Vegetation Variation Characteristics of Typical Grasslands on the Qinghai-Tibetan Plateau Based on BFAST Model
For further refined management of grassland resources on the Qinghai-Tibetan Plateau,based on GIMMS NDVI3g datasets from 1982 to 2015,BFAST model,and the linear trend method,we analyzed the ab-rupt breakpoint of the growing season NDVI for alpine meadow and alpine steppe,and revealed the spatiotempo-ral changing rule in growing season NDVI for the two grasslands during the different study periods.The results showed that:(1)the breakpoints of the growing season NDVI for alpine meadow occurred in 1988,1998,and 2010,but that for alpine steppe occurred in 1995,2002,and 2010.(2)For alpine meadow,the growing sea-son NDVI increased from 1982 to 1988 at a rate of 0.002 1/a(P＞0.05),but decreased during the study peri-ods of 1988-1998,1998-2010,and 2010-2015.For alpine steppe,the growing season NDVI increased dur-ing the periods of 1982-1995,1995-2002,and 2002-2010,with the largest growth rate between 1995 and 2002(0.001 5/a,P＜0.05).However,there was a downward trend in the growing season NDVI for alpine steppe from 2010 to 2015.(3)Spatially,34.45％and 17.05％of the alpine meadow areas showed a signifi-cantly decreasing trend in the growing season NDVI during the periods of 1998-2010 and 2010-2015,respec-tively(P＜0.05).The proportions of the alpine steppe areas with a significantly increasing trend in growing sea-son NDVI were 29.35％(1982-1995),39.13％(1995-2002),and 19.03％(2002-2010),respectively(P＜0.05).
万方数据
维普
