Ecological dynamics
Shasta red fir is the dominant climax overstory specie on this site. At maturity Western white pine and lodgepole pine may be present in the stand. Ponderosa pine may be present too, but at the lower drier elevations of the ecological site. Mountain hemlock is sometimes present in the overstory at the higher elevations of this site.
Fire return intervals are thought to be 70 to 130 years for Shasta red fir sites. Frequent fires (and moderately intense fires) would favor the pines, Ponderosa and Western white. Light intensity fires would favor all three tree species. Severe stand replacement fires would kill all trees, favoring the establishment of lodgepole pine.
Fire exclusion does not significantly change the plant community. Stocking density would increase and this would favor Shasta red fir, due to its moderate shade tolerance.
A severe stand replacement fire favors lodgepole and western white pine. Western white pine would not make up a large component of this community, but if conditions are right it could be larger than shown in the plant community.
Lodgepole pines abundance can be light to very heavy. Heavy and very heavy stands can become susceptible to mountain pine beetle outbreaks. An outbreak generally kills all trees. The lodgepole provides protection (temperature) for shasta red fir seedlings that will eventually re-establish.
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State 1 submodel, plant communities
State 2 submodel, plant communities
Community 1.1
Shasta red fir
Shasta red fir dominates the overstory and with fire exclusion only increases. Understory cover is very low and specie diversity is also low.
Forest overstory. The forest overstory compsosition for the Shast red fir plant community
Forest understory. The typical annual production of the understory species to a height of 4.5 feet (excluding boles of trees) under low, high, and representative canopy covers.
The percentages expressed are pecent canopy cover. Those species with "0" percent have a canopy cover of less than 1 percent.
Table 5. Ground cover
| Tree foliar cover |
25-35%
|
| Shrub/vine/liana foliar cover |
3-5%
|
| Grass/grasslike foliar cover |
1-3%
|
| Forb foliar cover |
0-1%
|
| Non-vascular plants |
0%
|
| Biological crusts |
0%
|
| Litter |
20-30%
|
| Surface fragments >0.25" and <=3" |
3-5%
|
| Surface fragments >3" |
3-5%
|
| Bedrock |
0%
|
| Water |
0%
|
| Bare ground |
20-30%
|
Table 6. Soil surface cover
| Tree basal cover |
0%
|
| Shrub/vine/liana basal cover |
0%
|
| Grass/grasslike basal cover |
0-1%
|
| Forb basal cover |
0%
|
| Non-vascular plants |
0%
|
| Biological crusts |
0%
|
| Litter |
30-40%
|
| Surface fragments >0.25" and <=3" |
5-10%
|
| Surface fragments >3" |
0-3%
|
| Bedrock |
0%
|
| Water |
0%
|
| Bare ground |
30-40%
|
Table 7. Canopy structure (% cover)
| Height Above Ground (m) |
Tree |
Shrub/Vine |
Grass/
Grasslike |
Forb |
| <0.15 |
0-1% |
– |
1-3% |
0-1% |
| >0.15 <= 0.3 |
0-1% |
3-6% |
– |
– |
| >0.3 <= 0.6 |
1-2% |
– |
– |
– |
| >0.6 <= 1.4 |
1-2% |
– |
– |
– |
| >1.4 <= 4 |
5-8% |
– |
– |
– |
| >4 <= 12 |
10-15% |
– |
– |
– |
| >12 <= 24 |
20-25% |
– |
– |
– |
| >24 <= 37 |
1-3% |
– |
– |
– |
| >37 |
– |
– |
– |
– |
Community 2.1
Lodgepole pine
The Lodgepole pine plant community occurs after a stand replacing fire, on a large or small scale. Lodgepole, a pioneer specie, readily establishes if a seed source is available.
Forest overstory. Lodgepole pine is the major tree specie in the overstory.
Forest understory. The typical annual production of the understory species to a height of 4.5 feet (excluding boles of trees) under low, high, and representative canopy covers.
The percentages expressed are pecent canopy cover. Those species with "0" percent have a canopy cover of less than 1 percent.
Table 8. Ground cover
| Tree foliar cover |
20-30%
|
| Shrub/vine/liana foliar cover |
3-5%
|
| Grass/grasslike foliar cover |
7-11%
|
| Forb foliar cover |
0%
|
| Non-vascular plants |
0%
|
| Biological crusts |
0%
|
| Litter |
20-30%
|
| Surface fragments >0.25" and <=3" |
8-12%
|
| Surface fragments >3" |
5-8%
|
| Bedrock |
0%
|
| Water |
0%
|
| Bare ground |
20-30%
|
Table 9. Soil surface cover
| Tree basal cover |
0%
|
| Shrub/vine/liana basal cover |
0%
|
| Grass/grasslike basal cover |
3-5%
|
| Forb basal cover |
0%
|
| Non-vascular plants |
0%
|
| Biological crusts |
0%
|
| Litter |
30-40%
|
| Surface fragments >0.25" and <=3" |
10-15%
|
| Surface fragments >3" |
5-10%
|
| Bedrock |
0%
|
| Water |
0%
|
| Bare ground |
20-30%
|
Table 10. Canopy structure (% cover)
| Height Above Ground (m) |
Tree |
Shrub/Vine |
Grass/
Grasslike |
Forb |
| <0.15 |
– |
– |
7-11% |
– |
| >0.15 <= 0.3 |
– |
3-5% |
– |
2-6% |
| >0.3 <= 0.6 |
0-1% |
– |
– |
– |
| >0.6 <= 1.4 |
0-1% |
– |
– |
– |
| >1.4 <= 4 |
2-4% |
– |
– |
– |
| >4 <= 12 |
5-10% |
– |
– |
– |
| >12 <= 24 |
20-25% |
– |
– |
– |
| >24 <= 37 |
– |
– |
– |
– |
| >37 |
– |
– |
– |
– |
Additional community tables
