Constant Changes in an Ecosystem. Succession. The series of predictable changes that occurs in a community over time. Ecological Succession. Ecosystems are constantly changing in response to natural and human disturbances.
Ecosystems are constantly changing in response to natural and human disturbances.
As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the communityEcological Succession
Succession that occurs on surfaces where no soil exists (an essentially lifeless area)
Usually takes a long time because there is no fertile soil to provide the nutrients needed to establish a plant community.Primary Succession
Common pioneer species are lichens and mosses
The seeds and spores of lichens and mosses are carried by the wind or on the coats of animals or in the droppings of animalsPrimary succession – the slow process of soil formation
Trap wind-blown soil particles and detritus, producing tiny bits of organic matter
Secrete mild acids that slowly break down the rock
After hundreds to thousands of years, the soil may be deep enough and fertile enough to store moisture and nutrients to support larger plant growthHow do Pioneer Species start soil formation?
When a disturbance of some kind changes an existing community without removing the soil
Land cleared and plowed for farming is abandoned.
Burned or cut forests
Flooded landSecondary Succession