Desert shrubs create distinctive thermal microclimates in the desert landscape

Desert shrubs create distinctive thermal microclimates in the desert landscape. Because they also shade the landscape, plants both create and respond to microclimates. For instance, trees, shrubs, and plant litter (fallen leaves, twigs, and branches) produce ecologically important microclimates in many communities. For example, the desert landscape, which often consists of a mosaic of vegetation and bare ground, is also a patchwork of sharply contrasting thermal environments. Such a patchwork is apparent near Kemmerer, Wyoming, a cold desert much like the Gobi in Mongolia. Kemmerer can be bitterly cold in winter and blistering hot in summer. On one summer's day, Robert Parmenter and his colleagues (1989) measured the temperatures in various parts of the landscape. They found that while the temperature on bare soil soared to 48°C, a few meters away in plant litter under a tall shrub the temperature was only 21°C. Meanwhile, temperatures under low shrubs with less leaf area were a bit warmer but still not as hot as soil in the open. A small organism in this landscape could choose microclimates differing in temperature by 27°C!