in average temperature and warm night days in spring was conducive to increase NPP, and there is a lag effect. Increasing the number of warm days in summer was unconducive to vegetation growth, and the NPP has a three-month lag response to the number of warm days in summer. Extreme heavy precipitation in summer was conducive to NPP increase, whereas summer drought was unconducive to vegetation growth, and NPP has a three-month lag response to the number of continuous dry days. (3) Both climate change and human activities contribute positively to NPP in the Pisha sandstone area. The climate contribution of the bare area and the covered sand area is dominant (62.13% and 60.06%, respectively), whereas that of the covered soil area is dominated by human activities (60.40%).

Key words: Pisha sandstone area, net primary productivity of vegetation(NPP), extreme climate, human activities, residual analysis