BS276 Lecture Notes - Primary Succession, Pedogenesis, Lichen
Document Summary
Ecological succession: a series of predictable stages of growth that a forest goes through. Primary succession: starts from bare rock in an area with no previous soil formation. Moss & lichen spores carried by the wind grow directly on rocks, breaking them down to form soil. Secondary succession - starts from already established soil in an area where a disturbance (fire/tornado/human land clearing) cleared out the majority of plant life. Grasses, sedges, wildflowers, and berry bushes have seeds dispersed by wind or animal droppings. Stages are characterized by which types of plant species dominate the ecosystem; different species are adapted to the conditions of different stages. Pioneer or early succession species appear first when the ground is simply bare rock, or bare soil after a disturbance. Characteristics - seeds spread by wind or animals, fast growing, tolerant of shallow soil and full sunlight. Ex. moss, lichen (bare rock) | wildflowers, raspberries, grasses/sedges.