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lecture exam #2
population ecology
Question | Answer |
---|---|
Population Ecology | |
Predators | are significant environmental resistance in controlling population size |
Biotic potential | theoretical maximum rate at which a population can increase |
Environmental resistance | factors preventing the maximum growth potential (ex: food, space, competition, interaction, natural events) |
Population size is influenced by ? | increase in birth rates / immigration decrease in death rates/ emigration |
Individuals in a population | rely on the same resources,are influenced by same environmental factors, and are likely to interact and breed with one another. |
Biotic potential and Environmental resistance | Balance population size |
Idealized models | predict patterns of population growth |
Exponential growth (J curve) | under ideal conditions, a continuously accelerating increase in a population size (Ex. Rabbit population) |
Exponential growth | occurs when environmental resistance is reduced (seen after species recovery)(seen with invasive species) |
Logistic population growth (s curve) | population increases up to a maximum number that the environment can sustain, then stabilizes. |
Logistic population growth | stabilize at carrying capacity |
Density dependent factors | intensity is related to population density (Ex: intraspecific competition ) |
INtraspecific competition | between individuals of the same species |
Density independent factors | limiting factors unrelated to population density (Ex: Abiotic factors such as weather) |
Boom and bust Population cycle | regular dramatic fluctuations in density (may be due to factors such as good shortage or predator- prey interactions) |
Population Ecology | is concerned with changes in population, size and factors that regulate populations over time. |
The Biosphere | |
Ecology | is the study of the interaction of organisms with their environment |
Abiotic | (NON- LIVING) factors |
Biotic | (LIVING) factors |
Niche | includes all of the biotic and abiotic factors of it's surroundings |
Population | a group of individuals of the same species living in a particular geographic area |
community | an assemblage of all the populations of organisms living close enough together for potential interaction |
Ecosystem | both the abiotic and biotic components of the environment |
Biosphere | all that is inhibited by life |
Why do we study Ecology? | it provides an insight into environmental problems |
DDt | an insecticide that was used heavily on crops during the 40's and 60's banned in 1972 ( had a negative impact on birds of prey it thinned out their shells so their offspring would die ) |
Abiotic factors | are energy sources |
producers | rely on sunlight (limiting factor for plants) |
consumers | rely on producers for food indirectly affected by solar energy |
Temperature | has a great influence on metabolism |
temperature | too extreme conditions cant maintain metabolism |
Adaptations | allow you to live in extreme environments |
Tonicity | has great influence on aquatic life |
The amount of rain determines what? | the type of terrestrial biome |
Inorganic nutrients | nitrogen and phosphorus are important factors in photosynthetic organisms |
inorganic nutrients | soil structure and ph are crucial |
climate | long term patterns of weather in a particular region |
What does the curvature of earth do ? | distributes solar energy unevenly |
How are seasons created? | seasons are created due to the permanent tilt of the planet on it's axis as it orbits the sun |
What three things play a role in climate? | oceans, continents, mountains |
ocean currents | moderate coastal climates |
elevation | effects temperatures |
mountains | modify rainfall patterns |
rainshadow | the dry side of the mountain |
Biome | large area with similar environmental conditions and adapted organisms |
phytoplankton | photosynthetic organisms in aquatic biomes |
zooplankton | small drifter animals that consume organisms |
estuary (MOST PRODUCTIVE aquatic biome) | where freshwater streams or rivers merge with the ocean (salt concentration varies greatly) (ex: crabs, oysters, fishes, and nesting birds) |
wetlands | transitional between an aquatic ecosystem (marine or freshwater ) and terrestrial ecosystem ) |
mudflats and salt marshes | coastal wetlands bordering estuaries (EX carpinteria salt marsh ) |
Lakes and ponds | fresh water,distant away from shore |
Rivers and streams | fresh water, distant away from the shore, flowing water moves in one direction sources may be a spring, snowmelt or lake nutrient levels vary from one end to the other |
Freshwater wetlands | can be rich in species diversity store water reduce flooding improve water quality |
marsh | reeds and grasses are common |
swamp | woody plants/ trees are common |
bogs | poor soil peat \moss content |
nine major biomes | defined by plant life |
plant life is determined by what characteristic? | temperature, and amount of rainfall |
Tropical Forest | near equator, warm rainforests have around 100 in rain/ year long days 11-12 hrs all year round rows of vegetation arboreal animals(arboreal means tree) highest biodiversity 6% earth, 50% species |
savanna | grasslands with scattered trees warm temperature, but less rain than rainforest (12-20 in/yr) impressive grazing animals and predators migration fire is crucial |
desert | driest of all biomes (12 in/ year) Not always got (coll and hot deserts) 30 degree N and S latitude as well as in rain shadows of major mountain ranges plants and animals are well adapted annual wildflowers take advantage of storms |
Desertification | converting semi-arid regions to desert) is a huge environmental problem |
Chaparrel (Mediterranean) | coastal regions bordering deserts rainfall is up to 30 in/year, nearly all falling during cool, wet winters hot, dry summers plants are drought resistant: small shrubs and small trees (oaks) summer fires by lightning are common |
Chaparrel Mediterranean | plants are adapted to natural fires rare biome (in only 5 regions of the world) considered a biological hot spot (high number of endemic species) |
Endemic species | only live in the specific area and are not found anywhere else |
Grassland | treeless, except along rivers or streams cooler winter, average rainfall 10-30 in/yr fire plays an important role plants are well adapted to fires rich soil- agriculture and towns |
Temperate deciduous forest | trees are deciduous(drop leaves seasonally) very cold in winter/ hot in summer rainfall 30-60 in/ year during winter, lack of liquid water (no leaves) decomposers and small animals live in leaf litter predators like bobcats, foxses, black bears, |
Coniferous forest | evergreen cone-bearing trees(conifers) northern coniferous forest is called Taiga temperate forest is also coniferous |
Alaska, oregon and other parts of the West Coast | long, cold winters/short, wet summers tree shape helps shed ice heavily logged |
Tundra | the arctic before polar ice treeless, rainfall less than 10 in / year a freezing desert |
Lack of liquid water | permafrost permafrost is a continuously frozen subsoil No deep roots on plants short growing season marshes support larvae of insects |
polar ice | Northern hemisphere, covers land north of tundra as well as ocean nearby southern hemisphere, polar ice covers Antarctica as well as ocean nearby small plants like mosses and lichens small invertebrates such as nematodes, mites , etc seals, gulls |
what factors influence a species? | composition and distribution |
ecosystem structure and dynamics | energy flow and chemical cycling |
community ecology | is the study of the interactions between different populations that live in the same geographical areas we often see co coevolution in communities |
Coevolution | reciprocal evolutionary adaptations in two species in which each acts as an agent of natural selection on the other evolutionary time |
competition | species A species B - - |
Mutualism | species A species B + + |
Predation | species A species B + - |
Herbivory | species A species B + - |
parasites and pathogens | species A species B + - |
iteractions | occur when species compete for the same and different species |
Interspecific competition | Ecological niches of two populations may overlap two species can't same the niche for long they will partition (divide) their niches or resources over time |
intraspecific competition | competition is more intense members of the same species have the exact same niche and adaptation this type of competition drives natural selection |
Mutualism | increases the fitness in both species ex Honeybees', clownfish |
Predators | lead to diverse adaptations in prey species |
cryptic coloration | allows an animal to hide in its environment |
mimicry | resemble something else |
mullerian mimicry | toxic species looks similar to one another, increasing avoidance |
Baetsian mimicry | a harmless species looks similar to a toxic species |
startle coloration | a color pattern is "flashed" giving the prey an advantage to escape |
warning coloration | bright coloration advertise distastefulness or toxicity mechanical and chemical defense |
Herbivory | not often fatal to the plant often we see co evolution and counter adaptations (ex Heliconius caterpillar and passion flower) |
parasites and pathogens | can affect community composition obtain nutrients from host internal(tapeworm) external(mosquitos) |
pathogens | microscopic parasites (bacteria, viruses) |
Trophic structure | is a feeding relationship with many levels |
Food chain | sequence of food transfer up the trophic level |
Detritivores | derive energy from dead material produced by all trophic levels |
Decomposers | secrete digestive enzymes to break down food outside their body |
Food web | a network of interconnecting food chains more realistic |
species diversity | species richness (# of diff species) relative abundance ( how many of each ) |
Keystone species | impact their community significantly removing them would drastically alter the community structure (ex. Sea otters) |
Invasive species | can devastate communities negatively affect environment by increasing in numbers and decreasing native biodiversity introduced by humans into an ecosystem in which they did not evolve *sometimes intentional, and sometimes accidental ex arundo Plant |
Non-native (exotic) | not naturally found in the given area |
European starlings | where introduced to central park new york in 1890 in an attempt to introduce all birds mentioned in the works of shakespeare |
Invasive species | can drive species to extinction damage the economy $120 billion in the us just to control the damage that is made' the small percent that make it cause devastating damage |
What does an ecosystem include? what does it depend on? | biotic and abiotic components of the environment photosynthesis and respiration |
Energy flow | the passage of energy through the components of an ecosystem 1% energy from sun to producers 10% energy through each trophic level 90% loss of energy as you go up the levels |
Carbon cycle | carbon is recycled |