Tuesday, October 26, 2010
Many people have probably never given much thought to why one would plant tropical trees, or any tree for that matter. A recent blog comment asked “Why plant trees? Is it just for carbon sequestration?” Before answering, it seems like a good idea to point out that this blog is about tropical trees for a reason. Their amazing diversity and therefore their wonderful and numerous uses not only answer the question with an endless list, but once again emphasize why tropical trees are such a profitable green investment. This article is a summary of some of the 25 principle reasons for planting and using tropical trees, with no effort being made to distinguish between plantation and native tree species. No doubt many other uses and reasons exist. Let’s review the 25 most common reasons.
1. Lumber: Tropical trees are an important source of the world’s hardwood supply. Hardwood trees are used in everything from fine furniture to building materials and from pulp and paper to renewable energy and firewood. World demand for tropical hardwood increases year after year. We plant tropical trees because it is better to have our coffee tables made with plantation wood, as opposed to natural rain forest wood.
2. Construction: It may seem strange to separate this from the general description of lumber, but people plant tropical trees for a range of applications, from flooring to cement boards, from plywood to roofing materials. Ironwood species like Congrio (Acosmium nitens) are used for utility and telephone poles, railway ties and heavy construction. Some of these hardwoods can be left untreated in the ground for decades without suffering from insect, fungus or moisture damage.
3. Musical Instruments: Many of our favourite musical instruments would not sound the same if we didn’t have tropical trees planted to provide the exotic woods used in their manufacture. Have you ever given thanks for ebony (Diospyros dendro and ebenum) piano keys or purpleheart (Peltogyne purpurea) guitar frets, or Brazilian Biriba wood (Rollinia mucosa) for berimbau sticks and Jacaranda wood (Jacaranda brasiliana) for atabaque drums?
4. Boat Building: Tropical trees have been essential for boat and ship building since before recorded history. Numerous species are excellent for their durability in water, their flexibility when being bent to shape a hull, or for their properties as canoes or dugouts. Teak is a well know ship and yacht building wood in Asia, but consider that where Amazonia Reforestation plants tropical trees in the Orinoco River basin there are 14 acknowledged boat building species, like Algarrobo (Hymenaea courbaril), Ceiba (Ceiba pentandra) and Sassafras (Ocotea cymbarum).
5. Carbon Sequestration: Tropical trees are the most efficient trees on the planet at removing CO2 from the atmosphere, especially in the first 10 years of their lives. CO2 isn’t just absorbed into their woody biomass, but is also deposited into the soil along their roots and due to deadfall around the tree. The average tropical tree planted by CO2 Tropical Trees sequesters as much as 50 lbs or 22.6 kg of carbon a year, compared to the best boreal tree at 2.2lbs or 1 kg a year.
6. Medicine: Some 7,000 commercial medicines currently in everyday use are based on tropical trees and the flora that depends on them. Science and researchers have barely scratched the surface, with new compounds and new cures originating from the rain forest all the time. Many indigenous people and naturopathic medicines like Ayurveda place great reliance on tropical trees for cures and treatments. Planting beneficial species is a no-brainer. At the Reserva Natural La Pedregoza in the Orinoco River basin they have 73 tropical tree species with known medicial properties.
7. Land Reclamation: A large number of tropical trees have proven themselves ideal for reclaiming old mine sites, for preventing erosion and landslides, or for stopping desertification. The trees rebuild top soil destroyed by mining or that was lost due to extreme erosion. Many tropical trees are good at nitrogen-fixing in the soil. Some of those same trees are able to absorb pollutants other than carbon from the atmosphere and from the soil, such as heavy metals like lead and mercury. Acacia mangium has a proud history of being planted for land reclamation purposes.
8. Soil Improvement: Some tropical trees can be planted to improve soils that are otherwise infertile, thanks to the ability of leguminous tropical trees to fix nitrogen and carbon in the soil. Many areas that have suffered from bad deforestation or mining in the past can be made productive again using careful species selection and permaculture or analog forestry processes. Better soil allows for a wider variety of tree species to be planted in future cultivation cycles. At Amazonia Reforestation Acacia mangium is planted for its recognized nitrogen-fixing capacity.
9. Infertile Soils: It may seem ironic, but many rain forests are perfect recyclers, and therefore do not need to rely on the soil. They get their energy from the air, the sun and their own deadfall. This means that many tropical tree species can be planted in rocks or sand, and with a little help can start a forest in what might otherwise seem like hopeless locations and conditions.
10. Wind Breaks: Fast growing tropical trees can be planted to prevent erosion or crop damage due to wind. Tropical trees set deep roots, so they can be very effective quickly. Eucalyptus pellita and other Eucalypts are often used to establish rapid wind breaks.
11. Fire Breaks: Numerous tropical tree species can act as a natural fire break. Due to the canopy effect there is little under growth that can burn, and because of the nature of hardwood trees areas planted with tropical trees are hard to ignite. Savanna wild fires will often peter out and die when they hit areas planted with tropical trees, while damage due to lighting strikes will be confined to one or two tropical trees hit directly inside a planted area. Two examples are Saladillo Rojo (Caraipa llanorum) or Moriche palms (Mauritia flexuosa).
12. Flood Resistant: People are often not sure what to do with low lying areas prone to flooding. Lots of tropical trees species will happily grow in very moist or flood conditions. Riparian and inundation forest species can survive in flood conditions for months on end. This means low lying areas can be productive for lumber, fruits or wildlife habitat once planted with appropriate tropical tree species. In the Orinoco River basin species like Congrio (Acosmium nitens), Saladillo Rojo (Caraipa llanorum), Saladillo Blanco (Vochysia lehmanii), Sassafras (Ocotea cymbarum) and many others thrive in very wet or flooded soils.
13. Wildlife: Tropical trees expand endangered wildlife habitat, providing food and shelter. This is especially true when native trees are planted, as many fauna species are niche dependent. Tropical trees are an important element in the conservation of biodiversity and the preservation of our natural world. Tropical rain forests are the most bio-diverse land areas on the planet.
14. Fruits and Seeds: Tropical trees bear an astonishing variety of fruits and seeds that feed humans, birds and animals. This variety includes species that do well in wet conditions, dry conditions, and at various elevations, or in conditions where soils are acidic or saline. The trees become an important element in local socio-economic development. A typical example would be Amazona Reforestation, where they plant mango, cashew, tamarind, lemon, merecure, almond and other fruit and nut trees for both human and wildlife use.
15. Water: Planting tropical trees helps hold ground water by preventing runoff and erosion thanks to their root systems. Holding ground water occurs even in places where the soil is porous and where water would otherwise drain away or sink out of sight. Perhaps even more importantly, trees are able to clean contaminated ground and runoff water by removing pollutants, solvents and fuels from the ground water.
16. Transpiration: Transpiration is similar to evaporation, but involves the sweating or release of water by plants. Tropical trees actively seed clouds thanks to the transpiration process. The clouds then reflect sunlight away from the Earth, cooling the planet. Transpiration is responsible for climate cycles relied upon by farmers to grow crops, making civilization possible. This is not just a local effect; for instance, the Amazon rain forest determines weather patterns as far north as Texas. Planting tropical trees for transpiration is another element in the struggle against climate change and for a cooler planet.
17. Cooling: Tropical trees cool our planet by 0.7º C per annum thanks to their canopy effect. The more rain forests we cut down, the hotter the planet becomes. This may be among the most important reasons to plant tropical trees.
18. Sap Products: Tropical tree saps supply raw materials for many valuable products, such as the latex from the rubber tree (Hevea brasiliensis) for products ranging from tires to condoms. Tropical tree saps are also used to make syrups, tonics, beers, liquors, sugars and medicines. A large number of tropical trees yield glues and pigments, as well as organic poisons used by indigenous peoples for hunting and fishing.
19. Honey: Tropical trees have flowers and extra-floral phylode stems that produce nectar for honey production. Some species, like Acacia mangium, can produce as much as 100 kg of honey per hectare of trees per year. This makes planting tropical trees important for local socio-economic development programs.
20. Air: Tropical trees sequester carbon and release oxygen, so that we can all breath. The more trees we plant, the better the air quality. The Orinoco River and the Amazon River basins are considered the green lungs of our planet because of the oxygen they release into the atmosphere.
21. Shade: Tropical trees provide shade for humans, cattle and others in extremely hot climates, like for example the majestic Guanacaste trees (Enterolobium cyclocarpum) of Costa Rica. This type of shade is also important for numerous crops beneficial to humans. Farmers will deliberately plant leguminous tropical trees for shade and nitrogen fixing in permaculture and analog forestry settings, such as Erythrina spp. trees to shield coffee shrubs for better production rates.
22. Other Products: The wood, bark and fruits of many tropical trees provide soaps and detergents, insect repellents and specialty oils like safrole, almond and eucalyptus oils. Some species, like Yopo (Anadenanthera peregrina) have hallucinogenic properties important to indigenous peoples. Yet others produce tannins and dyes used by industry or used in folkloric and artisan manufacture, while yet others provide fibres for ropes and linens.
23. Oil: Some tropical trees are planted because they have oil fruits suitable for human consumption as cooking oils. Yet others are planted because they have oil fruits that are ideal for the production of bio-diesel and other fuels. Jatropha curcas is reputed to yield 1.6 metric tons of oil for bio-diesel per hectare planted, while African oil palms (Elaeis oleifera) may yield over 3 metric tons per hectare per year, making these tropical trees important renewable energy sources.
24. Renewable Energy: Planting many species of tropical trees makes sense, because they are fast growing and offer an excellent renewable energy source. The woods of numerous tropical trees like Acacia mangium and Eucalyptus pellita have high calorific values that boost heat and power production, or that can be used in low-tech applications like charcoal. Tropical trees are also a very important source of bio-diesels for renewable energy purposes.
25. Development: Tropical trees are an essential element in socio-economic development programs using permaculture or analog forestry practices to assist developing countries to become emerging green economies. It should be stressed that planting tropical trees yields multiple results with just one species. While some tropical trees do indeed seem to grow “slowly”, virtually all tropical trees outperform the growth rates of boreal and temperate zone trees. For instance, the plantation woods planted by Amazonia Reforestation go from seedling to mature harvestable tree in just 10 year’s time, while an equivalent boreal tree would take from between 80 to 120 years to produce similar results as a softwood tree. This amazing diversity means that developing countries can benefit more from planting and maintaining their tropical rain forests and tropical tree plantations, than they ever could from deforestation for subsistence agricultural purposes.