Unit IV: Conservation Ecology Flashcards
Biodiversity
general term for the number of species present in the biosphere, by taking into account both the number of species and their relative abundance to each other
Genetic diversity
variety of genes in a species or other taxonomic group or ecosystem, the term can refer to allelic diversity or genome-wide diversity
- aka Genetic Variation
Groups with low genetic diversity have _____ potential to respond to selection pressures (recall natural selection)
lower
Small populations size typically have low genetic diversity due to what?
bottleneck/genetic drift
Chemical diversity
variety of metabolic compounds in an ecosystem; different species produce a variety of chemicals in their cells, both proteins as well as products and byproducts of metabolism
What does Chemical diversity collect?
proteins or RNA sequence data
Ecosystem diversity
variety of ecosystems, which is useful for larger areas (more diversity = better conservation)
Endemic Species
Species native to and found only in a specific geographic location
Where are high values of species endemism found?
small and/or isolated habitat patches
(eg. islands, mountains, isolated forests)
Phylogenetic diversity
variation of species of a branch in a phenology tree; incorporates information from the tree of life
What does conserving species poor clades do?
increase taxonomic diversity, including phylogenetic distance between species
What diversity is most important for prioritizing conservation efforts?
Genetic Diversity
What is one of the strongest patterns in ecology?
latitudinal diversity gradient: there are more species at low latitudes (closer to equator) than high latitudes (closer to poles)
Tropics have greater:
- Habitat stability over long periods of time
- Habitat heterogeneity (= more niches/specialization)
- Energy input from direct sun (greater npp, positive correlation between temp and rates of evolution)
Who pioneered the study of biodiversity hotspots?
Norman Myers
Biodiversity hotspots
areas with exceptional concentrations of endemic species and high levels of habitat loss
List criteria for a Biodiversity hotspots
- At least 1500 (0.5%) of world’s 300,000 plant species as endemics
- Lost 70% or more of its historic (traditional) vegetation
List Criticisms on Myer’s hotspots
- Focus on endemism
- Focus on historic, rather than current loss
- What about boreal and tundra biomes?
What is the Atlantic Forest? And does it classify as a Biodiversity Hotspot?
- Variety of tropical forest ecosystems in SE Brazil
- High levels of endemism
- Estimated 15% of historic range
Mass Extinction
event of environmental condition that wipes out the majority of species within a relatively short geographical time period
How many mass extinctions have there been? Which are most important?
5: end-Permian & end-Cretaceous
What results from mass extinction besides the extinction of a species?
- Leave empty niches
- Opportunties for adaptive radiations
When was the End-Permian mass extinction?
252 mya
Describe the End-Permian.
- Largest mass extinction
( >50% of all families and >80% of all genera
Up to 96% of all marine species, 70% of terrestrial species) - Causes unclear
(Events leading to massive changes in temperature, atmosphere, and oceans
Flood basalts - added heat, CO2, and sulfur dioxide)
How long ago was the End-Cretaceous mass extinction?
76 mya
What is the Impact Hypothesis regarding the End-Cretaceous mass extinction?
caused by impact of 10 km wide asteroid off the coast of Yucatan Peninsula, Mexico
- crater at impact site
- rocks from time period rich in rare minerals known from meteorites
When was there an increase in extinction rates? And why?
the end of the Pleistocene (~40,00-10,000 years ago), suspected to be correlated with dispersal of paleo-humans across the globe
What highlighted the increase in rates of extinction towards the end of the Pleistocene?
the extinctions of megafauna
Megafauna
large vertebrate animals (eg. saber-toothed cats, ground sloths)
Background extinction
normal extinction rate of various species as a result of changes in local environmental conditions; typically estimated at 1-2 extinctions per million species per year
Estimates of current extinction rates are often 10-100x ____ than the background rate
greater
What are the 2 leading factors in Background extinction?
habitat loss and degradation
Who are most at risk for extinction?
Amphibians, seen to be vulnerable because of semi-permeable skin and aqueous habitats (pollutants)
What is the leading factor in the extinction of Terrestrial organisms?
Habitat loss
What is the leading factor in the extinction of Freshwater organisms?
Habitat loss
What is the leading factor in the extinction of Marine organisms?
Overexploitation
As habitat degradation changes metapopulation dynamic, connection between patches _______
decreases; increasing the likelihood of local extinctions (particularly for top predators)
Species-area Relationship
relationship between area surveyed and number of species encountered
Overharvesting
unsustainable removal of wildlife from the environment for use by humans; major threat for marine species
Bush meat
wild-caught animal used as food (typically mammals, birds, and reptiles); generic term used for wild animals killed for food
Tragedy of the commons
economic principle that resources held in common will inevitably be overexploited
Exotic species
species that has been introduce to an ecosystem in which it did not evolve
Invasive species
exotic species that grows to a large population size and competes successfully with native species; introduction of species that can be pathogens to others
How did Invasive come about? And what was the affect from them in the past 500 years?
- Mediated by global trade and travel
- Estimated 58% of extinctions
Chytridiomycosis
disease of amphibians caused by the fungus Batrachochytrium dendrobatidis; thought to be a major cause of the global amphibian decline
White-nose syndrome
disease of cave-hibernating bats in the eastern United States and Canada associated with the fungus Geomyces destructans
General characteristics of Atrazine
- Herbicide used in agriculture since 1958
- 2nd most common used herbicide in USA
- One of the most commonly detected pesticides in drinking water
Atrazine
endocrine disruptor that affects amphibian and fish larval development
eg. “feminization” of male frogs
- lowered testosterone
- hermaphroditism
- feminized laryngeal development
- suppressed mating behavior
- reduced spermatogenesis
- decreased fertility
Ecosystem Services
Direct and indirect behaviors that humans derive from ecosystems
- Supporting
- Regulation
- Provisioning
- Cultural
Supporting service
vital functions that are necessary for the production of all other ecosystems services
eg.
- primary productivity
- nutrient recycling
- soil formation
Regulating services
benefits from the regulation of ecosystem processes
eg.
- eater purification
- flood and erosion control
- water control
- pollination
- disease and pest control
Increased Biodiversity leads to __________ and ____________.
higher productivity, greater resilience
eg.
- more efficient use of resources
- facilitations
- increases abundance
Resilience
a measure of how quickly a community recovers from a disturbance
Provisioning services
products obtained from ecosystems
eg.
- food
- raw materials
- energy
- genetic resources
- medicines (secondary plant compounds)
Secondary Plant Compounds
produced as byproducts of plant metabolic processes that are usually toxic, but is sequestered by the plant to defend against herbivores
Cultural services
referred to as nonmaterial benefits
eg.
- recreation and tourism
- aesthetic value
- spiritual and cultural
- mental health
Endangered Species Act
(1973)
- Aims to protect and recover imperiled species and ecosystems
- Successful: caused population sizes of many species to increase (38 species)
- Criticisms: May encourage preemptive habitat destruction (to keep away animals) & low success rate (not really tho)
Biomagnification
the concentration of toxins in an organism as a result of its ingesting other plants or animals in which the toxins are more widely disbursed.
Rachel Carson
Wrote “Silent Spring,” which highlights the danger of pesticides to wildlife and humans
Nature preserve
a protected area of importance for flora, fauna, or features of geological or other special interest; can be viewed as “islands” in “oceans” of unsuitable habitat
Given equal area, typically better to have one _______ preserve rather than several small preserves
large (species-area-relationship)
Buffer zone
area of suboptimal habitat around preserve (help connectivity???)
Wildlife corridor
strip of habitat connecting preserve (allows connectivity between sub-populations)
