Man

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Mans activities- Vietnam war and effects on the
landscape effects on species diversity?
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Chapt. 55 Conservation Biology
MAN ? EXTINCTION!! Hawaii-- 4.5 billion yrs
of evolution 2,000 yrs of extinction 39
bird species (7 geese, 9 flightless, eagle,
hawk, 3 owls, 2 crows, honeyeater, 15 finches)
now extinct
New Zealand-- 1,000 yrs 13 flightless birds
extinct
N. Amer. And Australia-- large mammals, birds,
reptiles extirpated in 20k yrs (13 of 15
genera)
Why Worry?? Do we really need all those
species??
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See Hotspot web site of Conservation
International (http//eelink.net/EndSpp/) Where
are the Hotspots? Approx. how many species are
involved? What kinds of species are involved?
Benefits of Biodiversity- Human ecology- on top
of the energy pyramid (food and resource use)
man within his ecosystem life w/o other
species?? e.g. Medicines (50 of all
prescription), soil erosion, recycling, pest
control, pollination, hydrology
Collapse of any ecosystem can result in harmful
effects on humans! Mans impact already
causing discomfort and even death on a world
scale. (examples?- introduced exotics in S.
Africa, Fig. 55.5)
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Does diversity result if greater stability,
resistance, or resiliency? Stability- constancy,
no change (two forces involved)
Also (1) Resistance- degree of resistance
to perturbation (2) Resiliency after change-
capability for returning quickly to the
original (pre-perturbed state) I.e.
successional restoration (3) Susceptibility-
likelihood of perturbance
Ecosystems, communities, populations-- which have
more or less of the above? ( Read. Assign
Case Histories)
Conservation Biology-- the study of biological
diversity and how to preserve it.
Threatened, Endangered, and Extinct!!
What are the causes??
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EXTINCTION!! Small populations increased
Susceptibility, less Resistance and
Resilience (islands and fragmentation)
Causes (1) Exploitation-- e.g
hunting (2) Inroduced Species-- pests,
competition, predation (vs. endemics!!) (3)
Impacts on Mutualists-- coevolved species, e.g
honey creepers and Lobelia of Hawaii (Fig.
55.8)
(4) Habitat Destruction and Fragmentation
agriculture, forestry (clear cutting),
agroforestry
e.g.Co-opted species-- favored for production
and use by humans (30 of all global terrestrial
production) generated by loss of, and
fragmentation of, natural habitats (see Table
55.1 and Fig. 55.10). How does the ratio of
area-to-perimeter change with decreasing area
of a patch (assume a circular patch)?
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Patch (island?) Size and Edge Effects-- what are
the effects of reducing patch size on species
diversity, extinction, etc.? (e.g. eastern
Songbirds and destruction of tropical/subtropica
l habitats)

• Patch size may not be large enough to accommodate
  a species
• natural home range.

(2) Forced movement from patch-to-patch can have
serious reper- cussion, e.g. predation, foraging
inefficiency.
(3) Patch size, shape, and spacing also important
(Reading Assn. Case Histories Landscape
Structure)
e.g. Edge effects (patch shape) ratio of patch
perimeter (P) to patch area can be used to
quantify and compare patch shape (S), e.g. for
a circle, S P / 2??A greater values than
1 indicate more elongate patches with greater
perimeter(edge) per unit area.
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The US Forest Service has changed clear-cut
policy from long, rectangular strips to large,
more rounded cuts, to much smaller cuts in
tightly spaced clusters. Why?? (See satellite
photos below) Why are the amounts of edge and
area both important?
What effects might this have on different
species? -Elk and deer -small
mammals -songbirds -birds of
prey -vegetation -livestock -insects
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Spacing and patch (island) density effects--
ratio of time inside patch away from edge
effects to time between patches.
Fractal geometry and measurement scale-- one
species ruler is anothers yardstick, e.g.
barnacles vs. eagles (Fig 18.7 Read. Assn.).
What effect does measurement scale have on
computation of P?
Metapopulations-- habitat fragmentation can
result in many small subpopulations instead of
one large population, e.g. small mammals in
Kansas prairie. Remember genetic drift,
emigration, bottleneck?
What are the expected effects of the above on
standard parameters of population biology and
island biogeography (species equilibrium
immigration, emigration and extinction rates)??
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Patch Size and Population Size-- Island
Biogeography on another scale??
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Edge Effects and fractals
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Habitat (Forest) Decline-- European temperate
deciduous forests, Patch size and edge effects
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Habitat (Forest) Decline-- USA
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Thus, other organisms are important for our own
survival!! Recovery of Biodiversity-- How??
Threatened, endangered, and extinct and species
Possiblities (1) Exploitation-
commercial interests such as hunting for food and
other products (pets, medicines,
adornment, domestication
(2) Habitat destruction- commercial logging,
air/soil pollution, development (wetlands),
urbanization, desertfication
(3) Habitat isolation- metapopulations,
fragmentation, dispersal, biotic
effects (predator/prey, home range, food
competition)
(4) Coevolution- removal of keystone species
leads to another species extinction
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FRAGMENTATION
Patch Size Edge Effects
Sumatra
Costa Rica
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Methods of Recovery -Preservation- design
of natural preserves (size, fragmentation),
captivity (zoos and parks), e.g. Quanacaste,
CR
-Change in demographics- b, d, and r (e.g. bird
nests of eastern songbirds, Kirtlands warbler
and Jack Pine, Fig 55.15-16)
-Species introductions- hard lessons learned,
matching microsite requirements, genetic
consequences (founder effects and drift) to
new and parent popuation
-Protection of keystone(umbrella/nurse) species
(African elephant)- concept of relative
community importance, mutualisms (figs and
palms of Peruvian forests)
-Captive propagation (peregrines and condors)-
maintenance, cost, reintroduction!! (molecular
preservation?) (Fig. 55.18)
Where should recovery be focused?? Endemism,
species richness, Fig. 55.22 (four categories
of priority). HOT SPOTS !!
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Conservation Priorities- Hot Spots
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CONSERVATION HOT SPOTS!!
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Restoration Ecology- can entire ecosystems be
restored? e.g. Guanacaste National Park in
Costa Rica Wetlands in San Diego
Great Difficulties!! Still experimental.

Economics of our Natural Resources ()- What is
the commercial value of a lizard, bird,
forest, pond, panoramic view, clean air,
butterfly farms, cancer cures (yew tree),
recreation?
Longrange value!!