1. Forestry & Succession Thursday, February 11 th, 2016

2. ‣ Different logging methods have different effects on the structure of a forest ecosystem. The two common methods used are: Clear-felling (or clear-cutting) exposes soil to erosion and results in less diverse regrowth. Selective logging has many variations, including a focus on particular species or thinning of small trees. Types of selective logging include harvesting: Single scattered trees Trees above a specified girth Selected groups of trees

3. ‣ A selection of mature forest is selected for removal based on tree height, girth, or species. ‣ During clear cutting, the understory is destroyed and a new forest of economically desirable trees may be planted. Clear Cutting Seedlings of the same species are replanted All the trees are removed A mature plantation forest is selected for harvesting The trees may be of a single species and may even be clones

4. Effects of Clear Cutting on Forest Chemical Cycling

6. Nitrate concentration in streams following logging and burning of slash (leaves branches and other tree debris = slash)

7. Fig. 10-8, p. 223 Trade-Offs Clear-Cutting Forests AdvantagesDisadvantages Higher timber yields Reduces biodiversity Destroys and fragments wildlife habitats Maximum profits in shortest time Can reforest with fast-growing trees Increases water pollution, flooding, and erosion on steep slopes Good for tree species needing full or moderate sunlight Eliminates most recreational value

8. Strip Cutting ‣ Strip cutting is a variation of clear cutting. ‣ Trees are cut down in strips narrow enough for forest on either side to reclaim the cleared land. ‣ After reclamation (3-5 years) the next strip is cut. ‣ A strip will not be cut again for another 20 - 30 years. Re-established forest Forest 6-10 years after cutting Forest 3-5 years after cutting Newly cut Uncut forest

9. ‣ Trees are selected for removal from a mature forest based on their height, girth, or species. ‣ These trees are felled individually and directed to fall in such a way as to minimize the damage to the surrounding younger trees. Selective Logging Mature trees are pre- selected for harvesting Usually, the trees are replaced with seedlings of the same species The trees are removed with minimal disturbance Continual regeneration of young seedlings provides a balance of tree ages that mirrors the natural age structure

10. Commercial Plantations ‣ Commercial plantations are specifically planted and grown for the production of timber and timber based products. ‣ They consist of a tree monoculture that is fast growing and produces straight, tall trunks ideal for logging and milling. ‣ Pinus radiata (monterey or radiata pine) is popular as a commercial timber tree as it is fast growing, produces strong general purpose timber, and is ready for logging just twenty years after planting. Pinus radiata is the leading commercial timber tree in many countries. The Kaingaroa Forest in New Zealand is the Southern Hemisphere’s largest planted forest, covering 2,900 km 2 Photo: CA

11. Fig. 10-3a, p. 219 25 yrs Weak trees removed Clear cut 30 yrs Years of growth 15 yrs Seedlings planted 5 yrs10 yrs

12. Succession Webquest

13. 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

14. Types of fires Surface 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

15. ‣ 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 Ecological Succession

16. ‣ 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 Communities Climax community, Hawaii Large number of species interactions

17. ‣ 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! Primary Succession Hawaii: Local plants are able to rapidly recolonize barren areas

18. Primary Succession Bare rock and lichens Pioneer species. Mosses and liverworts Ferns, grasses and herbaceous plants Shrubs and fast growing trees Mature, slow growing trees ‣ 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.

19. Why lichens are awesome… http://youtu.be/Te4qnLkHnS4

21. ‣ 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. Secondary Succession Cyclone Forest fire

22. ‣ 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. Secondary Succession Bare land Pioneer community (annual grasses) Grasses and herbaceous plants Shrubs and small trees Young fast growing trees Mature forest

23. ‣ 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. Gap Regeneration

24. Wangari Maathari and Kenya’s Green Belt Movement ‣ Green Belt Movement: 1977 ‣ 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

25. 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.

26. 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