Download Ecological Succession Another important concept related to biomes

Ecological Succession
Another important concept related to biomes is ecological succession.
Ecological succession is the non-seasonal change in the types of plant species that occupy
a given area through time. It progresses through stages from bare rock to a climax
community.
Succession is easiest to understand by using a generalized forest as an example. The next
few slides will show you the stages of succession.
Succession starts when some sort of disturbance causes an area to be cleared of
vegetation. A disturbance could be natural or human-caused; some of the many possible
types of disturbance include fire, flooding, disease, a volcano, logging, or climate change.
The first organisms to grow in the area are pioneer species. They have to be very tough
and able to adapt to difficult conditions. On rock, pioneer species are usually types of
bacteria and lichens, which are algae and fungi that live in a symbiotic relationship. On
bare sand, pioneer species are types of grasses, and in water, they are types of algae.
After the pioneer species have made the soil more habitable for larger plants, short-lived
annuals start to move in. These have short growing seasons and wide dispersal of seeds.
After a few years, the habitat is suitable for perennials, plants that can reproduce several
times over long lifespans.
Eventually the ecosystem can support full trees: the faster-growing softwoods like pines,
and finally, the slow-growing hardwoods. The hardwoods are the climax community, the
final stage of succession, in which no more major changes will occur to the array of
plants and animals until another disturbance occurs.
© K12 Inc.