Principles of Ecology 1 What is ecology a Study of the factors that govern the distribution and abundance of organism in natural environments 2 Basic habitats environments a Terrestrial b Aquatic i Freshwater ii Marine 3 Ecological Niche a The way a species relates to its environment b Requirements i Food and nutrients ii Resources iii Particular physical and chemical conditions 4 What factors limit which and how many organisms live where a Vegetation temperature resources b Physical land water c Chemical fresh saline water d Terrestrial species out competing for food e Predation heavy grazing mollusks preventing bacterial mats from 5 Ecosystem the organisms of a community and the physical environment growing they occupy Environments scale 1 Biogeography distributions and abundances of biota on a broad geographic a Main limitation climate i Long term distribution of global temperature precipitation humidity wind atmospheric pressure Interaction of ocean and atmosphere and long and biology ii b Physical barrios 2 Atmosphere a Temperature earth s surface is warmed by the sun i CO2 in atmosphere retains some heat 1 Tilt of earth affects solar insulation temperature and b Circulation complicated by the Coriolis effect wind direction and climate Earth s rotation c Net transport air sinks at the poles rises at the equator d More complicated i Circulation cells from rising sinking of air and Coriolis e Influences distribution of environments 3 Terrestrial realm a Vegetation patters parallel climatic zones i Tropics ii Savannahs grasslands iii Deserts iv Tundra v Glaciers vi Forests 1 Temperate 2 Coniferous b Moister and temperature c Climate change with elevation altitude d Fossil plants reflect paleoclimatic conditions i Used to reconstruct climate conditions in past ii Cycads only found today in tropics subtropics 4 Marine realm a Large scale circulation b Ocean currents wind driven i Large scale wind patters and Coriolis ii Large gyres form c Polar circulation i Sea ice leads to more saline water ii Cold dense water sinks iii Antarctic waters flow north at depth iv Arctic waters flow south at surface d Marine biota varies with water depth Implications of depth i ii Light iii Temperature iv Water movement v Salinity e Biota according to limiting factors i Photic has light for photosynthesis ii Pelagic mobile swimmers 1 Phytoplankton 2 Zooplankton iii Benthic suspension and deposit feeders f Temperature i Reefs g Salinity i Fresh ii Marine iii Brackish mixed iv Hyper saline hot arid high evaporation v Few species can tolerate rapid fluctuations h Shallow morphologic zones i Near shore 1 Barrier islands sand islands ii Marshes low lying vegetated iii Epicontinental seas broad inland seas 5
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