Even in the Desert, Plants Feel the Heat of Global Warming

"Global warming is a hot topic, and it's causing concern for scientists studying winter annuals in the Sonoran Desert. " Desert winters have become warmer and dryer over years, but still climate changes have forced winter rains to arrive later in the year, forcing winter annual plants like the "curvenut combseed" to come out later when temperatures are colder.In 1982, Larry Venable (an ecologist at the University of Arizona in Tucson, started to study at "The Desert Laboratory on nearby Tumamoc Hill" so he could study "bet-hedging" in plants. Part of the studying was studying the arrival of the "Sonoran Desert" winter rains that push the germination of the winter annuals into later in the year (and has affected the types of winter annuals that live there. In wet years, there was a high density of plants and the maps they (the researchers make) get very full. Also, if the winter rains keep on arriving later, the germitation will keep on arriving later and later in the year, and "the plant community will continuously change and favor plants that thrive in colder environments."

http://www.livescience.com/environment/desert-plants-global-warming-bts-100402.html