TODAY: ANNOUCEMENT: 1. Learning log G2.6 – 2.8 Succession TODAY: ANNOUCEMENT: 1. Learning log

What is succession? Series of changes to an ecosystem Caused by complex interactions between the community of living organisms and the abiotic environment

Types of succession Primary: Colonization of region where there is no pre-existing community Secondary: Occurs where an existing community has been cleared by a disturbance that does not involve complete soil loss Begins with no life Follows a disturbance of the primary succession No soil Soil is present New area e.g. volcanic island Old area e.g. following a forest fire Lichen and mosses are first plants Seeds and roots already present Glacier -

Primary succession

Secondary succession

G2.7 Change in species diversity and production Few species  many species Pioneer species  species that compete with others for nutrients Little diversity  high diversity Simple relationships  complex relationships of mutualism, competition, predation More and more biomass (dry mass of organic matter) at each stage of succession

G2.8 Interactions with organism and the environment Soils become deeper as a result of decay of plants Allows well-draining soil Organic matter (humus) in soil increases as a result of decay of plants Organic matter quickly absorbs and releases water so is a good medium for plant growth Mineral recycling increases bacteria and fungi become more active in soils that have high organic matter Soil erosion reduces plant roots that stabilize the sand Minerals added Alder plants fix atmospheric nitrogen which leads to increase of nitrogen in the soil Organic matter