Roles and Relationships Between Organisms and their Environments Ecology Roles and Relationships Between Organisms and their Environments

What is Ecology? Ecology: The study of the relationship between organisms and their environment. Example problems that ecology handles How do humans affect the atmosphere and contribute to global warming? How does the population of wolves in an area affect the population of rabbits? Do clownfish (Nemo!) and anemone benefit each other?

Ecosystems Ecosystem: An area containing an interaction of living and non-living factors in an area/region Example ecosystems: -Pine forests -Lakes -Deserts -Ocean -Grasslands

What is in an Ecosystem? Non-Living (Abiotic)-rocks, soil, temperature, gases in the air and light. Living (Biotic)-plants, animals,bacteria and fungus Producers-use light to make their own energy Consumers-eat other organisms to obtain energy Decomposers-break down dead organisms for energy

Food Chains A food chain shows the flow of energy between the organisms in an environment Notice that the arrow points from the organism being eaten to the organism that eats it. For example when you eat a burger. Plants Cow (burger) Human. The arrows represent energy flow within a food chain

Food Webs When we put many food chains together in one ecosystem, it is called a food web. In a food web, energy is shown in the direction it flows in an ecosystem.

Parts of a Food Web Producers: Organisms that use light to store energy in organic compounds. Example: plants and algae. Consumers: Organisms that eat other organisms to get organic compounds that they use for energy. Example: humans, cows, and insects.

Relationships in an Ecosystem Symbiosis: a long-term relationship between two organisms in an ecosystem. Mutualism: both organisms benefit from their relationship. Commensalism: one organism benefits, and the other is unaffected. Parasitism: one organism benefits, and the other is harmed.

Relationships in an Ecosystem Example of a symbiosis: leeches feed off of a lamprey and eventually cause it to die. This is considered to be a parasitism. Example of a symbiosis: a clown fish lives among the sea anemone. The clown fish gains protection, but the anemone is neither harmed nor helped. This is considered to be a commensalism. Example of a symbiosis: Ox-peckers live on the heads of the ox, eating insects and keeping the ox clean. The birds also get a place to live. This is considered to be mutualism.

Population Growth and Overpopulation Population: the number of organism from one species that live in a specific area Examples: the human population in different cities, the squirrel population in a forest, the grass population in a meadow. Populations are affected by many resources. These include: The amount of food available in an area The amount of sunlight (if it is a plant population) The amount of water The competition for food/shelter The predators in an area

Population Growth and Overpopulation Carrying Capacity: the maximum number of organisms in a population that are supported by the environment. Populations are typically limited by resources They reach carrying capacity when there aren’t enough resources to keep growing.

Predator vs. Prey Predator and Prey populations can affect one another As prey increases, predator will increase in response As predators increase, prey will decrease As prey decreases, predators will decrease

Human Overpopulation The problems with overpopulation include abuse of resources: Deforestation Fossil Fuel Overuse Freshwater Overuse Pollution Lack of adequate food Non-native species

Deforestation Cutting down forests leads to loss of biodiversity, which is when not as many different species in an area. This can affect local food webs, other species and even medicine.

Fossil Fuel Overuse Burning Fossil Fuels leads to excess CO2 in the air, traps heat, then the Greenhouse effect enhanced, which can then lead to global warming.

Freshwater Overuse Poor water quality, not enough freshwater in areas of need. Polluted runoff from factories.

Pollution Acid rain: From sulfur and nitrogen gases released from factories into the air. Falls in rain drops, slowly impacts pH of water, soil and etc. Ozone Layer Destruction CFCs: chlorofluorocarbons-released into the air through old refrigerator and spray cans, destroy ozone layer. Low ozone: leads to high UV radiation. UV radiation: can cause skin cancer through mutation. This is why we wear sun screen.

Non-native species Putting species into new ecosystems that aren’t supposed to be there The introduced species generally outcompete, or do better, than the native species. Example: pythons in the everglades.

What can we do? Use renewable resources for energy Water, wind, solar and geothermal energy Reduce carbon dioxide emissions Reduce water waste Investigate factories and their pollution levels Increase public awareness of the issues Promote sustainable practices Using renewable energy, rotating crops, avoiding pesticides and toxins, making sure we keep fishing populations high, conserve resources.