Environmental Engineering Reference
In-Depth Information
a
b
c
Plate 11.8
(Fig. 11.8 on page 302) (a) Current distribution of sweetgum trees across the eastern USA (darker colors show
greater habitat quality - an index of density and size of trees) with the 1971 range outlined in black. (b) Predicted
distribution of sweetgum in 2100, assuming that rate of dispersal can keep up with change in habitable area. (c) Actual
occupied area in 2100 is predicted to be very much less than the potential area, because of dispersal restrictions. This
panel, which focuses in on the current range boundary (indicated by the box in (b)), shows the presently occupied range in
gray and the surprisingly small addition by 2100 of newly occupied habitat immediately to the northeast. According to the
predicted distribution in (b), all of the area depicted in (c) could, in theory, be occupied by sweetgum if only they could
shift fast enough. (From Iverson et al., 2004.)
Search WWH ::
Custom Search