Biology Week 34 - Biological Succession

Day 1 | Day 2 - 5 | Weekly quiz

  • Succession
  • Pioneer species
  • Seral community
  • Climax community
  • Primary succession
  • Secondary succession
  • Eutrophication
  • Oliogotrophic
  • Eutrophic

Succession: link to an Internet Websitelink to an Internet Websitelink to an Internet Website
the gradual replacement of populations in an area.

click to find the answer to today's question Why are climax communities different from one area to another?

from bare dirt to a hardwood forest

Pioneer species - the first species to colonize a new haitat.

Seral community - each intermediate community that arises through succession.

Climax community - the community that will remain stable in a given area.

The Process of Succession:
  1. Bare rock is first colonized by lichens and bacteria.
  2. The small amount of soil formed by the lichens is colonized by mosses and ferns, which do not have roots and require little soil.
  3. As these plants live and die, the soil continues to develop to the point that grasses can successfully grow and a grassland community forms.
  4. Over time, the soil level increases to the point that shrubs can grow in the grassland. The grassland is replaced by a shrub community.
  5. The shrub community may be replaced by a forest.

Each stage alters the habitat in such a way that it prepares the way for the next invasion of species. As succession proceeds, soil is formed and thickens - the result of decomposition. When the changes in the composition of plants stop and the plant community remains generally the same for many years, the community is mature or at climax. A climax community is the relatively stable community at the end of succession.

Types of succession:

  1. Primary succession - establishing life in an area that has not previously supported life, such as bare rock or sand.
  2. Secondary succession - replacement of populations in disrupted areas that have not been totally stripped of soil and vegetation.
  3. Eutrophication - the increase of nutrients in an environment.
    • Oligotrophic environment - few organisms can survive because of the low nutrient content.
    • Eutrophic environment - many nutrients supporting a variety of life.

Succession in Ponds:link to an Internet Website

If left alone, succession will eventually cause a pond to disappear. Nature uses plants to help fill in the pond. One might classify ponds as new, young, and mature, based on the plants found.

Beaver Pond Mature Pond
Based on the visible plants, classify these ponds as new, young, or mature.

  • Algae are the first "green things" to grow in a pond.
  • Floating plants are usually the first true plants to appear.
  • Submersed plants are next to appear.
  • Emersed plants are usually the last to appear.
    new pond
    young pond
    young pond
    mature pond

Remember - moss is a land plant and does not grow in ponds.

diagram of a mature pond This drawing represents a mature pond. Notice all types of plants are found.

Dead plant material will fill the edges of the pond, making it smaller and smaller.

Each group of plants has successively more mass, which helps to fill in the pond quicker as they die. The portions of emersed plants above water also help to trap dirt, causing the pond to fill even faster. You will be able to see rings in the ground surrounding an old pond where the edge of the pond used to be.

Stages of Succession in a Pond
succession in a beaver pond succession in a beaver pond succession in a beaver pond succession in a beaver pond succession in a beaver pond succession in a beaver pond
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Day 1 Assignment - Biological Succession (Test Your Concept Understanding)

  1. How does Mount St. Helens demonstrate succession? link to an Internet Website
  2. People often use the term "weeds" to refer to certain plants. What are the characteristics of weeds?
  3. Why doesn't a lawn usually go through succession?
  4. Use this website link to an Internet Website for the following:
    1. Describe floating aquatic plants.
    2. Describe submersed aquatic plants.
    3. Describe emersed aquatic plants.
Biology Class










The plants and animals that are able to live in a certain area are determined by abiotic conditions such as climate, amount of water, and soil type. As these conditions differ from place to place, so with the climax community.