Sunday, March 1, 2009

Ecology Introduction

ECOLOGY INTRODUCTION

-Ecology-the study of organisms and their interaction with the environment

-Biosphere-the region of the earth that supports all living things

  • Includes all land, air, and water in which an organism lives
  • Everything an organism needs to survive
  • Natural resources are the products of the environment used by living things

-Biotic Factors-living things (plants, animals, trees)

-Abiotic Factors-nonliving parts (water, soil, houses)

-Ecosystems-large areas that contain groups of organisms living and interacting with one another, includes all biotic and abiotic factors of that area

-Every organism in an ecosystem has a niche (or a job) and that job has an effect on everyone in that ecosystem

Biomes

*Terrestrial-rainforest, tundra, taiga, desert, grassland, deciduous forest

*Aquatic

  • Marine-oceans, tropical (coral reefs)
  • Freshwater-wetlands, lakes/ponds/rivers/streams

Biome Maps:

Ecological Succession

-Community-all organisms living in an area

-Succession-a process in which a community develops

Levels of Succession

-Primary Succession-no existing community, life begins to develop

-Pioneer Community-the first organism to develop and occupy an area

  • (Ex. 1: lichens, mosses, grass)
  • (Ex. 2: an abiotic lake left behind by a retreating glacier; wind-borne spores of bacteria, algae, fungi, and protozoa drift into the water and germinate in the new sediment)

-Secondary-growth that occurs in an area where there is an existing community that has been partially destroyed (Ex: natural forest fires: shrubs, trees, flowers)

-Climax Community-a community that achieves relative stability (Ex. redwood forest)

  • also has a lot of biodiversity

Levels of Organization

Type of interaction:

  • Competition-competition from 1 or more species for 1 or more to the limited resources it needs
  • Predation-organism kill and consumes the other organism for nutrients and energy; Ex: lion & elk; Code: + -
  • Parasitism-organism benefits while the other organism is harmed; Ex: tick & dog; Code: + -
  • Mutualism-bother species benefit from this relationship; Ex: bees & flowers; Code: + +
  • Commensalism-one organism is nuetral and the other is receiving benefits; Ex: shark & cleaning fish; Code: + 0

* + means beneficial, - means harmful, 0 means neutral (neither helping nor harming)

-Symbiosis-a close relationship between 2 organisms

  • Three types of symbiosis is mutualism, parasitism, and commensalism.

-Mimicry-when one organism take the appearance of another organism

-Exponential Growth-the rate of growth of one generation is a multiple of the previous generation

  • Influences on exponential growth: emigration & immigration

-Carrying Capacity-the number of organisms supported by the environmental resources in an ecosystem

  • Limiting Factors: predation, disease, competition, and emigration
  • Random Changes: natural disaster, climate changes, weather, and requirements for growth

Population Statistics

  • Growth rate=change in # of individuals/time
  • Natality rate=# of births/time
  • Mortality rate=# of deaths/time
  • Population growth: natality>mortality
  • Population stable/constant=natality=mortality
  • Emigration=movement of organims out of an area
  • Immigration=movement of organisms into an area

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