Prior Experience With Fires And Forest Regeneration example essay topic

Ecological Restoration of Forests and Fires One of the most predominate ecosystems is the forest community. Covering about one-fourth of the land area on Earth, forests consist mainly of trees and other woody vegetation, growing closely together. The trees can be large and densely packed, as they are in the coastal forests of the Pacific Northwest, or they can be relatively small and sparsely scattered, as they are in the dry tropical forests of sub-Saharan Africa. Forests are complex ecosystems that also include "soils and decaying organic matter, fungi and bacteria, herbs and shrubs, vines and lichens, ferns and mosses, insects and spiders, reptiles and amphibians, birds and mammals, and many other organisms" (Audesirk, 2003).

All of these components constitute an intricate web with many biological interconnections. A bird may depend on the upper branches of a tree for nesting, while the tree may depend on the fungi surrounding its roots to obtain water and nutrients. A forest performs a number of vital environmental services, such as cleansing the air, moderating the climate, filtering water, cycling nutrients, providing a habitat for animals and provides humans with recreation and beautiful scenery. Resources from the forest supply raw materials, such as lumber, paper products, greenery and pharmaceuticals. Some of the developing issues today concerning forests are fires and what we as a society can do to restore the natural ecosystems within the forests around our world.

Many aspects are to be considered when looking at the ecology and bioremediation of forests such as, human activities, wildlife, endangerment and environmental changes. This paper will discuss the effect wildfires have on the forest ecosystem. Human beings cause most wildfires, directly or indirectly. In the United States lightning, the only truly natural cause is responsible for less than 10% of all such fires. In the West, lightning is the primary cause, with smoking (cigarettes, matches, and such) the second most frequent. Combined they account for 50 to 75% of all wildfires.

In the "13 southern states (Virginia to Texas) the primary cause is arson; this combined with smoking and debris burning makes up 75% of all wildfires" (Perry, 1994). The other causes of wildfires are machine use and campfires. Machine use includes railroads, logging, sawmills, and other operations using equipment. Due to rapid increases in human consumption, reforestation has become important. In our past, when human population was low, people utilized the forest for gathering wild plants and game to obtain food. There was not a great deal for concern about the changes of the ecosystems of forests.

Mature natural forests usually "produced wood at a rate of 14-28 ft, and this often exceeded the rate of harvesting firewood. However, with the adoption of agriculture, humans settled down and their populations increased, placing pressures on forests" (Perry, 1994). Not only did the demand for fuel wood increase, but forests were cut down to make room for agriculture. For example, in 1600 about 49% of the continental United States was covered with forests, but this had been reduced to 33% by 1900. In just 300 years, population pressures reduced forestland's by about 1 million acres.

Since natural regeneration was not keeping up with the rate of harvests, the need for rapid reforestation became more apparent. During the late 1800's, concern was expressed about future wood supplies in the United States due to floods caused by deforestation and fires. Two solutions to these problems were proposed. One resulted in the creation of national forests where wood and clean water could be produced in perpetuity, the other "promoted artificial regeneration, the establishment of trees by planting or direct seeding" (Perry, 1994).

Due, in part, to a combination of improved technology in both agricultural and artificial regeneration, the United States now has about the same amount of forestland as it did 80 years ago. This is not true in many countries where human populations are increasing but artificial regeneration has been limited. Truly this shows that humans have had a great impact on the ecosystems of forests in our past. Fire has shaped vegetative communities for a long as vegetation and lightning have existed on earth. Fire affects soil in several ways: the increase of temperature, the removal of plant matter and the soil's ability to absorb rainfall and snow melt.

If plants are killed, their roots will cease to hold the soil together increasing the danger of erosion. The increased temperatures caused by the fire can have effects on the characteristics of the soil. First of all, all organic matter in the soil will be removed. Other minerals and compounds may also be removed depending on how hot and long the fire burns.

High temperatures may also kill the biotic components of the soil which can seriously affect post fire productivity. The soil exposed by the fire will become more susceptible to freezing. Animals are affected by fire mainly through changes to their habitat. Typically, animals either die or flee the fire area. Influenced by fire intensity, severity, rate of spread, uniformity, and size, long-term faunal response to fire is determined by habitat change, which influences feeding, movement, reproduction, and availability of shelter (Ansley et al., 2000).

The extent of fire's effects on animal communities generally depends on the extent of change in habitat structure. Contrary to popular belief, fire usually injures or kills a very small portion of the animal population. Smoke inhalation is a greater threat. Most animals that are killed were the weak or very small that are trapped by the fire. Without the ability to move, flora is the hardest hit by fire. Understory fires change the canopy in two ways: by killing or top-killing a few of the most fire-susceptible trees, and by killing or top-killing a cohort of tree regeneration, also selectively according to fire resistance (Lyons et al., 2000).

Understory fires also reduce understory plant biomass, sometimes in a patchy pattern. Stand-replacing fires change habitat structure dramatically. When crown fire or severe surface fire kills most of the trees in a stand, surface vegetation is consumed over much of the area, and cover for animals that use the tree canopy is reduced. Crown fires eliminate most cover immediately; severe surface fires kill the tree foliage, which falls within a few months.

Stand-replacing fires alter resources for herbivores and their predators. The habitat is not "destroyed", but transformed: The fire-killed trees become food for millions of insect larvae and provide perches for raptors. Trees infected by decay before the fire provide nest sites for woodpeckers and then for secondary cavity n esters (birds and mammals) (Lyons et al., 2000). In mixed-severity fire regimes, fires either cause selective mortality of fire-susceptible species in the over story or alternate between understory and stand replacement, with overlapping burn boundaries. The need for assisted restoration is determined by ecosystem post-burn characteristics. Forests, in the long term, are adapted to recover from fires, although recovery may take tens to hundreds of years and sometimes result in modifications to forest type.

However, the bare soils of a severely burned forest may be susceptible to invasive, non-native species which compete with native species, limiting growth and productivity of desired vegetation. Knowledge of biology, in particular plant species and their natural environments is helpful. Prior experience with fires and forest regeneration can help to determine if the natural healing process is occurring. Sprouting is a means by which many plants recover after fire. Shoots can originate from dormant buds located on plant parts above or under the ground. Woody plant species have dormant buds located in the tissue of stems, above or below the surface of the ground.

These plants sometimes sprout from the root collar, the point where roots spread out from the base of the stem. Heat from fire may kill seeds that have recently fallen to the ground, preventing establishment of that species until after the next year's seed fall. Seeds may originate on-site from surviving trees or from seed stored in the soil before the fire. Light seeds may be carried by the wind.

Seeds with barbs or hooks may be carried in fur or feathers. Hard-coated seeds ingested along with their fruit pass through the bird or animal, sometimes with an enhanced likelihood of germination. Since the crown of the forest has been thinned or entirely removed by the fire. Our future forest will have more than just tress. As flora regenerates, fauna will move back into the area. You can now see moss, shrubs, wildflowers, birds, insects and other animals that make homes in the forest.

For 10 to 20 years after stand-replacing fire, biomass is concentrated on the forest floor, as grasses and forms, shrubs and tree saplings reoccupy the site. These provide forage and dense cover for small mammals, nest sites for shrub land birds, and a concentrated food source for grazing and browsing ungulates. In 30 to 50 years after stand replacing fire, saplings become trees and suppress the early successional shrub and herb layers. The forest again provides hiding and thermal cover for ungulates and nesting habitat for animals that use the forest interior. We need the forest for resources in our future. As long as there are forests people can count on supplies of forest products for about as long as we need and take care of them, for example: oil, minerals, coal, wood, and soil.

Without the forest, some of the plants and animals could not exist. Comprehensive planning for future endeavors has the importance of having scientists from different divisions work together to address society needs. There are issues that should be addressed. Mainly is the concern on water availability and quality, natural hazards, threats of contaminated environments, future land use, biological resources, and health effects that originates from the geological environments. What is the problem of the forest future? Studies of ecosystem consist of both natural and human disturbances, different uses of land disruption, the influences of plants, and the wind protecting landscape from erosion by wind and water.

As the next millennium beings, our understanding of natural resources and our innovative ways, can give light to this economic, and environmental network. In addition, information that provides data, and technology on these important issues of the immediate future in forests, plays a role in continuing the recovery and life expectancy of our forest. Earth and biological sciences provide scientific work issues as no other science has before. Fire is a dynamic process, predictable but uncertain, that varies overtime and the landscape. Ninety percent of the time, forests can heal themselves. Human consumption has made it necessary for forests to regenerate faster.

Ecosystem managers track and record the restoration progress in order to decide if intervention is needed.

Bibliography

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