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Ecology. Ecology. Ecology is the study of the relationships between living things and their interactions with the physical environment. All life is found in a thin band that surrounds the planet called the Biosphere .
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Ecology Ecology is the study of the relationships between living things and their interactions with the physical environment.
All life is found in a thin band that surrounds the planet called the Biosphere.
The biosphere extends from a few meters in the soil, to a few kilometers into the air.
The Biosphere Biosphere is made of biotic factors (living)
and abiotic factors (non living)
Biomes The biosphere is broken up into regions based on climate, & the resulting organisms.
Ecosystems The ecosystems are regions inside biomes that have the same climate. Ecosystems in different areas of Earth may have different organisms.
Communities Are all the living things that are found in an ecosystem. A forest community would have trees, deer, birds, bacteria, etc
Population All the creatures that are found in the same area and have the potential to reproduce together is considered a population Deer pop., tick pop., Pine tree pop.
biosphere ecosystem community population individual of a species
Niche and Habitat • In the ecosystem, each species has a niche and a habitat. • The habitat is where it lives, e.g. top of tree, open ocean, grasslands
Habitat and Niche An organism’s niche is what it does in that habitat (its lifestyle) e.g. eats a specific type of seed on a bush, hunts a specific prey
No more than one species can occupy a specific niche or there will be competition, and all but one species will ultimately die off.
Food Webs The main relationship between organisms is based on energy Organisms are placed into levels based on how they get their energy.
Trophic Levels The levels that organisms are placed into are called trophic levels (feeding levels). Producers- organisms that convert sunlight into chemical energy (glucose)
Trophic Levels Consumers- organisms that must eat other things for energy Herbivores- (primary consumers) eats only plants or producers
Trophic Levels Carnivores- (secondary consumers) eats only other consumers Ominvores- eats both producers and consumers
Trophic Levels Decomposers- breaks down large molecules into smaller ones to be reused by producers. E.g. bacteria and fungi
The flow of energy from one creature to another is a food chain. • Krill eats some algae, a cod eats the krill, a seal eats the cod, orca eats seal.
Algae minnow trout hawk
The combination of all the possible food chains in an ecosystem is a food web.
Energy Pyramids • Organisms are unable to utilize all the energy they consume. • Much of the energy is lost as heat.
Only 10% of the energy at one trophic level can be used by animals at the next trophic level. • The result is that there must be many more producers than herbivores & more herbivores than carnivores.
Biomass Because of the loss of energy at each trophic level, there is usually a larger mass of living tissue at the lower levels than at the upper levels.
BioMass Pyramid Secondary Carnivore Primary carnivore Herbivores Producers
Nutrient Cycles • Energy is not the only thing moved from one organism to another. • Nutrients (nitrogen, carbon, oxygen, water) are also cycled through the ecosystem
Nitrogen Cycle • Nitrogen gas (N2) is naturally found in the atmosphere. • N2 is unusable to most living things.
Some bacteria are able to change nitrogen gas into chemicals called nitrates, which are usable by plants. • The process of making nitrates is called nitrogen fixation
Plants use nitrates to make amino acids and proteins. • These proteins are then passed through the food web.
When an organism dies or gives off waste, the nitrogen trapped is changed back into nitrates or nitrogen gas by decomposing bacteria. • This process is called denitrification
