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AN INTRODUCTION TO ECOLOGY AND THE BIOSPHERE Ecology • What is ecology? • Study of interactions between organisms and their environment. • The environment includes both biotic and abiotic factors. • Biotic = living, abiotic = non-living • Ecology therefore will incorporate biotic and abiotic interactions Four Levels of Inquiry: 1. Organismal Ecology: • Ways the individual meets challenges posed by the environment. • What is this area of ecology concerned with? • Behavioral, morphological and physiological developments in the organisms that allow them to interact with their environment. 2. Population Ecology • What is a population? • Group of individuals of the same species living in the same area. • What is this area of ecology concerned with? • Factors that affect population size and composition. 3. Community Ecology • What is a community? • All of the organisms that occupy a particular area. • What is this area of ecology concerned with? • Involves predator/prey relationships, competition and disease. 4. Ecosystem Ecology • What is an ecosystem? • Includes all of the biotic and abiotic factors plus the community that exists in a specific area. • What is this area of ecology concerned with? • Energy flow, chemical cycling, primary productivity. Abiotic factors of the biosphere: • Biosphere - global ecosystem • temperature • water • sunlight • wind • rocks and soil • periodic disturbances (e.g. tornadoes, hurricanes…) Seasonal effects on climate: For example turnover in a lake: Biomes: • What is a biome? • A major community that is classified by the predominant vegetation and characterized by the adaptations of organisms that live there. Aquatic Biomes • Vertical stratification is important in aquatic biomes • Zonation in a Lake: Lake classification: • What is an oligotrophic lake? • Deep water and nutrient poor, water is very clear. • What is a eutrophic lake? • Shallower water, nutrient rich, murky water. Wetlands • What are wetlands? • Area covered with water that supports aquatic plants. • Very rich biome with diverse birds, invertebrates, mammals, etc. Estuary • What is an estuary? • The area where freshwater merges with salt water. • River nutrients enrich the estuary. • Salinity varies throughout the estuary. • Important source of oysters, crabs and fish. Marine Community • Zonation in a marine environment: Intertidal Zone • Rocky Shores: • What challenges are faced by organisms that live here? • Rough waves pounding the rocks • Salinity changes • Hard rocky substrate Coral Reef • Where are the producers in this community? • Symbiotic algae live in the coral, and are producers for this community. • Waves bring constant supply of nutrients • Water is shallow enough to allow for light penetration, and photosynthesis. Oceanic Pelagic Biome • Temperate oceans have seasonal turnover of nutrients like in lakes • Some tropical areas have stratification and no turnover of nutrients. • Photic zones have phytoplankton as producers. • Large animals move up to photoic zone to feed. Benthos • Ocean bottom of neritic and pelagic zones • Neritic benthic communities are very productive • Deep benthic communities - abyssal zone - are adapted to cold water, no light, and low nutrient levels. • Deep sea vents found here, producers are chemoautotrophs not photoautotrophs. Terrestrial biomes Review the characteristics of the different biomes and identify which biome is seen in the following slides... Desert biome Benthos Deciduous Forest Grasslands Tundra Desert Deciduous forest Tundra Coniferous forest Temperate grassland Savanah Tropical rain forest Taiga/Tundra Wetlands Where would this creature live? What adaptations does it have for life here? Where would these animals be found? Where would these short flowers be found? Regulators/Conformers • Cost benefit analysis of homeostasis • What is a regulator? • Organisms that can survive fluctuations in the environment through physiological regulations • What is a conformer? • Organisms that conform to their environment. Principle of Allocation • What is the principle of allocation? • Organisms have limited supply of energy that they can allocate to living. • The way they “spend” their energy will affect what sort of organism they are. Responses to Envoronmental Variations: • Physiological responses: • regulation and homeostasis are physiological responses • acclimation shifts an organisms’ tolerance to the environmental change • For example people who attempt to climb Everest must acclimate to the higher altitude. Morphological Responses • Responses that change the form or anatomy of the organism. • Mammals grow heavier coats n the cold months • plants are more morphologically plastic than animals. Behavioral Responses • Instantaneous response that can be easily reversed. • Moving away from unfavorable environment.
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