Ecology Notes for Sept. 28 through Oct. 1 Biomaginification, symbiosis, succession and carbon/nitrogen cycles

Evaluating Changes Changes occur in ecosystems for many reasons. Some of these changes have wide spread, drastic affects. Pesticides Fires Droughts Infectious diseases Deforestation volcanoes

Evaluating Changes Bats are being killed by a fungal infection called “white nose syndrome”. At least one million so far. One million bats can eat 700 tons of insects. Many of which are pests. Fewer bats means more mosquitoes and other pests. More problems for farmers. Bats control many insect populations.

Evaluating Changes How can a decrease in trees affect our ecosystem? Less O2 is produced organisms that live in/on or depend on the trees will decrease How would replanting trees affect the other biotic factors in the ecosystem? More O2 in the ecosystem more of a habitat for other organisms shade and shelter

Biological Magnification Organisms that are higher in the food chain will obtain/retain/accumulate more pesticides or chemicals. What happens to the amount of chemicals in an organism if the chemicals do not leave the body? They build up in the organism

Biological Magnification DDT and wildlife.

As you move up the food chain, energy will decrease because it is being used. As you move up the food chain, pesticides will increase because its not used (stays in the body) Mark on your pyramid and food chain where there is more energy, less energy, more pesticide, and less pesticide.

Symbiosis Any relationship in which 2 species live closely together There are 3 types of Symbiotic Relationships Mutualism – both species benefit   Commensalism – one species benefits, and other is not harmed or helped  :/ Parasitism – one organisms lives on or in another organism and harms it.  

Examples Parasitism Mutualism Commensalism A flea feeds on the blood of a cat or dog Aphids and ants live together. The ants care for the aphids and protect them. The aphids produce a sweet liquid the ants drink. Barnacles stick to the surface of whales. They benefit by finding a habitat on the whale where nutrients are available. The whales are neither hurt nor helped. Mutualism Commensalism

Non-Symbiotic Relationship Predation: An interaction in which one organism hunts/kills and feeds on another organism. The organism that does the killing is the predator. The organism that gets eaten is the prey. Example: Hawk eating mouse

Ecological Succession Succession is the natural and gradual changes that occur in a species in an area. Primary Succession – Gradual Growth in a previously bare area. Predict, on your chart what kind of organisms/animals would exist at each level.

Examples of Primary Succession Sides of volcanoes Landslides Retreating glaciers Emerging islands

Pioneer species – the first organism to grow in a bare area. Climax community – a stable group of plants and animals that is the end result of the succession process Would a climax community look the same in all environments? No, climax communities can range from grasses in prairies, cacti in deserts, and large trees in a rainforest. What factors limit the type of organisms in a climax community? Weather, climate, other organisms present, amount of water, etc.

Secondary Succession Begins in a place that already has soil and was once home of living organisms (much faster than primary because a thick layer of soil is present). Grasses grow first, then shrubs, then forest. Examples: land after a forest fire, floods, bulldozer, abandoned field

Look at the examples on your notes. Primary or Secondary? B. C. Secondary Primary Secondary http://safari.camas.wednet.edu/?p=a7d6da2e-26c4-11e3-bc20-0026b9612fd6

Biotic – Living Ex). animals, plants, bacteria Abitotic – Non-living Ex). Water, soil

Each cycle has two parts: 1). Living 2). Non-living Elements are crucial for life and must cycle through the environment. Cycles of elements are ABIOTIC

Nitrogen Cycle a. Nitrogen is an important component of proteins. Elements= C,H,O,N. Also a component of nucleic acids. Elements = C,H,O,N,P. b. The nitrogen found in the air is in a form that some living things cannot use.

c. Use the picture to determine how we get nitrogen in a form that living things can use.

Nitrogen fixing bacteria convert nitrogen into that usable form Nitrogen fixing bacteria convert nitrogen into that usable form. **Plants will then take in the nitrogen that the bacteria converted. d. Use the picture to determine how animals obtain this usable form of nitrogen.

animals eat plants and therefore obtain nitrogen. e. Use the picture; determine how nitrogen is replaced in the soil. Animals put nitrogen back into the soil when they die. (when they are decomposed)

Question What would happen to the Nitrogen Cycle if nitrogen-fixing bacteria decreased? Less nitrogen would be converted and brought back into the soil Less nitrogen to plants

Carbon Cyle

a. Use the picture to determine the following: i. Where do plants get their carbon? The air What form is that carbon in? CO2

a. Use the picture to determine the following: ii. How do animals obtain carbon? They eat other things (plants or animals)

a. Use the picture to determine the following: How is carbon replenished (put back) in the soil? Dead things are decomposed.

Why is burning fossil fuels contributing to global warming? CO2 is a greenhouse gas and retains more heat in the environment