researcher explore the morphological physiological and behavioral adaptations that al lows individuals to live in that particular area want to know how these individuals interact with organisms and with their surrounding Ch 52 An Introduction to Ecology 52 1 Levels of Ecology Organismal Ecology environment Population Ecology change over time Community Ecology particular area quences of those interacts spond to disturbances ex fires floods Ecosystem Ecology nents mosphere and soil or water Global Ecology population group of individuals of the same species researchers focus on how the number and distribution of individuals in a population community consists of populations of different species that interact with each other in a researchers ask questions about the nature of the interacts between species and the conse concentrate on predation parasitism and competition OR explore how communities re ecosystem consist s of all the organisms in a particular region along with abiotic compo study how nutrients and energy move along organisms and through the surrounding at biosphere thin zone surrounding the Earth where all life exist field of global ecology is rapidly growing want to quantify the effects of human impacts on the biosphere people always modifying landscape and releasing massive amounts of energy and nutrients to biosphere causes changes the actions of people in one part of the world may alter distant ecosystems this creates difficult education and public policy challenges Conservation Biology Applies All Levels of Ecological Study conservation biology the effort to study preserve and restore threatened genetic diver sity in populations species diversity in communities and ecosystem function prescribe remedies for threatened environments to preserve biodiversity clean air pure water and productive soil 52 2 What Determines the Distribution and Abundance of Organisms understanding why organisms are found where they are is one of ecology s most basic biogeography study of how organisms are distributed geographically no species can survive the full array of environmental conditions present on Earth temperature is an important factor has big impact of physiology of organisms organism limited in their ability to regulate their own temperatures no organisms can thrive in both hot springs and cold ocean water TRADE OFF because of fitness trade offs organisms tend to be adapted to limited set of physical con all organisms have a specific range of tolerance of abiotic conditions the ability for organism to live in a particular area is limited by biotic factors can be caused by competition disease reproductive reasons etc ex yucca moths lay eggs on flowers of yucca plants can t exist outside the range of yucca tasks Abiotic Factors ditions Biotic Factors plants changing ex songbird are limited to alpine habitats above range of diseases mosquitoes History Matters Past Abiotic and Biotic Factors Influence Present Patterns distribution of organisms is determined by past events as well as present ones abiotic and biotic factors that influence the distribution of organisms are constantly events have important impact on dispersal dispersal the movement of individuals from their place of origin to the location where they live and breed as adults Alfred Russel Wallace was among the first to document this The Wallace Line Barriers to Dispersal Wallace realized the plants and animals native to the more northern and western islands were very different from the species found on the more southern and eastern islands working on the Malay Archipelago Wallace line separates species with Asian and Australian affinities exist because a deep trench in the ocean maintained a water barrier resulted in the formation of land on either side of the line remained isolated even when most of the islands became connected The Influence of Humans people transported thousands of species across physical barriers to new locations sometimes purposefully or sometimes by accident invasive species exotic species that rapidly spreads and competes successfully with the native species mircoorganisms can be introduced to a new area effects species distribution by causing disease people continue to influence the distribution of species by affecting abiotic and biotic factors Biotic and Abiotic Factors Interact CASE OF THE ARGENTINE ANT invasion creates huge pest control problems and has grave ecological implications researcher observed that the invasive ants tend to wipe out the native ants experiment set up 28 plots in the contact zone between the invasive and native ants inva conclusion interaction between biotic and abiotic factors slowed the spread of invasive invasive ants more at a competitive advantage in moist soils disadvantage on dry soils sive ant activity measured ants more than the abiotic factors alone compare to native ants information can help predict Argentine ants dispersal pattern and design strategies to limit range of every species is limited by combination of abiotic and biotic factors that oc range of a species depends on the capacity to survive climate conditions the ability to find food and avoid being eaten and the ability to disperse the spread of them curred in the past and present 52 3 Climate Patterns Why Are the Tropics Wet one of the most striking climate patterns involves precipitation ares along the equator receives more moisture while areas 30 degrees latitude north and south of the equator are among the driests hadley cell major cycle in global circulation explains why the tropics are wetter than the regions 30 degrees latitude north and south areas with rising air tend to be wetter than regions with descending air Why Are the Tropics Warm and the Poles Cold areas of the world are more warmer if they receive a large amount of sunlight per unit area MORE ENERGY tion per unit area areas are colder if they receive a small amount of sunlight per unit area LESS ENERGY at the equator the sun is directly above receives the maximum amount of solar radia because of the shape of the earth when moving away from the equator towards the poles sunlight arrives at a much lower angle much less energy receives per unit area What Causes Seasonality in Weather seasons regular annual fluctuations in temperature precipitation or both result of the earth tilting the northern hemisphere is tilted toward the sun during June receives the largest amount of solar radiation per unit area southern hemisphere receives
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