Landscape ecology is the study of the interactions between the temporal and spatial aspects of a landscape and the organisms within it.
What do we mean by ‘landscape’?
It is worth observing that though fashionable, the use of the term ‘landscape’ is often applied rather loosely, and can include:
- A focus of attention, and a perceived quality often based on aesthetics e.g. ‘landscape planning’, landscape character areas, landscape view.
- A spatial scale and extent expressed in geographic terms e.g. ‘landscape scale’, several square kilometres.
- An arena within which to target action, e.g. projects aimed at forest landscape restoration.
- An entity with structural elements of patch, mosaic and corridor, reflecting a mix of ecosystems and habitats.
Many ecologists consider ‘landscape’ to be the latter point, any unit of the earth that contains heterogeneity: in vegetation structure, habitat type, soil type or any other attribute which could mean that organisms might react differently to different parts.
Lowland agricultural landscapes form typical ‘landscape mosaics’, with intermingled patches of woodland, arable fields and pasture, divided by hedgerows and roads
Much of landscape ecology has developed around the paradigm of a landscape mosaic consisting of patches (of e.g. habitat) arranged in a matrix (the predominant habitat or landcover), with elements that can be described as corridors, barriers, and edges. For more on the way landscapes can be divided into structural elements, read Landscape Ecology by RTT Forman & M Godron (1986, Wiley).
A question of scale
Landscape ecology research in British forestry has historically focussed on the area within the forest boundary but is now more likely be considered within catchments or other topographic or administrative units. Our definition of landscape scale is determined by the particular research issue being addressed. The appropriate scale may therefore vary from the forest (several square kilometres), through to the catchment or region (tens to hundreds of square kilometres) or to whole country (hundreds to thousands of square kilometres).
How do organisms interact with the landscape?
This question is the focus of a vast amount of research effort globally, but the following are some notable examples to give the general idea:
- Patches: species may prefer a certain kind of habitat, for example mature woodland, or ponds. Individuals of the species of concern may not be able to breed or feed outside of this type of habitat. The habitat thus defines the patch.
- Matrix: If one land use dominates the landscape, that landuse forms the matrix, e.g. arable land in eastern England. If the dominant land use is uniformly inhospitable, organisms become isolated in patches of suitable habitat. For example, some characteristic plants of ancient woodland cannot survive in arable fields, and do not have seeds equipped with a mechanism to disperse between isolated woodland fragments.
- Corridors: There has been a lot of research and debate about the role of hedgerows as corridors for small woodland mammals and birds. Such species may be able to move between woodland habitat patches along hedgrerows, whereas they might not feel safe enough to cross an arable field.
- Barriers: Roads, pipelines or fences might form barriers to movement of shy or less agile animals.
- Mosaic: Lesser horseshoe bats are an example of an animal that needs to live in a landscape mosaic. They sleep in old trees in mature woodland, then fly along hedgerows to open, wet places where they hunt for flies.