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Chapter 55
Conservation Biology and Restoration Ecology
I. The Biodiversity Crisis
1. conservation biology: integrates ecology, physiology, molecular biology,
genetics, and evolutionary biology to conserve biological diversity at all levels
2. Restoration ecology: applies ecological principles in an effort to return
degraded ecosystems to conditions as similar as possible to their natural,
predegraded
3. humans alter trophic structures, energy flow, chemical cycling, and natural
disturbance
II. Human Activities Threatens Earth’s Biodiversity
 Rate of extinction underlies the biodiversity crisis
A. The Three Levels of Biodiversity
1. Genetic Diversity
a) genetic variation within and b/w populations
b) if one population becomes extinct then a species may have lost some of the
genetic diversity that makes microevolution possible
2. Species Diversity
a) endangered species: one that’s in danger of extinction throughout all or a
significant portion of its range
b) threatened species: considered likely to become endangered
c) local extinction vs. global extinction
3. Ecosystem Diversity
a) the local extinction of one species can have a negative impact on the
overall species richness of the community
b) each ecosystem has characteristic patterns of energy flow & chemical
cycling that can affect whole biosphere
B. Biodiversity and Human Welfare
 biophilia: our sense of connection to nature & other forms of life
 religious theme: all species entitled to life
 concern for human generations
1. benefits of species and genetic diversity
a) species that are threatened could provide crops, fiber, and medicines
b) loss of species means loss of genes
- biodiversity represents sum of all genomes of all organisms on earth
2. Ecosystem services
a) encompass all of the processes through which natural ecosystems and the
species they contain help sustain human life on Earth
b) examples:
- purification of air & water
- reduction of severity of droughts & floods
- generation & preservation of fertile soils
- detoxification & decomposition of wastes
- pollination of crops & natural vegetation
- dispersal of seeds
- cycling of nutrients
c) functioning of ecosystems and capacity to preform services linked to
biodiversity
C. Four Major Threats to Biodiversity
1. Habitat Destruction
a) causes: agriculture, urbanization, forestry, mining, pollution
b) if species is unable to move – habitat loss could = extinction
c) habitat fragmentation = species loss
2. Introduced species
a) invasive, non invasive, or exotic that humans move intentionally or
accidentally from native locations to new geographic locations
3. overexploitation
a) human harvesting of wild plants or animals at rates exceeding ability of
populations of those species to rebound
b) commercial fishing, hunting, collecting & trading animals
c) especially susceptible
- large organisms w. low intrinsic reproductive rates
- species w. restricted habitats
4. Disruption of Interaction Networks
a) extinction of one species could cause extinction of another
b) important species that could impact others:
- keystone species
- an ecosystem engineer
- species w. highly specialized relationship to others
D. Restoration ecology attempts to restore degraded ecosystems to a more natural
state
 environmental damage can be restored BUT communities aren’t infinitely
resilient
1. Bioremediation: use of living organisms, usually prokaryotes, fungi, or plants, to
detoxify polluted ecosystems
2. biological augmentation: uses organisms to add essential materials to degraded
ecosystem
a) involves identifying what factors have been removed that are limiting
recovery rate