2.1 Ecosystem Structure

Ecosystems Have Living and Nonliving Components Abiotic – Non-living Water Air Nutrients Rocks Heat Solar energy Biotic- Living Any living or once living

Major Biotic and Abiotic Components of an Ecosystem Fig. 3-6, p. 59

Ecologists Study Interactions in Nature Ecology: Study of how organisms interact with each other and their environment Species- A particular type of organism Populations- A group of individuals of the same species living in the same place Communities-Populations of different species living in the same place, and potentially interacting with each other Ecosystems-A community of different species interacting with one another and with their nonliving environment of matter and energy Habitat-An environment where a species lives Niche- How an organism makes a living (role/job)

Smallest unit of a chemical element that exhibits its chemical properties Atom Molecule Chemical combination of two or more atoms of the same or different elements Cell The fundamental structural and functional unit of life Organism An individual living being Population A group of individuals of the same species living in a particular place Community Populations of different species living in a particular place, and potentially interacting with each other Stepped Art Ecosystem A community of different species interacting with one another and with their nonliving environment of matter and energy Biosphere Parts of the earth's air, water, and soil where life is found OxygenHydrogen Water Fig. 3-5, p. 58

Food Chain vs. Food Web Food Chain – shows flow of energy from one organism to another

Food Chain vs. Food Web Food web- shows flow of energy interconnected to many organisms (all possible food chains)

Lake Michigan Food Web

Trophic Levels Trophic Level = feeding level (position of an organism on a food chain)

Producers and Consumers Producers- (autotrophs “self-feeders”)--Plants Perform Photosynthesis: Use sun energy to make their own food Waste product is oxygen Consumers- (heterotrophs “other feeders”) – Organisms that obtain nutrients from living things Primary consumers = Herbivore (eats plants) Secondary consumers – omnivores (eats both plants and animals) primary consumers and producers Tertiary consumers- Carnivores(eat meat) other consumers

Producers Fig. 3-7a, p. 59

Consumers Fig. 3-8a, p. 60

Producers and Consumers Are the Living Components of Ecosystems (2) Decomposers Consumers that release nutrients Ex. Bacteria, Fungi Detritivores (scavenger) Feed on dead bodies of other organisms Ex. Earthworms, Vultures

Decomposer Fig. 3-9a, p. 61

Detritivores and Decomposers Fig. 3-10, p. 61

2.1.4 Ecological Pyramids Pyramids show differences that exist between trophic levels Always a decrease of energy and biomass when moving up a pyramid Only ~10% of the energy from the one level is passed to the next level ~90% of energy is used released as heat (respiration) Three types of pyramids (biomass, numbers, energy)

Pyramid of Biomass Biomass (g m -2 ) Dry weight of all organic matter of a given trophic level in a food chain or food web

Pyramid of Energy Pyramid of energy flow (J m -2 yr -1 ) Less chemical energy for higher trophic levels

Pyramid of Numbers Pyramid of numbers Shows the total number of organisms at each trophic level Snapshot in time

Pyramid structure Bioaccumulation- concentration of toxins increases in an individual organism’s tissues Biomagnification- concentration of toxins increases as the trophic level increases

Biomagnification of DDT

What is DDT? Dichlorodiphenyltrichloroethane…that’s why we call it DDT!! Insecticide used to fight malaria Started in 1948 to kill mosquitoes and fight spread of malaria Stored in the fats of organisms, and biomagnifies through the food chain Predatory bird populations suffered Banned in the US in 1972

2.1.7 Population Interactions Competition (- / -) Competition – Two or more organisms in the same community seek the same resource at the same time. Two types Interspecific – between two different species Intraspecific- within an individual species Resources must be in limited supply (food, water, light, shelter, space, mates) Mountain goat competition for mates

Inter or intra???

Predation ( + / -) Predation- One species killing another and consuming it in the process Lions prey on wildebeests in Africa

Herbivory (+/-) Herbivory- consumption (grazing) of producers by primary consumers Caterpillar eating leaf

Parasitism (+/-) Parasitism – Organism that lives on or in another host organism Parasite benefits and host is harmed Tapeworm in human intestine

Mutualism (+/+) Mutualism- both organisms benefit from interactions Best example is Lichen Lichen is algae and a fungus Fungus provides structure and algae provides food source

Commensalism (+ / 0) Commensalism – One organism benefits and the other organism is not affected Clownfish and the sea anemone

Ammensalism (- / 0 ) One species is harmed and another species is not affected. Ex. Algae blooms can lead to the death of many species of fish, however the algae do not benefit from the deaths of these individuals.

Neutralism (0 / 0) Two organisms do not affect each other Essentially they have no relationship Dandelions and salmon in a ecosystem (have little or no effect on each other

Big Ideas 1.Some organisms produce the nutrients they need, others survive by consuming other organisms, and some recycle nutrients back to producer organisms. 2.Human activities are altering the flow of energy through food chains and webs and the cycling of nutrients within ecosystems and the biosphere.