(1,640 ft) from the source and one of which was 100 m
from it? What are the differences between a 1 ha plot
and a 10 ha plot, both of which are 200 m (656 ft) from
the source forest? Does the tree community change in
fragmented patches, and if so, how? Are understory
bird species more sensitive to differences in area than
canopy species? Which species of monkeys are most
sensitive to area and isolation? What species increase
in density with fragmentation?
Various researchers have shown that virtually all
the taxonomic groups studied are sensitive in varying
ways to both area and distance effects. Some species
decline, others increase. For example, effects of isolation
included the following:- Isolated fragments experienced an influx of
understory birds (presumably emigrating from the
surrounding deforested area), but after about 200
days, the total number of birds dropped to below
what it had been before the forest fragment was
isolated. In other words, biodiversity plummeted. - Army- ant- following birds were negatively affected,
declining and disappearing from fragments. This
occurred because army ants require large areas
in which to forage for prey, so they are among the
species most likely excluded in small- area fragments.
(A similar pattern was evident on Barro Colorado
Island, Panama, after it became an island in 1913.) - Euglossine bees, which are important long- distance
Plate 18- 7. The Crested Guan (Penelope purpurascens) is
commonly hunted for meat in Central America. It is an
important seed disperser for some tree species. Photo by John
Kricher.Plate 18- 8. Skins for sale: two Ocelots, one red howler monkey,
one Puma, and one Jaguar. They were killed by bushmeat
hunters in Venezuela. Photo by John Kricher.Plate 18- 9. This photograph was taken near Alta Floresta,
Brazil. The foreground shows essentially total deforestation.
Fragmented forest remnants are visible in the distance. The
dense haze is smoke from fires set to burn the slash. Photo by
John Kricher.Plate 18- 10. Aerial image of a study fragment from the
Biological Dynamics of Forest Fragments Project (BDFFP).
Photo by Mark W. Moffett/Minden Pictures. Reprinted with
permission from Kricher, John. Tropical Ecology. Princeton, NJ:
Princeton University Press, 2011.chapter 18 the future of the neotropics 381