Lecture 23 Exam Questions

1. Name and explain or give examples of each threat in the "sextet of threats" to biodiversity.
Over-exploitation: commercial hunting, poaching, bushmeat trade
Exotic species: non-indigenous or invasive species such as the zebra mussel
Habitat destruction: habitat loss and fragmentation leave habitats too small to maintain viable populations
Climate change: climate change effects could shift habitats
Pollution: degradation of habitats
Domino effects: changes in species distribution or density have effects on nearby habitats

2. What influences the success of an invasive species?
Traits of the invader (trophic, behavioral, physiological, and life history traits)
Traits of the receiving environment (habitat matching and environmental resistance)

3. Give the equation for the relationship between number of species and area of habitat.
S = c AZ

4. What factors should be considered for the designation of new protected areas?
Uniqueness, representation, endangerment
Hotspots and endemism
Gaps in the network of protected lands
Size, shape, linkages, matrix
Principles of population and community ecology, species-area relationships

5. Explain gap analysis.
An approach intended to identify gaps in the network of protected areas based on mapping of vegetation, animals, and land ownership.
(It relies on three data layers: distribution of vegetation, habitat association of terrestrial vertebrates and vegetation, and land ownership)
6. What is "Distant past", “Recent past” ?
“Distant past” refers to average extinction rates as calculated from the fossil record. “Recent past” refers to extinction rates calculated from known extinctions of species (lower estimate) or known extinctions plus “possibly extinct” species (upper bound). A species is considered to be “possibly extinct” if it is believed to be extinct by experts but extensive surveys have not yet been undertaken to confirm its disappearance. “Future” extinctions are model-derived estimates using a variety of techniques, including species-area models, rates at which species are shifting to increasingly more threatened categories, extinction probabilities associated with the IUCN categories of threat, impacts of projected habitat loss on species currently threatened with habitat loss, and correlation of species loss with energy consumption.

7) If you were in charge of designing new nature preserves for a country, what are three things you would think about as you design the preserves? Why?
- I would make the reserve as large as possible. Reserves need to be large enough to house sufficient populations of the species you are trying to protect. If the population is too small, a certain species may go extinct within the preserve area. Larger populations also have more genetic diversity.
- I would minimize edges. Because an edge creates impact beyond the land directly involved at the border, minimizing edges will maximize the area of the habitat that is truly preserved.
- I would design the preserve to include “metapopulations” (spatially distinct populations that have some migration between them) because this will increase biodiversity and the species ability to survive a disturbance.

Other things to think about include: matching the needs of the inhabitance to the space preserved (e.g. are their nesting sites, watering holes, etc), are you preserving a matrix of surrounding land through public or private endeavors.

8) Discuss a shortcoming of “place based” conservation. If you were in charge of an agency such as US Fish and Wildlife Service, what are some actions you may take to address the shortcoming?
As the global temperature and the effects of global climate change unveil themselves, ecosystems in current nature reserves may change. The result may be less favorable for the species the reserve was designed to protect. If I were in charge of the US Fish and Wildlife Service, I would look for areas near my reserves (especially ones designed for preservation of plants and animals as opposed to geographic formations) that once the climate temperature has risen, 2, 3, or 4 degrees Celsius, may have a similar climate to the current reserve. Then I would work on securing and protecting those areas, as well as a corridor between the current and new reserve areas. Preserving that corridor is important so the species can move in the direction of the new reserve and climate change makes the current reserve inhospitable.

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