Reserve Design - Future Habitat

Future Habitat

Future habitat of the species we wish to protect is of utmost importance when designing reserves. There are many questions to think about when determining future species ranges: How will the climate shift in the future? Where will species move? What species will climate change benefit? What are potential barriers to these needed species range shifts? Reserves must be designed with future habitat in mind, perhaps incorporating both the current and future ranges of the species’ of concern.

The fundamental question in determining future species ranges is how the Earth is changing, both in the present and how it will change in the future. According to the United States Environmental Protection Agency the average surface temperature of the Earth has raised 1.2 – 1.4 °F since 1900. 1 °F of this warming has occurred since the mid-1970s, and at present, the Earth’s surface is heating up about 0.32 °F per decade. Predicted increases in global temperature range from 1.4 °C to 5.8 °C by the year 2100. Large changes in precipitation are also predicted to occur by both the A1Fl scenario and the B1 scenario It is predicted that there will also be large changes in the atmosphere and in the sea level. .

This rapid, dramatic climate change has affected and will continue to affect species ranges. A well-publicized study by Camille Parmesan and Gary Yohe published in 2003 that drew on data collected on more than 1700 species illustrates this point well. 434 of the species in their study were characterized as having changed their range and abundances in the last 17–1000 years, with a median value of 66 years. Of these species that had seen shifts, 80% of them had shifted in the direction predicted by global climate change. These range shifts averaged 6.1 km per decade toward the poles or upward. Many species colonized regions that had previously been cooler. An example of this was species of sea anemones thriving in Monterey Bay that had previously had a more southerly distribution. Species of lichens, and butterflies in Europe also followed the patterns of species range shifts predicted by models of future climate change.

These species were shown to be migrating northward and upward, to higher latitudes and sky islands. The data from this study also indicated “the dynamics at the range boundaries are expected to be more influenced by climate than are dynamics within the interior of a species range… response to global warming predicts that southerly species should outperform northerly species at the same site.”

These findings are of particular interest when considering reserve design. At the edges of a reserve, presuming that the reserve is also the species range if the species is highly threatened, climate change will be far more of a factor. Northern borders and those at higher elevations will become future battlegrounds for the conservation of the species in question, as they migrate northward and upward. The borders of today may not include the habitat of tomorrow, thus defeating the purpose of preservation by instead making the species range smaller and smaller if there are barriers to migration at the Northern and higher elevation boundaries of the reserve. Reserves could be designed to keep Northern migration a possibility, with boundaries farther to the North than might be considered practical looking at the today’s species ranges and abundances. Keeping open corridors between reserves connecting them to reserves to the North and the South is another possibility.