BSC2011 Exam 4 Ecology Lecture 26 Introduction to Ecology Reading Chapter 52 Concepts Know that ecology is studied at the levels of analyzes factors that affect population size concerned with how an organism s structure o Individual ecology single species physiology and behavior meet the challenges posed by its environment o Population ecology group of same species and how and why it changes through time o Community ecology group of populations such as predation and competition affect community structure and organization cycling between organisms and the environment of energy materials and organisms across multiple ecosystems o Ecosystem ecology community of organisms o Landscape ecology connected ecosystems emphasizes energy flow and chemical examines how interactions between species focuses on the factors controlling exchanges o and Biosphere ecology global ecosystem examines how the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere Understand that ecology is the study of factors affecting the distribution and abundance of organisms o Ecology o Why do wales migrate or why does a certain type of tree grow where it does the study of factors influencing the distribution and abundance of organisms would be questions an ecologist would ask o Why do species occur where they do Ecology analyzes these factors including biotic living other organisms and abiotic factors non living chemical physical factors such as temperature sunlight water nutrients etc Understand that global climate is determined by the pattern of solar radiation striking the surface and local features such as mountains and bodies of water o Climate is the long term prevailing weather conditions in a particular area Main components are temperature precipitation sunlight and wind all of which are affected by the solar o Earth s curved shape creates different intensities of solar radiation resulting in different areas for populations to arise o Earth s tilt causes seasonal variation in the intensity of solar radiation The planet is tilted by 23 5 therefore the tropics experience the greatest annual input of solar radiation and the least seasonal variation The seasonal variations of light and temperature increases toward the poles Page 1 o Intense solar radiation near the equator initiates a global pattern of air circulation and precipitation High temperatures in the tropics 23 5 cause warm air to rise and move toward the poles creating abundant precipitation in the tropical rainforest regions That dry air descends absorbing moisture from the land and creating a climate conductive to the desert regions around 30 The hot air rises again and releases abundant precipitation around 60 and then dry air rises again creating comparatively rainless and bitterly cold climates of the polar regions o Air flowing close to the surface creates global wind patterns that result from the heat of the tropics overlying air masses o Ocean currents influence climate along the coasts of continents by heating or cooling 1 Warm air over land rises 2 Air cools at high elevation 3 Cooler air sinks over water 4 Cool air over water moves inland replacing rising warm air over land o Mountains affect the amount of sunlight reaching an area and also the local temperature Every 1000 meter increase in elevation produces a temperature drop of approx and rainfall 6 C o When moist air moves in off the ocean and encounters mountains it flows upward cools at higher altitudes and drops a large amount of precipitation The other side of the mountain is left dry known as a rain shadow and a desert is often present Know that aquatic habitats are determined by the proximity to shore light bottom vs open water nutrients o The plants and animals in a particular zone are suited to survive in that zone Even animals on the sea floor manage to survive on the falling of nutrients from the surface Know that terrestrial habitats are determined by temperature and moisture o Temperature and moisture affect what kind of plants and animals and survive and reproduce in an area Ex high temp low moisture results in dry deserts with animals suited to that environment Population group of individuals of the same species living in an area Terms Community group of populations of different species in an area Ecosystem community of organisms in an area and the physical factors with which the organisms interact Biome major terrestrial or aquatic life zones in the Earth lakes wetlands deserts tundra etc Benthic the ocean floor made up of sand and organic and inorganic sediments Aphotic zone where little light penetrates Pelagic the vast realm of ocean blue water Photic zone where there is sufficient light for photosynthesis Page 2 Wetland area swamped by water at least some of the time supports plants adapted to water saturated soil River streams of water with a current Estuary transition area between river and sea Seawater flows up during rising tide down turning falling tide Coral Reef formed largely from the calcium carbonate skeletons of corals live in photic zone of relatively stable tropical marine environments with high water clarity primarily on islands and edges of continents Tropical Forest areas in the tropical regions layer with trees Rain forests 200 400 cm annual rainfall or dry forests 150 200 cm annually and a six to seven month dry season Desert occur near 30 north and south precipitation is low and highly variable less than 30 cm year Temperate plains and prairies such as the flatlands of the central United States Broadleaf Forest characterized by thick trees and distinct seasons such as central Europe Lecture 27 Populations and Life History Reading 53 1 and 53 2 Understand that populations can be described by size density dispersal and survivorship o Populations can be described by density the number of individuals per unit area or volume Ex of trees in one square kilometer Scientists use many techniques to estimate population density such as the mark recapture method defined below o Populations can be described by dispersion pattern of spacing among individuals Variations in local density provides insight to environmental interactions and social interactions between individuals of a population Common patters are Clumped many individuals together in patches such as fungus on a log Uniform evenly spaced often a result of territoriality where individuals compete for space such as penguins exhibiting
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