640 likes | 855 Vues
Ecology. Study of organisms and their relationships with their env . 2 types of environmental factors. Abiotic – nonliving Ex. Rocks, air, soil, sun, precipitation, dissolved O2 Biotic – living Ex. Plants, animals, people, fungi.
E N D
Ecology Study of organisms and their relationships with their env.
2 types of environmental factors • Abiotic – nonliving Ex. Rocks, air, soil, sun, precipitation, dissolved O2 • Biotic – living Ex. Plants, animals, people, fungi
Habitat: place/area where org lives (ex. Fungi live on decaying logs) • Niche: role org plays in the env(ex. Fungi recycle nutrients) • Can help reduce competition
Levels of organization • Species – org. that interbreeds and produces fertile offspring (ex. Chipmunk)
2) Population – group of org. of the SAME species that live in same place @ the same time (ex. Chipmunks in Raleigh)
3) Community – A group of different pop. of species living in the same area (ex. Chipmunks, birds, oak trees in Raleigh)
4) Ecosystem – interactions among biotic and abiotic factors (chipmunks, plants, water, sun)
5) Biome: Large group of ecosystems sharing similar climate and org (ex. Tundra, rainforest, desert)
6) Biosphere: any aspect of the Earth that supports life (ex. Hydrosphere, geosphere, ________)
Food in nature 1) Producer: (Autotroph) org that makes its own food (ex. Plants)
2) Consumer: (Heterotroph) org that must consume its food • 5 kinds: • Scavenger: eats already dead animals (ex. Vulture, hyena) • Decomposer: breaks down & absorbs nutrients from organic materials (ex. Fungi, bacteria) • Carnivore: eats animals (ex. Lions) • Herbivore: eats plants (ex. Cows, bees) • Omnivore: eats plants & animals (ex. Raccoon, humans)
Trophic levels: each org in a food chain represents a trophic level Energy: As you increase trophic levels you lose energy. Measured in calories -only 10% of the energy is transferred from one trophic level to next (90% used for movement, heat, wastes)
Food chains: Show how matter & energy move through an ecosystem (linear) Ex. Algae zooplankton small fish heron bear (producer) (1⁰ consumer) (2⁰ consumer) (3⁰ consumer) (4⁰ consumer) 10,000cal 1,000 cal 100 cal 10 cal 1 cal Arrows () = direction energy is moving
Pyramids – can show energy as well as biomass (# of org) Least Most 3rd Level Consumers (1 kcal) 2nd Level Consumers (10 kcal) 1st Level Consumers (100 kcal) Producers (1,000 kcal)
Food Web -Made up of multiple, connected food chains -More realistic and complex
Wolves • http://www.coolestone.com/media/8021/How-Wolves-Change-Rivers---For-The-Better/#.Uwvn9LuYaUl
Ecosystem 2025 Activity Shrimp
Symbiosis The relationship between 2 diff species of org that “live together” 3 kinds:
1. Mutualism Both organisms benefit (food, space, protection) Ex. • Pollination: Insect benefits (food) and so does plant (reproduces) • Clownfish(protection) and anemone (protection)
2. Commensalism • One org benefits and the other is unaffected • Ex: remora fish eating shark leftovers
3. Parasitism • One org benefits while other is harmed • Ex. Tapeworm, tick, mosquitoes (can be vectors [carriers] of diseases such as malaria)
Tapeworm • http://www.medicalook.com/Parasitic_diseases/Tapeworm.html
Cymothoaexigua • isopod (iso = identical, and pod = foot) parasite makes its living by getting into a fish’s mouth through its gills, eating its tongue and then replacing the missing tongue with its own body. Now, everything that comes into the fish’s mouth can be nibbled on by the parasite. • Causes tongue to disappear. It grabs on to the tongue, and sucks the blood out of it. The longer this goes on, the more the tongue atrophies (a = no, and trophic = feeding) and shrinks away to nothing. Then the parasite grabs hold of the stump with its back legs and takes its place. An amazing picture of the isopod parasite C. exigua acting • as the tongue of a captured fish. It lives in the gulf of • California and usually selects the rose snapper as a host. • Every once in a while, a fish lands in the grocery store • with a parasite still hanging on, looking for the next meal. • I’m guessing that fish gets returned and a lot of store • credit is issued. Photo credit to Dr. NicoSmit. Talk about exceptional; this is the only known instance where a parasite functionally replaces a host’s own organ. The isopod is willing to act like a tongue, holding food up against the small teeth on the roof of the fish’s mouth, because this is how it ensures food for itself.
Population dynamics • Positively affect population size (more life): • Good weather • Territory • Food • Birth rate Hi • Deaths Lo • No hunting • Healthy/no disease
Population dynamics • Negatively affect population size (more death) • Natural disasters • Death rate Hi • Disease • Predators • competition
Carrying capacity • Max. # of org an ecosystem can support • Logistic growth curve (S curve) is based on carrying capacity • Limited space, resources, food
Limiting factor • Anything that limits the size of a pop. • 2 kinds 1) Density dependent: DEPENDS on the # of org • Ex. Competition, predators, disease 2) Density independent: DOES NOT depend on # of org • Ex. Natural disaster
Exponential growth (J-curve) • Acceleration of population (rapid) • Ex. Human pop • Assumption – unlimited resources 7 Billion - http://video.nationalgeographic.com/video/the-magazine/the-magazine-latest/ngm-7billion/ Clock - http://www.census.gov/popclock/
Human population pyramids • Age structure diagram showing the distribution of various age groups in a human pop. Ex. USA Ex. Japan, Italy Ex. Ukraine, Russia Ex. Mexico, India
Carbon cycle (C) • CO2 gas in the air • Plants photosynthesize – turn gas to solid (C6H12O6) • Consumers eat plants – use carbon to make energy & release CO2 back into atm • Dead org are converted into fossil fuels • Burning of f.f. releases CO2 into atmosphere
Water cycle (H2O) • H2O evaporates from bodies of H2O (lakes, streams), condenses to form clouds • Plants transpire releasing H2O • Humans respire releasing H2O • H2O comes back to earth as precipitation
Nitrogen Cycle (N) • N is found in the atm • N-fixing bacteria converts N from gassolid so plants can use the N to make proteins • Lightning also fixes N into a solid • Animals eat the plants, using N to make their own proteins • Animals excrete wastes or dies & N is returned to soil
Human impacts on the environment • Discuss the following with your partner: • List some impacts we have on the earth. • Are they positive or negative?
Human population growth • Strain on resources • Increased pollution, habitat loss, less biodiversity • Biodiversity – variety of species in an area • http://video.nationalgeographic.com/video/the-magazine/the-magazine-latest/ngm-7billion/
Global Warming • Trapping of warm air close to Earth’s surface due to emission of greenhouse gases such as CO2 & methane, H2O vapor, • Increase in greenhouse effect • Increase in global temperatures
An Inconvenient Truth clips 1) http://www.youtube.com/watch?v=NXMarwAusY4 2) http://www.youtube.com/watch?v=9tkDK2mZlOo&feature=relmfu 3) http://www.youtube.com/watch?v=1KkrlhoFbBM&feature=relmfu
Acid Rain • Rain that dissolves nitrogen and sulfur oxides in the air (from pollution) • Rain pH is less than 7 • Harmful for… • Plants • Aquatic life (fish, frogs) • buildings
Eutrophication • Process where water bodies get extranutrients more plant growth • Result of fertilizer/manure runoff from farmlands
Ozone depletion Ozone hole– caused by CFCs (*chlorofluorocarbons) from aerosols leaking into atm and eating away ozone • Ozone blocks harmful UV rays • No ozone = higher cases of skin cancers • No longer an issue – global ban on CFC use
Invasive species (exotic, non-native species): • Compete with native species • Grow fast, decrease biodiversity • Ex. Kudzu (Japanese vine), zebra mussel
Bioaccumulation – build-up of subst. in an org. (can be chemicals) due to pollution A. Lead: can cause learning/behavior problems in children