Chapter 52Ecology study of interactions between organisms and their environmentClimate The long term prevailing weather conditions in a given area Environment has 2 parts:-abiotic-bioticAbiotic chemical and physical aspects of the environmentBiotic living organismsOrganismal ecology physiological, morphological, and behavioral ways an organism meets its abiotic environmentPopulation Ecology - interactions among individuals in a population that affect the size and distribution of a populationCommunity Ecology interactions among all the organisms in a given area. How do predation and competition affect populations?Ecosystem sum of all the communities and abiotic factors-community of organisms in an area and the physical factors they interact with Community A group of populations of different species in an areaPopulation A group of individuals of the same species living in an area Biosphere sum of all the ecosystems on the earthFactors controlling the distribution of organisms -Dispersal-Biotic factors-Abiotic FactorsBiotic factors (other species)PredationParasitismCompetitionDiseaseAbiotic factors Chemical factors:Water OxygenSalinitypHSoilNutrientsPhysical factors:TemperatureLightSoilStructure FireMoisture2 most important abiotic factorsTemperatureRain fallMacroclimate Climate patterns on the global, regional, and landscape levelMicroclimate Climate patterns that pertain to very fine, localized patterns, such as those encountered by the community of organisms that live in the microhabitat beneath a fallen logGlobal climate patternsare determined by:Latitude and proximity to oceans-also local geographyCause of seasonality Earth’s titled axis of rotation and its annual passage around the sun cause strong seasonal cycles in middle to high latitudes-changing angle of the sun over the course of the year affects local environments Effect of bodies of water on climateOcean currents influence the climate along the coasts by heating/cooling overlying air masses that pass across the landCoastal regions are usually wetter than inland areasBecause of the high specific heat of water, oceans and large lakes moderate the climate of nearby land Effect of mountains on climateMountains influence air flow over land -when warm moist air approaches a mountain the air rises and cools releasing moisture on the windward side of the mountainOn the leeward side of the mountain, cooler, dry air descends and absorbs moisture-mountains also affect the amount of sunlight reaching an area which affects local temp and rainfallMajor terrestrial biomes-Major factors determining the biomes-Temperature and rainfallBiome Major life zones characterized by vegetation type (in terrestial zones) or by the physical environmetn (in aquatic zones)Climate effect on terrestrial biomes-because of the latitudinal patterns of climate, terrestial biomes showlatitudinal patterns in where they are found-the range of precipitation in northern coniferous and temperate forests is similar but temperate forests are genrally warmer-grasslands are typically drier than both forests and deserts are the most dryGeneral features of terrestrial biomes-most terrestial biomes are named for major physical or climatic features and for their predominant vegetation-temperate grasslands have a moderate temperature and is dominated by various grass species-vertical layering is an important feature of terr. biomes: many forrests include a canopy (upper), low tree layer, shrub understory, ground layer, forrest floor and root layerEcotone Area of integradation (terrestial biomes usually grade into each other)Climograph A plot of the annual mean temperature and precipitation in a particular region Tropical forest Equatorial and subequatorial regionsConstant rainfall in tropical rainforestsSeasonal rainfall in tropical dry forestsHigh year round temperature with little variationLayered forests with competition for light Highest animal diversity than any other terrestial biomes Dessert Occur in bands near 30 degrees north and south latitude Low rainfall less than 30 cm a yearTemperature is variable seasonally and dailyWater conservation is an adaptation for plants/animalsSavannah Equatorial and subequatorial regionsSeasonal rainfall with dry seasonswarm year round but more seasonal variation than rainforestslow – med. low rainfall (12- 20 inches/year) rainfall is seasonal and drought commonChapparral Midlatitude coastal regions Rainfall is seasonal with rainy winters and dry summersFall, winter, spring are all coolcool winters, hot summers low – med. low rainfall (12- 20 inches/year) rainfall in winter and drought commonTemperate Grassland Rainfall is seasonal- dry winters and wet summers very cold winters, hot summers med. low rainfall (20 - 40 inches/year) rainfall in summer and drought commonNorthern coniferous forests Largest terrestrial biome on earth Annual precipitation with periodic droughts, however coastal coniferous forests are temperate rain forests that may receive over 300 cm of rainfall/yearWinters are cold summers may be hot Temperate broadleaf forestMainly at mid latitudes in northern hemisphere Rainfall is 70-200 cm annuallyWinters average around 0 degrees C while summers are hot and humid Tundra 20% of earth’s land surface-areas of the arctic High winds and low tempsAverage precipitation of 20-60 cm annually Winters are very cold summers range less than 10 degrees CAquatic biomes Marine biomes= salt concentrations that average around 3%Freshwater biomes= less than 0.1% salt [ ] Oceans make up the largest marine biome covering about 75% of earth -biomes are vertical and horizontally layered for both fresh and salt waterPhotic zone Upper zone where there is sufficient light for photosynthesisAphotic zone Lower zone where little light penetratesAbyssal zone Deep in the aphotic zone, the part of the ocean 2,00-6,000 m below the surfaceBenthic zone The bottom of all theaquatic biomes (deep or shallow)-made up of sand and organic and inorganic sediments-organisms called benthos live here that eat dead organic matter called detritus -cold-Thermocline Layer of abrupt temperature change that separates the more uniformly warm upper layer from the uniformly cold deeper watersCHPT 53Density The number of individuals per unit area or volumeDispersion The pattern of
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