<t all weather talk is small talk. Global anthropogenic climate change is the biggest conservation challenge of our lifetimes. An article from the Star Tribune discusses the ways climate change might affect Minnesota (http://www.startribune.com/local/228250501.html), providing yet another example of the conservation value of the Arb.
One of the major effects of climate change is that forest types are predicted to shift north. As the average temperature rises, the climate of a given latitude comes to resemble what has been historically characteristic of more southern latitudes. Since plant communities are largely determined by their climatic conditions, the more cold-hardy plants will begin to die off at the southern extent of their ranges, with warm-climate plants replacing them. This could mean that by the end of the century, the thick coniferous forests of the Boundary Waters of northern Minnesota could be replaced by grassy savannas dotted with bur oaks (Quercus macrocarpa)—much like the savannas in the Arb.
However, the transition may not be that easy. Climate change is happening at a pace much faster than many tree species can effectively expand their ranges. Some species may retreat before their southern counterparts advance, creating a window for opportunistic invasive species to take hold. If invasive species dominate, native species’ ranges will not simply shift, they will shrink. Extinction and biodiversity loss will soon follow.
All this makes the ecology of the Arb even more interesting. It represents what historically has been a site of transition, from prairie to oak savanna to deciduous forest. A changing climate means that everywhere is a site of transition, and it is possible the Arb will play a role in that. By preserving a variety of ecosystem types, it serves as a refuge to a diverse array of native plants and animals—a refuge that may be an important patch on a patchwork trail following a rapidly changing climate.
