Ecosystems & Communities Chapter 4 Ecosystems & Communities

4–1 The Role of Climate (87-89 interactive) & 4-2 What Shapes an Ecosystem (90-97 interactive)

Climate vs. Weather Weather: Day to Day conditions at a particular place and time Climate: Average yearly conditions Temperature & Precipitations Determined by latitude, wind & ocean currents, elevation, shape of landmass

Greenhouse Effect Goldilocks zone: CO2, methane, water vapor, and other atmospheric gases trap solar energy and maintain Earth’s temp. range

Effect of Latitude on Climate Earth’s tilt causes unequal heating of the earth based on latitude Three main climate zones Polar: 66.5-90° lat. Temperate: 23.5-66.5° lat. Tropical:23.5-23.5 °lat.

Heat Transport in the biosphere is caused by unequal heating of the earth Creates winds and ocean currents

What Shapes an Ecosystem? Biotic & abiotic factors Habitat = the area where an organism lives Niche = physical and biological conditions in which an organism lives and the way in which it uses those conditions

No two species can share the same niche in the same habitat

Community Interactions Competition = organisms attempting to use a resource in the same place at the same time Resource = any necessity of life (water, nutrients, light, food, or space) competitive exclusion principle = rule that says no 2 species can occupy the same niche at the same time

Predation = interaction in which one organism captures (kills) and feeds on another organism  Predator / Prey

Symbiosis = Any relationship in which two species live closely together mutualism commensalism parasitism

Mutualism = symbiotic relationship in which both species benefit from the relationship

Commensalism = symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed

Parasitism = symbiotic relationship in which one organism lives in or on another organism (the host) and consequently harms it Host / parasite

Ecological Succession Ecosystems are constantly changing as a result of natural disturbances and human interference Ecological succession = gradual change in living communities that follows a disturbance

Primary Succession  primary succession = succession that occurs on surfaces where no soil exists Volcano Glacier

pioneer species = first species to populate an area during primary succession Often lichens

Secondary Succession  secondary succession = succession following a disturbance that destroys a community without destroying the soil land cleared and plowed for farming is abandoned Wildfires

climax community = mature, stable community that did not undergo further succession Old growth forests