Warming climate shrinks conifer habitat

  In "A glimpse of the past in a grain of pollen," Cathy Whitlock comments that lodgepole pine probably has a bright future due to its ability to adapt to a warming climate (HCN, 5/30/05: A glimpse of the past in a grain of pollen). The question is: How warm? Since all high-elevation conifers (including lodgepole pine) are faced with a retreat upslope (growth at higher elevations) in a warming climate, and since land area decreases with altitude, their prospects of long-term survival don’t seem so great. This would be especially so in Southern California, where lodgepoles start around 8,000 feet. In a warming climate they will soon run out of room, since the highest peak is about 11,500 feet, and relatively little land is above even 8,000 feet. Conifers are generally considered relicts of wetter, cooler times when they grew at much lower elevations than now.

Geoffrey L. Rogers
San Diego, California