ScienceCh3Ecological progression.txt

process proposed by Darwin where environmental factors favour selection of fit individuals

• process by which members of a species adapt to a variety of habitats
• Galapagos finch beak

gradual change that occurs when organisms colonize a habitat, modify it, and are forced out by a new species better adapted to the now altered environment.

• area no soil exists eg rock/glacier retreat
• wind brings pioneer species: alter abiotic and biotic envron so other species can live there: Lichen (fungus and algea), mosses
• -> die = nutrients and soil -> insects and micro-organisms
• -> grasses wild flowers, shrubs, more insect organisms
• -> trees: sun-tolerant deciduous become replaced by coniferous, non-tol
• -> mature community

• occurs after major disturbance, like forest fire in an area already has soil and had living organisms
• soil contains seeds, micro-org, earthworns, insects
• more rapid than primary

stable group of two or more species is able to survive and reproduce indefinitely in same habitat

populations able to return to previous state when disturbed

• volume of water exceeds ability of water body to contain it
• run-off, melting snow, tsunami, heavy rain
• soil erosion, pollution, disease

• huge, rapidly moveing wave
• earthquakes, underwater volcanic eruptions
• salt changes soil, rips away plants and animals

• below-avg amount of precip over years/months
• can usually recover, crop failure, livestock death, plants and animals die

• destroys older weaker trees normally good, resin by young trees flush mountain pine beetle and blue stain fungus out
• suppression of forest fires, warmer temp = larvae surviving
• young trees attacked, forest in critical shape

ways we use land around us for urban develop, agricul, industry, mining, forestry

• destruction of habitats, can no longer support original species
• urbinization, clear-cutting

• division of habitats into smaller, isolated fragments
• roads

forests logged or cleared for human use

water and wind erosion remove topsoil

• soil squeezed together, air spaces reduced
• run-off, bad soil health, reduce growth of plants
• agriculture

small plugs of soil removed to help soil compaction

ways we octain and use raw materials

• introduction of chem, toxins, wastes, micro-organisms in concentrations harmful to living thing
• mining

use/extration of material until depleted, can result in extinction

dying out of species (carrier pigeon)

reflects human experience with native gained over centuries

grow or multiply by rapidly producing new tissues, cells, or offspring

• competition: Eruropean starling competes with blue jays,
• predation: Norway rats eats nesting birds, American bullfrog eats native BC frogs

spread by boats, dense mats at lake surfaces, cutting off sunlight to organisms below

bushy shrub, overloads nitrogen, ruins habitat of birds and butterfly, replaces native shrubs

outcompete red squirrels for acorns

larvae strip oak trees of leaves