Much has been said and written about this. Often the understanding of the subject is superficial or tendentious, or absent altogether. In Latvia, a country of forests, one would think the population should be well informed about the role forests play in our lives. Yet that is far from the case. So, by drawing together things that are supposedly common knowledge, let us think about them once more. Let us remember that, first and foremost, Latvia's forest resources must be used for the security and well-being of Latvia's people. Our country does not face the problems found in the lands of the rainforest regions or in drought-stricken territories with degraded soils. There is no need to go looking for "the Congo" in Latvia – our forests are excellently managed. Our foresters observe the principles of sustainability – not as a slogan, but in their daily work in Latvia's forests, however much that may displease some people…

So:

Trees are extremely important. They are the largest plants on the planet, providing us with oxygen, storing carbon, stabilising the soil and giving wildlife and plants a place to live. They also supply us with materials for tools and with shelter. Trees matter not only to life itself; they provide a link between the past, the present and the future. If we want to know the season – winter, spring, summer or autumn – we need only look at the trees. It is important that forests, rainforests and very nearly all trees the world over are genuinely managed in a sustainable way.
The latest research shows that trees have a beneficial effect on health, since they act as a physical filter, absorbing various polluting gases (nitrogen oxides, ammonia, sulphur dioxide and, of course, carbon dioxide) and trapping airborne dust with their leaves and bark.

Each individual tree "removes" up to 1.7 kg of pollutants every year. Trees provide shade and reduce noise pollution levels. It is well known that trees or parts of them can be used for medicinal purposes. Birch bark essential oil, for example, has antiseptic properties. Researchers point out that within a few minutes of being among green spaces and trees, blood pressure falls, the heart rate slows and stress levels drop.
A number of studies show that patients who live surrounded by trees recover faster and with far fewer complications. Children with ADHD (attention deficit/hyperactivity disorder) show fewer symptoms when they have access to nature and trees. The presence of trees helps with concentration by reducing mental fatigue.
Trees have a beneficial effect on the environment and help combat climate change, because as they grow they absorb carbon dioxide and store it in their wood. This helps to slow the rate of climate warming.

Deforestation

In recent years this subject has become extremely acute – both politically and practically. Deforestation is a serious global problem. It means the complete or almost complete felling of tree stands and the conversion of the land to other uses as a result of human activity. The UN Food and Agriculture Organization (FAO) defines a forest as land where the trees are at least 5 m tall, tree canopy cover exceeds 10% and the minimum area is 0.5 ha. Deforestation is understood as a semi-permanent reduction of tree canopy cover to less than 10%. Deforestation differs from forest degradation; forest degradation means substantial damage to forest ecosystems, but stand cover above 10% is retained.

It is thought that when agriculture emerged some 8,000 years ago, forests covered about 40% of the land surface. As agriculture spread across the world, many forests were cleared, particularly on the more accessible and fertile land. The areas most affected were the Middle East, the Mediterranean region, South Asia, Europe and the Far East.
From the end of the 18th century, forest clearance in temperate climate regions increased rapidly. The Industrial Revolution, growing prosperity and population growth placed enormous pressure on the remaining forest areas to supply fuel for industrial development and land for agriculture, and by the end of the 19th century large areas of forest had been cleared in Western Europe, Russia and China. In Denmark, for example, firewood had to be imported from Germany at the start of the 19th century. In effect, there were no forests of its own left…

Deforestation is a significant problem that affects regional ecosystems, local economies and the global climate – especially in the planet's southern hemisphere. It is estimated that deforestation generates around 15% of global greenhouse gas (GHG) emissions each year. These emissions arise from the burning of fuel in the course of logging, from the combustion or decomposition of felled timber products, and from other activities in rural areas, in particular poor agricultural practices that degrade the soil and increase CO₂ emissions.
Eliminating all the world's forests would release up to 3 trillion tonnes of carbon that is currently safely locked up in wood; preserving existing forest stocks would cut emissions by at least 15%, helping us meet global climate commitments. The world's forests can absorb around 25% of anthropogenic greenhouse gas emissions. Reducing deforestation would increase the capacity of forests to absorb greenhouse gases, especially if combined with a reduction in overall greenhouse gas emission levels.

Air pollution and forests

Forests cover 32% of the world's terrestrial ecosystems and provide many ecosystem services, including timber production, hydrological regulation, soil conservation, climate change mitigation and air quality regulation. Green infrastructure such as urban parks and street trees also improves air quality and mitigates the "heat island" effect.
Air pollution is a significant problem worldwide, affecting human health and well-being, ecosystem health, the climate, visibility, crops and man-made materials. The main air pollutants are: carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), lead (Pb), sulphur dioxide (SO₂) and particulate matter (PM), which includes particles with an aerodynamic diameter of less than 10 microns (PM10) and particles with an aerodynamic diameter of less than 2.5 microns (PM2.5). A number of health disorders are associated with air pollution, such as effects on the pulmonary, cardiac, vascular and neurological systems. Trees and forests alter air quality by directly removing air pollutants, by influencing the local microclimate and building energy consumption, and by emitting volatile organic compounds (VOCs), which can contribute to the formation of O₃ and PM2.5 (fine particulate matter is taken to mean particles with a diameter of 2.5 microns or less).

Increasing carbon sequestration.

Forests account for roughly 60–90% of the total terrestrial carbon stock. The natural net flow of carbon dioxide into the atmosphere from vegetative systems is close to zero (a state of equilibrium) when the system is in its natural, undisturbed condition. Under extensive and rapid logging, equilibrium conditions or conditions close to equilibrium may be lost. A number of studies have examined the potential of afforestation, forest regeneration, agroforestry and forest management to increase carbon sequestration. It should be noted that the carbon sequestration capacity of forests varies greatly depending on forest type, forest age, moisture availability, local climate and soil bearing capacity.

The carbon dioxide sequestration potential of different forests

The carbon sequestration potential of afforestation depends on the site, forest management practices and forest type. It is clear that better tended and fully managed forests, as well as forests established with genetically superior planting stock, offer considerable scope for increasing carbon sequestration capacity. Planting trees remains an effective carbon sequestration option. Once a tree matures, it can take up about 48 pounds of carbon dioxide a year (alongside other greenhouse gases such as ozone) and release enough oxygen to supply two years of breathing. In cities, trees help improve the microclimate, provide habitat for wildlife, increase property values, affect people's mood, absorb air pollution, conserve water, and reduce soil erosion and noise pollution.

Social values

Forests can create social values or be bound up with people's lives, enhancing (or diminishing) their social well-being. The term "social values" is used to denote aesthetic and existential values, emotional attachment, a sense of naturalness or freedom (informality), recreational values, privacy, moral and spiritual values, cultural values, mythical value (a sense of primevalness or mystery), rural employment opportunities, local people's needs for a livelihood or for a health-promoting environment and/or environmental improvement. Some researchers even describe carbon sequestration as a "social value"…

The social functions of forests are difficult to measure and can vary considerably between countries depending on a country's level of development and its traditions. In developed, post-industrial societies, for example, the benefits derived from forests provide recreation and leisure, or the preservation of a rural way of life. In developing countries, the area of forest available for securing a livelihood, or the number of people employed in the sector, may be a better indicator of social value. Given the difficulties involved in measuring the social benefits of forests, social functions are often assessed as inputs (for example, the area or proportion of forest used to provide various social functions). Both society and forestry have changed dramatically over the centuries as a result of forest management, and this has shaped the way social values are recognised – values that shift as society's organisation, beliefs, influences, level of education and leisure time change.

The socio-economic functions of forests

Every international process for developing criteria and indicators includes a section on monitoring and assessing the socio-economic functions or benefits of the forestry sector. A range of variables can be measured: production and consumption, recreation and tourism, funding and investment in the forest sector, cultural, social and spiritual needs and values, employment in forestry, health and safety, and the needs of society.

The importance of forest biodiversity

The greatest value of biodiversity may be something we do not yet know. Only a fraction of the species known to us have had their potential medicinal, agricultural or industrial value investigated. We do not fully understand how biodiversity contributes to environmental well-being globally, and we are only beginning to grasp how biodiversity helps people meet their economic, nutritional, health and cultural needs.
Forests are the most diverse terrestrial ecosystems, home to the majority of land species. Timber, pulpwood, fuelwood, fodder, meat, productive crops, plants and medicinal herbs obtained from forests provide a livelihood for hundreds of millions of people around the world, yet only a fraction of known species have had their potential medicinal, agricultural or industrial value investigated.
The rainforests of the tropics are the biologically richest terrestrial biome on the planet, home to 50–90% of all plant species. That is precisely why the clearing of tropical forests is the greatest threat to the diversity of the planet's flora and fauna. Estimates of species loss – 10 or 150 species a day – are at best informed assumptions. Many scientists believe that the rate of species extinction in the late 20th and early 21st centuries is comparable to the mass extinctions that occurred during the catastrophes of Earth's geological past.

The great biological diversity of forests is worth preserving for several reasons – from a utilitarian point of view, forest products bring direct benefits to people. A large proportion of agricultural plants originated in forests, and plants of potentially high commercial value may still be discovered. High genetic diversity improves plant breeding and productivity.
One of the best ways to conserve forest biodiversity is to establish protected areas within forests, but these areas must be of a certain size, or must form a network of forest areas, so that local forest ecosystems can remain viable and effective. The forest around a protected area must be carefully managed so that it serves as a buffer zone. The surrounding forests allow local people to earn a living without encroaching on the protected area.

The importance of forests in the world's drylands

About 90% of the roughly 2 billion people who live in areas regularly affected by excessive drought live in developing countries. To meet basic needs for food, shelter, medicines, cooking, firewood, heating, fodder for livestock and everyday income to live on, most of these people depend on forests and wooded areas, on grasslands and on tree stands on farms. Forests play an essential role in desertification processes. Forestry activities in dry regions are geared towards both production and protection, and forestry benefits greatly from the soil and water conservation created by plant cover, which helps maintain environmental stability.
Forest habitats provide biodiversity, protect against wind and water erosion and desertification, help water penetrate the soil and promote soil fertility, and help increase the resilience of landscapes and communities to global change. In Africa, growing trees in dry zones is both a forestry practice and a form of land use. The main forestry activities used to combat desertification are afforestation, plant tending, pasture management, agroforestry systems, water management, and the establishment of national parks and other protected areas.

Forests against air pollution

Air pollution is a global problem, particularly in the industrialised countries of Asia, where it is extremely high. Air pollution is one of the leading topics in discussions about the environment. High concentrations of harmful gases and particles in the atmosphere have a negative effect on the health of any living creature; it also causes temperatures to rise, intensifying climate change.
Forests absorb a third of the world's emissions every year. Fine particles, odours and polluting gases (nitrogen oxides, ammonia, sulphur dioxide) settle on tree leaves. Trees absorb toxic chemicals, taking them up from the air. They reduce the impact of greenhouse gases by trapping heat, lower ozone levels and release the oxygen that is vital to life. Trees also reduce exposure to particulate matter (which consists of a mixture of various chemical substances and soot that causes heart and lung disease). If the current rate of logging in the southern hemisphere continues, it will seriously affect air quality in many parts of the world.

Trees act as a "purification system", absorbing chemicals present in the air and releasing oxygen. To tackle air pollution internationally, deforestation must be halted and billions of trees planted. Forest regeneration, as is well known, is the restoration of trees and ground-cover plants in a place where forest previously stood. It must be stressed that afforestation has to be carried out professionally, on the basis of scientific knowledge and with the choice of species best suited to the particular area. Incidentally, more than 200 million hectares of deforested land yield little or no food production. Such an area is suitable for cost-effective forest restoration. It is roughly three times the size of Texas in the USA. Restoring forest on such areas would sequester 3 gigatonnes of carbon dioxide equivalent a year (GtCO₂e/year). That is comparable to the annual emissions of 642 million passenger cars. The quality of the air we breathe is directly linked to the trees (the stands) closest to us. The balance between the global and the local benefits that trees provide makes them irreplaceable in protecting our planet and human health.

Improving the environment and mitigating climate change

Trees play an essential part in improving the environment and slowing climate change, and are regarded as living air purifiers. Access to clean air is one of the fundamental human rights. Air pollution not only harms human health, it also damages rainforests and wildlife, and in many ways it holds back the economy. Nine out of ten people in the world breathe polluted air, which causes millions of illnesses and deaths. Tiny particles of pollutants travel hundreds of miles from cities, reaching places such as the Amazon rainforest. Reacting with sunlight and with volatile organic compounds from vegetation, they produce chemicals that can affect the local climate. Trees act as air purifiers, improving air quality in a number of ways. In addition to absorbing carbon dioxide, they substantially reduce the impact of toxic pollutants and harmful microscopic particles produced by wood burning, diesel vehicles and cooking.

Trees act as air conditioners, creating a local cooling effect, and also as a natural filter that absorbs hazardous pollutants. Particles that are especially harmful to the lungs are trapped on tree surfaces, while the leaves act as filters, absorbing polluting gases. If a tree has developed healthily, it can capture the maximum amount of carbon dioxide from the air and store the surplus carbon as carbohydrates in its woody tissue. The capture of carbon dioxide and the accumulation of carbon are affected by a tree's age, health and species.

The condition of the soil is another important factor. Recent research shows that a large share of carbon accumulates below ground in healthy roots and in the organic matter nearby. The intensity of a tree's growth and carbon accumulation processes is also affected by the climate. Trees are at their most active in sunny, warm and humid weather. Several studies show that the shade cast by large trees can significantly help reduce heat and act much like an air conditioning system for nearby homes. That in turn reduces the CO₂ emissions of heating and cooling equipment.

Planting trees

Planting a tree is a lifelong investment. Capturing carbon with the help of trees is likely to remain one of the most effective ways of limiting the rise in CO₂ concentrations worldwide. Planting billions of trees across the world is one of the most effective and cheapest ways to address climate problems and remove CO₂ from the atmosphere. Restoring forests can buy time to reduce carbon emissions. Planting trees is vital if we are to reverse current trends of rising greenhouse gas emissions caused by the burning of fossil fuels and by deforestation. Emissions would be cut to zero (or at least close to it).

Afforestation remains one of the most effective climate change mitigation strategies. There is enough suitable land in the world to increase forest area by a third without touching cities or agricultural land. However, as global temperatures rise, the amount of suitable land is shrinking. Even if global warming were kept below 1.5 °C, the area available for forest restoration could shrink by a fifth by 2050, because some tropical areas would already be too warm for forests. Excluding existing forest areas, agricultural land and urban areas, it has been found that a further 0.9 billion hectares of forest stands could be established, which could store 205 gigatonnes of carbon in territories where forest masses would form naturally. This suggests that afforestation worldwide is one of the most effective carbon sequestration solutions available to date. A recent study indicates that more than half of the potential for forest restoration lies in just six countries: Russia (151 million hectares), the USA (103 million), Canada (78 million), Australia (58 million), Brazil (50 million) and China (40 million). These countries have such great potential because they have already cleared a large share of their existing forests.

Afforestation in areas where forests once grew

Afforestation is the restoration of trees and ground-cover plants in a place where a forest stand previously grew. Forest restoration can be used to repair or prevent the consequences of deforestation or to improve people's quality of life by removing air pollution and dust, restoring natural habitats and ecosystems, and mitigating global warming, since forests both promote the biosequestration of atmospheric carbon dioxide and provide resources. Forest restoration can take place naturally, artificially or by combining the two methods, and it is important to many of the Earth's natural cycles, such as the carbon and water cycles. Afforesting deforested land with fast-growing tree species such as eucalyptus or Australian acacias can help solve immediate problems such as soil erosion and elevated carbon levels.

In areas where deforestation is very intensive, the remaining patches of forest are often a long way from surviving forests or from newly afforested areas. This makes survival and recolonisation more difficult for a number of animal species, hampers cross-pollination between plants, and can hinder the maintenance of rainforest ecology. Forestry specialists are trying to protect rainforest species by afforesting the "corridors" between plots of rainforest. This gives plants and animals access to a larger habitat and allows populations to mix, which can increase their genetic diversity and, for most species, help prevent extinction caused by isolation. Forest restoration is becoming ever more pressing on a global scale.

Protecting existing forests

Forest degradation is caused by short-term forest clearance, selective logging and other forms of land use. In some places, emissions from degradation can exceed those from deforestation. When natural ecosystems are affected, they become more vulnerable to fire, drought and climate change. Recent research shows that helping natural forests to regrow can have a globally significant effect on carbon dioxide levels. This approach, known as forest regeneration, is an immediate, more effective and cheaper method than planting trees for removing and storing atmospheric carbon over the long term. It can be applied in forests all over the world.

By avoiding further degradation and loss of primary forests and intact forest landscapes, and by allowing degraded forests to regrow naturally, global carbon emissions would fall by around 1 gigatonne (Gt) a year. Natural regrowth alone would cut carbon emissions by a further 2–4 Gt. A number of studies predict that protecting old-growth forests and allowing degraded forests to recover would remove 153 billion tonnes of carbon from the atmosphere by 2150. Research shows that land management is the best way to improve the condition of natural forests and help them recover from degradation. Any expansion of natural forest area is best achieved by allowing degraded forests to regenerate naturally.

Allowing a forest to regenerate naturally offers a better chance of creating a diverse forest than intensive planting does. Rather than afforesting entirely new areas, priority should be given to connecting existing forest areas and avoiding forest fragmentation. If forests are to help combat climate change effectively, regional and global policies are needed to protect and restore natural forests, along with an economy that produces no carbon emissions. Of course, this goal "sounds fine", but delivering it is extremely difficult, because rapid population growth on some continents places an enormous burden on local ecosystems. Planting trees is, of course, excellent and highly important work, but preserving existing forests matters just as much. This must be done bearing in mind the rapid population growth in the areas concerned, with all the consequences that follow from it.

Planting forests can help address climate change problems, claims the UN, which has announced plans to plant forests in the cities of Asia and Africa to help them become much greener. The hype around planting trees to save the planet needs to be reassessed. Planting trees could be a convenient and effective way of fighting the climate crisis.

Forest restoration is a term that, after nearly two centuries of industrial forest clearance, often means a new forest. Trees (wood) are made up of roughly a quarter carbon and, as they grow (or burn), they bind (or release) about four times more carbon dioxide than their own weight. Despite the attention given to carbon dioxide capture facilities, ecologists at the Massachusetts-based Partnership for Policy Integrity maintain that, when it comes to sequestering carbon, "forests are the only proven, measurable technology available to us". But not every area that could be afforested should necessarily be afforested. For the global forest restoration process to be viable, it is important to take account of local ecosystems and of the effect trees have on nearby communities. In other words, fighting climate change with tree stands that reduce carbon dioxide emissions requires serious planning and strategy, rather than simply planting trees wherever one can.

It must be remembered that it will take decades before new forests are mature enough to store large amounts of carbon. If climate change continues at its present rate, more than 220 million hectares of potential forest could be lost by 2050. Another issue is the tree species, as some species are not particularly well suited to storing carbon. Choosing the right tree species for a given soil is a fairly lengthy process.

But – trees alone are not enough, and they can give false hope. The world must reduce its emissions. It is not possible to halt climate change through tree planting, IT technologies and modern agriculture alone. Wars rage in many parts of the world, drinking water is scarce in many places, and the sharp rise in population in the southern hemisphere is generating all manner of crises, unrest, clashes, famine and uncontrolled migration. In such circumstances, priorities change… The situation is not, and will not be, simple for the foreseeable future.

Forest management

Around the world, many communities are heavily dependent on forest products (non-timber products) for their livelihoods and as a basis for trade. People use reeds, medicinal and food plants, resins, wood by-products and, of course, wild animals. Tropical forests are an essential source of energy for many communities: both directly, through burning wood for cooking and heating, and indirectly, by protecting water basins as a source of water for energy production. Tropical forests have a decisive role in protecting the physical and biological environment at local and regional level.

Forest management is a process that effectively combines and integrates the biological, social and economic factors influencing the decisions through which specific objectives are achieved. A forest management plan translates national or regional forest policy (as it ought to) into carefully prepared and well-coordinated programmes for regulating the forest and forestry activities over a defined period. Prescriptions are applied accordingly, setting out objectives, activities and control measures. This is an integral part of the forest management system, which must govern protection, inventory, timber volume determination, logging, monitoring and other forest-related activities.

The minimum term or duration of a forest management plan should be at least 10 years. A shorter period does not provide the medium-term stability needed to guide the consistent implementation of sustainable forest management measures. Local communities and individuals with historical rights or privileges in the forest are stakeholders whom it is important to involve in planning. The chances of achieving sustainability increase considerably if local people living in and near tropical forests can have their say and take part in management planning, and can share in the proceeds of forest use in order to meet their basic needs. Forests deliver a wide range of benefits at local and regional scale, and at national level too. The main objective is usually the harvesting of roundwood. National governments and companies derive revenue from this, and that is the principal driver of logging in tropical forests. The income obtained from roundwood harvesting is usually the main source of funding for long-term sustainable management of tropical forests. This is the case, of course, not only in the tropical forest belt but everywhere in the world where timber is harvested for the needs of the national economy.

Timber harvesting methods, or models, are one of the foundations of forest management. They provide essential information about tree growth and the potential productivity that can be expected in stands of different tree species with differing growth rates when they are managed in different ways. Harvesting models are essential for demonstrating that current and planned management complies with the principles of sustainable forestry.

To sum up everything said in this article – without forests, existence on our planet would be impossible. At least in the form in which we see and feel it. The most important principle in forest management is to build on the findings of modern science, without forgetting the particular significance forests have in each specific part of the world. What may be useful in managing rainforests is not applicable to us and to our conditions in Northern Europe, and vice versa. Let us remember that in Latvia forests are the foundation of the national economy. Nature protection requirements and restrictions here must be consistent with the interests of our country and our people, without exaggeration and without the tendentious, hysterical approach that is seen all too often. The question is – in whose interests is this hysterical approach being encouraged in our country? Especially in the current unstable geopolitical circumstances, which we find ourselves in through no fault of our own…