Ecology Chapter 3

What is Ecology Interactions between living and nonliving things or the biotic and abiotic. Biotic – all living organisms (plants & animals) Abiotic – all nonliving things (rocks, gases, minerals) Biosphere – where all living and non living things are found (land, water, air) Abiotic Biotic

Biosphere Different populations make up the biosphere –Population – groups of organisms of one species that live in the same place Populations use the same: food, water, mates, territory –Different populations that interact make up Communities Examples: fish and alligators share the same territory (habitat) and interact with one another (predator/prey) All the interactions make up the Ecosystem Biomass is the total amount of living tissue in a given area

Levels of Organization I.Biosphere – part of Earth that contains Life I.Ex. Air, water, land II.Biome – group of ecosystems that have similar climate and dominant communities I.Ex. Tropical rain forest, desert and tundra III.Ecosystem – collection of all the organisms that live in a particular place along with all abiotic factors (nonliving) I.Ex. Desert : cactus, snakes, rats, rocks, sand, ect… IV.Community – different populations that live together in the same area I.Ex. Forest : Deer, owls, rabbits all live together V.Population - Groups of individuals that live in same area I.Ex. All the bullfrogs living in a lake VI.Individual – one member of a species living in the population I.One bullfrog

Interactions Niche – role the organism plays in the environment. Ex.: Bacteria decompose dead organic material Autotrophs (producers) and Heterotrophs (consumer) –Autotroph – use sunlight to make food/energy ex. – plants –Heterotroph – consume producers and other heterotrophs for food/energy Herbivore –Consumer that eats only plant matter Ex. Cow Carnivore – Consumer that eats animals. There are two types: Predators which prey on live animals Ex. Lions, Tigers Scavengers which eat dead animals Ex. Vulture Omnivores eat both plants and animals Ex. Humans, Bears Decomposer – breakdown (eat) dead organic materials

Energy cycle Energy constantly cycles through the ecosystem. Example: rabbit is born, rabbit lives a happy life, rabbit gets run over by car, vulture and coyotes eat remains and gain energy from food, bacteria decompose the rest of the living matter for energy. Models of Energy Cycles –Food Chain – Most simple model which shows how energy flows from one organism to another. Only goes in one direction. Ex.: rabbit coyote bacteria –Food Web – network of interconnected food chains. Shows more than one path energy flows through environment –Trophic Levels – each organism represents a step in which there is a 10% gain and the rest of the energy is lost to heat –Ecological pyramid – puts populations by numbers and energy level starting with producers at the bottom of the pyramid

Food Web Energy flows through an ecosystem from producer to consumer and is eventually recycled by decomposers. Each living thing is dependant on the other living things in the community.

Ecological Pyramid At each level energy is lost in the form of heat. The greatest amount of available energy is found at the bottom level of the pyramid. Producers are the living things that have the most energy available to them.

100% 10% 1%

Environmental Homeostasis Life is sustained by a balance of environmental factors and by maintaining a balance of nutrients that are necessary for living organisms. These are water, carbon and nitrogen. Each of these cycles through the environment such that the balance can be maintained.

Water Cycle How the environment maintains Homeostasis

Carbon Cycle How the environment maintains Homeostasis

Nitrogen Cycle How the environment maintains Homeostasis

Phosphorous cycle

Biomes The Major Biomes –Tropical Rain Forest –Savanna –Desert –Grassland –Tundra –Temperate Forests and Grasslands –Mountains –Temperate and Coniferous Forest –Freshwater and Saltwater Aquatic

Population Dynamics Population Growth is limited by certain factors –Space available –Food –Competition for resources between different species –Number of mates –Natural disaster –Disease –Temperature Each ecosystem has a carrying capacity. This means the area can only support a certain number of each species due to the limiting factors for populations