(by Jacqueline Loos)
“…Scientists have to use words correctly to communicate with each other” (Hall et al. 1997)
Sustainability science is an interdisciplinary approach, and therefore effective communication is needed between scientists from different disciplines. Both for theoretical developments and practical applications, accurate definitions of basic concepts are needed. One term that is often used in ecology and conservation biology is “habitat”.
However, the term “habitat” is described with a lack of precision and is misused in many cases, even in the natural sciences (Hall et. al 1997, Dennis 2003): Wildlife scientists, conservation biologists, plant ecologists and restoration ecologists developed inconsistent definitions for habitat and habitat-related words. Already in 1960, John H. Davis complained that the use of the term “habitat” was “vague and restricted”. Whittaker also stated in 1973, that the word is “most confused in usage”. Unfortunately, early attempts to clarify the semantic of the word failed or were even more confusing.
The word “habitat” derived from Latin and means “it inhabits”. Carl von Linné already used the term to describe the places where plants naturally live, and in scientific publications the occurrence of the word goes back until 1892. One very simple definition designates the geographical location of the home of the target organism. Whittaker recognized that habitat is “the range of environments over which a species occurs” (Whittaker 1973). In biological sciences, “habitat” sometimes is understood to have an even broader meaning: The environment provides more than just a space to live in – it must contain the resources necessary for the survival and the reproduction of a certain species. Therefore, the phrase always indicates a “species-specific entity” (Lindenmayer & Fischer 2006b). In 1997, Hall et al. suggested a standard terminology, namely “the resources and conditions present in an area that produce occupancy – including survival and reproduction – by a given organism”.
Often, habitat is allied to the concepts of patch and matrix, in which the patch is the (homogenous) unit where a species occurs and differs in appearance from its surrounding, and the matrix functions as a barrier to movement. But for many species, this concept does not fit, because the habitat of a certain species can include different elements which might play important roles during different life stages. Habitat provides both consumables and utilities for a certain species. Beneath alimentation, habitat has to provide conditions for existence and persistence and these requirements can vary enormously between species (Hall et al. 1997, Dennis 2003).
Misunderstandings of the word “habitat” have led to confusion with related concepts, for example “habitat loss”, which must not be confused with (and is not synonymous with) “loss of natural vegetation” (Lindenmayer & Fischer 2006a). To designate the habitats of animals, often the description of vegetation communities has been used, but this is inappropriate also, because many species use more than one vegetation type. Often the word “habitat” is misused as a surrogate for the term “environment”. One example of incorrect use of the term is “…the species was absent in habitat types lacking rocks”. In this case, it would probably be more correct to say “substrates”. The ambiguities and misuses of the word “habitat” should be avoided because conceptual clarity is essential to advance both conservation and sustainability science.
Davis, J.H. 1960. Proposals Concerning the Concept of Habitat and A Classification of Types. Ecology 41(3):537–541.
Dennis, R.L.H. 2003. Towards a functional resource-based concept for habitat: a butterfly biology viewpoint. Oikos 102(2):417–426.
Hall, L.S., P.R. Krausmann, and M.L. Morrison. 1997. The habitat concept and a plea for standard terminology. Wildlife Society Bulletin 25(1):173–182.
Lindenmayer, D.B. and J. Fischer. 2006a. Habitat Fragmentation and Landscape Change. An Ecological and Conservation Synthesis. Island Press.
Lindenmayer, D.B. and J. Fischer. 2006b. Tackling the habitat fragmentation panchreston. Trends in Ecology and Evolution 22(3):127–132.
Whittaker, R.H., S.A. Levin, and R.B. Root. 1973. Niche, Habitat, and Ecotope. The American Naturalist 107(955):321–338.