3a. Landscape Ecosystems and RNV
In the last part, you learned how the Forest Plan is applied in local logging projects. It sets goals for moving the forest toward more balanced forest types. Now let's look at how those goals work.
The Echo Trail logging project covers a large chunk of the Jack Pine-Black Spruce LE, so the RNV goals for that LE apply.
| One set of goals is measured by the percent of the project area in age classes. Each forest stand is counted in a class based on its age, such as 0-9 years (recently logged) or 120+ years (old growth). The computer compiles hundreds of stands within the larger landscape ecosystem, and calculates the total acreage of each age class in the LE. | Forest Watch: Echo Trail
project What are LEs, MAs and Zones again?
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| The other main set of goals measures how much of the project area is in various forest types. Forest type is named after the current dominant tree in a stand. (Remember, LEs are named after the naturally dominant tree species in the ecosystem, encompassing hundreds of stands.) | |
| Each LE has a distinct balance of different forest types and age classes. After a century of logging, this balance is tipped toward forests of pioneer tree species (species that are first to grow up after a clear-cut). Look at this example for the Jack Pine-Black Spruce LE: | |
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| The first column shows the different forest types found in
this LE.
The second column shows the RNV--the natural proportion of the land that forest type or age class covered around the year 1850. The last two columns show the current proportion of the LE each forest type or age class covers. ("All lands" includes patches of state, county, and private land within the national forest boundary.) |
This table is on page 3.2-11 of the forest plan Environmental Impact Statement (EIS). |
| The first forest type row is aspen (also called poplar or popple), a pioneer species. Aspen naturally would cover 19% of this LE. It currently covers 43%. Aspen is "over-represented" in this LE. Other species that cover less than their RNV are "under-represented". | |
| The age class table shows that 9-17% of the LE is naturally
forest younger than ten years. The current proportion of 10% falls within
the range of natural variation.
The forest plan maintains this proportion by prescribing clear-cutting on 9% of the LE each decade, setting the age class of those stands back to zero. It is assumed that fire and wind will add to that proportion, up to 17%. |
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| The Jack pine LE is unusual because its older age classes
are over-represented. This is because it is the most fire-dependent
LE. In fact, jack pine cones only open in when burnt.
Historically, fires would start in jack pine stands as often as every seven years, often replacing an entire stand. Note that this pattern caused 28-41% of the forest to be 11-50 years old--far less than current conditions. Suppression of forest fires--and using clear-cutting to "mimic" them--has led to older forests (52% in the 81-180 age classes) with less jack pine. |
How does Sierra Club propose to solve this imbalance? |