Lecture 21
Conservation Biology
Conservation Biology
Integrative discipline that applies the principles of ecology to the protection of biodiversity
Defined as – scientific study of phenomena that affect the maintenance, loss, and restoration of biodiversity
Spearheading the effort
Alfred Russell Wallace
Dan Janzen
E.O. Wilson
Alwyn Gentry
Rate of loss estimations
Mostly indirect
Fossil record can be used to establish ‘background’ rate to which current rates can be compared
Species-area relationships
10% habitat reduction 50% diversity reduction
Changes in conservation status over time
Endangered Critically endangered
Rates of population decline or range contraction of common species
Safe estimates
Worldwide (optimistic): ~ 100 spp / day become extinct (~ 27,000 / yr)
Current extinction rates parallel typical mass extinction events at the end of the Permian & Cretaceous periods
Whenever man has arrived large animals have gone extinct
HUMANS
Passenger pigeon
Extinction was sudden
Not gradual
Spread of introduced species & native generalists, coupled with declining abundances & distribution of native specialists
TAXONOMIC HOMOGENIZATION
Threats to biodiversity Habitat loss & degradation
Loss, fragmentation, degradation
Invasive species
Overexploitation
Pollution
Disease
Climate Change
Invasive species – those that are not native to an area, become naturalized, and have negative effects on ecosystem function
Exotic Species Considered Invasive USDA
Overexploitation
Pollution & Disease
Fireproof Killer Whales
Biomes face different threats
Genetic Analyses
As we have seen, deleterious effects are more pronounced in small populations
Puma concolor coryi underwent ‘genetic rescue’
PVA
Examines population extinction risks
Moore et al. 2012 PVA of Trillium recurvatum
Conservation measures
Ex-situ conservation
Zoos
Direct introduction of new individuals
Extensive habitat manipulations
In-situ conservation
Habitat protection
Defending from predation
Legal issues
Endangered Species Act
Protects 1,300 native species in US & 570 from other countries Convention on International Trade in Endangered Species of Wild Fauna & Flora (CITES)
In effect for 35 yrs
167 countries involved
33,000 species receive some protection
How to rank species
Those in greatest risk are first on the list
Surrogate species
Surrogates – Species whose protection will indirectly protect other species with overlapping habitat requirements
Flagship species – Fuzzy, cute factor
Umbrella species – Typically require large areas, i.e., grizzly bears
Similar to surrogate
Assumes that protection of its habitat will serve as an ‘umbrella’ to protect many other species