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ECOLOGY Ecosystems and Communities Slide 2 I. The Role of Climate A. General Info 1. Climate is important in shaping Earths ecosystems 2. Species are sensitive to climate and can only tolerate limited environmental conditions Why dont we see banana trees growing in Maine? Slide 3 B. Weather vs. Climate 1. weather = day-to-day conditions of Earths atmosphere 2. climate = average, year-after-year conditions of temperature and precipitation a. Can be measured over thousands of years b. Caused by heat trapped in atmosphere, latitude, winds and ocean currents, & precipitation Slide 4 C. Greenhouse Effect 1. CO 2, methane, H 2 O vapor, and other gases naturally trap solar heat in the atmosphere 2. Maintains Earths temp DRAW Fig 4-1, pg 87 Sunlight Some heat escapes into space Greenhouse gases trap some heat Atmosphere Earths surface Greenhouse Effect Slide 5 Greenhouse Effect Movie Slide 6 Intro to Ecosystems Movie Slide 7 II. Abiotic Factors (Non-Living) A.Light 1.Ecosystems are driven by solar energy Why? Temperature Temperature affects an organisms metabolism Normal range is 0 50C (32 - 122 F) C.Oxygen 1.Depth of life in soil affected by oxygen 2.Aquatic organisms are limited by oxygen supply in water Slide 8 D.Water 1.Water is necessary for life because a.Cells are mostly made of water b.Water dissolves chemicals within cells c.Most of the chemistry in living things involves adding or removing water d.Many organisms live in water Soil Conditions Soils physical makeup (clay, sand, rocks etc.) affects organisms Animals feed on plants, which are affected by soil conditions Slide 9 III. Biotic Factors (Living) Food Predation 1. Interaction where one organism captures and feeds on another organism Disease Competition 1. Organisms of the same or different species attempt to use an ecological resource in the same place at the same time For which resources do organisms compete? Slide 10 IV. Habitat and Niche A. All of the biotic and abiotic factors make up an organism's habitat 1. It is where an organism lives B. The way of life or role an organism plays in its environment is its niche 1. Place in the food web 2. Temperature range 3. Type of food 4. Reproductive season 5. No two species can share the same niche (competitive exclusion principle) Slide 11 V. Community Interactions Competition Predation Symbiosis - Relationship where two species live closely together (3 main types): 1. Mutualism - Both species benefit, (ex. honey bee and flower, clown fish and sea anemone, shark and remora) Slide 12 Commensalism - One organism benefits, while the other is neither helped or harmed (ex. barnacles and whale) Slide 13 Parasitism - One organism lives in or on another (host) and harms it (ex. mistletoe, fleas/ticks, tapeworm) Slide 14 Community Interactions Movie Slide 15 VI. Ecological Succession Succession 1. The process by which an existing community is gradually replaced by another one (may take hundreds or thousands of years ) Types of Succession Primary Succession - begins where there is no living organisms or soil (e.g. lava flows, above the timberline or bare rock exposed after glaciers melt) Slide 16 a. Pioneer organisms - first species to populate (e.g. lichens, grasses and mosses; help build-up the soil) i. Lichens are a combination between 2 organisms (fungus and algae) that obtain nutrients through photosynthesis and by breaking down rocks Slide 17 Climax Community - somewhat stable, permanent community (e.g. forest, desert, grassland) Slide 18 Primary Succession Slide 19 Secondary Succession a. Occurs in an established ecosystem after it is destroyed or damaged by a disaster (e.g. fires, plowed field, clear cut forest) Slide 20 Stages of Succession Movie