What Is the Definition of Landscape Ecology?

Landscape ecologists study the interactions of species in a diverse landscape.

The term "landscape ecology" first was described in 1950 by Carl Troll, a German scientist who studied the distributions of species across geographic space. Landscape ecology began to gain ground as a science during the 1980s, and newer technologies such as aerial photography, satellite imagery and computer mapping have enabled ecologists to gain a new perspective on how species use landscapes. Landscape ecology focuses on how spatial patterns influence the interactions among species and between species and their environment.

Landscape Patches and Heterogeneity

Natural landscapes are heterogeneous, or structurally variable. Heterogeneity is the result of geological, climatic and biological factors as well as human land use practices. The term "patch" is used to describe an area on a landscape that differs from its surroundings in nature or in appearance. Landscape ecologists view the landscape as a quilt-like mosaic comprised of patches of different types. The pattern of the landscape mosaic influences the movements and interactions of species.

Ecological Boundaries

Boundaries are the interfaces between patches of different types. Conditions within one patch, such as a forested area, may be very different from another patch, such as an adjacent open meadow. The boundary between two patches generally includes characteristics of each patch and serves as a transition zone for species that use the landscape. In a 2003 article in "BioScience," scientists identified four types of flows that cross boundaries: materials, energy, organisms and information. The width of the boundary depends on the type of flow. The transition between organisms from grass species to tree species at a meadow-forest boundary may result in a narrow boundary zone, whereas encompassing the full transition from high light levels in a meadow to lower light levels on the forest floor may require a wider boundary zone.

Habitat Fragmentation

Habitat fragmentation occurs when patches are broken up into smaller ones, often as a result of human alteration of the landscape. Habitat fragmentation results in a larger proportion of boundary area, or habitat edge, relative to core patch area. Habitat fragmentation is a concern because many species are sensitive to conditions in the boundary area, where they may be more susceptible to predators, competitors or inhospitable environmental conditions.

Habitat Connectivity and Corridors

Species whose habitat has been fragmented can be helped by increasing habitat connectivity. Landscape ecologists use geographic analysis techniques to identify locations to preserve or restore patches of habitat that contribute to the size of existing habitat patches. Similarly, they can identify corridors that facilitate movement of species between larger patches.

Issues of Scale

Landscape ecology is typically thought to apply to large-scale, landscape-level systems, but it can apply equally to small-scale systems. Landscape ecology focuses on the interactions between spatial patterns and ecological processes, and the scale used is determined by the species and processes under study.

References

• "Annual Review of Ecology, Evolution, and Systematics"; Landscape Ecology: What is the state of the science?; Monica Turner; December 2005
• "Annual Review of Ecology, Evolution, and Systematics"; Toward an integration of landscape and food web ecology: the dynamics of spatially subsidized food webs; Gary A. Polis, Wendy B. Anderson and Robert D. Holt; December 1997
• "BioScience"; A framework for a theory of ecological boundaries; Mary L. Cadenasso, Steward T. A. Pickett, Kathleen C. Weathers, and Clive G. Jones; August 2003