Forest

Hayedo in the Gribskov (Denmark)

Proportion of land covered by forests

A forest is an ecosystem where the predominant vegetation is trees and shrubs. These plant communities cover large areas of the Earth and constitute habitats for animals, modulators of hydrological flows, and preservers. soil, constituting one of the most relevant aspects of the biosphere of the globe. Although often thought of as consumers of atmospheric carbon dioxide, old-growth forests are nearly carbon neutral, with only disturbed and young forests acting as such consumers. Mature trees play an important role as stable reservoirs in the global carbon cycle, and their removal leads to an increase in atmospheric carbon dioxide levels.

Forests can be found in all regions capable of supporting tree growth, up to the tree line, except where the frequency of natural fire is too high, or where the environment has been damaged by natural processes or human activities.. Forests sometimes contain many tree species within a small area (such as tropical rainforest and temperate deciduous forest), or relatively few species over large areas (for example, taiga and dry montaneous coniferous forests). Forests are often home to many animal and plant species, and the biomass per unit area is high compared to other vegetation communities. Most of this biomass is found underground in root systems and as partially decomposed plant debris. The woody component of a forest contains lignin, which decomposes relatively slowly compared to other organic materials such as cellulose and other carbohydrates.

Synonymy and related terms

Forest of hardwoods with fern sotobosque in Venezuela.

The term floresta was equivalent to forest in the books of chivalry, as corresponds to its origin (from the Latin foresta), but the phonetic crossing with flower was added later the idea of amenity that is associated with it today. Jungle was equivalent to forest according to its etymological origin, but today it is associated with dense tropical and/or rain forest. Park is a natural or artificial forest with a delimited area. Grove is a small or planted wooded area.

Forests differ from wooded ones by the degree of cover of the plant canopy. In a wooded ecosystem, the presence of trees is a minority because herbs or scrub predominate; in a forest the branches and foliage of different trees often meet or intertwine, although there may be gaps of different sizes within a forest. A woodland has a more open canopy, with trees noticeably spaced farther apart, allowing more sunlight to reach the ground between them; Such is the case of the wooded savannah and the wooded prairie, where grasslands predominate.

Classification of forests

Depending on the type of vegetation

A deciduous broad-leaf forest.

A classification is established by the predominant composition of the forests according to the type of leaf: broadleaf, needle-like (coniferous such as pine), or both.

• Forest of hardwood or wide leaf forest, like the jungles, are the forests dominated by angiospermas and which are richer of species than those dominated by conifers.
• Coniferous Forest or acicular leaf forestThey are those dominated by gymnastics.
• Mixed forest, where there is balance between both types of trees, for example, in the conifers forests with abedules and alarms of the northern latitudes, which have very few species.

According to the seasonality of the foliage

One way of classifying forests is to determine the longevity of the leaves of most trees.

• Perennial forest and subperennial, if perennial leaves predominate.
• Deciduous forest and subcaducifolio, if deciduous leaves predominate.

According to latitude and climate

Mixed mountain temperate forest south of Germany.

• boreal forest: These are the subpolar and continental climate forests that occupy the subartic area, and are usually conifers with perennial leaves.
• Tempered forest: These are the temperate and continental climate forests, such as wide leaf cave forests and coniferous forests. In warm temperate areas there are wide-leaf perennial trees, such as the Mediterranean forest and laurisilva (laurifoliated leaves forest).
• Subtropical forest: Includes subtropical, humid or dry climate forests.
• Tropical forest: Of tropical climate like the equatorial jungle that is the rainiest ecosystem or tropical dry forest.

Depending on altitude

• Lowland forestbasal, plain or plain. In turn it can be flooding.
• Mountain forest. With a mountain climate that varies according to its height. In turn it can be premontano, montano or subalpino.

Depending on the degree of intervention

Forest in Northern Savonia (Finland)

Physiognomy classifies forests by their overall physical structure or stage of growth. Forests can also be classified more specifically by the dominant species present in them. From the point of view of their history and degree of alteration, forests can be classified as:

• Primary forests: Also called natives; they are those who have not suffered antropic interventions. Natural forests only have the original patterns of biodiversity. This biodiversity and its processes have not been affected by humans with a frequency or intensity that can be considered serious.
• anthropogenic forests, they have been affected by humans with enough frequency or intensity to mark great changes in forest patterns. Often in these types of forests are exotic species.
  • Side forests: those that have been regenerated after a first stem, partial or total.
  • Artificial or plantation forests: those that have been planted by man for any purpose.

Biomes

WWF classifies forests into the following biomes:

• 01. Wet tropical and subtropical forests of hardwoods.
• 02. Tropical dry and subtropical forests of hardwoods.
• 03. Tropical and subtropical forests of conifers.
• 04. Tempered hardwood and mixed forests.
• 05. Tempered conifer forests.
• 06. boreal/Taiga forests.
• 07. Mediterranean forests and scrublands.
• 08. Mangrove.

Forest management

The scientific study of forests is called forest ecology, while their management is generally known as silviculture, usually for the purpose of sustainable resource extraction. Forest ecologists specialize in forest patterns and processes, usually with the goal of clarifying cause-and-effect relationships. Foresters typically focus on harvesting timber and silviculture, including the regeneration and growth process of trees.

Forests can be disturbed when events such as felling of trees, forest fires, acid rain, herbivores, or pests, along with other things, cause damage. In the United States, most forests have historically been "attacked" by humans to very high points, although in recent years silvicultural practices have improved, thus helping to regulate the impact. But still, the United States Forest Service estimates that about 1.5 million acres (6,000 km²) of the nation's 750 million (3,000,000 km²) are lost each year.

The ten countries with the largest forest area

The ten countries with the greatest forest wealth account for 67% of the total forest area. Russia alone has 20% of the world total.

Position	Country	Area - Forest area (thousands of hectares)	Percentage of territory	Percentage of global forest area
1	Russia	814.931	50	20
2	Brazil	493.538	59	12
3	Canada	347.069	38	9
4	United States	310.095	34	8
5	China	208.321	22	5
6	Democratic Republic of the Congo	152.578	67	4
7	Australia	124.751	16	3
8	Indonesia	91.010	53	2
9	Peru	73.973	58	2
10	India	70.682	24	2
	Total	2.686.948		67

Environmental impacts of natural forest management

The plant of Celulosa Argentina in Puerto Piray (Misiones)

The management of natural forests can have several objectives:

• The production of wood and other forest products (non-timber forest products, described as secondary; but of equal importance).
• Protecting the watershed.
• The conservation of biodiversity.

For example, in Misiones, Argentina, almost two thirds of its surface is covered with forests. The native forest is exploited for different uses. The most valued species are cedar, peteribi (furniture) and guatambu (plywood). There are extensive areas of forest planted with pine (non-native species) and araucarias (native species) mainly on the banks of the Paraná River. The forest production goes to the cellulosic pulp factories of Puerto Esperanza, Puerto Piray, and Puerto Mineral, to the sawmills and other existing forest industries in the province.

Main environmental threats to forests

Climate change, pollution or pests, among others, are some of the factors that stress forests. In many cases, the interest of multinational nomadic companies in mineral resources, the construction of dams that flood extensive jungle areas or the growth of cities and communication routes (roads, canals, etc.) are many other reasons for the regression or fragmentation of the forest.

While the world's forest area is decreasing, it is increasing in Europe. During the 1960s and 1970s, great concern arose over the decline of the forest on the continent, when 45% of the forests showed symptoms of disease: defoliation, mortality of individuals, etc. Most of the studies related forest decay to air pollution. The process was particularly serious in Central Europe, on acid soils, where the strong emissions of sulfur dioxide lowered the pH of rainwater to values whose average could be close to 3.^{[citation required]}

External impacts

There are some external factors that can cause the deterioration or destruction of the forest ecosystem, among which are the flooding of the dam land to form a reservoir (see the chapter on “Dams and Reservoirs”), the clearing of the forest for cattle ranching (see the chapter “Livestock Management and Grazing Land”), shifting cultivation, and its conversion to commercial agriculture (rubber, African palm, coffee, rice, and cocoa).

Lowland tropical moist forests

Deforestation in the low Peruvian tropical Amazon rainforest.

The rapid deterioration or complete destruction of many areas of lowland tropical humid forest, characterized by its great diversity of species and environmental complexity, and the difficulties that arise when trying to manage them in a sustainable manner, is cause for worldwide concern. While conserving these unique forest areas, through the establishment of parks and reserves, is potentially the best way to protect their biodiversity, environmental processes, and the lifestyles of their indigenous inhabitants, it can only be protected, in this way, some limited areas. Economic pressures and population growth are intensifying land use that was previously sustainable (shifting cultivation), but is now reaching unsustainable and destructive levels, motivating clearcutting logging, and driving large-scale conversion, from forest land to agriculture and livestock, which are generally unsustainable and cause permanent damage to the forest ecosystem. One of the best ways to protect forests and prevent their conversion to other production-oriented activities, and to preserve a large part of their environmental values, is to manage natural forests so that their production of wood and other products is sustainable. and produce important economic results.

The two critical issues in managing humid tropical forests for timber production are:

• The development of sustainable management systems.
• The implementation of these systems so that forest values do not decrease at unacceptable levels.

In theory, humid tropical forests can provide forest products indefinitely. The reality, however, is that there are few systems that have proven to be sustainable, or that can be applied to most of these natural forests with a limited number of species. For this reason, and due to the economic pressures that demand quick income generation, only a small portion of the lowland moist tropical forests currently being logged are managed sustainably.

The most suitable forest management system for humid tropical lowland forests, due to its great diversity of species, is selective exploitation with which only a small number of trees per hectare are extracted. If this is done carefully, with minimal damage to the surrounding soil and vegetation, environmental damage can be limited. The impacts on the biodiversity of the forest and its capacity to provide environmental services (the forest provides four of these servicesː carbon dioxide fixation, biodiversity, water cycle and soil fixation) are minimized, because large spaces are not created in the forest, as is the case with clearing.

Social Issues

Almost in all initiatives that have an impact on natural forests, be it commercial exploitation of the wood, processing industries, or its conversion to other uses, for other activities (mining, dam construction, irrigation, development industrial), or the closure of forests for rehabilitation or conservation, important social questions arise. Development projects that clear forests for other uses can displace people or reduce their access to the forest resources on which they depend for their livelihoods. Commercial logging can destroy resources that are locally important for subsistence economies, and can open up areas to uncontrolled colonization, causing further environmental degradation and social conflict. Also, the closure of forests for rehabilitation or conservation can reduce the income of surrounding populations, depriving them of important nutrients or income-generating products. This closure may cause further degradation. If the pressure on the closed area is too great, conservation and rehabilitation efforts may fail.

Forest dwellers have a great deal of knowledge about the qualities, potential use, and sustainability of local flora, fauna, and geological resources, often based on knowledge gained from centuries of sustainable use.

In highland, arid and semi-arid areas, where fodder sources are limited, forests and local livestock production systems are usually closely linked; Farmers often adopt mixed subsistence strategies, in which livestock production in the forest plays an important role. For example, in the Himalayan region, the productivity of upland agriculture depends mainly on compost, and humus that is collected in the forests.

Forest in Alsace, France

Hunting and gathering, as well as shifting cultivation, have been practiced for hundreds of years in humid tropical forests.

Artisanal fishing in the alluvial zone is important for many of the inhabitants of the lowland forests.

Generally, the social organization of traditional groups is highly adapted to the demands of production systems. Knowledge, both technical and administrative, of these resources can be very useful for technical specialists seeking to intensify or modify production in this or a similar area, that is, to adapt agricultural recommendations to the areas where, currently, production is being carried out. practices migratory cultivation, or to develop forest management and use models for the forests that will be rehabilitated. As forest-dwelling groups move, their indigenous technical knowledge of forest management and use is often lost. A careful evaluation, including a real economic analysis, must be carried out before assuming that current uses of the forest should be abandoned for something 'better'.

Land tenure issues are almost always a concern in forestry projects. Often, there are overlapping rights, including state-recognized tenure, and customary tenure and/or concessionary rights systems regarding products. In the case of ethnic minorities living in the forests, there may be very strong customary rights to forest lands that are constitutionally valid despite authority over these lands having subsequently been transferred to the government.

In many societies, rights to land and to trees may be separate, with specific rules for different species. Forest-dwelling groups often have complex ownership regulations regarding forests and products. For example, rights to fruit trees may be different from those that allow individuals to put other uses of forest land, including shifting cultivation. Traditional tenure systems may be more appropriate for managing fragile lands than state-sponsored options.

The closure of forests, or restriction of access and use of resources, affects different groups of the population in different ways. For example, landless ranchers may be hardest hit economically by the closure of these areas because they, unlike landed farmers, cannot obtain fodder from their own land. Women may have a much higher workload due to the need to travel much greater distances to find the necessary resources; however, local people may not identify this burden as a problem, due to women's lower status in society. If migratory herders' routes are affected, they may be forced to excessively use other lands outside the project area that are still available, producing negative impacts both for those lands and for the sedentary groups that depend on them.

Planners are increasingly exploring ways to integrate the needs of local people into forest conservation and rehabilitation initiatives, through promoting proper management of common property resources or systems. of joint administration between the government and the users. It is important to document existing local management systems, including those that have failed due to increased pressure. In areas of unique biodiversity, other measures have included the creation of protection zones, which generate alternatives for the people who traditionally depend on the area to be conserved, or conservation systems have been designed that allow local people to use, in a controlled manner, the protected area. Examples:

• A project in Mexico has sustained traditional rights to forests and provided technical assistance to timber-processing cooperatives.
• Papua New Guinea ' s forest plan presents a similar proposition to tribes with traditional ownership rights over forests.
• A World Bank project in Nepal contemplates the comprehensive rehabilitation of hill forests, through the strengthening of the rights of local user groups, to undertake their protection and controlled use, in consultation with the silvicultors of the area.

Improved wood processing technologies

Expanding the use of forest products can help to intensify forest management. Many species are not used for lack of the necessary processing or marketing infrastructure. In tropical forests, with their high species diversity, individual commercial species are often dispersed over a large area, making harvesting difficult and often uneconomical. Logging in less diverse but remote or low-density forests may not be profitable.

If the new products were from other species, or if it were possible to take advantage of many different sizes, thanks to the improvement of the process or the development of new markets, a greater proportion of the forest material could be used. There is a lot of scope, not only to develop the new products, but also to conserve current stocks (e.g. developing more efficient veneer, plywood and chipboard, using logging waste and recycling plant waste processing) can help balance supply with demand, and take pressure off natural forests. The benefits of these methods are obvious, as are the dangers. Increased use of a broader selection of species can lead to large-scale clearing, or 'mining', of the forest resource.

Project alternatives

The alternatives for the management of primary and secondary forests, for wood, non-fire products and agricultural and livestock production, broad and low impact, are the following:

• Reduce demand for wood through conservation, improving stoves for drying wood and alternative fuels;
• Use more efficient sheets, stubborn wood, and sprinkle, and recycle the wastes of wood;
• Making greater use of forest species through the expansion of processing technologies, and the development of products and markets;
• Develop plantations to increase the production of idle forest resources;
• Implement community forest and reforestation programmes, carried out by land owners, to produce wood products;
• Develop ecotourism as a cost-effective and sustainable way of using tropical forests;
• Encourage local processing to take advantage of additional benefits, rather than promote policies that emphasize the short-term exploitation of trees;
• Use, completely, the trees that are destroyed (which are often lost) during the debroce of the forest for other non-forest activities (e.g. dams and reservoirs, road construction, industrial and urban development, etc.);
• Intensify agricultural production and reforestation in fertile soils or in areas that have been broken down, before opening new spaces of the forest for exploitation.