1. Succession
Monday, November 14th, 2016

2. Forest Fires
Forest fires are a natural forest development and may naturally occur as a result of:
lightning strikes
concentration of heat on dry tinder.
In some situations, forestry or fire services start controlled burns to remove dry tinder and material that could lead to potentially uncontrollable fires in the future.
Photo: CA

3. Types of fires Surface fires Crown fires Ground fires
Burns undergrowth and leaf litter
Kills seedlings & small trees
Stimulates germination for some species (giant sequoia & Jack Pine)
Crown fires
Occurs in forests that have not had surface fires for a very long time
Extremely hot!
Leap from treetop to treetop
Kills wildlife & increases soil erosion
Ground fires
Occur underground, burn partially decayed leaves
Common in peat bogs
Difficult to extinguish

4. Ecological Succession
Succession proceeds in several stages, until the formation of a climax community, which is stable until further disturbance.
Early successional (or pioneer) communities are characterized by:
Simple structure, with a small number of species interactions
Broad niches
Low species diversity
Pioneer community, Hawaii
Broad niches

5. Climax Communities
In contrast to early successional communities, climax communities typically show:
Complex structure, with a large number of species interactions
Narrow niches
High species diversity
Climax community, Hawaii
Large number of species interactions

6. Hawaii: Local plants are able to rapidly recolonize barren areas
Primary Succession
Primary succession refers to colonization of a region where there is no pre-existing community. Examples include:
Newly emerged coral atolls & volcanic islands
Newly formed glacial moraines
Islands where the previous community has been extinguished by a volcanic eruption
Paved Parking lots
Remember: No soil!
Hawaii: Local plants are able to rapidly recolonize barren areas

7. Primary Succession
A classical sequence of colonization begins with lichens, mosses, and liverworts, progresses to ferns, grasses, shrubs, and culminates in a climax community of mature forest.
In reality, this scenario is rare.
Mature, slow growing trees
Shrubs and fast growing trees
Ferns, grasses and herbaceous plants
Pioneer species. Mosses and liverworts
Bare rock
and lichens

8. Why lichens are awesome…

10. Secondary Succession
Secondary succession occurs where an existing community has been cleared by a disturbance that does not involve complete soil loss.
Such disturbance events include cyclone damage, forest fires and landslides.
Cyclone
Forest fire

11. Secondary Succession
Because there is still soil present, the ecosystem recovery tends to be more rapid than primary succession, although the time scale depends on the species involved and on climatic and soil factors.
Mature forest
Young fast growing trees
Shrubs and small trees
Grasses and herbaceous plants
Pioneer community (annual grasses)
Bare land

12. Gap Regeneration
The reduced sunlight beneath large canopy trees impedes the growth of the saplings below.
When a large tree falls, a crucial hole opens in the canopy (gap), allowing sunlight to reach the saplings below.
The forest regeneration following the loss of a predominant canopy tree is called gap regeneration.
Gap regeneration is an example of secondary succession.

13. Wangari Maathari and Kenya’s Green Belt Movement
Self-help group of women in Kenya
Success of tree planting
50,000 members planted 40 million trees
Women are paid for each tree that survives
Slows soil erosion
Shade and beauty
Combats global warming
Nobel Peace Prize: 2004

14. A History of Parks
1864 – Yosemite was the first designated national park in the world.
1872 – Yellowstone was established and was the first park to be called a “National Park”
A national park not only provides public access but it affords protection of nature. In the 20th century conservation became the focus of national parks worldwide.
Additionally keep in mind that a goal of park and nature preserve management is maintaining biodiversity in national parks for recreation such as hunting.

15. Who is in charge? Dept of Interior Bureau of Land Management (BLM)
Division of Fish and Wildlife (F&W)
National Parks Service (NPS)
Dept of Agriculture
US Forest Service