As a practical matter, empiricists begin studies of the habitat of a given organism by focusing on the areas in which it currently lives and reproduces. However, an area can provide suitable habitat for an organism without currently being occupied by any members of that species. The assumption that a habitat can be suitable but empty lies at the heart of many important concepts in basic and applied ecology. Metapopulation biology is based on the assumption that populations live in patches linked by dispersal, and that at any given time, some of the patches in a given landscape may be unoccupied. Similarly, restoration ecology is based on the premise that humans can change previously unusable habitat into habitat that is suitable for a given species, but that newly suitable habitat will remain empty until it is colonized (either artificially, via translocations, or naturally, via dispersal) by the members of that species.
The concept of empty, suitable habitat is also relevant to range shifts and range expansions, topics of particular interest for applied ecologists in this era of global warming. Many areas which currently sustain the members of a given species may become unsuitable in the future, as a result of changes in temperature, rainfall, and all of the changes in biotic factors that can occur as an indirect result of climate change. Conversely, other regions which currently lack any members of a given species may become suitable for them within a few decades, as a result of the direct and indirect effects of global warming.
While it is difficult to predict how climate change will affect the ranges of particular species, the geographic locations of suitable habitat are already beginning to shift for many organisms, and they are likely to shift even more in the coming years. As a result, ecological models which are based on the assumption that habitats are fixed in space across long periods of ecological and evolutionary time are gradually giving way to new approaches which acknowledge temporal shifts of habitat across the landscape.
Was this article helpful?