What is conservation biology?
It is the scientific study of the amount of biodiversity, how human activities are impacting it, and how best to maintain it and prevent its loss. One goal of conservation biology is to understand the scope of biological diversity on earth, ranging from genes to species to ecosystems.
What methods can be used to indirectly estimate extinction rates?
- Comparing background extinction rates from fossil records with current extinction rates.
- Relationship between number of endemic species and area is used to estimate the number of species that would be driven to extinction given the amount of habitat loss.
- Changes in conservation statuses of species over time to project future extinction rates.
- Rate of population decline or range contraction of common species.
What is extinction vortex?
A cyclic chain of events that lead to small populations dropping further in size, deeming them even more vulnerable to genetic, environmental and demographic stochasticity.
What is taxonomic homogenization
This is the spread of introduced species and native generalists, resulting in the loss of native specialists. Island biotas are especially vulnerable to this.
What are the primary threats causing extinction?
- Habitat loss, fragmentation and degradation (loss of quality)
- Invasive species
- Climate change
- The relative importance of these factors differ, especially between terrestrial and marine animals.
What disciplines does conservation involve?
- Land use planning
- Public policy
- Constitutional law
- Enforcement policy and law
How many species are there on earth?
- Described species are only a fraction of the total number of species.
- Estimated number ranges from 3 million to 100 million.
- Little is known about the diversity of microbes.
- Fungi are poorly known in most parts of the world.
- Vertebrates and flowering plants are much better known.
- New species are being discovered every year.
What are biodiversity hotspots?
- Key areas of the world containing great biological diversity.
- High levels of endemic taxa and experiencing high rates of habitat loss.
- 2.3% of land surface, yet contains 50% of plant diversity and 42% of land vertebrate diversity.
What is the current trend in extinction rates?
Extinction rates are up to 1000 times the extinction rates in the fossil record. Projected future extinction rates are 10 times higher than current extinction rates.
What are the three dimensions of rarity?
- Small population size
- Narrow geographic range
- Specialized habitat requirements.
What is the most important source of biodiversity loss?
- Habitat loss and fragmentation.
- Certain species are tied to a very narrow subset of habitats (habitat specialists).
- These are often the most vulnerable species to human alteration of the landscape.
What are edge effects?
Abiotic and biotic changes associated with an abrupt habitat boundary created by habitat fragmentation. As habitats become more fragmented, edge effects increase. As the habitat becomes smaller, the percentage of it affected by edge effects will increase. Additionally, the shape of the habitat also affects the amount of edge effects.
What are the consequences of habitat loss and fragmentation?
- Increased edge effects
- Reduction in the number of suitable habitats
- Decreased breeding success.
- Loss of predators and associated indirect effects.
- Human health implications. (increase of habitat fragmentation leads to increased Lyme’s disease. Less predators means more mice and deer, meaning more ticks.)
What should be preferred in the design of protected areas?
- Larger reserve (less edge effects, migratory species, larger species, larger population size, larger genetic diversity)
- Single large as opposed to several small due to edge effects.
- Reserves should be closer for migration, genetic diversity
- Reserves should be connected for migratory pathways,
- Reserves should be as circular as possible to minimize edge effects.
- Reserves should have buffer zones to minimize human impact etc.
List the causes of extinction from highest threat to lowest threat
- Habitat loss and fragmentation
- Invasive species
- Overexploitation (american bison, passenger pigeon, african elephant - recent conservation efforts include allowing for trophy hunting for huge fees to pay for further conservation efforts etc-
- Climate change
What are the pros and cons of the limited trophy hunting of african elephants?
- The purpose of this is to fund local communities and further conservation efforts.
- However, this provides minimal employment and only a small portion of the money actually reaches local communities.
- Corruption can be a problem.
- This doesn’t stop poaching, especially in countries with a poor record of maintaining and protecting wildlife.
What is conservation biology’s main application of science?
- To predict the future outcomes of complex biological interactions that are affected by current-day resource management strategies, always based on an incomplete knowledge of:
- The biology of the target species and ecosystems.
- The nature of their ecological interactions.
What are coldspots?
- Areas protecting any, or all of the following:
- Ecosystems functions,
- Distinct evolutionary lineages,
- Rare species not found in hotspots,
- Landscapes that contribute to the spiritual/cultural wellbeing of human populations.
What are the levels of biological organization targeted for conservation by hotspots and coldspots?
Genetic, species and ecosystem.
What are the scales of areas protected by hotspots and coldspots?
Hotspots generally focus on target habitats / specific biota or community as a biogeographical unit. Coldspots may focus on target habitats or ecosystems (ecoregions).
What are the advantages of hotspot conservation?
- Allows for the conservation of the most species at least cost (silver bullet strategy).
- Highest payoff.
- Most extinctions already occur in these hotspots.
- The prospect of mass extinction can be made far less daunting and more manageable through concentrated conservation efforts in hotspots.
What are the advantages of coldspot conservation?
- Accounts for more than just the number of species protected, but the level of ecosystem functioning maintained, giving more of a sense of purpose to conservation efforts.
- 2. Able to provide protection for species that require larger tracts of relatively undisturbed habitats.
- 3. Protects rare species not found in hotspots.
- 4. Protects areas with cultural/spiritual value for humans.
What are the disadvantages of hotspot conservation?
- Focuses conservation dollars on a limited area of the globe.
- Fails to protect habitats and species falling outside ‘hotspot’ areas.
- Ignores populations and ecological processes as important manifestations of biodiversity.
- Hotspots for different taxa do not coincide with each other. Major losses in other taxa could occur due to the focus on endemic plant species.
- Altering the course of evolution by favoring endemic species.
What are the disadvantages of coldspot conservation?
- 1. Very anthropocentric point of view.
- 2. Species have innate values regardless of the ecosystem services they provide to human beings.
What outcomes does coldspot conservation consider to gauge success?
The percentage of diversity protected and ecosystem functions maintained as opposed to the total number of species protected.
What outcomes does hotspot conservation consider to gauge success?
Number of species protected.