By Thembi Borras
According to the Mendocino County Air Quality Management District, it is now winter burning season. Burning is allowed between the hours of 9am and 3pm only on permissive burn days. The burn forecast recording for Mendocino County is available 24-hours a day at 707-463-4391. It is not legal to burn anything except vegetative matter. A good rule of thumb is if it didn’t grow on your property, you may not burn it.
Burn permits are required for single piles in excess of 4' by 4'. They cost $10 and are available through the Mendocino County Air Quality Management District; the District can be reached at 707-463-4354.
In Mendocino County between 1994 and 2003, 18% of assigned fires were caused by escaped debris fires. The following are measures intended to minimize fire danger health issues and nuisance smoke:
1. Establish a 10-foot clearance from any combustible material.
2. Have shovel and water on hand until the fire is out.
3. Have a responsible adult present.
4. Consider a no-burn option. Composting and chipping may be feasible alternatives. Limbs and other debris may also be piled for wildlife habitat if located where they do not pose a fire hazard.
5. Burn one pile at a time.
6. Check the weather. It may be too windy to burn if trees are swaying, flags are extended, or waves appear on open water. It is not a good idea to burn on a day with a strong inversion because inversions trap pollutants at or near ground level and do not allow them to disperse. An inversion is when a layer of warm air traps a layer of cold air beneath it.
For more information, visit the website http://www.co.mendocino.ca.us/aqmd/. In Humboldt County, you can contact the North Coast Unified for burn information at 707-443-3093.
A portion of this production was gleaned from http://www.dnr.wa.gov/htdocs/rp/stewardship/bfs/WESTERN/safedebrisburning.html
October 30, 2005
October 23, 2005
Considering Wildlife Trees During Tree Marking
By Thembi Borras
Wildlife occupies every layer of a tree. In a light intensity single tree selection, during tree marking, you have the opportunity to evaluate each tree individually for wildlife value. Trees that provide preferred habitat to wildlife include goose pens, trees with broken tops and decadent trees.
Goose pen is the name given to a basal tree cavity, which during the homestead era could provide shelter for a goose or a gaggle of geese, depending on the size of the cavity. Goose pen is now used to describe any tree with a basal cavity, most often created by fire. Species that use goose pens include bats for roosting and birds for nesting.
Trees with broken tops facilitate fungal entry causing rot in the stem, which allows primary cavity nesters to begin excavation. Secondary cavity nesters follow. Flat tops provide nesting platforms and are preferred by several owl species if they are concave; meaning the top breaks off below the remaining canopy. Ospreys, a fish eating raptor, will nest in exposed flat tops. Portions of broken tops that stick above the rest of the canopy may be used by birds for roosting and perching.
Decadent trees, trees in a condition of decline, may possess oversized limbs and exfoliating bark, dense clusters of branches caused by a mistletoe infection and rotten cavities caused by some physical damage such as lightening or wind. Large limbs are platforms that support wildlife, the larger the limb the wider the range of species able to use the platform. Exfoliating bark is used by birds and bats to nest and roost. Dense clusters of branches may be used as cover or rest sites for animals including martens, fishers and squirrels. Northern spotted owls have used them as locations to nest. Decaying wood provides the medium in which woodpeckers forage and cavity nesters build nests.
Goose pens and decadent trees are not easily recreated given fire has been suppressed and stand age has been lowered. There is often an inverse relationship between the economic value and the wildlife value of a tree, which facilitates the decision to retain trees with high wildlife value and low economic value.
Wildlife occupies every layer of a tree. In a light intensity single tree selection, during tree marking, you have the opportunity to evaluate each tree individually for wildlife value. Trees that provide preferred habitat to wildlife include goose pens, trees with broken tops and decadent trees.
Goose pen is the name given to a basal tree cavity, which during the homestead era could provide shelter for a goose or a gaggle of geese, depending on the size of the cavity. Goose pen is now used to describe any tree with a basal cavity, most often created by fire. Species that use goose pens include bats for roosting and birds for nesting.
Trees with broken tops facilitate fungal entry causing rot in the stem, which allows primary cavity nesters to begin excavation. Secondary cavity nesters follow. Flat tops provide nesting platforms and are preferred by several owl species if they are concave; meaning the top breaks off below the remaining canopy. Ospreys, a fish eating raptor, will nest in exposed flat tops. Portions of broken tops that stick above the rest of the canopy may be used by birds for roosting and perching.
Decadent trees, trees in a condition of decline, may possess oversized limbs and exfoliating bark, dense clusters of branches caused by a mistletoe infection and rotten cavities caused by some physical damage such as lightening or wind. Large limbs are platforms that support wildlife, the larger the limb the wider the range of species able to use the platform. Exfoliating bark is used by birds and bats to nest and roost. Dense clusters of branches may be used as cover or rest sites for animals including martens, fishers and squirrels. Northern spotted owls have used them as locations to nest. Decaying wood provides the medium in which woodpeckers forage and cavity nesters build nests.
Goose pens and decadent trees are not easily recreated given fire has been suppressed and stand age has been lowered. There is often an inverse relationship between the economic value and the wildlife value of a tree, which facilitates the decision to retain trees with high wildlife value and low economic value.
October 16, 2005
Marking to Improve Stand Structure
By Thembi Borras
Sustainable forestry is largely determined by how a forest management strategy is interpreted on the ground. Single tree selection does not imply sustainable forestry as it can easily be corrupted by high grading; taking the biggest and best trees. Tree marking, deciding which trees will be cut and which trees will be retained is the most important way a forester translates single tree selection on the ground. Although there are a hundred things to consider before marking a tree, the core criteria to improve stand structure, in descending order of priority, are:
1. Remove damaged, dying, or diseased trees. Generally, trees which may die prior to the next harvest. However, some dying trees may be retained to become snags, which are important to wildlife. This is a “sanitation” strategy.
2. Remove suppressed and intermediate crown class trees. These are trees that neither are presently contributing growth to the stand, nor are they expected to do so prior to the next harvest. This is a "thinning from below” strategy.
3. Remove selected larger trees that improve spacing for the higher quality trees, which will be retained. This is a “spacing improvement” strategy.
Target diameters also guide tree marking. For example, at age 50 the largest redwoods in the Jones Family Forest have not yet reached the target diameter of 36" specified in the long term management plan. Therefore, selection leans toward retaining the largest trees.
At age 80, the largest redwoods in the Jones Family Forest have reached the target diameter and selection leans toward removing them to benefit smaller diameter trees. However, not all trees that have reached the target diameter are cut. They are simply preferred if the situation warrants. In a situation where 18" to 24" redwood trees on the north side of the clump would benefit if the 36" tree on the south side were removed, then cutting the target diameter redwood may be warranted. If the removal of the target diameter tree will not benefit surrounding conifer trees because it is out on its own then retaining it may be warranted.
In conclusion, each harvest is used as an opportunity to upgrade overall stand quality by choosing which trees are retained and how they are spaced.
A portion of this production was gleaned from an unpublished paper by Craig Blencowe entitled, Craig Blencowe: Building up the Forest.
October 9, 2005
Increasing Timber Inventory to a Sustained Yield Goal
By Thembi Borras
Developing a sustained yield goal is in part based on site quality, which conveys the relative productivity of a land area. According to the Soil Survey Report for the western part of Mendocino County, the potential annual production from a fully stocked stand can be as low as 245 board feet (bf) per acre per year to as high as 2,050 bf/acre/year. Although different for each soil complex, often the potential annual production from a fully stocked stand of redwood and Douglas-fir is closer to 750 bf/acre/year. The sustained yield goal can be determined given the potential annual production and a selected long-term annual growth rate that can be maintained while protecting forest related values.
For example, if the potential annual production on the Jones Family Forest is 800 bf/acre/year and the Jones Family selects a long-term annual growth rate of 4%, the sustained yield goal is 20,000 bf/acre. This is determined by the following formula: 800 bf/acre/year = (.04/year)*X; X=20,000 bf/acre. The Jones Family Forest is 200 acres. Therefore, the sustained yield goal is 4,000,000 bf on the entire Jones Forest.
Critical to this exercise is to compare the sustained yield goal to the current standing volume and the current annual growth rate to the long term annual growth rate.
Continuing with this example, based on information from a timber cruise, the Jones Family Forest supports a current standing volume of 2,000,000 bf or 10,000 bf/acre. The Jones Family now knows the starting point, which is 2,000,000 bf, and the goal, which is 4,000,000 bf. At this point, a Potential Harvest Schedule can be developed, which will reflect how quickly this goal is reached based on the volume harvested at each entry, the responding growth rate and the frequency of entries.
By cutting less than growth over several cycles, the inventory of the stand will build and eventually the sustained yield goal will be attained, at which point, the periodic growth can be harvested without ever depleting the inventory.
The inventory can be viewed as “principle” and the growth as the “interest” earned on that principle. A truly sustainable forest allows the perpetual harvest of the interest without ever having to touch the principal.
The Soil Survey Report for the western part of Mendocino County is available at http://www.ca.nrcs.usda.gov/mlra02/wmendo.html. A portion of this production was gleaned from an unpublished paper by Craig Blencowe entitled, Craig Blencowe: Building up the Forest.
Developing a sustained yield goal is in part based on site quality, which conveys the relative productivity of a land area. According to the Soil Survey Report for the western part of Mendocino County, the potential annual production from a fully stocked stand can be as low as 245 board feet (bf) per acre per year to as high as 2,050 bf/acre/year. Although different for each soil complex, often the potential annual production from a fully stocked stand of redwood and Douglas-fir is closer to 750 bf/acre/year. The sustained yield goal can be determined given the potential annual production and a selected long-term annual growth rate that can be maintained while protecting forest related values.
For example, if the potential annual production on the Jones Family Forest is 800 bf/acre/year and the Jones Family selects a long-term annual growth rate of 4%, the sustained yield goal is 20,000 bf/acre. This is determined by the following formula: 800 bf/acre/year = (.04/year)*X; X=20,000 bf/acre. The Jones Family Forest is 200 acres. Therefore, the sustained yield goal is 4,000,000 bf on the entire Jones Forest.
Critical to this exercise is to compare the sustained yield goal to the current standing volume and the current annual growth rate to the long term annual growth rate.
Continuing with this example, based on information from a timber cruise, the Jones Family Forest supports a current standing volume of 2,000,000 bf or 10,000 bf/acre. The Jones Family now knows the starting point, which is 2,000,000 bf, and the goal, which is 4,000,000 bf. At this point, a Potential Harvest Schedule can be developed, which will reflect how quickly this goal is reached based on the volume harvested at each entry, the responding growth rate and the frequency of entries.
By cutting less than growth over several cycles, the inventory of the stand will build and eventually the sustained yield goal will be attained, at which point, the periodic growth can be harvested without ever depleting the inventory.
The inventory can be viewed as “principle” and the growth as the “interest” earned on that principle. A truly sustainable forest allows the perpetual harvest of the interest without ever having to touch the principal.
The Soil Survey Report for the western part of Mendocino County is available at http://www.ca.nrcs.usda.gov/mlra02/wmendo.html. A portion of this production was gleaned from an unpublished paper by Craig Blencowe entitled, Craig Blencowe: Building up the Forest.
October 2, 2005
A Type of Forest Management
By Thembi Borras
I did not leave college knowing how to practice sustainable forestry on the ground. In fact, if I had depended solely on what I had learned in college I would not have thought the type of forest management I have learned and been privileged to implement for the last seven years was viable because, in part, economic return is not maximized. The type of forest management that I now use is quite simple. First, establish a long-range sustained yield goal based on the productive capacity of the site and a reasonable growth rate. After the long range sustained yield goal is established, build inventory by cutting less than growth until the goal is met. Once the goal is met, growth can be harvested. The other aspect of this approach is to improve stand structure by not cutting the biggest and best trees.
Although short-term profit is not maximized this approach provides a periodic income to the landowner and is an effective way to support forest related values. Pre harvest habitat is the same as post harvest habitat, so wildlife habitat does not decline. Aesthetics are bolstered by maintaining a continuous forest canopy and encouraging fewer large stems as opposed to many small stems. Also, this type of forest management can minimize adverse watershed effects through the low level of canopy removal. The lower the level of canopy removal the lower the increase in peak flow. Conversely, an increase in peak flows can mean an increase in sediment production.
Other arguments against this type of forest management, which can be described as a light intensity single tree selection, are natural regeneration suffers due to lack of adequate light and reentry every 10 to 15 years does not allow the land to rest. While these arguments have some validity, they are not insurmountable. Redwood sprouting is usually adequate post harvest but it is sometimes necessary to remove trees in small groups to encourage Douglas-fir seedlings. In addition, seedlings can be interplanted in openings created by the harvest to supplement natural regeneration. Finally, periodic entry every 10 to 15 years is an opportunity to improve a permanent truck road and skid trail network and correct accessible legacy problems.
A portion of this production was gleaned from an unpublished paper by Craig Blencowe entitled, Craig Blencowe: Building up the Forest.
I did not leave college knowing how to practice sustainable forestry on the ground. In fact, if I had depended solely on what I had learned in college I would not have thought the type of forest management I have learned and been privileged to implement for the last seven years was viable because, in part, economic return is not maximized. The type of forest management that I now use is quite simple. First, establish a long-range sustained yield goal based on the productive capacity of the site and a reasonable growth rate. After the long range sustained yield goal is established, build inventory by cutting less than growth until the goal is met. Once the goal is met, growth can be harvested. The other aspect of this approach is to improve stand structure by not cutting the biggest and best trees.
Although short-term profit is not maximized this approach provides a periodic income to the landowner and is an effective way to support forest related values. Pre harvest habitat is the same as post harvest habitat, so wildlife habitat does not decline. Aesthetics are bolstered by maintaining a continuous forest canopy and encouraging fewer large stems as opposed to many small stems. Also, this type of forest management can minimize adverse watershed effects through the low level of canopy removal. The lower the level of canopy removal the lower the increase in peak flow. Conversely, an increase in peak flows can mean an increase in sediment production.
Other arguments against this type of forest management, which can be described as a light intensity single tree selection, are natural regeneration suffers due to lack of adequate light and reentry every 10 to 15 years does not allow the land to rest. While these arguments have some validity, they are not insurmountable. Redwood sprouting is usually adequate post harvest but it is sometimes necessary to remove trees in small groups to encourage Douglas-fir seedlings. In addition, seedlings can be interplanted in openings created by the harvest to supplement natural regeneration. Finally, periodic entry every 10 to 15 years is an opportunity to improve a permanent truck road and skid trail network and correct accessible legacy problems.
A portion of this production was gleaned from an unpublished paper by Craig Blencowe entitled, Craig Blencowe: Building up the Forest.
Subscribe to:
Posts (Atom)
