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67 Cards in this Set
- Front
- Back
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disturbance
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disturbance is a temporary change in average environmental conditions that causes a pronounced change in an ecosystem.
ex) earth quake |
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succession
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succession is the observed process of change in the species structure of an ecological community over time.
The community begins with relatively few pioneering plants and animals and develops through increasing complexity until it becomes stable or self-perpetuating as a climax community. |
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climax community
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climax community is a biological community which, through the process of ecological succession has reached a steady state.
occurs because the climax community is composed of species best adapted to average conditions in that area. -Cyclic patterns of change -Mosaic distribution (forest with gaps and dense areas) -Alternative stable states |
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sere
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intermediate stage found in ecological succession in an ecosystem advancing towards its climax community.
In many cases more than one seral stage evolves until climax conditions are attained. |
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primary succession
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succession of plant life, occurring in an environment in which new substrate devoid of vegetation and usually lacking soil (lava flow or area left from retreated glacier) is deposited.
In other words, it is the gradual growth of an ecosystem over a longer period. |
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secondary succession
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secondary succession is a process started by an event (e.g. forest fire, harvesting, hurricane) that reduces an already established ecosystem to a smaller population of species
occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil. |
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weed
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Weeds generally share similar adaptations that give them advantages and allow them to proliferate in disturbed environments where soil or natural vegetative cover has been damaged.
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ruderal
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plant species that is first to colonize disturbed lands.
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r-selected
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-populations are governed by their biotic potential (maximum reproductive capacity, r).
-production of numerous small offspring followed by exponential population growth is the defining characteristic of r-selected species. -r-selected species thrive in disturbed habitats |
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k-selected
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-species whose populations fluctuate at or near the carrying capacity (K)
- relatively stable populations and tend to produce relatively low numbers of offspring -individual offspring tend to be quite large in comparison with r-selected species |
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gradient analysis
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analytical method used in plant community ecology to relate the abundances of various species in a plant community to various environmental gradients by ordination or by weighted averaging. (temperature, water availability, light, and soil nutrients)
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climax species
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plant species that will remain essentially unchanged in terms of species composition for as long as a site remains undisturbed.
aka: late-succesional / k-selecetd |
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tolerance
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ability for an ecological environment to endure damage in a manner that enables it to preserve the environment and natural resources.
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invasive species
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introduced species that adversely affect the habitats and bioregions they invade economically, environmentally, and/or ecologically.
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early successional
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high # seeds
small Seed size Dispersal with wind/stickers much Seed viability (inverse with seed size) low Root:shoot ratio fast Growth rate small Mature size low Shade tolerance (competitive ability) |
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late successional
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low # seeds
large Seed size Dispersal eaten/gravity low Seed viability (inverse with seed size) high Root:shoot ratio slow Growth rate large Mature size high Shade tolerance (competitive ability) |
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Continuum index
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which sere is succession in?
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Facilitation
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A process by which one species increases the probability of another species becoming established, particularly during early succession
-Colonising plants enable later-stage species to invade |
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Inhibition
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the suppression of one species by the presence of another, especially during a sucessional sequence
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Priority effect
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The result of an interaction between two species during a sucessional sequence whose outcome depends on which becomes established first.
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Seed banks
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Seeds that are dormant in the soil that and can germinate when conditions are favourable
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Transient climaxes
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A climax community that develops in a ephemeral habitat, such as a temporary pond
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Cyclic climax
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A self-perpetuating, repeating sequence of stages produced by ongoing succession, none of which by itself is stable, but which together constitute a persistant pattern
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predator tactics
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camouflage
hide & wait poisoning traps bid/bad/fast combination |
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prey tactics
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camouflage
flee poisons aposematic coloration mimicry armor play dead disguise strength in #s |
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batesian mimicry
mullerian mimicry |
B: looks toxic, but is not
M: looks like another toxic organism, and is also toxic |
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Gleeson
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individualistic: species evolved individually
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Clement
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holistic/super-organism: everything evolves together
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intraspecific competition
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same species
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interspecific
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diff species
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competition outcomes
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competitive exclusion
coexistence mutual extinction |
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interference competition
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competition
organism does action/creates substance which hurts/affects a competitor types: territoriality alleopathy |
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alleopathy
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producing chemicals to interfere with competitor
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apparent competition
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prey competing indirectly w/ other prey (predated on by same predator)
ex: mayfly larva and amphipods |
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exploitative competition
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consuming/withholding all of a limited resource from competition
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fundamental niche:
realized niche: |
F: the niche you are capable of inhabiting
R: the niche you do inhabit because of competitive exclusion ex) chthulamas vs. balanus barnacles |
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food web
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web of interaction among species
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types of competitioin
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interference
exploitation apparent |
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asymmetric competition
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unequal division of resources among competing species, so some species per chnace get more resources
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trophic levels
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primary producer
primary consumer secondary consumer detritivores |
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guild
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shared method of eating
ex) leaf eaters and nectar sippers |
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connectedness web
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feeding relationship of species
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energy flow web
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energy flux connections
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functional web
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influence of species population growth rates on other species populations
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constancy
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Resistance to change
ex) soil buffering |
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resilience
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ability to recover from disturbance
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top-down control
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keystone species controls size of lower trophic levels
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bottom-up control
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food source determines size of above trophic levels
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trophic cascade
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when all trophic levels arfe affected by a single change
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obligate mutualism
facultative mutualism |
O: must live together to survive (lichen)
F: benefits from each other, but does not need the other to survive (sharks and cleaner fish) |
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components of biodiversity
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genetic: variation of genetics w/in a species
ecosystem: diversity of communities/population species: #/variety of species |
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morphological species concept
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a group of individuals that is morphologically, physiologically, or biochemically distinct from other groups in some important characteristic;
primarily used by taxonomists |
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biological species concept –
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a group of individuals that can potentially breed among themselves in the wild and that cannot breed with individuals of other groups; used by most other biologists
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ecological species concept
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a lineage which occupies an adaptive zone minimally different from that of any other lineage in its range, and which evolves separately from all lineages outside its range
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evolutionary species concept
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A species is a population or group of populations that shares a common evolutionary fate through time
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alpha diversity
gamma diversity beta diversity |
A: # diff species found in a community
G: # diff species found in a very large area B: gamma/alpha |
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describe what happens to species #/size as you go down soil
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Species richness increases with
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(1) Habitat patch size
(2) Habitat diversity (3) Structural complexity (4) Decreasing latitude (5) Decreasing altitude (6) Decreasing depth (aquatic systems) (7) Ecotones (“edges”) |
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latitudinal gradient:
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species richness increases toward the equator.
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how many species does rainforest have
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over half of the worlds
- 90% of all insects - 2/3 of plants - 30-40% of birds |
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Why do tropical forests have such high species diversity?
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-more solar energy than temperate regions.
- higher yearly rate of productivity in terms of biomass per hectare = greater resource base = wider range of species. - greater stability (no glaciation) has allowed uninterrupted evolution and speciation -Warm temperatures and high humidity -no need to spend energy adapting to the cold, which is energy high |
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is there a dominating group of species in the rainforest?
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no.
greater pressure pests and parasites (no freezing to kill them) prevents any species or group of species from dominating communities |
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why are coral reefs so diverse?
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- 32 of the 34 known animal phyla are represented in the world’s coral reefs (9 animal phyla in tropical forests).
- high primary productivity or coral reefs - coral reef species are more widely distributed, they may be less prone to extinction |
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what are the 5 mass extinctions?
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ODPEN
ordovician devonian permo-triassic end-triassic cretaceous |
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cause of current mass extinction
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“HIPPO”:
• Habitat alteration (by humans) • Invasive species (primarily through human efforts) • Pollution • Population growth (of humans) • Overexploitation (by humans) In most cases, extinctions occur because of a combination of factors. |
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biodiversity benefits
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• Food, fuel, and fiber
• Shelter and building materials • Air and water purification • Waste decomposition • Climate stabilization and moderation • Nutrient cycling • Soil fertility • Pollination • Pest control • Genetic resources |
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Biodiversity hotspot
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an area that supports an especially high number of species endemic to the area, found nowhere else in the world
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