Driving forest succession in karst areas of Chongqing municipality over the past decade

Forest Ecosystems

Table 1 Classification criteria for effects of desertification sensitivity

Grading	No rocky desertification	Potential sensitive	Mildly sensitive	Moderately sensitive	Highly sensitive	Extremely sensitive
Lithological characters	Insoluble rock, non-carbonate rocks	Buried soluble rock, insoluble rock, non-carbonate rock	Sub-pure limestone	Impure limestone	Dolomite	Limestone, limestone and dolomite
Precipitation (mm)	< 300	< 400	400–800	800–1500	1500–2000	2000–2500
Slope (°)	< 3	< 5	5–15	15–30	30–45	> 45
Vegetation cover (%)	High cover forestland, shrubs, grassland (vegetation-cover > 75%)	High cover forestland, shrubs, grassland (vegetation-cover > 70%), paddy fields (water bodies, towns)	Covered forest land, shrubs, grassland (vegetation-cover 40%–70%)	Low-cover forestland, shrubs (vegetation-coverage < 40%)	Low-cover grassland (vegetation-coverage < 40%), dry land	Bare soil, bare rock, no vegetation
Assignment	0	1	3	5	7	9

Note: 1) No rocky desertification includes mainly non-carbonate rocks and insoluble rock; Potential sensitive includes buried soluble rock, insoluble rock, non-carbonate rock; Mildly sensitive includes sub-pure limestone; Moderately sensitive includes limestone and kata-rocks; Highly sensitive includes dolomite; Extremely sensitive includes limestone, limestone and dolomite (Li et al. 2014). 2) Normalized vegetation index is used to calculate vegetation coverage. NDVI value is composed of information contributed by green vegetation and non-vegetation coverage (Tang et al. 2019)