Figure 1.
Vegetation sampling locations (circles), four mountains passes (triangles) whose uppermost 200 m elevations were studied for plant species richness, and the locations of the temperature recording stations (stars).
Figure 2.
Change in the elevational range margins for endemic plant species during the last century.
Change in elevation of the lower (left panel) and upper (right panel) range margins for 124 endemic plant species between historical (1850–1909) and recent (2007–2010) periods. The dashed horizontal line represents zero net shift. A linear regression line (and 95% confidence intervals) is also shown for each subplot.
Figure 3.
Magnitude of shift (m) in elevational range margins of alpine species in Lhonakh and Lachen valleys in Sikkim during the last century.
(A) Shift in lower elevational range margin. (B) Shift in upper elevational range margin. Dark grey portion of the pie chart represents proportion of species with no upward shift in upper or lower range margins, whereas light grey represents species showing upward shifts in upper or lower range margins. Note that significant upward shifts were observed in lower range margins of the species.
Figure 4.
Magnitude of range expansions and contractions in alpine species of Sikkim Himalaya.
The difference in lower and upper range margins for a species is taken as its range extent. ‘0′ represents no changes between historic and recent range extents, ‘+’ represents positive changes in historic and recent range extents i.e., range expansion, whereas ‘−’ represents range contraction between historic and recent range extents.
Figure 5.
Comparative species richness patterns of endemic alpine species.
The recent and historical patterns are shown by elevation, scaled by available habitat area (summed across 100 m elevational bins). The vertical lines represent the 50% cumulative species count for historical (solid) and recent (dashed) surveys.
Figure 6.
The increase in number of species at the uppermost 200 m elevations of the mountain passes during the last century, scaled by available habitat area.