Ecological Succession

Ecological Succession Definition of succession: The regular progression of species replacement in a changing ecosystem (= stages/steps of an ecosystem changing as different species replace others) http://www.blueplanetbiomes.org/climate.htm

Types of Succession Primary Succession Takes place in areas that have not supported communities before or no life exists anymore Secondary Succession Takes place in an area that had once supported communities

Primary Succession Starts with: Bare Rock Lava Flows Sand Dunes Clear/cold Lakes http://www.hawaiipictures.com/pictures/volcano_lava.html

Primary Succession First species to show up in the community is called the Pioneer Species Lichens and Moss Native Prairie Grass

Succession Each intermediate community that appears after the pioneer species is called a Seral Community. Each seral community alters the physical factors of the area May have small shrubs, start to have trees such as Jack Pine and Aspen May have small animals such as rabbits, squirrels, deer

Succession The last community to show up in an area is called the Climax Community. This community is stable and permanent. A state of homeostasis has been met. May have large trees such as Balsam Fir and White Spruce May have animals such as elk, bear, wolves, owls. http://www.blueplanetbiomes.org/deciduous_forest.htm

Secondary Succession Usually occurs after a disturbance or natural disaster EX: fire, landslides, floods, wind, farming http://www.sover.net/~kenandeb/fire/hotshot.html

Primary Vs. Secondary Succession Secondary Succession tend to develop faster because typically there is already a soil or nutrient base present – there may even be some seeds or other dormant life. Both types of succession go through similar phases of pioneer, seral, and climax communities.

Primary Succession Balsam fir, paper birch, and white spruce Time Small herbs and shrubs Heath mat Jack pine, black spruce, and aspen Balsam fir, paper birch, and white spruce climax community Exposed rocks Lichens and mosses Fig. 8.15, p. 188

Mature oak-hickory forest Secondary Succession Time Annual weeds Perennial weeds and grasses Shrubs Young pine forest Mature oak-hickory forest Fig. 8.16, p. 189

Oligotrophic Lake Succession of lake starts with a lake that does not have a lot of nutrients in it. Characteristics: Cold, Clear water Support few Species Not much biomass http://www.satirewire.com/news/july02/viagra.shtml

Eutrophic lake Process of adding nutrients to a water ecosystem is called Eutrophication. This results in a lake that has a lot of nutrients Is Warm Looks “Dirty” or “Cloudy” Supports many species Lots of Biomass

Fig 10.7 Diagram of bog succession. Fig 10.7 Diagram of bog succession. Open water (a) is transformed through formation of a floating mat of sedge and deposition of sediments (b) into wetland forest (c). © 2003 John Wiley and Sons Publishers