Fig 1.
Study area:(a) Asian drylands, which mainly includes Kazakhstan (KAZ), Turkmenistan (TKM), Kyrgyzstan (KGZ), Tajikistan (TJK), Uzbekistan (UZB), Mongolia and the western provinces of China (Xinjiang, Gansu, Qinghai, Ningxia, Shaanxi, and Inner Mongolia).
(b) Spatial distribution of vegetation change zones in Asian drylands, including intersection, increase, decrease, and change zones. (NO.: GS (2016)2966). (c) Overview of study area and the study’s targeted climate factor changes, i.e., TMMX, TMMN, PRE, DEF, PDSI, SOIL, SRAD, PET, AET, VSP, VAP, and VPD, from 1990 to 2020.
Table 1.
Data product type and source.
Fig 2.
Grid statistics process roadmap.
Fig 3.
Spatial distribution of land covers in 2001 and 2022.
Land cover types: (a) needleleaf forests, (b) deciduous broadleaf forests, (c) mixed forests, (d) shrublands, (e) savannas, (f) grasslands, (g) permanent wetlands, (h) croplands, (i) vegetation, (j) barren, (k) urban, (l) WSI (Water, Snow, and Ice). Only vegetation biomes are considered and classes in IGBP were grouped as indicated in parentheses in Fig 1b: NF = Needle-leaf Forest (1 + 3), DBF = Decidious Broadleaf Forest (4), MF = Mixed Forest (5), SH = Shrublands (6 + 7), SAV = Savannas (8 + 9), GRA = Herbaceous (10), WET = Permanent Wetlands (11), CRO = Cultivated (12 + 14), BAR = Barren (16), UR = Urban and Built-up Lands (13), WSI (Permanent Snow and Ice and Water Bodies(15 + 17)).
Fig 4.
Relative changes of 12 land covers during 2001-2022.
(a) needleleaf forests, (b) deciduous broadleaf forests, (c) mixed forests, (d) shrublands, (e) savannas, (f) grasslands, (g) permanent wetlands, (h) croplands, (i) vegetation, (j) barren, (k) urban, (l) WSI (Water, Snow, and Ice).
Fig 5.
Multi-year average TDI for each land cover.
Fig 6.
Multi-year average SDI for each land cover.
Land cover types: (a) All of land cover (SDI ≠ 0), (b) BAR (barren)-UR (urban)-WSI (Water, Snow, and Ice), (c) deciduous broadleaf forests, (d) needleleaf forests, (e) mixed forests, (f) shrublands, (g) savannas, (h) grasslands, (i) permanent wetlands, (j) croplands.
Fig 7.
Transition probability matrix of land cover types from 2001 to 2022, highlighting dominant conversion pathways, particularly transitions from BAR to GRA and from GRA to CRO.
Fig 8.
Spatiotemporal dynamics of land cover transitions across the Asian drylands from 2001 to 2022.
(Note: In the table, “Transition Types” represent transitions from the left-hand type to the right-hand type, and “Raster Counts” indicate the number of pixels involved in the transition).
Fig 9.
Climate factor trends for the intersection zone of the same vegetation types from 2001 to 2020 in Asian drylands.
(a), (b), (c), (d), (e), (f), (g), (h), (i), (j), (k), and (l) show trends for TMMX, TMMN, PRE, DEF, PDSI, SOIL, SRAD, PET, AET, VSP, VAP, and VPD, respectively. Note: n is climate trend, percent (%) is ranked size comparison. “Clockwise” indicates a positive trend (i.e., n > 0), and “Counterclockwise” indicates a negative trend (i.e., n < 0).
Fig 10.
Climate factor trends for the increase zone of the same vegetation types from 2001 to 2020 in Asian drylands.
(a), (b), (c), (d), (e), (f), (g), (h), (i), (j), (k), and (l) show trends for TMMX, TMMN, PRE, DEF, PDSI, SOIL, SRAD, PET, AET, VSP, VAP, and VPD, respectively. Note: n is climate trend, percent (%) is ranked size comparison. “Clockwise” indicates a positive trend (i.e., n > 0), and “Counterclockwise” indicates a negative trend (i.e., n < 0).
Fig 11.
Climate factor trends for the decrease zone of the same vegetation types from 2001 to 2020 in Asian drylands.
(a), (b), (c), (d), (e), (f), (g), (h), (i), (j), (k), and (l) show trends for TMMX, TMMN, PRE, DEF, PDSI, SOIL, SRAD, PET, AET, VSP, VAP, and VPD, respectively. Note: n is climate trend, percent (%) is ranked size comparison. “Clockwise” indicates a positive trend (i.e., n > 0), and “Counterclockwise” indicates a negative trend (i.e., n < 0).
Fig 12.
Climate factor trends for the change(transition) zone of the same vegetation types from 2001 to 2020 in Asian drylands.
(a), (b), (c), (d), (e), (f), (g), (h), (i), (j), (k), and (l) show trends for TMMX, TMMN, PRE, DEF, PDSI, SOIL, SRAD, PET, AET, VSP, VAP, and VPD, respectively. Note:n is climate trend, percent (%) is ranked size comparison. “Clockwise” indicates a positive trend (i.e., n > 0), and “Counterclockwise” indicates a negative trend (i.e., n < 0).
Fig 13.
Temporal variation of precipitation in the study area during the historical period (1950-2014) and future period (2015-2100), and the average precipitation and trends under different future scenarios.
Fig 14.
Temporal variation of average temperature in the study area during the historical period (1950-2014) and future period (2015-2100), and the average temperature and trends under different future scenarios.
Fig 15.
Comparison of climate change trends in vegetation intersection zones, increase zones and decrease zones.