CHAPTER 3: ECOSYSTEMS

What are they and how do they work?

Cell Review

Smallest functional unit of life Cell theory

All living things are made of cells

Single or multi-cellular Prokaryotic Eukaryotic

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Ecology

Study of how organisms interact with one another and with their physical environment (matter and energy)

Connections in Nature

Levels of Organization

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Species

Set of individuals that can mate and produce fertile offspring

Classification system KPCOFGS Genus species or Genus species

Population

Group of individuals of the same species hat live in the same place a the same time Variation – genetic diversity

Habitat – where they live

Community

Biological community All the populations of

different species that live in a particular place

Ecosystem

Community of different species interacting with one another and with their nonliving environment (soil, water, other forms of matter, and energy)

No clear boundaries Not isolated

Biomes

Large regions of land with distinct climates and certain species Especially vegetation

Aquatic Biomes Marine Freshwater (2%)

http://www.life.illinois.edu/bio100/lectures/s97lects/04Ecosystems/BiomeMap.gif

Biosphere

The Global ecosystem in which all organisms exist and can interact wit one another

Parts of the atmosphere hydrosphere and geosphere where life exists

Atmosphere

Thin spherical envelope of gases surrounding the earths surface Troposphere – greenhouse gases

Stratosphere – ozone layer

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Hydrosphere

All the water on or near the earth’s surface

Liquid, solid, gas forms 71% in Ocean

Geosphere

Earth’s core, mantel and outer crust

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4 SPHERES MAKE UP THE LIFE – SUPPORT SYSTEM

3 Factors work together within the Spheres

Gravity

Allows the planet to hold onto its atmosphere

Enables movement and cycling of chemicals through air, water, soil and organisms

Recycling of Matter within and between Ecosystems

One way flow of high quality energy

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2 components of an Ecosystem Abiotic

Nonliving components water, air, nutrients, rocks, heat, solar energy

Biotic Living and once living biological components

Plants, animals, microbes

Range of Tolerance

Different species and their populations thrive under different physical and chemical conditions

Limiting Factor Principle

Too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance

Contributes to population control

Examples?

Trophic(feeding) levels

Producers Autotrophs “Self – feeders”

Photosynthesis6CO2 + 6H2O = light = C6H12O6 + 6O2

Chemosynthesis

Trophic(feeding) levels

Consumers Heterotrophs “Other – feeders” Herbivores, Carnivores, Higher-level Carnivores, Omnivores,

Decomposers, Detritivores

MANY OF THE WORLD’S MOST IMPORTANT SPECIES ARE INVISIBLE TO US

Page 61 Science Focus

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Food Chains

Sequence of organisms, each of which serves as a source of food or energy for the next

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Food Web

Complex network of interconnected food chains

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Useable energy decreases

Ecological efficiency % of usable chemical energy transferred from one tropic level to the next

Typically 10% Pyramid of Energy Flow

http://www.mlms.logan.k12.ut.us/~mlowe/speds2o2b.html

http://www.tutorvista.com/biology/ecological-pyramids

OWL PELLETS, FOOD WEBS, AND BIOMASS PYRAMIDS

NUTRIENT CYCLING IN THE BIOSPHERE