Ecology Notes – Part 1: Principles of Ecology

The multiple levels of biological systems Ecology - The study of the interactions of organisms with one another and their physical environment

The multiple levels of biological systems organism – an individual living thing ex) a black bat population – all of the individuals of a species that live in the same area ex) the black bats

The multiple levels of biological systems Community – a group of different species that live together in one area ex) the black bats, worms, moss, mushrooms, bacteria, and beetles living in the cave Habitat – place where an organism usually lives ex) a cave is a habitat for a black bat

The multiple levels of biological systems ecosystem – the different species (community) plus the environment (soil, water, weather); biotic factors + abiotic factors ex) soil in the bottom of the cave, light entering the cave, temperature in the cave, humidity in the cave, plus the community biome – major regional or global community of organisms characterized by the climate conditions and the plant communities that thrive there

Vocabulary Quiz match the phrase to the correct word community ecosystem population organism biome habitat fish, snails, & plants that live in a stream a large group of zebras tropical rainforest rocks, water, mice, deer, oak trees one mockingbird

Biotic & Abiotic Factors biotic factors – are organisms in a habitat ex) animals, plants, fungi, protists, bacteria abiotic factors – are the physical aspects of a habitat” ex) wind, water, rocks, sunlight, shade, etc.

What abiotic factors do you see here? What biotic factors do you see?

biodiversity is threatened by human activity Ecosystems are complex. Changes to the biotic OR abiotic factors in an ecosystem affect all species. biodiversity – the assortment or variety of living things in an ecosystem biodiversity is threatened by human activity pollution global warming habitat destruction

Biotic and Abiotic Factors keystone species – a species that has an unusually large effect on its ecosystem ex) sea otter – has a tremendous effect on the ecosystem it is a part of sea otters eat sea urchins, which keeps the sea urchin population under control

Biotic and Abiotic Factors keystone species continued when the sea otter population is over-hunted, there are not enough otters to eat the sea urchins the sea urchins, in turn, eat too much kelp (an aquatic plant, like seaweed) from kelp beds and the kelp population declines without kelp beds, fish have no place to lay their eggs, so the fish population declines; when hunters stop hunting the sea otter population, the urchin populations decrease and the kelp beds and fish populations go back to normal

Food Chains and Food Webs Producers provide energy for other organisms in an ecosystem producer – organism that obtains energy from nonliving resources; organism that makes its own food basis for ecosystem’s energy most rely on sunlight almost all producers obtain energy from sunlight most producers use sunlight as their energy source photosynthesis – 2-stage process that green plants and algae use to produce energy 6CO2 + 6H2O C6H12O6 + 6O2 (SUNLIGHT)

Food Chains and Food Webs autotroph – another word for producer; word parts: self feeder consumer – organism that gets its energy by eating other living or once-living resources, such as plants and animals; connected to producers through energy, which ultimately comes from the sun heterotroph – another word for consumer; word parts: different feeder

Food Chains and Food Webs Label the organisms below as producer, autotroph, consumer, heterotroph (use all words that apply) producer, autotroph consumer, heterotroph consumer, heterotroph producer, autotroph

Types of Consumers herbivores – organisms that eat only plants; ex) rabbit carnivores – organisms that eat only animals; ex) snake omnivores – organisms that eat both plants and animals; ex) chicken (eats seeds and insects) detritivores – organisms that eat dead, organic matter; ex) millipede decomposers – organisms that break down organic matter into simpler compounds; ex) fungi and bacteria responsible for the last step in every food chain, returning nutrients to the environment receive energy from every other level

A food chain is a model that shows a sequence of feeding relationships ***Energy FLOWS through ecosystems*** food chain – sequence that links species by their feeding relationships note that the arrows that link one organism to another show the direction that energy is flowing; energy flows from the organism being eaten to the organism doing the eating

Draw the arrows to complete the food chain below: Hawk

Trophic Levels trophic levels – levels of nourishment in a food chain; ex) producer  herbivore  carnivore represents a food chain with 3 trophic levels energy flows up the food chain from the lowest trophic level to the highest producer – autotrophs – level 1 primary consumer (1̊ ) – herbivores & omnivores – level 2 secondary consumer ( 2̊ ) – carnivores & omnivore – level 3 tertiary consumer (3̊ ) – carnivores that eat carnivores, and some omnivores – level 4

Trophic Levels tertiary consumers secondary consumers primary consumers producers

A food web shows a complex network of feeding relationships food web – model that shows the complex network of feeding relationships and the flow of energy within and sometimes beyond an ecosystem at each link, some energy is stored in the organism and some energy is dissipated (lost) to the environment stability depends on the base – the producers (plants, algae, phytoplankton, some bacteria)

marine food webs show multiple trophic levels and food chains

Don’t forget about the online textbook resources like “Build a Food Web”

Pyramid Models An energy pyramid shows the distribution of energy among trophic levels energy in ecosystems comes from sunlight energy flows UP the food chain from producer to consumer some energy is lost from the ecosystem, mostly as heat each level of a food chain contains less useful energy than the level below it

Pyramid Models 10%

Loss of Available Energy biomass – measure of the total dry mass of organisms in a given area incorporated into the body of a consumer up to 90% of the energy stored in the eaten organism may be lost as heat (energy)

Energy Pyramids the longer a food chain, the more energy lost energy pyramid – diagram that compares energy used by producers, primary consumers, and other trophic levels illustrates how available energy is distributed among trophic levels in an ecosystem energy is measured in kilocalories (kcal)

Label the correct amount of energy at each trophic level: ? ? ?

End of Part 1