Identifying the drivers of vegetation changes in Inner Mongolia based on residual analysis and Hasse diagram technique

Exploring the effect of climate change and human activities on vegetation
is a key requisite for the reconstruction of regional ecological
environments. Therefore, based on long-term vegetation GIMMS NDVI data,
climate data, and statistical data, the present study applied the Hasse
diagram technique and combined the multivariate regression residual
analysis to quantitatively analyze the impact of human activities and
climate change on vegetation in Inner Mongolia from detail human
activities with some innovations. The results showed that (1) NDVI showed
an overall increasing trend over the last 39 years, with an abrupt change
in 2000; moreover, vegetation growth was better before the abrupt change
(PⅠ: 1982–2000) than after it (PⅡ: 2001–2020), with significant downward
trends in Xilin Gol and Hulunbuir. (2) Human activities can promote as
well as inhibit vegetation, and the promotion effect was larger during
1982–2000 than during 2001–2020, whereas the inhibition effect was larger
during 2001–2020. In addition, during PI, vegetation in Inner Mongolia
generally experienced promotion by human activities and climate change,
while during PII, climate-driven promotion had the strongest effect,
followed by human-driven inhibition mainly distributed in Xilin Gol. (3)
The result of the Hasse diagram analysis showed that the dominant pathways
of human activities affecting most of the cities were economic factors and
urbanization during PⅠ and economization during PII.