Ecology (part 1)

Levels Within Levels An ecosystem is a collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment. Within an ecosystem, there are several levels of organization. Your school and its grounds are similar to an ecosystem. 1. What living things are found in and around your school? 2. What nonliving things are found in your school? 3. Into what large groups are the students in your school divided? 4. Into what smaller groups are these large groups divided? 5. Are these groups ever divided into even smaller groups? If so, what are these groups?

What is Ecology? Study of interactions among 1. Organisms (Living-Living) 2. Organisms and their environment (Living-Nonliving)

Species- a group of similar organisms that can breed and produce fertile offspring.

What are the Simplest Levels? Atom Molecule Organelle Cell Tissue Organ System

individual

3-2 Ecological Levels of Organization Section 3-1 Go to Section:

Levels of Organization Individual- one organism (living) Ex. a moose

Levels of Organization Population- (living-living same species in same area) Ex. many moose

Levels of Organization Community- groups of different populations (more than one population or different groups of species) Ex. many groups of moose beavers, trees, grass (all living)

Levels of Organization Ecosystem- all organisms in a particular area along with the nonliving. (living and nonliving) Ex. many groups of moose beavers, trees, grass, rocks, water, mountains

Levels of Organization Biome- group of ecosystems that have the same climate and similar dominant communities (same climate and communities) Biomes: tropical rain forest, tropical dry forest, tropical savannah, temperate grassland, desert, temperate woodland and shrubland, temperate forest, northwestern coniferous forest, boreal forest (taiga), tundra, mountains and ice caps

Levels of Organization Biosphere- all of the planet where life exists, includes land, water, and, air (EARTH) Life extends 8 km up and 11 km below the surface

Populations, Community & Ecosystems Organism Community Ecosystem

Checkpoint Would all the insects in a forest be considered a population? Why or why not? No, there are many different species of insects this would be considered a community of insects.

What shapes an ecosystem? Biotic factors- biological (living) influences on ecosystem Ex. Interactions between organisms, predation, symbiosis, etc. Abiotic factors- nonliving influences on ecosystems Ex. Temperature, precipitation, nutrient availability, soil type, sunlight.

Abiotic Factors Nonliving parts of an ecosystem Includes- water, sunlight, oxygen, temperature, and soil

Biotic Factors Living parts of an ecosystem Includes- grass, trees, people, animals, insects

Make a list of 5 biotic factors that can affect the environment Now You do: Make a list of 5 biotic factors that can affect the environment Make a list of 5 abiotic factors that can affect the environment.

Habitat vs. Niche Habitat- an area where an organism lives Niche- an organism’s way of life or its role in its environment including where in the food chain it is for example herbivores. Habitat is like an address in an ecosystem and a niche is like an occupation in an ecosystem.

Energy Flow (Trophic Levels) Producers (autotrophs)- make their own food. Get energy from the sun-by photosynthesis Get energy without light- by chemosynthesis (chemicals) Consumers (heterotrophs)- get energy from consuming producers and other organisms.

KEY POINT: Types of HETEROTROPHS (foldable) Herbivores- eats only plants Carnivores- eats animals Omnivores- eat both plants and animals Detritivores (scavengers)- eat dead matter (plants and animals) Decomposers- break down wastes and dead organisms and return nutrients to the soil/environment

Feeding Relationships Energy flows through an ecosystem in one direction from: 1. the sun or inorganic compounds 2. To autotrophs (producers) 3. To heterotrophs (consumers) Decomposers get energy from decomposing dead organisms

Food Chain- a series of steps in which organisms transfer energy by eating or being eaten. Food Web- A network of feeding relationships. (More realistic than a food chain)

Trophic levels Each step in a food chain or a food web is called a trophic level. Producers are the first trophic level Consumers are the second, third, or higher trophic level Each trophic level depends on the one below for energy.

Energy Pyramid Only part of the energy stored in one level can be passed to the next- most energy is consumed for life processes (respiration, movement, etc., and heat is given off) Only 10% of the energy available within one trophic level is transferred to organisms in the next trophic level—the rest is given off as heat. **Meaning that 90% is LOST as energy moves to the next trophic level.

Pyramid of Biomass Biomass- the total amount of living tissue within a given trophic level. A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

Pyramid of Numbers A pyramid of numbers shows the relative number of individual organisms at each trophic level.

Community Interactions when organisms live together in an ecological community they interact constantly. Three types of interactions Competition Predation Symbiosis

Competition- competing for resources occurs due to a limited number of resources Resource- any necessity of life. water, nutrients, mates, space, shelter & food. Competitive exclusion principle- no two species can occupy the same niche in the same habitat at the same time

Predation Predation- when an organism captures and feeds on another organism. Predator- hunter Prey- hunted

Symbiosis Symbiosis- any relationship where two species live closely together. (3 types) Mutualism Commensalism Parasitism

Symbiosis Mutualism- both species benefit from a relationship. (+, +) Examples: Lichens (fungus and Algae) Clownfish and Sea Anemone

Symbiosis Commensalism – One member of a symbiotic relationship benefits and the other is neither helped or harmed (+,0) Ex. Shark and Remora fish

Symbiosis Parasitism- One creature benefits and one creature is harmed (+,-) - Parasite harms the host Ex. tapeworm-Feeds in a humans intestines absorbing his/her nutrients. Flea and dog

Ticket out the door 1. List in order the levels of organization starting with cells and ending with biosphere. 2. Compare the 3 types of symbiotic relationships and provide an example for each: Mutualism Commensalism Parasitism