Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
49 Cards in this Set
- Front
- Back
land trusts
|
private, nonprofit groups that purchase or accept donations of land for conservation
|
|
What is the focus of the Endangered Species Act (1973)
|
to provide a means whereby ecosystems upon which T&E species depend are conserved
|
|
What is "take"?
|
law prevents harming or taking of listed species, includes indirect means, habitat loss/alteration
-limit private landowner -listed species act as indicator for biological communities -reactive rather than proactive |
|
Is the ESA effective?
|
-most species listed when at low number (1000,120)
-economic impact limit listing -once it is low, very difficult to recover only 13/1200 delisted and 22 downgraded yet 7 extinct -50% declining and 50% stable -no effective because needs $4 billion to remove all species and species are listed faster than money earned -gov't must compensate private landowners for lack of economic development -leads to "shoot, shovel and shut up" |
|
Is the ESA effective? How can it be more effective?
|
1. greater funding
2. longer time of listing 3. critical habitat and recovery plans 4. buy-in from private property owners |
|
Strength of international treaties?
|
1. most biodiversity is in tropical countries
2. need to protect species through out range (migration) 3. international trade is common 4. benefits are international (ecosystem, medicine, ag) 5. global problems require global solutions 6. Montreal Protocol remove CFC and recover 2050 |
|
Weaknesses of international treaties?
|
1. CITES mislabeled items, hard to identify, underground
2. Law of Sea: economic independence? taxation on unregulated resources 3. depends on consensus of many countries 4. slow negotiations, compromises 5. member states can choose enforcement= inconsistent effectiveness 6. globalized world= pressing need for cooperation! |
|
Needs of a successful conservation program?
|
1. concern: donor and recipient
2. contract: mutually satisfactory 3. capacity: info, skills, able? 4. causes: not just symptoms |
|
debt-for-nature swap
|
developing countries borrow $ to stimulate economy and are in debt!
1. country develops environmental project 2. NGO offers to finance by buying out that outstanding loan to our bank 3. bank sells at bargain rate |
|
Relationship between habitat loss and habitat fragmentation:
|
Both lead to habitat degradation! (process by which the quality for a given species is diminished) Fragmentation: discontinuity in spatial distributions of resources and conditions. Loss: outright loss of habitat due to land conversion or when quality is too low to be used.
Both deal with: 1. island biogeography: degree of isolation determines rate of immigration, size influences species richness 2. metapopulation theory: movement of organisms among patches increases stability of the regional population 3. landscape ecology: movement of organisms, materials, and energy through structural elements of the landscape are critical to landscape function |
|
Edge effects
|
Microenvironmental changes: more light, more variable temperatures, more wind, less humidity, interspecific interactions
|
|
Metapopulation
|
natural collection of populations with interchange among them, human-caused fragmentation of populations
|
|
Source and sink populations
|
Source: reproducing, increasing
Sink: exist because of immigration Protect source, minimize sink |
|
Bioaccumulation
|
concentration of pesticides up trophic levels, DDT, PCB
|
|
Tropic transfer is inefficient
|
the total biomass goes down as the trophic levels rise, 10% estimation, trophic transfer efficiency ranges from 1-56%
|
|
Acid Rain
|
due to release of sulfur dioxide and nitrogen oxides into the air, fossil fuel combustion, lower pH of rain, ponds, lakes
|
|
How acidic is acid rain?
|
2-5
|
|
Sentinel species
|
biological indicators of ecosystem impacts, lichens are rain dependents, trap airborne particles for sampling metal pollution
|
|
ocean acidification
|
pCO2 the partial pressure of CO2 in the ocean mimics the atmospheric rise observed drop in pH of .1 units pH. This causes slower growth, reduced calcification
|
|
phenology
|
the timing of biological events, earlier breeding of birds, amphibians, blooms, changes in migration
|
|
Proof of climate change:
|
1. shifting species range
2. mortality from thermal stress 3. extinctions 4. phenology 5. new species combinations and changes in species interaction 6. melting glaciers 7. rising sea levels |
|
What can we do for climate change
|
1. protected area planning
2. adaptive management (protect species more effected by CC) 3. assisted migration |
|
Invasive species
|
Colonization->establishment->impact
1. Round Goby in great lakes: decline in native benthic fishes, recruitment of through consumption of eggs and fry, prey of sport fish, avian botulism |
|
What characteristics are common to most invaders?
|
1. abundant in original range
2. wide environmental tolerance 3. high genetic variation 4. short generation time 5. rapid growth 6. early sexual maturity 7. high reproductive capacity 8. broad diet 9. gregariousness 10. possessing natural mechanisms of rapid dispersal 11. good in disturbed, commensal with human activity |
|
Overfishing
|
some level of extraction is sustainable but legally under the Magnuson Stevens Act, overfishing is when fishing rates exceed the Maximum Sustainable Yield. Overfishing is assessed by: decline in abundance, decline in size, increase in effort needed to catch same # fish, need to travel farther to collect same fish. Leads to decline of target species, fishery collapse, serial depletion
|
|
Bycatch
|
animals caught by fisheries but discarded:
1. economic discard 2. regulatory discard 3. collateral mortality Can reduce by: 1. selectivity of gear 2. education 3. limit destructive fishing methods 4. aquaculture 5. certification programs to promote responsible consumption 6. fishery co-management |
|
Maximum sustainable yield
|
the largest yield that can be taken over an indefinate period of time, to maintain high growth rates by reducing numbers. The effect is to maintain stock below carrying capacity in its pristine biomass
Ymax=rB/4 where r is growth rate, B is carrying capacity |
|
CPUE
|
catch per unit effort, goes up with overfishing
|
|
Minimum viable populations (MPV)
|
smallest number of individuals having a very high (99%) chance of surviving for the next 1000 years = 500-5,000 individuals
|
|
Minimum dynamic area (MDA)
|
amount of suitable habitat necessary to maintain MVP, based on home range of individuals and colonies
|
|
Extinction Vortices
|
feedbacks that pull small populations toward extinction:
1. loss of genetic variability: inbreeding depression and genetic drift (50, no 500), heterozygosity is the individual having genetic allelic differences and genetic drift is loss of alleles due to random chance <- maintain with migration, mutation (500, no 50000 individuals needed to compensate) 2. demographic fluctuation: from random variation in birth and death rates 3. environmental fluctuation: natural catastrophes |
|
inbreeding & inbreeding depression
|
mating among close relatives reduces genetic diversity, the depression when offspring receive identical defective alleles and leads to higher mortality of offspring, fewer, weaker offspring, recessive homozygotes expressed
|
|
outbreeding depression
|
incompatible mating of 2 (sub)species or populations
|
|
Consequences of reduced genetic diversity:
|
1. loss of evolutionary flexibility
|
|
Factors that maintain genetic diversity:
|
1. migration: need 50/500 to reduce effects of genetic drift
2. mutation: need 500/5,000 to produce mutations that compensate for losses |
|
genetic drift:
|
loss of alleles due to random chance, smaller population loose alleles faster
|
|
Ne<Nc
|
Ne is the effective population size and is affected by 3 demographic factors:
1. unequal sex ratio Ne=4(Nm)(Nf)/(Nm+Nf) 2. variation in # offspring produces: among individuals; results in unequal contributions to next generation Ne= t/(1/N1+1/N2+1/N3+1/N4) 3. pop bottleneck: over time, not all individuals equally represented in genetic composition of the next generation- loss of individuals with rare alleles, loss of genetic variation |
|
Bottlenecks
|
extreme reductions in population size can lead to loss of individuals with rare alleles or loss of genetic variation (unequal representation of surviving genotypes)
|
|
Founder effect:
|
type of bottleneck, few colonizing individuals have a non-random, incomplete set of genes as compared to the larger population
|
|
Minimum viable population for most species
|
500-5,000
|
|
minimum population to reduce the effects of genetic drift
|
500
|
|
Effects of overfishing on biodiversity:
|
Fishing causes Harvest mortality, physical impact of fishing gear, bycatch... the last two cause incidental mortality. All of these mortalities cause biological interactions: predator-prey interactions, competitive interactions and changes in marine food webs. This causes altered ecosystem structure and function!
|
|
atmospheric CO2 concentration is at:
|
397
|
|
How can a disease lead to extinction?
|
1. persist: biotic or abiotic reservoir
2. rapidly deplete host: high virulence, life history of host changed |
|
Example of emerging diseases:
|
1. Chytrid fungus, spread by pet trade in african clawed frogs and is a lethal skin infection
2. white nose syndrome, spread by tourism and gets on bats and they wake up too early and starve to death |
|
non reactive and reactive nitrogen
|
non reactive is the free nitrogen in the atmosphere and denitrofying bacteria is what changes the reactive nitrogen in nitrates, nitrites and ammonium in the soil into this non reactive state. Nitrogen fixing bacteria and cyanobacteria leads to reactive nitrogen in soil.
|
|
Eutrophication
|
this process of too much nitrogen in the water and hypoxia and fish kills and marine dead zone
|
|
marine dead zone
|
eutrification result
|
|
types and relative influences of different drivers of extinction
|
1. habitat loss
2. climate change 3. invasive species 4. over exploitation 5. pollution |