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he subalpine
forests of the Southwest, dominated by Englemann spruce and subalpine
fir, are a special place to many people. In the lower subalpine zone,
found at approximately 9,500 feet, spruce-fir forms as extensive,
relatively homogeneous, closed stands. These are dark, cool forests that
inspire reverence and mystery. In the upper subalpine zone, found at
approximately 11,500 feet, the forest forms a parkland of scattered tree
islands and ribbon forests. Summer’s arrival in this environment is a
visual delight of sun, wind, water, and wildflowers.
The spruce-fir
forest was absent in the Southwest until relatively recently. Around
50million years ago, in what is known as the Tertiary Period, North
America had a much warmer, wetter climate. Mixed temperate forests
comprising both conifers and deciduous trees covered the continent from
the Arctic Circle to the northern part of what is now the United States.
Most of the region south of this area (the Southwest included) was
covered with a subtropical forest.
Two natural
events, the uplift of the Rocky Mountains and a subsequent climatic
cooling, allowed spruce-fir to "migrate" to the Southwest from far
northern latitudes. The cooling of the climate allowed these forests to
shift southward along migrational avenues created by the newly uplifted
mountains. By the end of the Ice Age – about 10,000 years ago –
spruce-fir forests had reached their southern most extent.
All
communities are dynamic systems that change through time in response to
both small and large-scale events. The southward migration of spruce-fir
is an interesting example of how geology and climate have interacted to
form the present-day Southwestern subalpine forest.
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Wildlife
cover is the physical habitat component or landscape feature that
provides protection from hazards and predators. Elk cover is generally
described in terms of thermal cover and hiding cover, and ideal cover
values are thought to comprise approximately 40 percent of an elk’s
range. This 40 percent value is based primarily on observations that elk
occasionally use dense forest stands out of proportion to their
availability, and by modeling efforts based on energy balance equations.
However, these descriptive approaches do not answer why elk utilize
cover, and weak assessments of the benefits they supposedly obtain.
Elk
utilization of cover, especially winter cover, has been associated with
thermal benefits to the elk. This is a reasonable interpretation given
that cover moderates weather. However, the value of thermal cover,
especially winter thermal cover, is debatable. In a landmark, four-year
study conducted in the Blue Mountains of Oregon, the value of summer and
winter thermal cover was evaluated with respect to elk condition. No
significant positive effect of thermal cover could be correlated to elk
condition. In fact, heavily stocked, dense cover units were found to
provide the most costly energetic environments and clearcuts the least.
These
illogical results have led biologists to ask what environmental
variables are required to make elk herds productive. Data indicate that
two factors, solar radiation and forage quality, appear to be far more
important to elk productivity than thermal cover. Solar radiation has a
strong positive effect on overwinter elk performance. Furthermore,
shading by thermal cover may induce negative consequences, and as
temperatures decline, the relative value of solar radiation may
increase, thereby moving thermal cover further into the negative range.
With respect to forage quality, data indicate that the energy saved
through protection from thermal cover is negligible compared to the
energy taken in through nutrition.
The Blue
Mountains study cannot prove that thermal cover is never important.
However, there was considerable weather variation in the four winters of
the study suggesting that the findings might be applicable across a
variety of climatological conditions and regions.
One
conclusion of this work is that the value of cover needs to be
considered in relation to that of other habitat attributes. This
consideration should be in the context of the ability of each attribute
to contribute to the overall productivity of elk herds.
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New Mexico
State Forestry has legally mandated regulations pertaining to timber
harvest on private lands, non-municipal lands, and non-federal lands.
These regulations were enacted by the State Legislature in 1970 and
revised in 1989 to ensure minimum standards for erosion control, slash
treatment, and tree utilization. By regulating a small number of basic
practices, the State sought a balance between the protection of
citizens’ rights and the rights of private forest landowners.
Last year,
and for a variety of different reasons, New Mexico State Forestry once
again revised their regulations. The new regulations went into effect in
January of this year, and now take a more proactive approach to
regulation by requiring greater levels of timber sale planning. A
summary of the new regulations includes the following:
1. an estimate of trees per acre and average
diameter both pre-harvest and post-harvest
2. harvest goals
and objectives
3. harvest
boundaries and cutting units on a topographic map
4. the access route
to and from the harvest permit area to a public road
5. identification
of excessive slopes
6. identification
of lakes, watercourses, and wetlands on a topographic map
7. a description of
the proposed silvicultural cutting method
8. a description of
the equipment to be used during the harvest
9. a description of
the regeneration method
10 erosion control
practices
11. streamside management zone
practices
12. slash treatment practices
13. fire precautionary
information
14. an explanation of how
harvesting will be conducted on excessive slopes
Harvest
permit applications must be completed and submitted to the appropriate
State Forestry District 30 days before the proposed harvest is to start.
Upon receipt, District personnel review permits and make approval or
denial based upon merit and adherence to the law. After harvesting
commences, State Forestry personnel make formal inspections of harvest
activity to ensure compliance with the permit. Non-compliance may bring
a written "Notice of Deficient Condition" outlining needed actions and
timeframes for remedy of work. A failure to correct deficiencies may
bring criminal penalties.
A harvest
permit application may propose alternate practices in lieu of the
requirements set forth in the regulations. The Forestry Division may
approve the use of alternate practices if they represent sound forest
conservation practices which meet or exceed the standards of the
regulations.
This summary
of New Mexico’s harvest regulations is not complete; further information
can be found on the New Mexico State Forestry website at
www.emnrd.state.us/forestry. SEC can also provide complete assistance
with the preparation of a harvest permit application and the
implementation of a timber sale.
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