Patchsizes, edges, and habitats 227plus three characteristics subject to rapid change: (1) present ecological
attributes of the land; (2) land cost and subsequent management cost;
and (3) threats (urgency) to the land.Species-focused conservation
(A) Species of small isolated habitats.Toprovide some long-term protection
forspecies of dispersed small distinct habitats requires protection of
extensive heterogeneous areas, or of numerous small sites, or of several
large patches with enough connections across the landscape that most
species distributions will be included in the large patches.
(B) Species ‘‘ perception” and conservation priority.Animals and plants ‘‘perceive”
and respond to different-sized structures and patterns, and thus success-
ful conservation focuses on species especially sensitive to large struc-
tures and patterns, which are most likely to be lost or degraded by
human activities in the landscape.
(C) Keystonespecies.Landscape patterns that protect keystone species (those
with a disproportionately large effect on ecosystem function relative
to their abundance or biomass), particularly predators, are likely to be
especially effective in protecting biodiversity.
(D) Species extinction proneness.Alandscape pattern that enhances the follow-
ing species types -- low mobility animal, large body size, low reproduc-
tive rate, top of food chain, large home-range size, hunted species, small
population size, habitat specialist, and strong dependence on another
species -- reduces the chance of species loss.
(E) Invasive species.Ifaninvasive non-native or feral species degrades a nat-
ural habitat, and ecological succession and other natural processes are
unlikely to be an effective control, then carefully researched human
control of the species is normally appropriate to restore the habitat.
Wetlands
(A) Hydrologic functions of wetlands. When not ‘‘full” of water, wetlands act
as sponges slowing down and absorbing water flows, and then slowly
releasing water through evaporation to air, percolation into ground, and
runoff into surface water-bodies, that effectively reduces downstream
peak flows and flooding (Figure9.1).
(B) Pollutants and wetlands.Particulate pollutants settle out in wetlands, dis-
solved substances are absorbed by plant roots, diverse pollutants are
filtered as water moves through soil, and some pollutants are broken
down by microorganisms, that together results in cleaner water flowing
out of a wetland.