JOURNAL OF NATURAL RESOURCES ›› 2018, Vol. 33 ›› Issue (3): 425-438.doi: 10.11849/zrzyxb.20170139

• Resource Ecology • Previous Articles     Next Articles

Spatial-temporal Variation of the Vegetation Coverage in Qinling Mountains and Its Dual Response to Climate Change and Human Activities

DENG Chen-hui1,2, BAI Hong-ying1, GAO Shan3, LIU Rong-juan1, MA Xin-ping1, HUANG Xiao-yue1, MENG Qing1   

  1. 1. College of Urban and Environmental Science, Northwest University, Xi’an 710127, China;
    2. Shaanxi Continuous Education College, Xi’an 710004, China;
    3. Xi’an Meteorological Bureau, Xi’an 710016, China;
  • Received:2017-02-23 Revised:2017-07-29 Online:2018-03-20 Published:2018-03-20
  • Supported by:
    A General Program from the Shaanxi Province Scientific Research and Development Plan, No. 2016JM4022; National Forestry Public Welfare Industry Scientific Research Project, No. 201304309.

Abstract: The Qinling Mountains, a key ecological zone of terrestrial ecosystem, has experienced a significant change of vegetation coverage in recent years. Based on MODIS-NDVI data, DEM data and meteorological data such as temperature, precipitation, sunshine, humidity and wind speed, this paper calculated the Fractional Vegetation Coverage (FVC) in Qinling Mountains, analyzed the background characteristics of the “pattern-process-trend” change, and explored the dual response mechanism of the vegetation coverage to climate change and human activities with trend analysis method, multiple regression method-residual method and PLS regression method. The results of the study showed that: First, the FVC in Qinling Mountains showed a significant increase trend at a growth rate of 2.77%/10 a during 2000-2015, with a very significant upward trend in the southern slope at a growth rate of 3.8%/10 a and a non-significant downward trend in the northern slope. In the space, FVC showed the pattern that is “high in the middle, low in the surroundings; high in the west, low in the east; high in the south-slope, low in the north-slope”. Second, the level of FVC in Qinling Mountains varied greatly, and the order of each FVC grade in area was Ⅴ, Ⅳ, Ⅲ, Ⅱ and Ⅰ, the area of Ⅰ and Ⅴ showing significant upward trend while the area of others showing decline trend. Third, the change of FVC at different altitudes was significantly different. There was a significant upward trend under 1 500 m and obvious downward trend at 2 600 m, while there was no obvious change at 1 500-2 600 m. With the increase of altitude, the FVC reached a maximum at 2 200 m. The FVC at 700-3 200 m was more than 0.7 and at 1 300-2 700 m was more than 0.9, and values below 0.5 mainly appeared in high altitude area above 3 400 m. Forth, there were significant spatial differences in the response of vegetation coverage to climatic factors. The response of vegetation coverage to precipitation had time lag, with a lag of one month, while the response to temperature did not have time lag. Fifth, the role of human activities was increasing rapidly, with the growth rate of 2.10%/10 a. The positive effect of human activities on FVC mainly distributed in the eastern region, and the negative effect of human activities mainly distributed in the central and western regions. Finally, the FVC changes were the results of both climate change and human activities, and the impact factors from strong to weak are human activity, precipitation, temperature and potential evapotranspiration.

Key words: climate change, double responses, fractional vegetation cover, human activity, Qinling Mountains

CLC Number: 

  • Q948