Outline Ecology SCBI 113 Essential Biology Nuttaphon Onparn, PhD. 7 May 2009 Ecology Introduction Ecology and ecosystem Ecosystem Structure Function Interactions Biomes 1 2 Ecology Introduction Greek oikos+ logos(home + study) Distribution and abundance of organisms and their interactions with their environment. Ecosystem Unit of nature consists of living organisms that interact and function together in the environment. Ecology and Human Why do we need to know about ecology? To find food (hunter gatherers) To grow food (cultivation, agriculture) To understand nature (biologists, ecologists) Values Intrinsic values (scientific, pleasure) Extrinsic values (food, cloths, shelter, medicine; money) 3 4 Ecology and Evolution Ecology and evolution are closely related. Darwin Interactions between organisms and environment lead to evolution. Natural selection Timeframe Ecological timescale (e.g. seasons, years) Evolutionary timescale (e.g. 10 6 years) Example of cats and mice Ecology and Environment Ecology raises public awareness Silent Spring Rachel Carson (1962) Overuse of DDT affected birds (nontarget species) Public awareness Scientific discoveries Scientific communication Politicians/policy makers 5 6 1
Ecosystem Ecosystem Structure and Function of ecosystem Structure Abiotic factors Biotic factors Function Species interactions Nutrient cycles Ecosystem services Interactions Level of interactions in ecosystem Population level A group of individuals of the same species. Human population Community level A group of populations inhabit a particular area with potential to interact. Community on grassland Ecosystem level All communities and their surrounding Forest ecosystem 7 8 Abiotic factors Abiotic Factors Temperature Thermodynamics; range: 0-45 o C; Thermophiles Ectotherms, endotherms Water Solvent of life Salt and freshwater Abiotic Factors Sunlight Drive photosynthesis in green organisms. Main source of energy for the planet. Wind Moving air, amplifies effect of temperature. Increase evaporation. Flgged morphology 9 10 Flagging of tree limb due to wind 11 Doi Intanont (April 2, 2009) 12 2
Rock and soil Abiotic Factors Nutrients and ph limit the distribution of plants, and animals that associate with the plants. Climate Combination of effects from temperature, water, sunlight, and wind. Global climate vs local climate 13 14 15 16 17 18 3
19 20 Organisms and Environment How organisms respond to the environment? Physical factors can trigger responses in living organisms. Organisms that respond well will be fitter. Examples Hibernation Estivation Migration Biotic Factors Structure: biotic factors Species diversity Species abundance Species distribution Trophic levels 21 22 23 24 4
Trophic Levels Trophic levels Producers (plants, algae, cyanobacteria) Consumers Herbivores (eat plants) Carnivores (eat animals) Omnivores (eat both) Detritivores (eat detritus) Scavengers (eat remains) Decomposers Change organics to inorganics 25 26 Species Interaction Interspecific interactions Predation Parasitism Disease Competition Mutualism Commensalism Venus flytrap (กาบหอยแครง) Sundew (หยาดน าค าง) http://en.wikipedia.org/wiki/image:drosera_capensis_bend.jpg http://en.wikipedia.org/wiki/image:vft_ne1.jpg 27 28 Ecosystem services Ecosystem Services Fundamental life-support services for all life on Earth, that human and our technology cannot replicates. Nutrient cycles Pollinations Detoxify natural substances Climate moderation Etc. Nutrient cycles Carbon cycle Nitrogen cycle Phosphate cycle Water cycle Nutrient Cycles 29 30 5
31 32 33 34 Biomes Biomes A major biotic community characterized by the dominant forms of plant life and the prevailing climate. Total of all biomes/ecosystem = Earth (biosphere) Types of biomes Aquatic biomes Terrestrial biomes Aquatic Biomes Aquatic biomes World s major ecosystems Fresh or salt water (less than 1% or average 3% of salt) Coverage 75% of Earth s surface Impact Rainfall World climate Oxygen and carbondioxide consumption and production 35 36 6
Lake Stream and River Freshwater biomes Estuary 37 Wetland 38 Intertidal zone Coral reef Oceanic pelagic zone Marine Benthic zone 39 Marine biomes 40 Terrestrial biomes Terrestrial Biomes Biomes on land Climate determines type of terrestrial biomes. Climograph (precipitation and temperature) Vertical stratification Canopy, tree stratum, shrub, ground layer, litters, root layer Various ecological niche Horizontal (ecotone) 41 42 7
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Journal Trends in Ecology and Evolution References Textbook Campbell, N. A. (2008). Biology. San Francisco, Pearson Benjamin Cummings. Internet Ecology, http://en.wikipedia.org/wiki/ecology, retrieved May 2009 Ecosystem, http://en.wikipedia.org/wiki/ecosystem, retrieved May 2009 55 56 10