Energy and Matter Exchange in the Biosphere 2

Question 1

What is an ecosystem?

Answer 1

community of interacting organisms and their abiotic environment (terrestrial and aquatic)

Question 2

What is an ecotone?

Answer 2

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

Question 3

Why is higher biodiversity good?

Answer 3

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

Question 4

What is an ecological niche?

Answer 4

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

Question 5

What is an exotic species? What happens when an exotic species enters an ecosystem?

Answer 5

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)

Question 6

What are the two main causes for extinction?

Answer 6

habitat loss and introduction of new species

Question 7

What are problems with introducing exotic species?

Answer 7

no natural pop. control, native species may not be able to compete for space, food, reproductive sites, prey org may not have defense mechanisms

Question 8

What is a biome?

Answer 8

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

Question 9

What are the major biomes?

Answer 9

muskeg (alberta), tundra (canada), taiga/boreal forest (canada, alberta), temperate deciduous forest (canada), grassland (canada, alberta)

Question 10

Describe the muskeg region

Answer 10

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

Question 11

Describe the tundra region

Answer 11

permafrost, little precipitation, little plants (lichen, moss)

Question 12

Describe the taiga/boreal forest

Answer 12

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

Question 13

Describe the temperate deciduous forest

Answer 13

edge of grassland before it turns to taiga, high biodiversity, 30-60 degree, flowers, 75-250 cm/a

Question 14

Describe the grassland

Answer 14

25-100 cm/a, rich, fertile soil, prairie and savannahs

Question 15

What are the zones of a lake?

Answer 15

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)

Question 16

What factors affect terrestrial ecosystems?

Answer 16

soil, available water, temperature, sunlight

Question 17

What are the layers of soil?

Answer 17

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)

Question 18

What factors affect aquatic ecosystems?

Answer 18

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)

Question 19

What is biotic potential?

Answer 19

max # of offspring a species produces with unlimited resources, affected by birth potential, capacity for survival, breeding frequency, length of reproductive site

Question 20

What are limiting factors?

Answer 20

factors prevent population from attaining biotic potential, resource in short supply (food, water, territory, light)

Question 21

What is carrying capacity?

Answer 21

max number of individuals of species that can be supported by an ecosystem, population fluctuation based on biotic and abiotic factors

Question 22

What are the laws of limits of tolerance?

Answer 22

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)

Question 23

What are factors of population density?

Answer 23

density independent (affect pop regardless population density, fire, flood)
density dependent (affects pop because of population density, food, water quality, disease, sun)

Question 24

What are the three forestry practices?

Answer 24

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)

Question 25

What is the effect of fire?

Answer 25

renewal, clean dead mat accumulation

Question 26

What are the two types of lakes?

Answer 26

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

Question 27

What are the 5 categories of water pollution?

Answer 27

organic solid wastes, disease causing organisms (e. COLI), inorganic solids and dissolved minerals, thermal energy, organic chemicals

Question 28

What are 2 indicators of water quality?

Answer 28

bacteria count, dissolved oxygen

Question 29

What are sources of pollution?

Answer 29

point sources (single, severe), non-point