AEC 360  Ecology


Landscape Ecology

I.  Background

    A. The focus of this class is often at the smaller scales of individual locations or habitats, or else at very big scales of continents or the globe


    B.  A landscape is a large area composed of diverse habitat types


    C.  Landscape ecology is the study of how the types and arrangement of habitats affects populations, communities, and ecosystems

    D.  New technologies are increasing the power of landscape approaches
       - Global positioning systems
       - Aerial imagery
       - Satellite imagery
       - Geographic information systems

II.  Legacy effects: long-lasting effects of historical processes on modern day ecosystems


III.  Landscape ecology analyzes how the spatial arrangement of habitats affects populations, communities, and ecosystems

    A.  There are many links between landscape ecology and study of habitat fragmentation

       -  Fragment area affects lyme disease incidence
      
       -  Fragment area affects mammal diversity

       -  Some mammals dilute lyme disease


    B.  Because landscape ecology considers multiple habitats, boundaries between habitats, or edges, are important

       1.  A brief history of edge effects, I

            - term popularized by Aldo Leopold (1933)
            - "desirability of simultaneous access to more than one [habitat]"; and "the greater richness of [edge] vegetation" supported more individuals and species
            - a widely accepted “law of ecology” (Odum, 1958)
            - management maximized edge:area ratio

       2.  A brief history of edge effects, II

            - habitat edges as point of entry for invasive or weedy species that have detrimental impacts on species of conservation interest
            - new dichotomy "edge species" v. “interior species”
            - new management outlook: edge effects are bad because they reduce the amount of habitat available to sensitive species of interior habitats

             - Case study of edge effects on indigo buntings

                High edge patches have lowest success “Ecological Traps”

       3.  A brief history of edge effects, III

          - human created edges should be minimized, but natural or semi-natural edges between reserve and matrix habitat can be created to improve habitat for native species



    C.  Edge and other landscape effects are intrinsically related to matrix effects

       1.  The “matrix” is the habitat that intervenes habitats that we are focusing on


                -Effects in patches can spillover to the matrix



        2.  Contrast landscape and previous approaches



       3.  The matrix can affect what happens within patches, movement between patches

          -- case study from Ft. Bragg



       4.  The matrix around agricultural fields can increase pollination, yield


       5.  Ecosystem services provided by pollinators depends on landscape


IV.  Landscape ecology will interact powerfully with climate change to affect biodiversity


       1.  The amount of protected area is small


       2.  Landscape conservation will be needed to accommodate climate change