Ecology
- Ecology
- Is the study of interactions of organisms with one another and with their surroundings.
- An ecosystem is the physical features and living organisms in an area
- Biotic factors-living organisms
- Abiotic factors-non living ex. Rocks, water etc.
- A community is all of the organisms living together in an area
- Energy Flow-
- Energy cannot be cycled or used again!
- Sun is the ultimate source of energy
- Energy flows through an ecosystem from the sun to producers then to consumers.
- Producers
- Autotrophs-make their own food
- Example plants and certain bacteria
- Consumers (generally carnivores)
- Get energy from producers
- Primary-1st consumer-get energy from producers
- herbivores (eat plants)
- Secondary-2nd consumer (eats primary)
- Tertiary-3rd consumer (eats secondary or primary)
- Quarternary-4th consumer (eats tertiary and secondary)
- Ecological Pyramids
- Represent energy relationships among trophic(feeding) levels.
- 3 types
- pyramid of biomass
- pyramid of numbers
- pyramid of energy
E. Food chains
i. Simple feeding relationship
F. Food Webs-More complex then food chains
a. complicated network of feeding relationships
G. Cycles
i. nutrients move through the biosphere in a series of nutrient cycles.
ii. nutrients can be used over and over again
- Water cycle
- Movement of water from air to land and back to air again.
- Nitrogen Cycle-movement of nitrogen through biosphere
- Organisms require nitrogen to build protein
- Nitrogen makes up 78% of the air
- Found in wastes also
- Bacteria change nitrogen in atmosphere to nitrogen we can use, this is called nitrogen fixation.
- Plants use nitrogen to make plant protein
- Animals eat the plants and use the protein to make animal proteins
- When organisms die, the nitrogen goes back into the soil.
- Bacteria break down nitrogen in soil and make free nitrogen, this is called denitrification and nitrogen is returned back into atmosphere.
- Carbon Cycle and Oxygen
- Carbon is moved through the environment in the carbon cycle
- producers taken in carbon dioxide from the atmosphere during photosynthesis (carbon fixation)
- organisms release CO2 into the air during respiration.
- decomposers (worms and bacteria) break down waste and dead organisms, this releases carbon into the atmosphere.
- Carbon can be stored in oil or gas which can be used as fossil fuels. When they are burned, carbon dioxide is released.
- Carbon in atmosphere helps warm our planet (greenhouse effect). Too much Carbon raises the Earth’s temperature(global warming)
- Oxygen is moved through the environment in the oxygen cycle
- Symbiosis
- Relationships between organisms
- There are 3 types of symbiotic relationships
- Commensalism-one member benefits and the other is not harmed
- ex. Shrimp living within stinging cells of sea anemone (like Nemo)
- shrimp are protected from predators
- ex 2 barnacles on a whale
ii.Mutualism-two species live together and benefit from each other.
- ex. Clown fish and the sea anemone
- the fish chase away sea anemones predators, while the fish gets protected from its predators.
- Parasitism-one organism benefits, the other is harmed.
- ex. Tapeworm living in a humans intestine
- ex lice living on the scalp
- Succession
- An existing community of organisms is replaced by a different community over periods of time ranging from a few decades to thousands of years.
- Sometimes can occur where no living organisms ever existed.
- Ex. When a volcanic island arises from the sea, no life exists.
- First organisms to arrive are known as pioneer species
- examples of pioneers are lichens that live on a bare rock.
- lichens break down the rock and then mosses start to form. Life begins in the area with plants, then small insects, animals etc.
- succession can dramatically change an area
- succession can lead to climax communities
- stable collection of organisms
- usually indicated by the ones that are most obvious in the area.
- Ecosystem can return to the way it was
- after trees are cut down
- land is dug up for mining
- environmental damage has occurred
- Sometimes ecosystems never return to the way it used to be.
- Biomes
- Environment that has a characteristic climax community
- Terrestrial (land)
- Tundra-thin, moist topsoil over permafrost (frozen ground)
- Moss community
- Coniferous forest(taiga)-long winters, short summers.
- Pine trees and moose
- Deciduous forest-trees lose their leaves in the fall
- Grassland-dominated by grasses-prairies and savanna
- Deserts-dry areas
6. Rain Forest-lots of precipitation
- Tropical- found near equator;Diverse life
b. Temperate -moderate temp. and high humidity
-Redwoods
- Aquatic Biomes
- Marine-3 parts: ocean, intertidal and estuary
- Freshwater-lakes, ponds, rivers and wetlands
MarineFreshwater