| | Alternative Land Uses | Land Use Capability | Conservation Considerations | Timber Harvest Methods | Planning Land Use Activities
Your decisions on whether or not to log, on timber harvesting methods and on subsequent land uses will have long-term implications. To make these decisions, ask yourself the following questions:
- What land use alternatives should I consider?
- What is my land's capability for timber production or for agricultural production? Do my trees have merchantable value?
- What are the conservation concerns if the trees are cleared?
- Which harvesting methods are best for possible future land use options?
- Which options best meet my goals for my farming operation and my land?
Alternative Land Uses
Woodlot management
Sustained yield timber management for your woodlot involves carefully planned, periodic timber harvesting and reforestation. It can provide long-term supplemental income. Woodlot management allows you to obtain economic benefits from your forested land without eliminating the forest's environmental benefits. A forester or forestry technician can provide technical assistance in planning this land use.
Developing agricultural land
Some agricultural activities, such as carefully managed bush grazing, do not require total forest clearing. However, your goals may call for permanent clearing of forested land for agricultural production. The sale of timber removed during clearing can help to offset development costs. An agrologist can give technical assistance in determining the agricultural potential of your land and in addressing possible conservation concerns.
Timber liquidation
In timber liquidation, timber is harvested for its cash value and the cutover land may remain undeveloped and unmanaged. Although you obtain economic benefits from the timber, problems such as soil and water degradation may also arise. Assess the costs and liabilities as well as the short-term benefits.
Forest conservation
Your goals may be best served by not harvesting. Perhaps the forest is immature or the benefits it provides are worth more than the cash value of the timber. However, forests are not static, and forest management may be needed to keep your forest healthy.
Land Use Capability
The land's capability to produce timber, annual crops or forages will depend on the soil, climate and topography. Collect and assess soil information for the land. Assess the quality, quantity and age of the existing timber resource as well as any limitations to current or future timber production.
Is the area of adequate or marginal quality for timber production? for agricultural production? for wildlife habitat? You may want to consult a forester, forestry technician, agrologist and/or wildlife biologist to assess the land's capability for the various land use options you are considering.
Conservation Considerations
Soil
Review your soil information. Are certain areas of the property prone to erosion due to steep slopes, sandy soils or other factors? Can you control erosion by conservation farming practices or should you not clear these areas?
Consider legislation such as the Soil Conservation Act which holds you responsible for soil erosion on your land. Repairing erosion damage often costs more than avoiding it.
Water
Cleared land (cultivated or pasture) generates more runoff than forested land. Consult with an expert to identify the runoff sensitive areas of your farm. These areas rapidly convey runoff to a surface channel or basin. Rapid runoff following rainstorms or snowmelt can cause flooding, erosion, sedimentation and water quality degradation. Consider keeping runoff sensitive areas under forest cover. If you do harvest timber from these areas, selective harvesting or small cutblocks will minimize the effect on the watershed.
Watercourses require particular attention even on less sensitive areas. Be aware that a defined drainage pattern may not develop until trees and litter cover are removed. Changes in land use may also affect the watertable. Vegetated watercourses, stream bank protection and assessment of potential watertable effects should form part of your conservation planning.
Wildlife habitat
For some landowners, wildlife is an important consideration. To maintain habitat for a variety of wildlife species, you can take a number of measures.
- Maximize edge (the transition between forest and cleared areas) to provide better habitat for many species.
- Limit line-of-sight along clearings and trail systems to improve protection from predators.
- Leave some dead or dying trees (snags) to provide important roosting, nesting and denning habitat for birds and small mammals.
- Leave dead and downed logs and brush piles to provide habitat for birds and small mammals.
- Leave travel corridors between small parcels of habitat to improve habitat value.
- Use selective harvesting or small clearcuts to conserve important components of wildlife habitat.
In some cases, forest conservation may be the only option that allows you to protect all the components necessary for adequate habitat. Consult a wildlife biologist or habitat technician for additional advice on managing habitat.
Aesthetics
Although aesthetics is a subjective matter, failure to recognize the concerns of your neighbours can result in hard feelings. Consider the surrounding landscape. Would clearing your forest have a significant visual impact? Smaller clearings, visual buffers, selective harvesting and prompt clean-up after logging are some ways to minimize the impact on aesthetics.
Timber Harvest Methods
Several methods can be used to harvest timber. Each method has advantages and disadvantages. Your objectives for the present and future use of your forested land will influence the harvest method that you choose. The harvest method will, in turn, affect other decisions such as cutblock size, layout and road location.
Clearcut Harvest
Clearcutting removes all merchantable trees from the cutblock at the same time. This method is the most economical way to harvest. It is appropriate for most species but is especially suited to even-aged stands of sun loving ( shade intolerant) species such as lodgepole pine or aspen. For land use options that require removal of the forest, clearcutting is probably the only realistic option.
One common misconception about clearcutting is that you must remove all the forest at once. Although you harvest all the merchantable trees in a certain area, the size of that area can be large or small depending on your objectives. A series of small clearcuts, promptly regenerated, can provide periodic, sustainable income while maintaining a healthy forest with diverse age classes.
Partial cut harvest
In partial cut harvest systems, the initial harvest does not remove all the merchantable trees from any unit of land. Partial cut methods are intended to encourage natural regeneration. The three partial cut systems are:
- Selection method
- harvesting selected trees in an uneven-aged stand either individually or in small groups at periodic intervals throughout a harvesting rotation. Harvested trees may be the most valuable trees, the poorest quality trees, the oldest trees or trees of a certain species.
- Shelterwood method
-harvesting mature trees in two or more cuttings to allow establishment and early growth of seedlings under partial shade and shelter of older trees.
- Seed tree method
- leaving individual trees or groups of trees uncut to provide seed to regenerate the cutover area.
The amount of tree cover initially removed increases from selection to shelterwood to seed tree method.
The selection method is best adapted to uneven-aged stands of shade tolerant species such as spruce or fir. It can also be used to convert even-aged stands to uneven-aged stands if the species being managed is capable of regenerating in a partially shaded stand. Selection cuts are often considered to be less visually offensive than clearcuts. As such, they are frequently favoured in areas where recreation or scenic values are important. Selection cuts may also be used to harvest timber from sensitive areas such as steep slopes or buffer strips where it is desirable to maintain permanent tree cover.
Unlike the selection method, the shelterwood and seed tree methods will not provide a continuous cover of mature trees. Once young trees are well established on the cutover, the remaining larger trees are removed, leaving only the even-aged regeneration.
Windthrow is a serious concern in all partial cut systems. If residual trees blow down, uprooted stems can displace significant amounts of soil and can be unsightly. The impact on soils, watersheds and aesthetics may be worse than if the trees had been harvested. As well, salvage harvests usually cost more than clearcutting.
Planning a partial harvest to minimize windthrow requires considerable expertise. The risk of windthrow is related to soil texture, soil moisture, wind speed and the species, age, rooting habit, size and crown development of the residual trees. In general, selection cutting that removes very little of the mature stand in the initial harvest is the least likely to result in windthrow problems. Consult a professional forester for advice on the shelterwood and seed tree methods.
No harvest
You may decide not to harvest if the benefits of the forest are worth more to you than the cash value of the timber. However, not harvesting can have long-term impacts. If the forest is overmature or if it consists of an even-aged stand with just one or two tree species, it may be more susceptible to damage from insects, disease or fire. Management activities, including timber harvesting, may be desirable to maintain a healthy, diverse forest.
Planning Land Use Activities
Planning will help you to select land use choices compatible with your long-term goals. The preceding sections identify some impacts associated with logging and provide suggestions for dealing with these concerns. If you have not yet decided whether logging helps you meet your goals, please review the previous sections again. If you have decided that logging fits with your goals and you plan to proceed, the next chapter provides tips for logging in a cost-effective, environmentally responsible way.
Source: Conservation and Logging on Private Land in Alberta Agdex 581-2. |
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