Available at Ecology Primer: What is Ecology? Nicklaus Kruger NISL An Optional Graphic can go here

  Ecology is the study of the interactions and interrelationships between organisms and their environments   The term “ecology” was coined by Ernst Haeckel in the nineteenth century, from the Greek:   Oikos, meaning “home”   Logos, meaning “to study” What is Ecology? 1,2,3

  Organisms in different environments are exposed to different stresses, and exhibit a variety of responses   Ecologists are interested in individual organisms, but also in patterns in nature beyond those embodied in organisms   The diversity and complexity of biological communities   Energy and nutrient flows   The structure and function of ecosystems   Ecologists are interested in individual organisms, but also in patterns in nature beyond those embodied in organisms   Human beings are a part of the natural world, having evolved to suit our changing environments as other organisms did   Recently, humans have acquired the ability to significantly alter our environments (through the use of tools, from fire to automobiles) Ecology: A bit about it all 1,2,3

  Ecology is comprised of many sub-disciplines   Autoecology deals with the individual organism in relation to its environment   Population ecology studies the dynamics of a single population in a single species   Community ecology examines the interactions among all the populations of different species living in a specific area   Ecosystem ecology is the study of the biotic (living) and abiotic (non- living) interactions in an ecosystem The Many Faces of Ecology 2,3,4

  Other more specific and highly-specialized sub-disciplines of modern ecology include:   Physiological ecology: examines how the bodily processes of an organism have adapted to its physical environment   Genetic ecology: examines the ways in which genes affect ecological processes, and vice versa   Systems ecology: uses mathematical modeling to examine the interactions among the many components of an ecosystem   Landscape ecology: examines the spatial patterns associated with ecological processes The Many Faces of Ecology (cont) 1,4

  Three fields of scientific study are particularly closely related to ecology   Natural history is the study of the habits, behaviour and interactions of organisms in their natural environments   Environmental science is the study of the ecological effects that human activities have on the natural environment   Conservation biology uses the principles of ecology to manage and maintain biological diversity in both natural systems and systems affected by human activity Sciences associated with Ecology 1,4

  Long before there was a science of ecology or evolution, there was natural history   Through the ages, people have observed and documented organisms and their interactions with the environment   The chief difference between natural history and ecology is that natural history is more of a descriptive study of natural phenomena, while ecologists attempt to test hypotheses and answer specific questions Natural History 1,3,4,5

Natural History: Some famous faces

  The organism is the fundamental unit of ecology   Organisms fall into natural groups called species   The natural world can be conceived as a set of patterns Ecology: Some important points1

  We have already defined ecology as the study of the interaction between the biotic and abiotic environments   Physical resources are abiotic factors that an organism requires for survival   Physical factors are abiotic parameters that define an area where a particular organism may be able to prosper   Limiting factors are factors that govern or control the presence of a species within a certain area Physical resources and limiting factors 1

  The ecosystem is an integral concept to ecology   It can be defined as: any situation where there is interaction between the biotic and abiotic environment   This can apply to units of variable extent:   Microecosystems   Mesoecosystems   Macroecosystems The Ecosystem Concept 6,7,8

  The outer layer of the Earth can be divided into three compartments: the atmosphere, hydrosphere and lithosphere   To this, ecologists normally add a fourth category: the biosphere   The biosphere is usually defined as that porion of the Earth that is inhabited by life The Biosphere 9

  The biosphere is divided up into several different ecosystem types   These are defined by climate   the interaction of temperature and rainfall is particularly important   Biomes vary in both biotic and abiotic make-up Biomes

Biomes: A few examples

  The study of organisms at the community level is made more difficult by the natures of communities themselves   To deal with this difficulty, ecologists introduced the concept of the ecological niche   The niche concept expresses the relationship of the individual to all aspects of its environment   The term was originally introduced by Joseph Grinell, and developed more fully by Charles Elton, and then George Hutchinson Ecological Niche 10,11,12

  Hutchnison defined the niche concept formally:   The activity range of a species can be described along every dimension of the environment, including biotic and abiotic factors   Each of these dimensions can be thought of as a dimension in space   We cannot visualize n-dimensional space where more than three dimensions are involved, but we can handle them mathematically Ecological Niche (cont)

  Niche overlap determines the degree to which species fulfill similar roles in an ecosystem   The more similar two species are, the greater the degree of competition between them   Within a species, all individuals are specialized to some degree with respect to the population as a whole Ecological Niche (cont…)

1. 1.Krohne, D.T. (2001) General Ecology (2nd Ed.) Brooks/Cole, Pacific Grove Wikipedia contributors. Ecology [Internet]. Wikipedia, The Free Encyclopedia; 2006 Aug 26, 00:20 UTC [cited 2006 Sep 1]. Available from: Weiner, J. (1995) On the practice of Ecology. The Journal of Ecology 83: de Laplante, K. (2004) Toward a more expansive conception of ecological science. Biology and Philosophy 19(2): Downie, R. (1999 ) What is natural history, and what is its modern role? Glasgow Naturalist 23(4): Golley F.B.: (1993) A History of the Ecosystem Concept in Ecology: More Than the Sum of the Parts, Yale University Press, London Wikipedia contributors. Ecosystem [Internet]. Wikipedia, The Free Encyclopedia; 2006 Aug 31, 12:39 UTC [cited 2006 Sep 1]. Available from: S.L. Pimm (1984)The complexity and stability of ecosystems. Nature 307: Wikipedia contributors. Biosphere [Internet]. Wikipedia, The Free Encyclopedia; 2006 Aug 31, 23:53 UTC [cited 2006 Sep 1]. Available from: Patten, B.C. and G.T. Auble (1981) System theory of the ecological niche. American Naturalist 117: G.E. Hutchinson (1959) Homage to Santa Rosalia, or Why are there so many kinds of animals? The American Naturalist 870: Colwell, R.K. and D.J. Futuyma (1971) On the measurement of niche breadth and overlap. Ecology 52: References