Reasons For Prescribed Fire In Forest Resource Management
Higher wind velocities and cooler temperatures minimize scorch damage. Southern pine plantations averaging 10 to 12 feet in height can be burned by experienced people under the right conditions without damage. Young plantations on industrial lands are often burned for the first time when they are 15 to 20 feet tall using aerial ignition; close spacing of ignition spots (e.g., 2 chains by 2 chains), and cool, damp conditions with some wind are a must to avoid crown damage.
Subsequent fuel reduction burns need not cover the entire area. The objective is to break up fuel continuity. Fuel reduction on 75 to 80 percent of the area is sufficient. An added advantage of "patchy" burns is that the unburned islands provide cover for wildlife. These unburned patches will not have a dangerous accumulation of fuels at the time of the next burn if they resulted from a lack of fuel during the previous fire. If, however, they were too wet to burn, these islands could result in a hot spot the next time if a heading fire was allowed to sweep through them under appreciably drier conditions. One reason excessive crown scorch should be avoided is because, under some circumstances, it can add more fuel to the forest floor than the fire consumed.
After harvest, unmerchantable limbs and stems are left either scattered across the area or concentrated at logging decks or delimbing gates, depending upon the method of logging. This material is an impediment to both people and planting equipment. If a wildfire occurs within the next few years, fireline construction can be severely hindered; the result being larger burn acreages and higher regeneration losses. Although not all large material will be consumed by a prescribed fire, what is left will be exposed so it can be avoided by tractor-plow operators. In stands that produce a large amount of cull material, the debris is often windrowed and burned. This practice should, however, be avoided whenever practical because of smoke management problems and the potential for site degradation. Broadcast burning is generally a much better alternative. If the debris must be piled before burning, construct round "haystack" piles when the debris and underlying ground are both fairly dry. This step will limit the amount of dirt in the pile. Piles containing large amounts of dirt can seldom be burned efficiently. They almost always smolder for long periods, creating unacceptable smoke problems.
In some cases overstory pines are left during harvest as seed trees, and in others an unevenaged management system such as shelterwood is used. In both situations, the logging debris can still be burned, but you must take more care to protect the remaining trees.
Prescribed burning is useful when regenerating southern pine by direct seeding, planting, or natural regeneration. On open sites, fire alone can expose adequate mineral soil and control competing vegetation until seedlings become established. Where competing vegetation cannot be adequately reduced by fire, follow up with mechanical or chemical treatment. The fire will improve visibility so that equipment operators can more easily see the stumps of the harvested trees, as well as any other hazards. In addition, if the area is to be bedded before planting, burning first consumes much of the debris. The result is more tightly packed beds and thus better seedling survival. Where herbicides are used to kill competition, subsequent burning will give additional vegetation control. This step also permits more efficient and easier movement of hand-planting crews. Prescribed fire also recycles nutrients, making them available for the next timber crop.
For natural regeneration, knowledge of anticipated seed crop and date of earliest seed fall is essential. If the seed crop is inadequate, burning can be postponed. Complete mineral soil exposure is not necessary or desirable; a thin layer of litter should remain to protect the soil. Generally, burning should be done several weeks prior to seed fall. Timing varies with species and locality.
preferences of several endangered species, including the Florida panther, gopher tortoise, indigo snake, and red cockaded woodpecker are also enhanced by burning. Wildlife benefits from burning are substantial. For example, fruit and seed production is stimulated. Yield and quality increases occur in herbage, legumes, and browse from hardwood sprouts. Openings are created for feeding, travel, and dusting.
Selecting the proper size, frequency, and timing of burns is crucial to the successful use of fire to improve wildlife habitat. Prescriptions should recognize the biological requirements (such as nesting times) of the preferred wildlife species. Also consider the vegetative condition of the stand and, most importantly, the changes fire will produce in understory stature and species composition.
burning and the frequency of burns will vary somewhat by species and physiographic region.
Generally, a winter (dormant season) fire results in less root kill than a late spring or summer burn. One system recommended in both the Piedmont and Coastal Plain is a dormant season burn to reduce initial fuel mass, followed by two or more annual (if enough fuel is present) or biennial summer burns.
If not controlled, the hardwoods will form a midstory and capture the site once the pine is harvested. If a large pine component is wanted in the next rotation, these unmerchantable hardwoods must be removed during site preparation - an expensive proposition. Generally, fire is required in combination with other treatments involving heavy equipment, chemicals, or both. In many locations the preferred system is a combination summer burn and herbicide treatment. However, in the lower Appalachians of South Carolina, another relatively inexpensive technique is employed. All residual hardwoods are felled and the area broadcast burned under exacting fuel and weather conditions.
after it comes out of the grass stage. Therefore, a reburn will likely kill some seedlings, so such a decision should be made in consultation with experienced personnel. Your local State forestry office is a good place to begin.
Prescribed burning seems to reduce problems from Fomes annosus root rot. This fungal disease is less frequent where periodic burns have reduced the litter. The fire alters the microenvironment of the forest floor and perhaps destroys some fruiting bodies and cauterizes tree stumps.
Prescribed fire has been successfully used under very exacting fuel and weather conditions to control cone insects such as the white pine cone beetle (Conophthorns coniperda) while the pest is overwintering in cones on the ground. Prescribed burning costs mush less than traditional chemical control methods used to control this beetle.
Prescription burning improves recreation and aesthetic values. For example, burning maintains open stands, produces vegetative changes, and increases numbers and visibility of flowering annuals and biennials. Burning also maintains open spaces such as mountain balds, and creates vistas. Unburned islands increase vegetative diversity which attracts a wider variety of birds and animals. A practical way to maintain many visually attractive vegetative communities and perpetuate many endangered plant species is through the periodic use of prescribed fire.
Using fire to manage landscapes and enhance scenic values requires judiciously planned and executed burns, especially where exposure to the public is great. Burning techniques can be modified along roads and in other heavily used areas to ensure low flame heights, which in turn will reduce crown scorch and bark char while still opening up the stand and giving an unrestricted view.
Prescribed Burning = Good wildlife Habitat
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Last updated on Monday, March 24, 2003 at 04:33 PM
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