Energy and Matter Exchange in the Biosphere 2 Flashcards
What is an ecosystem?
community of interacting organisms and their abiotic environment (terrestrial and aquatic)
What is an ecotone?
ecosystems rarely have sharp boundaries, organisms move back and forth between ecosystems, ecotones are the transition area between ecosystems where organisms from both bordering ecosystems interact, greater biodiversity than either ecosystem
Why is higher biodiversity good?
less fragile, if a predator relies on single food source, existence tied to survival of prey, by providing alternative food sources, ecotones help guard against extinction
What is an ecological niche?
organisms place within the ecosystem, place in food web, habitat, breeding area, time of day it is most active constitute its ecological niche, everything done to survive and reproduce, reduces competition
What is an exotic species? What happens when an exotic species enters an ecosystem?
species not native to ecosystem, new species comes into competition for a niche with one or more of the species in the ecosystem (animals mobile, plants seeds by wind)
What are the two main causes for extinction?
habitat loss and introduction of new species
What are problems with introducing exotic species?
no natural pop. control, native species may not be able to compete for space, food, reproductive sites, prey org may not have defense mechanisms
What is a biome?
large geographical region with a specific range of temperatures and precipitation and the organisms that are adapted to those conditions, terrestrial and aquatic, determined by climate
What are the major biomes?
muskeg (alberta), tundra (canada), taiga/boreal forest (canada, alberta), temperate deciduous forest (canada), grassland (canada, alberta)
Describe the muskeg region
northern regions Alberta, layer of permafrost beneath the soil that never melts, rain and melted snow cannot drain, water soaks decomposing plants and peat moss, forms muskeg (ground swampy in summer) musket supports different organisms than are found in conifer forest ecosystems, low temp limit growth of soil bacteria, limits amount of organic matter, lichens, moss, stunted conifers (fibrous root system close to ground), caribou
Describe the tundra region
permafrost, little precipitation, little plants (lichen, moss)
Describe the taiga/boreal forest
northern alberta, rocky mountains, conifers, found in every province in canada, conifers adapted to warm summers, cold winters, slightly acidic soil, 50-250 cm/a
Describe the temperate deciduous forest
edge of grassland before it turns to taiga, high biodiversity, 30-60 degree, flowers, 75-250 cm/a
Describe the grassland
25-100 cm/a, rich, fertile soil, prairie and savannahs
What are the zones of a lake?
littoral (area from shore to where no more plants grow)
limnetic (open water, enough sun for photosynthesis, plankton)
profundal (no sun, cold, fish)
benthic (bottom of lake, decompose)
What factors affect terrestrial ecosystems?
soil, available water, temperature, sunlight
What are the layers of soil?
litter (decomposed leaves or grasses, limits temperature variations in soil, reduce water loss by evaporation)
topsoil (made of rock particles and humus or decaying matter)
subsoil (more rock particles, smaller amounts of organic material)
bedrock (layer of rock)
What factors affect aquatic ecosystems?
chemical environment (fresh/salt water, amount of oxygen dissolved in water which is dependent on temperature, pressure (depth), amount of salt and other sub)
temperature and sunlight
water pressure
seasonal variations (fall turnover)
What is biotic potential?
max # of offspring a species produces with unlimited resources, affected by birth potential, capacity for survival, breeding frequency, length of reproductive site
What are limiting factors?
factors prevent population from attaining biotic potential, resource in short supply (food, water, territory, light)
What is carrying capacity?
max number of individuals of species that can be supported by an ecosystem, population fluctuation based on biotic and abiotic factors
What are the laws of limits of tolerance?
Law of minimum (Liebig), nutrients in least supply limits growth
law of tolerance (Shelford), organisms survive in a particular range, higher or lower than range die, generalists typically have higher tolerance than specialists)
What are factors of population density?
density independent (affect pop regardless population density, fire, flood) density dependent (affects pop because of population density, food, water quality, disease, sun)
What are the three forestry practices?
slash and burn (vegetation is removed, piled up, burned for nutrients, increase NO3 in runoff)
clear-cutting (removal of all trees)
selective cutting (certain trees harvested)
What is the effect of fire?
renewal, clean dead mat accumulation
What are the two types of lakes?
oligotrophic (little nutrients, deep and cold, low nutrients, low biomass, low turbidity, high oxygen, big fish)
eutrophic (shallow and warm, high nutrients, high photosynthetic organisms, murky, high turbidity)
oligotrophic lakes turn to eutrophic through eutrophication, accelerated through human wastes, fertilizers, household products, thermal energy
What are the 5 categories of water pollution?
organic solid wastes, disease causing organisms (e. COLI), inorganic solids and dissolved minerals, thermal energy, organic chemicals
What are 2 indicators of water quality?
bacteria count, dissolved oxygen
What are sources of pollution?
point sources (single, severe), non-point
