Lichens are a __________ of fungi and bacteria. ______________ _______________ Pioneer Species These pioneer species are the ______ to inhabit an area. Examples: ______________, _______________ These organisms will modify or ___________ the environment (by forming soil, etc.) and eventually the habitat becomes ___________ to other species. Start recovery following a _____________ in BOTH _____________ and ______________ succession. In primary, pioneer species create _________. New Soil Soil begins to form as lichens weather and break down rocks into ___________ ____________. When the lichens die, they add ________ matter to the rock. Plants such as ___________ and ferns grow in this _______ _______. The soil layer _________, and grasses, wildflowers, and other plants take over. When these plants die, they add more ____________ to the soil. The soil can now support the growth of shrubs and trees and eventually _______________. Secondary Succession After a forest fire, not much seems to be left except dead trees and ash-covered ________. All that remains is ______ ______. But, the soil already contains the seeds of ________, __________, and ________. Causes: ________, floods, changes in ____________, etc. Climax Community A community of plants that has reached an _________ ___________ of succession. There are fewer changes of species _________ _________ unless there is fire, etc. This community is a relatively ____________ environment that can last for ____________ of years. Ecological Succession Succession refers to the normal, slow _________ that occur in the ____________ that live in an area. The ________________ way in which an ecosystem develops _______ ________. Succession ________ differently in different places. Ecological succession can be classified in two ways: _______________________________ _______________________________ Primary Succession Primary succession ___________ in an area that was previously ____________ ________. Involves the ___________ of soil, micro- organisms, plants and animals to establish or restore populations in areas that are _______ of living things. It starts with ____________. .