Intro to ECOLOGY (Chapter 33) 33.1

The study of the interaction of organisms with each other and their physical environment

Organisms are organized into: Populations – ex: Perch (Members of a species living in an area) Communities –ex: Perch, Walleye, Algae (All the populations in an area) Ecosystems –ex: Fish, Algae, Rocks, water (A community and its physical environment) includes biotic and abiotic factors Biomes –ex:Tundra, Rainforest (A large group of similar ecosystems containing distinct types of plants, animals, etc…determined by climate) Biosphere (all the communities on Earth whose members exist in air, water, and on land) ONE species! More than ONE species! Adds NONliving components!

How do populations grow? BIOTIC POTENTIAL: highest possible per capita rate of increase for a population Per capita rate of increase= (Births-Deaths) / # of individual LIMITING FACTORS: (create environmental resistance) Biotic-living parts of the ecosystem vegetation, etc Abiotic – nonliving parts of the ecosystem Precipitation Temperature Inorganic nutrients

Exponential Growth…J curves Has two phases: Lag phase: growth is slow because the population is small Exponential Growth Phase: growth is accelerating, and the population is exhibiting BIOTIC POTENTIAL. Cannot usually continue for long because of …

Environmental Resistance & Carrying Capacity Environmental Resistance: all the environmental conditions that prevent populations from reaching their biotic potential Ex: limited food supply, accumulation of waste, predation, competition…(biotic and abiotic limiting factors) MOST populations taper off around their… Carrying Capacity: # of individuals the environment can normally support We call this kind of growth…

1. Where is the carrying capactiy in this curve? Logistic Growth This creates an “S shaped curve” Four phases: Lag Exponential growth Deceleration phase (pop growth slows) Stable equilibrium phase/stationary phase (births and deaths start to even out) 1. Where is the carrying capactiy in this curve?

Discussion Topics… …Survivorship Curves p. 683 …Human Population Growth developed vs. less developed countries …Age distributions

What do the wolves in this picture represent? Population Ecosystem Community Biome 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Which of the following could be the wolves COMMUNITY? All the populations of wolves in that biome The wolves, and the moose The wolves and the soil 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Everything in this picture would add up to a/an… Population Biome Ecosystem Species 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

The Atmosphere, Water and Soil pictured below are examples of… Biotic Factors Abiotic Factors Ecosystem Population Community . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

The rabbit and wolf below represent a/an… Biotic Factors Abiotic Factors Ecosystem Population Community . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24