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Post 3 - Disturbance

Behind you, you can see a small patch of forest that is in the first stages of succession. Can you see new shrubs and trees growing in the exposed sunlight? The first stages of succession begin after a disturbance, such as a flood, disease, landslide, insect outbreak, or wind, alters the physical environment. A disease like laminated root rot, which cleared the patch in front of you, kills many Douglas-fir trees and may seem devastating. But the clusters of trees that die create "canopy gaps" that allow light to reach the forest floor, thereby enabling sun-loving plants light to grow in these new spaces. Some of these disturbances can leave lots of standing dead trees known as snags that provide habitat for fungi, spotted owls, and other species. Over time, disturbances create a mosaic of forest patches in different stages of succession, contributing to diversity in the forest.

You can see lots of downed logs in the canopy gap that are contributing nutrients to the soil and providing habitat for species such as newts, insects, and fungi.

Do you think logs can be beneficial for streams too?

Click on the pictures below to enlarge them.

Disturbance-1 Disturbance-2 Disturbance-3


Post 2-DecomposersArrow Left   Arrow Right Post 4-Woody Debris in Streams