Ecology—the study of the interaction between organisms and their environment

I. Feeding relationships A.Autotrophs=producers MAKE their own food Ex: plants, algae, some bacteria B.Heterotrophs=consumers Eat other organisms; do NOT make their own food

Types of Consumers: 1. Herbivore—only eat plants 2. Carnivore—kill and eat other animals 3. Omnivore—eat both plants and animals 4. Scavenger—eat dead animals 5. Decomposer—(also called saprobe/ saprophyte)—break down and absorb nutrients from dead organ isms

II. Survival relationships A. Predation (Predator-prey)— Predator hunts and eats prey. B. Competition—occurs when 2 species fight for the same limited resources

Predators

Competition

C. Symbiosis-2 species living together; at least one depends on the other

Types of Symbiosis: 1. Mutualism—BOTH species benefit (mutually beneficial!) Ex: clownfish & sea anemone flower & bee cattle & white birds

Mutualism

2. Commensalism—One species benefits and the other is NOT AFFECTED Ex: orchid & tree human & eyelash mites

Commensalism

3. Parasitism—One species benefits and the other is HARMED. Ex: tick on a dog mistletoe in a tree mosquitoes on humans

Parasites

III. Matter and Energy relationships A. Food Web — expresses ALL possible feeding relationships in a community

Food Web example

B. Food chain — one path in a food web

Food chain example

1.A food chain MUST start with a producer. 2.Arrows are used to show the direction of energy transfer. 3.A food chain does NOT typically have more than 5 levels.

Why are food chains this short? Only about 10% of the energy at each level is passed to the next level.

C. Trophic level —represents a feeding step in a food web 1. First trophic level— producer 2. Second— herbivore / omnivore 3. Third— carnivore / omnivore 4. Fourth— carnivore / omnivore 5. Fifth—carnivore/ omnivore/ decomposer

D. Ecological or energy pyramids— describe energy conversion in an ecosystem

1. The SOURCE of energy for all pyramids is the SUN. 2. The BASE of the pyramid is PRODUCERS. 3. The TOP is the top CARNIVORE or omnivore.

4. Biomass —the total mass of all organisms at any one level in the pyramid

5. Biological Magnification— the concentration of toxic substances increases as it moves up the food chain *Will be highest in top level

IV. The Organization of Life A. Organism—3 Things that affect organisms: 1. habitat—where it lives 2. niche—its way of life 3. trophic level—its feeding level in the food chain

Niche

B. Population—all members of the same species that live in a certain area --Animal population is also called a breeding group.

A group of individuals of one species usually occupying a defined area. Populations

C. Community—All populations in a certain area

D. Ecosystem—the biotic and abiotic factors interacting in an area 1. biotic—living things 2. abiotic—nonliving things Ex: water, soil, temperature, precipitation

Ecosystem

E. Biome—A large area defined by the presence of certain plants and animals

Biomes

Permafrost

F. Biosphere— the area on Earth where life exists (the SURFACE)

Biosphere

V. Geochemical Cycles

Water Cycle

Nitrogen Cycle

Carbon Cycle

Oxygen Cycle

Types of Lakes Types of Lakes Oligotrophic Eutrophic

Estuary Place where freshwater, such as a river, meets the sea Ex: bay, swamp, marsh, bayou

VI. Homeostasis in Communities A. Carrying capacity—the largest number of organisms from a species that can be supported by the environment Ex: There is only enough food for a certain number of deer.

Why Hunting is Legal

B. Limiting Factor—any living or nonliving thing that restricts the existence, numbers, reproduction, or distribution of organisms Ex: food available, temperature

Why These Animals Live Only in Certain Places

C. Tolerance—the ability to withstand fluctuations (changes) in environmental factors --There is a range of conditions (temp., amt. of food, etc.) in which organisms can survive.

D. Succession—orderly, natural changes that take place in a community *climax community—a stable, mature community that undergoes little to no succession

1. Primary—establishment & development of an ecosystem in an area that was previously UNINHABITED 2 Types of Succession: 1. Primary—establishment & development of an ecosystem in an area that was previously UNINHABITED

Lichens and algae on bare rock

Succession of plant species on abandoned fields in North Carolina. Pioneer species consist of a variety of annual plants. This successional stage is then followed by communities of perennials and grasses, shrubs, softwood trees and shrubs, and finally hardwood trees and shrubs. This succession takes about 120 years to go from the pioneer stage to the climax community. From on Pioneer speciespioneer climaxhttp://

2. Secondary- REESTABLISHMENT of a damaged ecosystem in an area where the soil was left intact

Secondary succession occurs in an area where life once existed but has then been destroyed. Secondary Succession —Illustration of (1) a climax forest (2) destroyed by wildfire and (3) and (4) its eventual recovery. Secondary succession occurs in an area where life once existed but has then been destroyed. (Reproduced by permission of The Gale Group)