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58 Cards in this Set
- Front
- Back
extinction |
no living individuals of the species are left e.g carolina parakeet and the monteverde golden toad |
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extinct in the wild |
no living individuals left reproducting and maintaining without human controlled conditions e.g. northern white rhino |
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locally extinct/ extirpated |
species has been lost ina specific area but still exists in the wild in other areas e.g. the chinook salmon is extirpated from many of the drainages in the pacific northwest |
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regionally extinct |
species has been lost in a regoin but still exists in the wild in other regions e.g. the cougar is regionally extinct from the northern US |
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ecologically extinct |
species still occurs in the wild but in so few numbers that its ecological impact is insignificant e.g Helena ebony (only two left in the wild) |
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natural mass extinction |
extinction is part of a natural process, but short periods of intense extinction have occurred |
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background extinction rate |
'normal' rate (or non-human cause) of loss of species. anthropogenic rates represent a several thousand fold increase over the background rate of extinctions |
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high levels of species threathened with extinction means... |
the extinction rate will remain high in the near future |
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extinction debt |
extinction delayed; because of habitat loss that has already occured, across a wide range of organisms 9% will go extinct even if no further loss occurrs e.g. Madagascar |
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Why are island biotas so threatened? |
high percent of species are endemic; small geographic ranges with small pop. sizes and limited number of pop.s; evolved with limited predators parasites etc; limited spaces, limited habitat, easy to succumb with habitat destruction |
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equilibrium theory of island biogeography |
a theory dealing with predictions of island biodiversity levels based on immigration but also predictive of extinction rate on islands (MacArthur and Wilson) |
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E.O. Wilson |
came up with ideas of sociobiology, biodiversity, biophilia, also the preeminent taxonomist of ants |
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Robert MacArthur |
developed niche partitioning, brought hypothesis testing to ecology and led to theoretical ecology, and island biology |
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they noted larger areas had more species when they looked at diff. islands, factors lead to this? |
more local enviroments leads to more specialization, more populations within a species, more chances for speciation from larger populations and local enviroments, less chance for extinction |
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S = CA^z |
species richness on an island = constant relating to a groups diversity x area of island ^ constant (slope of relationship between species and area) |
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island equilibrium |
there is an equilibrium between incoming species, new speciation, and extinction of species. as new island is being colonized the rate of colonization and speciation is higher than extinction, islands starts to become full and extinction rates increases until equilibrium |
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if island is larger, colonization rates high, why? |
larger target to find for colonist species and greater area to allow establishment |
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islands closer to mainland mass will have higher colonization rates, why? |
closer distance means easier target for dispersing colonizing species |
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extinction rates will be higher for smaller island than larger, why? |
smaller population and less habitat on smaller islands, easier to lose populations and therefore the species from the island |
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species richness of islands |
species richness > larger island near mainland > large island farther from mainland > small isalnd near mainland > small island farther from mainland |
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Dan Janzen |
disputed that fragmented habitats are like islands; each fragment isn't surrounded by ocean, and this can lead to movement, but also predators and disease; gradients of habitats |
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Metapopulations |
linked populations; shifting, populations of populations e.g american burying beetle; once widespread, possible victim of extiction cascade, metapopulation structure closer to that of oceanic islands? |
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designing reserves based on fragmented populations, how best? |
edge effects, how quickly habitats degrades outside the borders; larger>small, one large> many small, close together>far apart, connected by corridors> unconnected, compact to minimize boundary length, surrounded by buffer zone>no buffer zone |
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Characteristics of rare species |
lives in a narrow geographical range, occupies only one or a few specialized habiats, found only in small populations |
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Are rare species redundant in function? |
some say yest, study showed that rare species could have important function or combination of function e.g. moray eel in coral reef; keystone? |
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endemism |
restricted to an area; if that area is a narrow geographical range could mean the species is 'rare' and more vulnerable to extinction but could refer to large area |
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why some states have few endemics and some have many? |
size, latitude, climate, stability, topographic variablility; unique biological communites |
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characteristics of species vulnerable to extinction |
narrow geographic range, small population, declining population, hunter or wild harvested, need large home range, large bodied, dont disperse much, migrate seasonally, little genetic variability, specialized niche requirements, rely on stable pristine enviroment, form aggregation, didnt evolve with people, close relatives went extict/are threatened |
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population bottleneck |
population goes through a crash of pop. size and the resulting succeeding population has lost genetic diversity as a result; the smaller pop. going through the bottleneck lost genetic varibaity by chance |
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IUCN |
International Union for the Conservation of Nature; put out Red LIst: conservation status of species, mostly vertebratess |
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NGO |
non-governmental organization; IUCN, NJCF, Nature Conservancy |
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Red List catagories |
extinct, extinct in the wild, critically edangered, endangered, vulnerable, near threatened, least concern, not rated, data deficient |
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Living Plant Index |
from WWF(world wildlife fund); a measure of the status of the worlds biodiversity based on vertebrate populations |
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Endangered species Act (ESA) |
1973 US law which governs which species are classified and protected as endangered and reveive management plans; administered by the US fish and wildlife service (UCFWS) and dept of commerce; also guides regulation of trade in endangered species through CITES not red list |
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Natural Heritage (nature serve) classifications |
through Nature Conservancy; G1-5 (global) and S1-5 (state), X (presumed extinct) H (possibly extinct) 1(critically imperiled) 2 (imperiled) 3 (vulnerable) 4 (apparently secure) 5 (secure) U (unrankable) NR (unranked) |
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EDA; FWS considers 5 factors |
damage/destruction of species habitat, overutilization of the species for commercial/recreation/scientific/educational purposes, disease or predation, inadequacy of existing protection, and other natural or manmade factors that affect the continued existance of the species |
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Seven major impacts to biodiversity |
all from human activites; *habitat loss, *habitat fragmentation, habitat degredation, *overharvesting, disease, invasive species, climate change |
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three ways humans dominate the global ecosystem |
land surface, nitrogen cycle, human use of fossil fuels and deforestation |
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primary forest |
never been logged and has developed following natural disturbances and under natural processes |
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secondary forest |
logged and recovered naturally or artificially |
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Most threatened habitats |
tropical rain forests, tropical deciduous forests (dry forest), grasslands, freshwater wetlands, marine coastal areas (mangroves and coral reefs) |
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slash and burn agriculture |
cutting out trees and burning the remains, usualy only useful for a few years before nutrients in soil are leached out, forest cant regenerate on these wasted lands |
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palm oil |
most widely used vegetable oil, monoculture |
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edge effects |
fragmentation and greater risk to losing smaller isolate populations, change climate into the interior (wind/drying), allow edge species to invade deeper into interior, interior species which need certain size habitat lose a lot as fragmentation my reduce area |
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eutrophication |
pollution; too much nutrients feeding excessive algal growth, then die off in large amounts, decomposers rob the water of oxygen, fish die |
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biomagnification |
toxic chemicals in water become successively concentrated at higher levels in the food chaing, leading to health problems for humans, marine mamals, sea birds, and raptors e.g. mercury and PCBs and DDT |
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eutrophication effects |
algal blooms, decomposition robs oxygen from the water, fish and invertebrates die |
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Acid rain |
major problem in the past, laws regulatin power plant emisions reduced compounds causing acidity |
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climate change impact on species and ecosystems |
increasing temperatures, melting of glaciers and ice packs, rising sea levels, earlier spring activity, shifting species ranges, shifting species phenologies, decline of mountain habitat, hybrid zones formed, population declines |
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impacts of glaciers and ice sheet melting |
areas that rely on runoff likey to experience severe water shortages, reduced ability to irrigate crops; sea level rise |
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lost resilience |
ecosystems in the 21st century start from an already massively shifted baseline
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overexploitation of species |
intense harvest of a resource or species that results in its decline or lose |
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reasons for overexploitation |
common resource with no controls or monitoring, poverty, global markets, multinational issue as most species exist in multiple countries, decline of local controls that were often traditional or religious |
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fishing down the food web |
as we overexploit larger higher trophic fish, and then move our fisheries to smaller abundant fish |
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bycatch |
in marine fishing, other species in the net that are not used and wasted |
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fish farming |
better now with less nutrient waste and disease, is needed to provide protein needed worldwide, ecological methods use the waste to feed other species that can be penned and harvested |
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bushmeat |
unregulated hunting of wild animas, an important source of protein in africa; also timber, firewood, medicinal plans and animal parts |
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causes for invasive species |
colonization by humans, agriculture, accidental transport, biological control |