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33 Cards in this Set
- Front
- Back
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Outline the factors that affect the distribution of plant and animal species
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1. Climatic (light, temp., water, wind)
2.Edaphic (soil-texture, pH, temp., organic content) 3.Topographic (angle and aspect of slope) |
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Random sampling methods
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Quadrat sampling- enables comparable samples to be obtained from areas of consistent size and shape
1. Random sampling 2. Systematic sampling |
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use of a transect
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Transects are used to correlate the distribution of a plant or animal species with an abiotic variable
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Niche concept
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1. habitats are sub-divided so that each species comes to live where it will survive and propagate without direct competition
2. if two species are in direct competition it will result in in virtual elimination of the lesser specie 3. if natality+immigration=mortality+emigration the population will be stable |
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Symbiotic relationships
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Mutualism-reciprocal usefulness
Parasitism-one benefits, one suffers Commensalism-one benefits, other unharmed Predation-prey with best defense and predator with best hunting strategies survive |
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fundamental and realized niches
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fundamental-the part of the habitat that the species could live if there were no competitors and predators
Realized-the part of the habitat that a species is restricted to by competitors and predators |
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Biomass
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the dry mass of all organisms in the same trophic level
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measurement of biomass
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take a small sample, weigh it dry it out and then reweigh it.
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gross production, net production,
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gross- total light production energy converted into chemical energy by autotrophs
net- energy available to consumers- about 10% |
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production equation
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NP=GP-R
net production= gross production-respiration |
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difficulty in classifying organisms
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an organism may be difficult to classify because it may belong to two or more different trophic levels
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biomass at trophic levels
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energy goes from on etrophic level to the next as the energy in the chemicals of one organism (10%) are taken in. Making it impossible for the higher levels to have more biomass. Energy can also be lost by: no consumption or assimilation, heat loss, respiration.
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succession
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primary- nothing but bare rock initially(eg. after volcanic eruption)
secondary-already soil(eg. after forest fire) |
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changes occurring during primary succession
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productivity increases over time
lichens-mosses-grasses-shrubs-trees |
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effects of living organisms on the abiotic environment
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1. soil development
2. accumulation of minerals 3. reduced erosion |
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biome vs. biosphere
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biome- large areas where the vegetation type shares a particular suite of physical requirements. May occur widely separated regions of the world
biosphere- the part of the earth where living organisms are found |
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six major biomes
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1. desert
2. grassland 3. shrubland 4. temperate deciduous forest 5. tropical rainforest 6. tundra |
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simpson diversity index
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d=(N(N-1))/(n(n-1))
d=diversity index N=total number of organisms of all species found n=total number of individuals of a particular species. |
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what is the diversity index?
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The diversity index is a measure of species richness of an ecosystem. The higher the index the greater the diversity. Environmental change cause changes in the index. (Pollution, environmental disturbance, etc lower the index)
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reasons for conservation
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extinction is a fact of life, but species are becoming extinct at an alarming rate mostly because of human activities.
Ecological- if species become extinct, the ecosystem may collapse Economic-environmental disasters caused or not caused by humans have huge economic effects whether it be misery or clean-up bills ethical reasons- why do we have the right to decide who has the right to live or die? Do we have the right? |
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impacts of alien species
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the introduction of non-native species to an ecosystem is one of the major causes of decreased biodiversity
effects- increase in predation and competiton, extinction of native plants or animals and genetic change |
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biological control of invasive species
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invasive alien species are such a widespread problem. Such species are a real threat to the biodiversity of the planet, with many species facing extinction because of it, The uniqueness and cultural diversity of human populations are also being affected
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Biomagnification
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The concentration effect occurs because it is metabolised and excreted more slowly than the nutrients that are passed from one trophic level to the next, so it accumulates in the body and remains as the net production
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cause and consequences of biomagnification
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cause-mercury was introduced as a contaminant in the environment even though it occurs naturally
consequences-affects the immune system and can alter genetic and enzyme systems, damage the nervous system including coordination and the senses |
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effects of UV radiation
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UV radiation can penetrate living cells and
damage DNA, thereby disrupting cell function and sometimes causing cancer UV radiation can be harmful to phytoplankton and other producers, thereby reducing the productivity of ecosystems |
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CFC's
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the breakdown products of these gases were detected in the stratosphere. decreasing the ozone especially over the ice caps.
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Ozone
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there is a limit to UV absorption in the stratosphere.
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Biotic indices and indicator species
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an indicator species is an organism that occurs only when specific environmental conditions are present
a biotic indices will only be relevant to a local area |
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biogeographical features of natural features
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large nature reserves usually promote conservation more effectively than smaller ones
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active management techniques
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biological control-component of an integrated pest management strategy
classical control augmentation purchase and release of natural enemies |
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in-situ vs. ex-situ conservation
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in-situ=conservation of habitats where they naturally occur
ex-situ=conservation of habitats where they don't naturally occur |
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r-strategists vs. k-strategists
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r=live fast, die young
early maturity, short lifespan, reproduce once, small size many offspring(unstable environment) k=slow and steady longer lifespan, reproduce many times, larger body mass, fewer offspring (stable environment) |
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catch+release
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various catch and release methods exist.
pop. size= (n1xn2)/n3 n1=indiv. initially caught n2=total caught second time n3=recaptures |
