Chapter 10

Ecological Restoration

The Balance of Nature

– An environmental myth that states that the natural environment, when not influenced by human activity, will reach a constant status, unchanging over time.

– Major Tenets:• Nature undisturbed achieves a permanency

• If disturbed momentarily, returns to exact permanent state

• Place for each creature and each creature in its place

What is “Natural”?

• Restoring an ecosystem to its historical range of variation and to an ability to sustain itself and its crucial functions, including the cycling of chemical elements, the flow of energy, and the maintenance of the biological diversity that existed previously.– Examine populations that have decline and ecosystems

that have been damaged and learn what is lacking.

– Science and nature

What needs to be restored?

1. Wetlands, Rivers and Streams(Ex: Kissimmee River, Everglades National Park)

2. Prairie Restoration(Ex: Allwine Prairie)

*Roads and railroads

When Nature Restores Itself: The Process of Ecological Succession

Ecological Succession: The process of the development of an ecological community or ecosystem.

Two Types:1. Primary Succession: The initial establishment

and development of an ecosystem2. Secondary Succession: The reestablishment of

an ecosystem where there are remnants of a previous biological community

Patterns in Succession

1. An initial kind of vegetation specially adapted to the unstable conditions

2. Small plants and other early-successional species grow and seeds spread rapidly.

3. Larger plants and other late successional species enter and begin to dominate the site.

4. A mature forest develops.

Examples of Succession:Dune Succession, Bog Succession, Old-Field Succession

Dune Succession

• Shores of Lake Michigan

• Dune Grass– Runners stabilize soil

• Other plants• Eastern Red Cedar,

White Pine• Beech and Maple

Bog Succession

Old-Field Succession

• Farm-land• Abandoned and

allowed to grow back to forest

• Small plants, larger plants, to trees (Sugar Maple, Beech, Yellow Birch, White Pine)

Biomass and Diversity with Succession

• Biomass, production, diversity and chemical cycling change during succession

• Biomass and diversity peak in mid-succession, increasing at first to a maximum, then declining and varying over time.

Succession and Chemical Cycling

• Storage of chemical elements (nitrogen, phosphorus, potassium..) increases from early to mid-succession– Organic matter stores chemical elements– Live and dead organic matter retards soil erosion

• Greater amounts of organic matter, greater amounts of chemicals elements retained

• Soils store more elements than does live tissue but cycle them at a slower rate.

Species Change in Succession

Earlier and later species in succession may interact in three ways:

1. Facilitation2. Interference3. Life history differences

If they do not interact, the result is termed chronic patchiness

Facilitation

• During succession, one species prepares the way for the next (and may even be necessary for the occurrence of the next)

• Can be useful in the restoration of damaged areas.

• Ex) Tropical Rain Forest

Interference

• During succession, one species prevents the entrance of a later species into an ecosystem.

• Ex) Some grasses produce dense and thick mats so the seeds of trees cannot reach the soil to germinate

Life History Difference

• The difference in the life histories of the species allow some time to arrive first and grow quickly, while others arrive late and grow more slowly

• Early vs. Late-Successional Species

• Ex) seed disbursal

Chronic Patchiness

• Species don’t interact• Harsh Environments

– Limited chemical elements or energy; frequent disturbances

• Deserts– Patches of mature shrubs (few seedlings)– Persist for a long period of time

Applying Knowledge for Restoration

• Great Britain and lead mining

• 55,000 hectares

• 1st: heavy fertilizers and fast-growing grasses

• 2nd: slow growing native-grasses, adapted to minerally deficient soils