Forests provide the raw material for the pulp and paper industry, furniture manufacturing, and more; so the resource should be renewed. However, reforestation is important not only to support industrial needs. Reforestation reverses climate change as trees consume carbon dioxide and produce oxygen. Reforestation efforts are also rewarded with improved health statistics of the Earth’s population and the environment in general. For forest farms, it is a business that requires wise management to bring profit.
What Is Reforestation And Its Causes
Reforestation is replacing cut trees with a new generation for various purposes:
- restoration after harvesting merchantable timber;
- compensation after the land expansion due to human activities;
- refreshing after forest aging;
- regeneration after natural calamities;
- maintaining the ecosystem balance and biodiversity;
- providing habitats for eco-communities, etc.
The best reforestation practices recommend immediate planting once a forest is cut or destroyed. Thus, tree-felling companies are to restore the balance by planting new trees after logging, according to governmental regulations in many countries.
The UN New York declaration of 2014 obliged countries to reduce deforestation twice by 2020 and halt it by 2030. However, its annual rate almost doubled instead.
Why Is Reforestation Important?
The importance of reforestation is explained by the role trees play on our planet. New forests help prevent soil erosion or desertification; they are important to protect buildings and fields from winds. Trees along river banks or shorelines fortify and stabilize the coastal area. Woods are natural habitats for unique species, which in some cases cannot be found anywhere else. This is why it is important not only to regenerate the degraded or destroyed areas but also to plant new ones to refresh the tree cover.
Reforestation also applies to restore destroyed forests after natural calamities like fires, floods, earthquakes, etc. This technique is also used to recover forests due to artificial interventions as mining, archeological site deployment, or construction. Thus, reforestation is an efficient method to tackle deforestation and improve the ecological situation.
Planting takes place two ways, either naturally or artificially. The natural reforestation process relies on the rooting of seeds and sprouts from nearby trees without human assistance. Yet, natural reforestation is insufficient and should be supported by other techniques when tree replacement involves the participation of people.
Reforestation is a routine operation for designated forest farms. Their optimal approach combines reforestation with deforestation when forests are cut in a way that helps to establish new ones. The idea is to turn the end into the beginning whenever possible.
There are two classification options of reforestation techniques, depending on the age of co-existing trees:
- even-aged stands – mature overstory is removed to let the new stand grow;
- uneven-aged stands – older and younger trees grow together.
Both of them are applied throughout the USA. The choice depends on the fact whether the species can grow in shelter or not and the climatic peculiarities of the region. This is how deforestation gives rise to new tree stands when the remaining mature trees promote new generations. They provide seeds, wildlife habitat, shelter from excessive sunlight or wind, etc.
The uneven-aged system suggests selective cutting a group of trees or separate trees, providing space for a new stand.
The area size in group cuts differs by width and can reach two heights of mature trees. The width depends on the amount of light the species require. Spruce, fir, maple, hemlock, red cedar can tolerate shade and will do with a smaller opening. Oaks, loblolly pine, Douglas fir need more light and, correspondingly, more space. The group selection covers the whole forest tract.
The single tree reforestation technique chooses separate trees of all sizes and cuts them evenly through the patch. Since the opening is too narrow, the method is suitable only for shade-tolerant species (e.g., hemlock, sugar maple). It also applies to frosty or dry areas.
The even-aged system is used to provide sufficient sunlight for saplings. It includes clear-cutting, seed tree, and shelterwood options.
Clear-cutting is complete removal of mature overstory to let new trees grow. However, some trees may be preserved as a shelter for wildlife or riparian buffers. This is a popular reforestation method to regenerate aspen, yellow poplar, white birch, Douglas fir, red and white oak, jack pine, etc.
Reforestation is performed via natural or direct seeding, sprouting, or planting. In some cases, it can be enhanced with a stronger planting material (genetically improved).
Seed tree implies leaving several mature trees for seeds (6-15 per acre). Typically, they are cut after the seedlings root or left for wildlife or landscape aesthetics.
The seed reforestation technique can be combined with planting if natural seeding is not enough. Seed tree reforestation is good for some species of pines and oaks.
Shelterwood suggests growing saplings with mature trees that provide shelter. The method includes three typical stages:
- preparatory cut for better seed production;
- establishment cut that supplies seeds;
- removal cut off mature trees to eradicate competition with seedlings.
The method is used for sugar maple and some types of oak and pine.
Benefits Of Reforestation
Reforestation brings a number of advantages, and the most important of them are as follows.
Reforestation And Climate Change Mitigation
Excessive carbon release is a major driver for global warming, and this is where we can use reforestation to combat climate change. How does reforestation affect the carbon cycle? In the process of photosynthesis, trees absorb carbon and convert it to nutrients required for their development. The younger the forest, the more carbon it can store. Basically, kiln-dried wood is about 50% carbon, which means that trees’ ability to accumulate carbon is impressive. Furthermore, much carbon is sequestered in forest soils. Thus, reforestation is an important practice to eliminate climate change.
Improving Air Quality
Photosynthesis explains another benefit of reforestation since plants not only absorb carbon but release oxygen, maintaining the balance. For this reason, forests are known as the lungs of our planet. Correspondingly, the more forests we have, the purer air we breathe. Also, reforestation is efficient to prevent dust storms, adding to air purity.
Woods fascinate with their ecosystem variety, and one of the richest communities is found in tropical forests. In particular, Amazon rainforests count thousands of tree species and 50,000 other plants, apart from abundant fauna.
World Resources Institute ranked tropical primary forest losses 2019 third-largest in the 21st century. In this regard, rainforest restoration is an ultimately significant task nowadays. It combats rare species extinction, both in the kingdom of plants and the kingdom of animals.
Restoring Wildlife Habitats
Forest cuts deprive wildlife of their natural habitat, yet some species can exist only in isolated areas. So, reforestation is essential to preserve their populations.
Maintaining Water Cycle And Water Quality
Trees store rainwater through absorbing it with leaves and roots. At the same time, they also release moisture in the atmosphere via transpiration and increase humidity. This way, forests stabilize the air temperature in the nearby locality. They also help to maintain a sufficient water level in local water bodies. Since trees retain moisture and reduce runoffs, reforestation also improves water infiltration and water quality.
Enriching Soil Fertility
Reforestation contributes to soil health for several reasons:
- It is a habitat for soil microorganisms that participate in decomposition, boosting fertility.
- Fallen leaves and branches form the organic matter.
- Strong root systems hold the earth in place and prevent erosion and landslides.
- Reducing water runoffs, trees conserve nutrients in the soil.
Trees not only absorb moisture but make a barrier for water flows during floods or downpours. Thus, they slow down the speed of currents and improve water absorption. By impeding floods, reforestation mitigates damage and losses.
Bare soils are prone to wind and water erosion that lead to desertification. Reforestation addresses the issue two ways: with tree roots and vegetative cover of the forest floor.
Reforestation effects are more obvious with proper management. So, it is important to develop a reforestation plan, depending on what is the purpose of reforestation (restoration after illegal deforestation, harvesting, wildfires, etc.).
With different purposes, the best trees for reforestation will be different, too. One species are the most carbon-absorbing, while others are the fastest-growing. Some better fit the established ecosystem. In other words, there is no universal answer to this question.
Another discussion point is whether or not reforestation can restore the ecosystem of the previous forest. Here it depends on the species. A single tree type will give a monoculture forest, while multiple species will enhance biodiversity. Monoculture forests are more susceptible to tree diseases and other unfavorable conditions, while polyculture forests have more chances to survive. Besides, clear cuts or prescribed fires prove to be an efficient means to speed up natural restoration and ecosystem diversification.
Reforestation management and monitoring are easier with remote sensing, especially in hard-to-reach places. With satellite imagery by EOS Data Analytics, foresters can monitor reforestation progress, timely notice if things go wrong, and react accordingly. Low and medium-resolution remote sensing can detect the changes after 1-2 years of tree planting, while high-resolution remote sensing can provide information much earlier.
EOSDA offers satellite monitoring of young forests to identify areas with an unhealthy canopy so that foresters could take timely actions to save trees. Also, change detection assists in framing forest loss in these areas, too. For example, low NDVI values alert to a problem in the area. It cannot classify the exact cause, yet it summons to scout the area for further analysis. A decrease in NDVI values can be the result of forest cuts, illegal deforestation, wildfires, hurricane damage, excessive use of chemicals, or pest infestation. Low index values may also be a signal of droughts or excessive dryness, too.
To analyze the forest cover, you can use a ready-made product LandViewer and a bunch of band combinations available on it or request for a custom solution. With LandViewer, you can currently detect the deforested area to restore the cut forest.
One of the indicators of how a forest is restoring is ground coverage around the trees, too. EOSDA can help to differentiate the overstory canopy from the forest floor vegetation and assess the quality of each.
EOSDA Forest Monitoring is a new platform for forest management. Be always aware of how the young stands develop. With EOSDA, it is possible to monitor how the forest grows and manage risks. For more custom solutions for forest management, contact our sales department at email@example.com.
Kateryna Sergieieva joined EOS Data Analytics in 2016. She has a Ph.D. in information technologies and a 15-year experience in remote sensing.
Kateryna is a Senior Scientist at EOSDA. Her specialty is the development of technologies for satellite monitoring of natural and artificial landscapes and surface feature change detection. Kateryna is an expert in the analysis of the state of mining areas, agricultural lands, water objects, and other features based on multi-layer spatial data.
Kateryna is an Associate Professor conducting research at the Dnipro University of Technology. She is the author of over 60 scientific papers.