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Unit 2 Ecology. Ch. 4 Ecosystems & Communities. The Role of Climate. Plants & animals vary in their adaptations to temp., rainfall, etc. They also vary in tolerance for conditions outside their normal ranges. What Is Climate?.
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Unit 2 Ecology Ch. 4 Ecosystems & Communities
The Role of Climate • Plants & animals vary in their adaptations to temp., rainfall, etc. • They also vary in tolerance for conditions outside their normal ranges
What Is Climate? • Weather - the day-to-day condition of Earth’s atmosphere at a particular time & place • Climate - the average, year-after-year conditions of temp., & precip. in a particular region
What Is Climate? • Climate is caused by trapped heat by the atmosphere, latitude, transport of heat by winds & ocean currents, & amount of precip. • Energy from sunlight drives Earth’s weather & helps determine climate
The Greenhouse Effect • Carbon dioxide, methane, water vapor, & other atmospheric gases trap heat energy & maintain Earth’s temp. range • These gases function like the glass windows of a greenhouse
The Greenhouse Effect • Just as the glass keeps the greenhouse plants warm, these gases trap the heat energy of sunlight inside Earth’s atmosphere • Greenhouse effect - the natural situation where heat is retained by the layer of greenhouse gases
What Shapes an Ecosystem? • Biotic factors - living things within an ecological community • Ex.) plants, animals, etc. • Abiotic factors - physical, or nonliving, factors that shape an ecosystem • Ex.) climate, temp., precip., rocks, etc.
What Shapes an Ecosystem? • Biotic & abiotic factors determine the survival & growth of an organism • Habitat - the area where an organism lives
What Shapes an Ecosystem? • If an organism’s habitat is its address, its niche is its occupation or job • Niche - the full range of physical & biological conditions where an organism lives & the way the organism uses those conditions • Includes: how it obtains food, the type of food it eats, how it reproduces, etc.
What Shapes an Ecosystem? • No 2 species share the same niche in the same habitat
Community Interactions • Community interactions, such as competition, predation, & various forms of symbiosis, can affect an ecosystem • Competition: • Occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time
Community Interactions • Competition: • Resource - refers to any necessity of life, such as water, nutrients, light, food, or space • Direct competition in nature often results in a winner & a loser, with the losing organism failing to survive
Community Interactions • Competition: • Competitive exclusion principle - states that no 2 species can occupy the same niche in the same habitat at the same time
Community Interactions • Predation: • Predation - an interaction where 1 organism captures & feeds on another organism • The organism that does the killing & eating is called the predator • The food organism is the prey
Community Interactions • Symbiosis: • Symbiosis - any relationship where 2 species live closely together • Ex. of symbiotic relationships: mutualism, commensalism, & parasitism • Mutualism - both species benefit from the relationship
Community Interactions • Symbiosis: • Commensalism - 1 member of the relationship benefits & the other is neither helped nor harmed • Parasitism - 1 organism lives on or in another organism & harms it • The organism that the parasite is feeding on is called the host
Ecological Succession • Ecosystems are constantly changing in response to natural & human disturbances • As an ecosystem changes, older inhabitants gradually die out & new organisms move in, causing further changes in the community
Ecological Succession • Ecological succession - series of predictable changes that occurs in a community over time • It may be caused from slow changes in the physical environ., or from a sudden natural disturbance from human activities, such as clearing a forest
Ecological Succession • Primary succession - succession that occurs on surfaces where no soil exists • It occurs on bare rock exposed when glaciers melt • Pioneer species - the first species to populate the area, often lichens
Ecological Succession • Secondary succession - community interactions that tend to restore the ecosystem to its original condition • Usually takes place after a fire, or when land cleared for farming is abandoned
Biomes • Biome - terrestrial communities that covers a large area & is characterized by certain soil & climate conditions & particular plants & animals • Variations in plants & animals help different species survive under different conditions in different biomes
Aquatic Ecosystems • Aquatic ecosystems are determined by depth, flow, temperature, & chemistry of the overlying water
Aquatic Ecosystems • Freshwater ecosystems can be divided into 2 main types: flowing-water ecosystems & standing-water ecosystems
Aquatic Ecosystems • Marine ecosystems can be divided into 3 main types: intertidal zone, the coastal ocean, & the open ocean