Presentation on theme: "ECOLOGY Ecosystems and Communities. I. The Role of Climate A. General Info 1. Climate is important in shaping Earth’s ecosystems 2. Species are sensitive."— Presentation transcript:
I. The Role of Climate A. General Info 1. Climate is important in shaping Earth’s ecosystems 2. Species are sensitive to climate and can only tolerate limited environmental conditions Why don’t we see banana trees growing in Maine?
B. Weather vs. Climate 1. weather = day-to-day conditions of Earth’s 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
C. Greenhouse Effect 1. CO 2, methane, H 2 O vapor, and other gases naturally trap solar heat in the atmosphere 2. Maintains Earth’s temp DRAW Fig 4-1, pg 87 Sunlight Some heat escapes into space Greenhouse gases trap some heat Atmosphere Earth’s surface Greenhouse Effect
II. Abiotic Factors (Non-Living) A.Light 1.Ecosystems are driven by solar energy Why? Temperature Temperature affects an organism’s metabolism Normal range is 0° – 50°C (32° - 122° F) C.Oxygen 1.Depth of life in soil affected by oxygen 2.Aquatic organisms are limited by oxygen supply in water
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
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?
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)
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)
Commensalism - One organism benefits, while the other is neither helped or harmed (ex. barnacles and whale)
Parasitism - One organism lives in or on another (host) and harms it (ex. mistletoe, fleas/ticks, tapeworm)
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)
a. Pioneer Organisms - first species to populate (e.g. lichens, grasses and mosses; help build-up the soil i. Lichens are a combination of two organisms (fungus and algae) that obtain nutrients through photosynthesis and by breaking down rocks
Climax Community - somewhat stable, permanent community (e.g. forest, desert, grassland)