Scope and Significance of Ecology : A review

Abstract

Once it was determined that rotifers could live for months without water, the current scientific study of desiccation tolerance could begin in 1702. In 1860, the debate over whether or not living things might be dried out without perish, led to the creation of a special French commission to settle the issue once and for all. Today in the year 2000, we know that some groups of animals and many species of plants are able to withstand desiccation while they are actively reproducing in the adult stage of their life cycles. There are a wide variety of lichens and bryophytes here, along with some ferns and a very few flowering plants, but no trees or gymnosperms. When plants are dried, they can withstand temperatures ranging from 272 to 100 _C and can live without water for more than ten years without significant loss of vitality. Plants that can withstand dry conditions are widespread over the globe, although they are most common in arid regions. These patterns raise two major questions. First, how can plants manage to survive periods of drought? The question then arises as to why desiccation-resistant plants are not more prevalent in the natural world. In light of recent findings from molecular and biochemical research, it is becoming clear that tolerance may be achieved via a variety of processes, many of which include shielding against oxidants and the re-configuration of macromolecules that occurs during dehydration.