Plant Succession
Natural vegetation of a particular location evolves in a sequence of steps involving different plant communities. The evolutionary process is known as plant succession. Plant succession usually begins with a fairly simple community known as a pioneer community. The pioneer community, and each successive community alters the environment in such a way to permit new communities to occupy a site. These alterations of the environment include changes in site microclimate and soil conditions. A climax community is the result of a long period of plant
succession. Climax communities usually exhibit a good deal of species diversity and thus
are relatively stable systems. Disturbance renews a successional
sequence. Plant
succession was renewed after the explosion of Mt. St. Helens with the subsequent
disruption of biotic communities that inhabited the region. Human disturbance related to
tropical deforestation has renewed the successional sequence of plant communities in the
tropical rain forest. However, this Morning Edition (NPR) segment from
April 8, 1996 reports that disappearing forests poses a threat to the "
Biodiversity
in Madagascar" (7:15) |
(RealAudio Required)