Forest Succession. How forests work. – shade tolerance pioneers climax species – forest...
-
Upload
muriel-mclaughlin -
Category
Documents
-
view
295 -
download
0
Transcript of Forest Succession. How forests work. – shade tolerance pioneers climax species – forest...
![Page 1: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/1.jpg)
Forest Succession
![Page 2: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/2.jpg)
Forest Succession
• How forests work.– shade tolerance
• pioneers• climax species
– forest succession
![Page 3: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/3.jpg)
Shade Tolerance
![Page 4: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/4.jpg)
Pioneer Species: Used to describe species that are intolerant to very intolerant to shade. The first tree species to inhabit a site after a stand-replacing event. They are typically fast-growing, are characterized by open or low density crowns, and have a relatively short life span.
Climax Species: Used to describe the most shade tolerant tree species that are native to a particular region.
![Page 5: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/5.jpg)
Almost all North American woods that are used for structural timbers
are pioneers or intolerant to shade.
![Page 6: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/6.jpg)
Relative Shade Tolerance of North American Tree Species
Eastern Eastern Western Western Conifers Deciduous Conifers Deciduous
Very Intolerant
Jack pine Aspen Alpine larch Quaking aspen
Longleaf pine Gray birch W. larch Cottonwood
Sand pine River birch Bristlecone pine Willow
E. redcedar Black locust Digger pine
Tamarack Post oak Foxtail pine
Turkey oak Whitebark pine
Blackjack oak
Willow
Construction lumber
Structural timbers
Furniture wood
![Page 7: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/7.jpg)
Relative Shade Tolerance of North American Tree Species
Eastern Eastern Western Western Conifers Deciduous Conifers Deciduous
Intolerant
Baldcypress Paper birch Juniper Madrone
Loblolly pine Butternut Bishop pine Bigleaf maple
Pitch pine Catalpa Coulter pine Oregon ash
Pond pine Black cherry Jeffrey pine Calif. w. oak
Red pine Chokeberry Knobcone pine Oregon w. oak
Shortleaf pine K. coffeytree Limber pine G. chinkapin
Slash pine Honeylocust Lodgepole pine
Virginia pine Pecan Pinion pine
Persimmon Ponderosa pine
Y. poplar
Sycamore
Construction lumber
Structural timbers
Furniture wood
![Page 8: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/8.jpg)
Relative Shade Tolerance of North American Tree Species
Eastern Eastern Western Western Conifers Deciduous Conifers Deciduous
Intermediate
E. white pine Ash Douglas fir Red alder
Black spruce Basswood Monterey pine
Y. birch Sugar pine
Am. elm W. white pine
Hackberry Blue spruce
Silver maple Giant sequoia
Black oak Noble fir
N. red oak
S. red oak
White oak
Construction lumber
Structural timbers
Furniture wood
![Page 9: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/9.jpg)
Relative Shade Tolerance of North American Tree Species
Eastern Eastern Western Western Conifers Deciduous Conifers Deciduous
Tolerant
N. white cedar Rock elm Cedar Calif. laurel
Red spruce Blackgum Grand fir Canyon live
White spruce Sourwood Subalpine fir oak
Red maple Calif. red fir Tanoak
Hickory White fir
Redwood
Sitka spruce
Englemann sp.
Construction lumber
Structural timbers
Furniture wood
![Page 10: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/10.jpg)
Relative Shade Tolerance of North American Tree Species
Eastern Eastern Western Western Conifers Deciduous Conifers Deciduous
Very Tolerant
Balsam fir Beech W. redcedar
E. hemlock Hornbeam Silver fir
Dogwood W. hemlock
Holly Calif. Torreya
Hophornbeam Pacific yew
Sugar mapleConstruction lumber
Structural timbers
Furniture wood
![Page 11: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/11.jpg)
Forest Succession: The gradual supplanting of one community of plants by another, usually as a result of differences in shade tolerance.
![Page 12: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/12.jpg)
Pioneer species quickly occupy a site following clearing. They grow rapidly to compete with grasses and shrubs.
![Page 13: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/13.jpg)
As the crowns of pioneer species close, seedlings from these trees are unable to survive in the resulting shade.
![Page 14: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/14.jpg)
Different species that have a higher tolerance to shade soon become established beneath the pioneers.
![Page 15: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/15.jpg)
As the short-lived pioneers near the end of their life spans, the more tolerant trees in the forest understory begin to take over the site. The result is a major change in plant
and animal species.
![Page 16: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/16.jpg)
Spruce begins to take over an aspen dominated site in northern Minnesota as the short-lived pioneer aspen
crowns thin with aging.
![Page 17: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/17.jpg)
Beneath the second successional stage species, that often form thicker crowns than pioneers, new species that
are even more shade tolerant become established.
![Page 18: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/18.jpg)
The process of succession continues until the most shade-tolerant species suitable for the site (climax species) become established.
![Page 19: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/19.jpg)
Seedlings of highly shade tolerant climax species thrive in the shade of their parents. Because of this, climax species
will persist until disturbance sets back the succession process to the pioneer or some other stage.
![Page 20: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/20.jpg)
Consider what happens following the harvest of lodgepole pine in
the western U.S.
![Page 21: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/21.jpg)
Clearcutting in Lodgepole pine - Montana.
![Page 22: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/22.jpg)
The clearcut site looks barren immediately following harvest.
![Page 23: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/23.jpg)
Similar area, two years following harvest, showing that grass has covered the site. Young pine seedlings are
barely visible in the foreground.
![Page 24: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/24.jpg)
At ten years following harvest young lodgepole pine trees, that have sprouted from seeds present in the soil and
spread by wind and wildlife, are well established.
![Page 25: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/25.jpg)
Compare this to developments following a clearcut by nature.
![Page 26: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/26.jpg)
In early summer 1988, as today, much of Yellowstone park was covered by aging stands of lodgepole pine. Many trees
had been killed by frequent outbreaks of the endemic Mountain Pine Beetle.
![Page 27: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/27.jpg)
This condition led to the Great Yellowstone fire, 1988
![Page 28: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/28.jpg)
Vast areas of lodgepole pine and other forest types were killed.
![Page 29: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/29.jpg)
Eleven years later showed a landscape again dominated by lodgepole pine that had sprouted from
seeds present in the soil.
![Page 30: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/30.jpg)
Take a look at the commercial harvest of aspen in Minnesota.
![Page 31: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/31.jpg)
Clearcut harvesting in Minnesota aspen.
![Page 32: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/32.jpg)
Aspen harvest site one year following clear-cut harvest.
![Page 33: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/33.jpg)
A good site several years following harvest. 50,000 to 100,000 stems per acre from stump sprouting.
![Page 34: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/34.jpg)
Mature aspen stand. 65-70
years old. Approximately
200 stems/acre.
Question:
Assuming that 50,000 stems occupied each acre of the harvested site several years following stand establishment, what happened to the other 49,800 trees?
![Page 35: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/35.jpg)
When reproduction of species with medium to high shade tolerance is desired following logging, selective harvest methods can be used.
![Page 36: Forest Succession. How forests work. – shade tolerance pioneers climax species – forest succession.](https://reader036.fdocuments.us/reader036/viewer/2022081416/56649cf55503460f949c4607/html5/thumbnails/36.jpg)
Question:
Based on what you have learned about forest succession and the kinds of trees that are most useful in producing structural timbers, why would anyone who cares anything about forests ever harvest by the clearcutting method?