Turner College & Career High School  2015 Ecology Turner College & Career High School  2015

What is Ecology Ecology is the scientific study of interactions among organisms and between organisms and their environment.

Biotic & 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 Biome

Levels of Organization Biosphere Biome Ecosystem Community Population Individual

Levels of Organization Biosphere – part of Earth that contains life. Biome – group of ecosystems that have similar climate and dominant communities. Ecosystem – collection of all the organisms that live in a particular place along with all abiotic factors (nonliving). Community – different populations that live together in the same area. Population - Groups of individuals that live in same area. Individual – one member of a species living in the population.

Levels of Organization Air, water, land Rainforest, desert, tundra Cactus, snakes, rocks, sand Deer, rabbits, owls Frogs in a lake One frog

Sunlight Sunlight is the main energy source for life on Earth. Some organisms rely on the energy stored in inorganic chemicals.

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.

Autotrophs Organisms that capture energy from sunlight or chemicals and use that energy to produce food are called autotrophs or producers. They use light energy to convert carbon dioxide and water into oxygen and carbohydrates during a process called photosynthesis. Several types of bacteria do this process. Green Slime

Heterotrophs Organisms that do not get energy directly from the physical environment, but from other organisms are called heterotrophs or consumers. Heterotrophs are the consumers of the food chain. They can't produce their own food using energy from the sun like an autotroph can. Heterotrophs eat plants or other animals to get energy for life.

Types of Hetrotrophs Herbivores - obtain energy by eating only plants ex: cows, caterpillars, deer Carnivores - obtain energy by eating animals ex: snakes, dogs, owls Omnivores - obtain energy by eating both plants and animals ex: humans, bears, crows Detritivore - obtain energy by feeding on plant and animal remains ex: mites, earthworm, snails, crabs Decomposers - breakdown organic matter ex: bacteria, fungi

Energy Transfer When an organism eats another organism, energy is transferred. Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers).

Inter-Dependence Symbiosis – living together. Types of Symbiosis One organism depending on another for it’s survival. This is a relationship all living things share. Types of Symbiosis Mutualism – both organisms benefit; ex. plants giving off O2 for animals and animals giving off CO2 for plants to use. Parasitism – one organism benefits and the other is harmed; ex. tapeworm living in a persons intestine. Commensalism – one organism benefits and the other is not affected; ex. birds nesting in trees.

Energy Cycle 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. 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 Chain Energy is stored by producers can be passed through an ecosystem along a food chain. A food chain is a series of steps which organisms transfer energy by eating and being eaten.

Food Web A food web links all the food chains in an ecosystem together. A food web is used to represent the feeding relationships among the various organisms in an ecosystem that form a network of complex interactions.

Trophic Levels Each step in a food chain or web is called a trophic level. Producers make up the first trophic level and consumers make up the higher levels.

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.

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

Ecological Homeostasis Limiting factors are biotic and abiotic conditions that maintain balance in every community and keep populations from growing out of control Availability of food Temperature Shelter Availability of mates The Ways communities grow into new niches is called Succession Primary Succession – colonization of new environments (ex. islands) Secondary Succession – usually happens after natural disasters or other major changes to the environment

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.

Human Populations Factors affecting Human Population growth Birth rate and Death rate Birth rate – Death rate = population growth rate Fertility When fertility is high populations increase Population Age Very young / immature pre-reproductive Reproductive mature ( only ones that can increase population ) Post-reproductive / very old Mobility Immigration – movement into a population Emigration – movement out of a population