Energy forestry is a form of forestry in which a fast-growing species of tree or woody shrub is grown specifically to provide biomass or biofuel for heating or power generation.
The two forms of energy forestry are short rotation coppice and short rotation forestry:
The main advantage of using "grown fuels", as opposed to fossil fuels such as coal, natural gas and oil, is that while they are growing they absorb the near-equivalent of carbon dioxide (an important greenhouse gas) to that which is later released in their burning. [2] In comparison, burning fossil fuels increases atmospheric carbon unsustainably, by using carbon that was added to the Earth's carbon sink millions of years ago. This is a prime contributor to climate change.
According to the FAO, compared to other energy crops, wood is among the most efficient sources of bioenergy in terms of the quantity of energy released by unit of carbon emitted. Other advantages of generating energy from trees, as opposed to agricultural crops, are that trees do not have to be harvested each year, the harvest can be delayed when market prices are down, and the products can fulfil a variety of end-uses. [3]
Yields of some varieties can be as high as 11 oven dry tonnes per hectare every year. [4] However, commercial experience on plantations in Scandinavia have shown lower yield rates. [5]
These crops can also be used in bank stabilisation and phytoremediation. [6] In fact, experiments in Sweden with willow plantations have proved to have many beneficial effects on the soil [7] and water quality [8] when compared to conventional agricultural crops (such as cereal). This beneficial effects have been the basis for the designed of multifunctional production systems to meet emerging bioenergy demands and at the same time, increase the local biodiversity, reduce soil erosion and nutrient emissions to water, increase soil carbon, enhance pollination, and avoid or mitigate flooding events. [9]
Although in many areas of the world government funding is still required to support large scale development of energy forestry as an industry, it is seen as a valuable component of the renewable energy network and will be increasingly important in the future. [10]
Growing trees is relatively water intensive.[ citation needed ]
The system of energy forestry has faced criticism over food vs. fuel, whereby it has become financially profitable to replace food crops with energy crops. It has to be noted, however, that such energy forests do not necessarily compete with food crops for highly productive land as they can be grown on slopes, marginal, or degraded land as well – sometimes even with long-term restoration purposes in mind. [11]
Populus is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar, aspen, and cottonwood.
Coppicing is the traditional method in woodland management of cutting down a tree to a stump, which in many species encourages new shoots to grow from the stump or roots, thus ultimately regrowing the tree. In a coppiced wood, which is called a copse or coppice, young tree stems are repeatedly cut down to near ground level, the resulting living stump called a stool. New growth emerges, and after a number of years, the coppiced tree is harvested, and the cycle begins anew. Pollarding is a similar process carried out at a higher level on the tree in order to prevent grazing animals from eating new shoots. Daisugi, is a similar Japanese technique.
A windbreak (shelterbelt) is a planting usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted in hedgerows around the edges of fields on farms. If designed properly, windbreaks around a home can reduce the cost of heating and cooling and save energy. Windbreaks are also planted to help keep snow from drifting onto roadways or yards. Farmers sometimes use windbreaks to keep snow drifts on farm land that will provide water when the snow melts in the spring. Other benefits include contributing to a microclimate around crops, providing habitat for wildlife, and, in some regions, providing wood if the trees are harvested.
Bioenergy is energy made or generated from biomass, which consists of recently living organisms, mainly plants. Types of biomass commonly used for bioenergy include wood, food crops such as corn, energy crops and waste from forests, yards, or farms. The IPCC defines bioenergy as a renewable form of energy. Bioenergy can either mitigate or increase greenhouse gas emissions. There is also agreement that local environmental impacts can be problematic.
The blue willow beetle, formerly Phyllodecta vulgatissima, is a herbivourous beetle of the family Chrysomelidae. It is dark with a metallic sheen that ranges from a blue color to bronze. It is distinguished from P. vitellinae by the latter more commonly displaying bronze coloration. European Phratora species can be distinguished based on morphology of female genitalia. The larvae undergo three instar stages from hatching to pupation. This beetle is found throughout Europe and Scandinavia, and occurs in China.
Pellet fuels are a type of solid fuel made from compressed organic material. Pellets can be made from any one of five general categories of biomass: industrial waste and co-products, food waste, agricultural residues, energy crops, and untreated lumber. Wood pellets are the most common type of pellet fuel and are generally made from compacted sawdust and related industrial wastes from the milling of lumber, manufacture of wood products and furniture, and construction. Other industrial waste sources include empty fruit bunches, palm kernel shells, coconut shells, and tree tops and branches discarded during logging operations. So-called "black pellets" are made of biomass, refined to resemble hard coal and were developed to be used in existing coal-fired power plants. Pellets are categorized by their heating value, moisture and ash content, and dimensions. They can be used as fuels for power generation, commercial or residential heating, and cooking.
Lignocellulose refers to plant dry matter (biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the Earth for the production of biofuels. It is composed of two kinds of carbohydrate polymers, cellulose and hemicellulose, and an aromatic-rich polymer called lignin. Any biomass rich in cellulose, hemicelluloses, and lignin are commonly referred to as lignocellulosic biomass. Each component has a distinct chemical behavior. Being a composite of three very different components makes the processing of lignocellulose challenging. The evolved resistance to degradation or even separation is referred to as recalcitrance. Overcoming this recalcitrance to produce useful, high value products requires a combination of heat, chemicals, enzymes, and microorganisms. These carbohydrate-containing polymers contain different sugar monomers and they are covalently bound to lignin.
Energy crops are low-cost and low-maintenance crops grown solely for renewable bioenergy production. The crops are processed into solid, liquid or gaseous fuels, such as pellets, bioethanol or biogas. The fuels are burned to generate electrical power or heat.
The Willow Biomass Project is a collaborative effort by members of the Salix Consortium to grow willow and other sustainable woody crops in upstate New York. The project, funded through the U.S. Department of Energy's Biomass Power for Rural Development Program, seeks to commercialize willow bioenergy crops as a renewable source of biofuel. To date, the project has planted willow on at least 465 acres (1.9 km2) of privately leased land and 25 acres (100,000 m2) of farmer-contracted land.
Biomass, in the context of energy production, is matter from recently living organisms which is used for bioenergy production. Examples include wood, wood residues, energy crops, agricultural residues including straw, and organic waste from industry and households. Wood and wood residues is the largest biomass energy source today. Wood can be used as a fuel directly or processed into pellet fuel or other forms of fuels. Other plants can also be used as fuel, for instance maize, switchgrass, miscanthus and bamboo. The main waste feedstocks are wood waste, agricultural waste, municipal solid waste, and manufacturing waste. Upgrading raw biomass to higher grade fuels can be achieved by different methods, broadly classified as thermal, chemical, or biochemical.
Miscanthus × giganteus, also known as the giant miscanthus, is a sterile hybrid of Miscanthus sinensis and Miscanthus sacchariflorus. It is a perennial grass with bamboo-like stems that can grow to heights of 3–4 metres (13 ft) in one season. Just like Pennisetum purpureum, Arundo donax and Saccharum ravennae, it is also called elephant grass.
Short rotation coppice (SRC) is coppice grown as an energy crop. This woody solid biomass can be used in applications such as district heating, electric power generating stations, alone or in combination with other fuels. Currently, the leading countries in area planted for energy generation are Sweden and the UK.
Short rotation forestry (SRF) is grown as an energy crop for use in power stations, alone or in combination with other fuels such as coal. It is similar to historic fuelwood coppice systems.
Biomass heating systems generate heat from biomass. The systems may use direct combustion, gasification, combined heat and power (CHP), anaerobic digestion or aerobic digestion to produce heat. Biomass heating may be fully automated or semi-automated they may be pellet-fired, or they may be combined heat and power systems.
On April 25, 2006, Executive Order S-06-06, the Bioenergy Action Plan was issued by the then governor of California, Arnold Schwarzenegger, outlining a set of target goals which would establish the increasing use and production of biofuels and biopower for both electricity generation and substitution of natural gas and petroleum within the state of California. The plan asked multiple state agencies to work towards the advancement of biomass programs in California. The order would also help provide statewide environmental protection, mitigation and economic advancement. The plan was passed on July 7, 2006, with progress reports issued in 2007 and 2009.
Treethanol is an ethanol fuel made from trees.
Second-generation biofuels, also known as advanced biofuels, are fuels that can be manufactured from various types of non-food biomass. Biomass in this context means plant materials and animal waste used especially as a source of fuel.
Woodchips are small- to medium-sized pieces of wood formed by cutting or chipping larger pieces of wood such as trees, branches, logging residues, stumps, roots, and wood waste.
Bioenergy with carbon capture and storage (BECCS) is the process of extracting bioenergy from biomass and capturing and storing the carbon, thereby removing it from the atmosphere. BECCS can be a "negative emissions technology" (NET). The carbon in the biomass comes from the greenhouse gas carbon dioxide (CO2) which is extracted from the atmosphere by the biomass when it grows. Energy ("bioenergy") is extracted in useful forms (electricity, heat, biofuels, etc.) as the biomass is utilized through combustion, fermentation, pyrolysis or other conversion methods.
Reinhart Jan Maria Ceulemans is an emeritus professor of Ecology and previous director of the Research Center of Excellence PLECO of the University of Antwerp. He has been vice-dean of the Faculty of Sciences at the University of Antwerp, and was a visiting professor at the University of Washington, Seattle, USA (1987-1988), at the Université Paris-Sud XI, Orsay and at the University of Ghent. He officially retired in October 2019 and is now a visiting professor at the University of Antwerp (Belgium), a researcher at CzechGlobe Academy of Sciences in Brno and an international consultant to the Slovenian Forestry Institute.
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