Designing protected areas
-largest parks usually occur in areas where few people live and the land is
unsuited for human economic activity "the lands that nobody wanted"
Ex. huge desert parks in SW USA and the tundra in Alaska
-principles of preserve design are based on ideas from the island biogeography
model Figure 16.1
16.1 Principles of reserve design proposed based in part on theories of island biogeography
For protected areas to effectively preserve species, the following six
characteristics should be considered:
1) Three R's of Protected Area design
Representation of all conservation units in preserve.
Resiliency so that all conservation units are in a large well protected area so
that they remain healthy for the foreseeable future.
Redundancy so that reserves protect enough examples of conservation units to
ensure their long-term existence.
2) Principles based on island biogeography and experience of protected area
managers Figure 16.1
3) Area should be sufficient in area to preserve large populations because
population size is the best predictor of extinction probability
-one of the biggest debates is the SLOSS debate- single large or several small
protected areas Figures 16.2 and 16.3
16.2 Large parks and protected areas in Africa contain larger populations of each species
16.3 Each dot represents the extinction rate of animal populations for a particular park
3) Size cont.
-generally bigger is better, but the value of several smaller preserves is that they
may be able to include a variety of habitat types and more populations
Ex. Possibly true in some cases for the 10,000 small protected areas in Britain
Figure 16.4
Ex. the number of large mammal species in three national parks in contrasting
habitats (Big Bend, North Cascades in Washington, and Redwoods in
California) is > than Yellowstone, which is larger than the combined areas
of the three parks
-ideally a reserve should be large enough to include a viable population of the
most wide-ranging species in it and this umbrella species may provide
protection for other species as well
Figure 16.5 Red cockaded woodpecker of SE USA needs extensive stands of
longleaf pine and this protects rare plant species as well
-conservation networks can be used to aggregate small nature reserves and this
has been accomplished by organizations such as The Nature Conservancy
Box 16.1 and the Chicago Wilderness Project Figure 16.6
16.4 10,000 small (< 3 square km on average) protected areas in Britain managed for biodiversity
conservation
16.5 Longleaf pine habitat in the southeastern U.S. is being managed to protect the red-cockaded
woodpecker
16.6 The Chicago Wilderness Project-240 organizations form a conservation network
4) parks should be designed to minimize the harmful effects of edge
-edge has greater temperature variations, more wind, less humidity, more
fire and disease, as well as different species compositions
-in the past, edge was advocated as it increased the number of certain
species. However, most often, those of greater conservation concern
occupy large blocks of undisturbed habitat
-circular plots have less edge than rectangular
-usually boundaries are irregular because land acquisition is often due to
opportunity rather than design
5) Internal fragmentation such as roads, fences, etc. should be avoided to
prevent divisions of large populations and lessen chances for
introduction of exotics
6) protected areas should be linked with habitat corridors. Corridors
facilitate migration and gene flow and allow animals that migrate
seasonally to move along protected areas. Figure 16.7
16.7 (A) An overpass allows animals to migrate between two forested areas. (B) Individuals
disperse between two large protected areas using smaller protected areas as stepping-stones
Landscape Ecology- discipline that investigates interactions between habitat
types and their influences on species distribution and ecosystem processes
-a landscape is an area where a cluster of interacting ecosystems is repeated in
similar form Figure 16.9
-in more traditional landscapes such as those in earlier Europe and Japan,
fields, villages, and forest created a mosaic with a rich diversity of habitat
and in such habitats many species move between habitats or live at borders
between habitats. These kinds of habitats are becoming more rare Figure
16.10 and often checkerboard landscapes of different sizes occur today
Figure 16.11
16.9 Four different landscape types: (A) patch, (B) network, (C) interdigitated, (D) checkerboard.
16.10 Traditional rural landscape near Tokyo, Japan
villages
(black);
secondary
forest (dark
green);
wet rice fields
(light green);
and hay fields
(beige)
16.11 Two square nature reserves, each 100 ha in area (shaded = forest; white = pasture)
Edge effects in landscapes that are square, which is common due to our surveying system
Edge in the landscape often does not favor the organisms of greatest
conservation concern.
-conservation networks can attempt to link all protected natural areas
in a landscape to form larger habitat units
Ex. The Yellowstone to Yukon Ecoregion plan Figure 16.12
-Y2Y plan proposes to link national parks and other
government lands along the Rocky Mountains in the USA and Canada
-Managing these landscapes on a regional scale may be the
best way to control populations of large mammals
-Habitat corridors have been proposed as a way to link
isolated conservation areas allowing for dispersal and colonization of
new sites and the resulting gene flow that occurs with those events
Ex. U.S. National Wildlife Refuge System is a linked park system
that has had some success in preserving bird migrations through a
landscape that is highly fragmented with large amounts of edge
16.12 The Yellowstone to Yukon (Y2Y) plan proposes to link government lands of the U.S. and Canada