Reforestation

Tropical tree nursery at Planeta Verde Reforestación S.A.'s plantation in Vichada, Colombia.
Biodiversity on a 15-year-old reforested plot of land.
A 21-year-old plantation of red pine in Southern Ontario.

Reforestation is the restocking of existing forests and woodlands which have been depleted.[1] Reforestation can be used to improve the quality of human life by soaking up pollution and dust from the air, rebuild natural habitats and ecosystems, mitigate global warming since forests facilitate biosequestration of atmospheric carbon dioxide, and harvest for resources, particularly timber.

The term reforestation is similar to afforestation, the process of restoring and recreating areas of woodlands or forest that may have existed long ago but were deforested or otherwise removed at some point in the past.

Contents

Management

Reforestation of large areas can be done through the use of measuring rope (for accurate plant spacing) and dibbers, (or wheeled augers for planting the larger trees) for making the hole in which a seedling or plant can be inserted. Indigenous soil inoculants (e.g., Laccaria bicolor) can optionally be used to increase survival rates in hardy environments.

A debatable issue in managed reforestation is whether or not the succeeding forest will have the same biodiversity as the original forest. If the forest is replaced with only one species of tree and all other vegetation is prevented from growing back, a monoculture forest similar to agricultural crops would be the result. However, most reforestation involves the planting of different seedlots of seedlings taken from the area often of multiple species. Another important factor is the natural regeneration of a wide variety of plant and animal species that can occur on a clearcut. In some areas the suppression of forest fires for hundreds of years has resulted in large single aged and single specied forest stands. The logging of small clearcuts and or prescribed burning, actually increases the biodiversity in these areas by creating a greater variety of treestand ages and species.

For harvesting

Reforestation need not be only used for recovery of accidentally destroyed forests. In some countries, such as Finland, the forests are managed by the wood products and pulp and paper industry. In such an arrangement, like other crops, trees are replanted wherever they are cut. In such circumstances, the industry can cut the trees in a way to allow easier reforestation. In Canada, the wood product and pulp and paper industry systematically replaces many of the trees it cuts, employing large numbers of summer workers for treeplanting work.

In just 20 years, a teak plantation in Costa Rica can produce up to about 400 m³ of wood per hectare. As the natural teak forests of Asia become more scarce or difficult to obtain, the prices commanded by plantation-grown teak grow higher every year. Other species such as mahogany grow slower than teak in Tropical America but are also extremely valuable. Faster growers include pine, eucalyptus, and gmelina.

Reforestation, if several native species are used, can provide other benefits in addition to financial returns, including restoration of the soil, rejuvenation of local flora and fauna, and the capturing and sequestering of 38 tons of carbon dioxide per hectare per year.

The reestablishment of forests is not just simple tree planting. Forests are made up of a diversity of species and they build dead organic matter into soils over time.[2] A major tree-planting program in a place like this would enhance the local climate and reduce the demands of burning large amounts of fossil fuels for cooling in the summer.[2]

For climate change mitigation

Forests absorb carbon dioxide through their photosynthesis cycle, and by using this idea, increasing forests with reforestation and discouraging deforestation will help mitigate global warming. Forest ecosystems are especially important to the global carbon cycle in two ways[3]. First, they are responsible for moving around three billion tons of anthropogenic carbon every year. This amounts to about 30% of all carbon dioxide emissions from fossil fuels.[3] Second, forest ecosystems are terrestrial carbon sinks in that they store large amounts of carbon which accounts for as much as double the amount of carbon in the atmosphere.[3]

Canadell and Raupach (2008) believe that there are four major strategies available to mitigate carbon emissions through forestry activities: increase the amount of forested land through a reforestation process; increase the carbon density of existing forests at a stand and landscape scale; expand the use of forest products that will sustainably replace fossil-fuel emissions; and reduce carbon emissions that are caused from deforestation and degradation.[3]

However, achieving the first strategy requires great effort of land transformation. For example, China has used 24 million ha of new forest plantation and natural forest regrowth to offset 21% of Chinese fossil fuel emissions in 2000 (Canadell & Raupach, 2008, p. 1456). In theory, any tree would cover more forest area and absorb more carbon dioxide from the atmosphere. On the other hand, a genetically modified tree specimen might grow much faster than any other regular tree.[4] Some of these trees are already being developed in the lumber and biofuel industries. These fast-growing trees would not only be planted for those industries but they can also be planted to help absorb carbon dioxide faster than regular trees.[4].

Mitigating the rate of deforestation has huge potential toward a cost-effective contribution to protect the atmosphere’s climate. At this point, there are 13 million ha of tropical regions that are deforested every year. These regions can reduce rates of deforestation by 50% by 2050.[3]

A study from the National Center for Atmospheric Research in Boulder, Colorado, USA, found that, unlike previous belief that forests in higher latitudes soak up a vast amount of carbon dioxide, more carbon dioxide is absorbed in tropical climates. Trees in temperate latitudes have a net warming effect on the climate. The heat that dark leaves absorb outweighs the carbon they soak up [5], therefore, tropical trees absorb carbon dioxide as well as being able to cool the planet by up to 0.7 °C.

Trees in tropical climates have, on average, larger, brighter, and more abundant leaves than non-tropical climates. The advantage of planting trees in a tropical setting is the quicker growth rate due to the longer rainy seasons. There is no need for the trees to hibernate and can therefore grow year-round.

An incredible portion of the Earth's biodiversity is situated in tropical areas. The lack of reforestation in tropical climates is putting a larger portion of species at risk of becoming endangered.

A study of the girth of 70,000 trees across Africa has shown that tropical forests are soaking up more carbon dioxide pollution than previously realized. The research suggests almost one fifth of fossil fuel emissions are absorbed by forests across Africa, Amazonia and Asia.

Simon Lewis, a climate expert at the University of Leeds, who led the study, said: "Tropical forest trees are absorbing about 18% of the carbon dioxide added to the atmosphere each year from burning fossil fuels, substantially buffering the rate of change."[6]

Extensive forest resources placed anywhere in the world will not always have a positive impact. For example, large reforestation programs in boreal regions have a limited impact on climate mitigation. This is because it substitutes a bright snow-dominated region that reflects the sunlight with dark forest canopies. On the other hand, a positive example would be reforestation projects in tropical regions, which would lead to a positive biophysical change such as the formation of clouds. These clouds would then reflect the sunlight, creating a positive impact on climate mitigation.[7]

Incentives

Some incentives for reforestation can be as a simple as a financial compensation. Streck and Scholz (2006) explain how a group of scientists from various institutions have developed a compensated reduction of deforestation approach which would reward developing countries that disrupt any further act of deforestation (p. 875). Countries that participate and take the option to reduce their emissions from deforestation during a committed period of time would receive financial compensation for the carbon dioxide emissions that they avoided (Streck & Scholz, 2006, p. 875). To raise the payments, the host country would issue government bonds or negotiate some kind of loan with a financial institution that would want to take part in the compensation promised to the other country. The funds received by the country could be invested to help find alternatives to the extensive cutdown of forests. This whole process of cutting emissions would be voluntary, but once the country has agreed to lower they emissions they would be obligated to reduce their emissions. However, if a country was not able to meet their obligation, their target would get added to their next commitment period (Streck & Scholz, 2006, p. 876). The authors of these proposals see this as a solely government-to-government agreement; private entities would not participate in the compensation trades (Streck & Scholz, 2006, p. 876).

Examples

Indonesia

In Java, Indonesia each newlywed couple is to give whoever is sermoning their wedding 5 seedlings to combat global warming. Each couple that wishes to have a divorce has to give 25 seedlings to whoever divorces them. ref> http://news.bbc.co.uk/2/hi/asia-pacific/7124680.stm

Criticism

Reforestation competes with other land uses such as food production, livestock grazing, and living space for further economic growth.

There is also the risk that through a forest fire or insect outbreak much of the stored carbon in a reforested area could make its way back to the atmosphere.[3] Reduced harvesting rates and fire suppression have caused an increase in the forest biomass in the western United States over the past century. This causes an increase of about a factor of four in the frequency of fires due to longer and hotter dry seasons.[3]

See also

References

  1. ↑ "Reforestation - Definitions from Dictionary.com". dictionary.reference.com. http://dictionary.reference.com/browse/Reforestation. Retrieved 2008-04-27. 
  2. ↑ 2.0 2.1 (Woodwell, Janzen, Wilcox, North, Swartz, & Hoyer, 1988, p.1493).
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 (Canadell & Raupach, 2008, p.1456)
  4. ↑ 4.0 4.1 (“A changing climate of opinion?” 2008, p. 93).
  5. ↑ B.W., Time Magazine, 2007
  6. ↑ http://www.guardian.co.uk/environment/2009/feb/18/trees-tropics-climate-change
  7. ↑ (Canadell & Raupach, 2008, p.1457).

2. (2008). A changing climate of opinion? Economist, 387, 93-96.

3. Bonan, G. B. (2008). Forests and climate change: Forcings, feedbacks, and the climate benefits of forests. Science, 320, 1444-1449.

4. Canadell, J. G., Raupach, M. R. (2008). Managing Forests for Climate Change. Science, 320, 1456-1457.

5. Streck, C., Scholz, S. M. (2006). The role of forests in global climate change: whence we come and where we go. International Affairs, 82, 861-879.

6. Woodwell, G. M., Janzen, D. H., Wilcox, H. A., North, W. J., Swartz, J., Hoyer H. (1988). CO2 Reduction and reforestation. Science, 242, 1493-1494.

External links