Planted Forests: Characterization and Sustainable Management
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Planted forests are predominantly composed of trees established through planting and/or through deliberate seeding of native or introduced species. Establishment is either through afforestation on land which has not carried forest within living memory or by reforestation of previously forested land (FAO 2010a).
The concept of planted forests covers a continuum of forest conditions, from mixture of native species planted or seeded for biodiversity enhancement on the one side to the monoculture forest plantations on the other side of the spectra (Zhang and Stanturf 2008; Ivetić and Vilotić 2014). This continuum is due to various economic, social, cultural, and environmental contexts that influence policy objectives and management practices for planted forests in different countries (FAO 2010b). Planted forests are characterized by a human manipulation of stand genetic by use of improved reproductive material at large areas (Christophe Orazio 2018, personal communication). In addition to level of human intervention in forest establishment, planted forests are also defined by level of management, which is usually more intensive in productive, and less intensive in protective and planted forests established for conservation or socioeconomic purposes (Carle and Holmgren 2003).
Changes in definition of planted forests concept in FAO forest resources assessments since 1980
Topic and definition
Plantation: The term “plantation” corresponds to forest stands established artificially by afforestation on land which previously did not carry forest; forest stands established artificially by reforestation on land which carried out forest within the previous 50 years or within living memory and involving the replacement of the previous crop by a new and essentially different crop. This exclude stands established by artificial regeneration and essentially similar to those they are replacing
Plantation forests: Forests established artificially by afforestation on lands, which previously did not carry forest within living memory. Forests established artificially by reforestation of land, which carried forest before and involving the replacement of the indigenous species by a new and essentially different species or genetic variety
Forest plantation: A forest established by planting or/and seeding in the process of afforestation or reforestation. It consists of introduced species or, in some cases, indigenous species
Planted forests: Forests that comprise all forest plantations and parts of semi-natural forests. All planted forests of introduced species were classified as forest plantations in FRA 2005. Planted forests of native species were classified as forest plantations if characterized by few species, straight, regularly spaced rows, and/or even-aged stands. If they resembled natural forests of the same species mix, such as many planted forests in Europe, they were classified as semi-natural forests
Planted forests: Forest predominantly composed of trees established through planting and/ or deliberate seeding
Planted forest: Forest predominantly composed of trees established through planting and/or deliberate seeding. In this context, predominantly means that the planted/seeded trees are expected to constitute more than 50% of the growing stock at maturity. This includes coppice from trees that were originally planted or seeded, and rubberwood, cork oak, and Christmas tree plantations, but excludes self-sown trees of introduced species
Planted forest: Forest predominantly composed of trees established through planting and/or deliberate seeding. In this context, predominantly means that the planted/seeded trees are expected to constitute more than 50% of the growing stock at maturity. Includes coppice from trees that were originally planted or seeded
Plantation forest: Planted Forest that is intensively managed and meet all the following criteria at planting and stand maturity: One or two species, even age class, and regular spacing. Specifically includes: short rotation plantation for wood, fiber, and energy. Specifically excludes: forest planted for protection or ecosystem restoration. Specifically excludes: forest established through planting or seeding which at stand maturity resembles or will resemble naturally regenerating forest
Other planted forest: Planted forest which is not classified as plantation forest
The scope of planted forests in the continuum of forest types: planted forests comprise the planted component within semi-natural forests and forest plantations for productive and protective purposes (FAO 2006a)
Naturally regenerated forests
Forest of native species, where there are no clearly visible indications of human activities and the ecological processes are not significantly disturbed
Forest of naturally regenerated native species where there are clearly visible indications of human activities
Assisted natural regeneration through silvicultural practices
Forest of native species, established through planting, seeding, or coppice
Forest of primarily introduced and native species, established through planting or seeding mainly for production of wood or non-wood goods
Forest of native or introduced species, established through planting or seeding mainly for provision of services
The complexity and need for overall definition of planted forests resulted with the most rudimentary and inclusive definition, used in FRA since 2005, which covers a range of ecosystems from semi-natural forests, where trees were planted with subsequent light management, to strictly man-made tree plantations with short rotations (ICPF 2013; Batra and Pirard 2015).
Characterization of Planted Forests at a Global Scale
Importance of Planted Forests at a Global Scale
As a result of thousands of years of tree planting for food or other nonwood forest products (Evans 2009), area of planted forests increase constantly to reach total of 277.9 million hectares, or 6.95% of total forest area in the latest global Forest Resource Assessment (FAO 2015). Opposite to increase of planted forest area, in recent 25-year period (1990–2015), we are witnessing the decrease of total global forest area (from 4.28 billion hectares to 3.99 billion hectares) and percent of global forest cover (from 31.85% to 30.85%) (Payn et al. 2015). It is estimated that each year over 15 billion trees are cut down, and that the global number of trees has fallen by approximately 46% since the start of human civilization (Crowther et al. 2015). Planted forests are not evenly distributed over the world, with 50% of world’s planted forests grown in Asia, 30% in Europe, 10% in North and Central America, 4% in South America, 4% in Africa, and 2% in Oceania (FAO 2006b).
The potential importance of planted forests was globally recognized for the first time at the FAO World Symposium on Manmade Forests and Their Industrial Importance, Canberra, Australia, 1967 (Carle and Holmgren 2008). From that point, planted forests are recognized to have an important role in many international processes and restoration targets and objectives. These include the United Nations Convention to Combat Desertification, the Convention on Biological Diversity, the United Nations Framework Convention on Climate Change including the Kyoto Protocol, the United Nations Forum on Forests, the Bonn Challenge, the New York Declaration on Forests, Article 5 of the Paris Climate Change, as well as many regional and national initiatives. Furthermore, establishment of planted forests is an important component of functional reforestation and play a key role in forest restoration strategies, such as: rehabilitation, reconstruction, reclamation, and replacement (Stanturf et al. 2014). Yet, despite their importance, planted forests remain controversial and they are constantly questioned, meeting both skepticism and support (Baral et al. 2016). The expansion of planted forests is praised by some for their higher production capacity that alleviate pressure on natural forests, support of rural development by jobs creating, and provision of a range of ecosystem services; but disputed by others because their potential negative social and environmental impacts (Batra and Pirard 2015). Poorly designed and managed, planted forests can affect valuable landscapes, alienate people from their traditional lands, and disturb the dynamic and relationships that keep communities and societies together (FAO 2010b). It is interesting that together with increase of global restoration targets, in period 2010–2015 global rate of planted forests area increase (1.2%) is only half of the rate of 2.4% suggested to supply the world’s demands (Payn et al. 2015).
Role of Planted Forests in Sustainable Development
Planted forests are important source of various forest products and services, and they are a vital resource for future green economies (ICPF 2013). In addition to their undoubted importance in production of goods as forest products, planted forests provide a number of services, both ecological and social. In many cases, the benefits from planted forests are mixed and include timber and fuel production, carbon sequestration, biodiversity conservation, protection against erosion, avalanches, protection against desertification, jobs opportunity, rural development, and others. Good design and management of planted forests can support the rural communities in their livelihoods and standard, and thus to contribute to sustainable development (FAO 2010b).
The difference between planted forests and natural forests in species diversity, regeneration characteristics, ecosystem functioning, and associated ecosystem services provision, which is generally larger in early stages of establishment, diminish with time, reaching the similar number and types of ecosystem services to those of natural forests later in planted forest development (Baral et al. 2016). These ecosystem service types includes food, raw materials, fresh water, medicinal resources, local climate and air quality, carbon sequestration and storage, moderation of extreme events, erosion prevention and maintenance of soil fertility, pollination, water regulation, biological control, habitat for species, maintenance of genetic diversity, recreation and mental and physical health, and tourism (see Baral et al. 2016 for detailed review).
One of the most important benefit of planted forests is reducing the pressure on natural forests. Planted forests are more productive than natural forests, which increase economic return and decrease demand for forest products from natural forest. Planted forests reduce prices of forest (24–37%) and wood products (4–14%), and at the same time increase world production of fuelwood (4%) and industrial roundwood (14%), but more important, utilization of planted forests reduce harvest of roundwood from natural forests by 26% (Buongiorno and Zhu 2014).
The top 20 countries by area accounted 85% of total planted forest area, but these top 20 countries do not match the list of top 20 countries by roundwood production, indicating that planted forests did not reach their production maximum in all countries (i.e., in China which is the 1st by planted forest area, but 3rd by roundwood production, Payn et al. 2015). Although not all planted forests are established with predominantly production goal, and many planted forests are aiming to protection and conservation purposes (Ivetić and Devetaković 2016), it is important to increase productivity of planted forests and their contribution in provision of forest goods, as well as services. Currently, with only 6.95% of total forest area, planted forests have a potential to produce over 65% of global industrial roundwood demand, and this contribution is possible to increase up to 80% by 2030 (Carle and Holmgren 2008). However, in 2012, forest plantations provided 520 million of cubic meters, just one-third the real global demand for industrial roundwood which was just over a 1.5 billion of cubic meters (INDUFOR 2012). The same study anticipated the rise of global demand up to 2 billion cubic meters by 2050, when in the same time forest plantations will be able to provide up to 1 billion of cubic meters of industrial roundwood per year. According to Jürgensen et al. (2014), in 2012, global production of industrial roundwood reached almost 562 million of cubic meters, with Brazil ranked at the first place on a global list (almost 132 million of cubic meters) and Island ranked as the last (with reported 2000 cubic meters). Their study also shows that, in general, countries of temperate zone (except Spain, Great Britain, and USA) produce less of industrial roundwood in forest plantations and more in planted component of semi-natural forests. In 2000, the fast growing industrial plantations at 40 million of hectares, or only 1% of global forest area, provided between 15% and 20% of fuelwood, and around 25% of global demand for wood fibers (Cubbage 2003). Increase of wood production in forest plantations will certainly reduce the pressure on natural forests (Sedjo and Botkin 1997; Fox 2000). If the forest plantations, as the most productive component of planted forests, can provide annual wood volume increment of 10 cubic meters per hectare, only 200 million of hectares of forest plantations will be able to meet the global demand for industrial roundwood in 2050.
Another important contributions of planted forests in sustainable development and climate change mitigation is carbon sequestration and biomass production. Growing in similar physical conditions, plantations in China aged 0–80 years have similar biomass but much higher productivity compared to natural forests, including the much higher carbon sequestration rates (Guo and Ren 2014a). Better performance of planted forests compared to natural are explained by early succession, planting on lower elevation, and use of highly productive species in planted forests. It is estimated based on average growth rates and carbon expansion factors that 271 million hectares of planted forests all over the world sequester about 1.5 giga tonnes of carbon (= to calculated losses from global deforestation), plus an estimated 0.5 giga tonnes of carbon stored long term in forest products from planted forests every year (Carle and Holmgren 2008). However, the mitigation potential of planted forests is much larger than carbon sequestration, and include use of wood and woody biomass as a replacement for fossil fuels, or as a replacement for energy-intensive materials used in construction and other industries (Silva et al. 2018). At present, biomass is by far the most important source of renewable energy in Europe. In 27 countries of the European Union, in 2010, biomass accounted for 8.4% of total energy consumption, which is 64% of renewable sources (AEBIOM 2012). Countries with the most forest cover rate in Europe (Sweden, Finland, and the Baltic countries) receive 20–30% of the total energy from forest biomass. Countries with a high share of biomass in energy production, which have low forest cover rate, like Denmark, rely on agricultural residues. Despite the intense increase in the use of forest biomass for energy, the standing volume of European forests is increasing (Ivetić and Vilotić 2014). Most of the energy obtained from biomass in Europe is used for heating dominated by firewood in private households (75%), then for biofuels (14%), and for electricity (11%) (AEBIOM 2012).
Planted Forests Management Issues
Without proper management and silviculture, planted forests can result in opposite to what they were established for, i.e., they will not meet their productive, protective, and socioeconomic goals. The inappropriate governance frameworks and insufficient application of established knowledge, technology, and techniques are recognized as the causes of planted forests failure in the past (FAO 2010b). Planted forests are less resilient compared to natural forests, due to their simpler and often even-aged structure, narrow diversity, and high density, especially during establishment phase. This is why planted forests require more intensive management. Yet, in many regions all over the world, planted forests are under thinned and simple in structure. The lack of simple silviculture practices of thinning in the right time and with appropriate intensity can decrease the quality of wood and increase risks of pests, disease, disturbances, and extreme weather events, like fire, windthrow, or snow damage, resulting with poor outcome of planted forests (Ivetić 2017).
Excluding industrial plantations which are under intensive management and with targeted rotation, there is a question on how to manage the vast areas of old planted forests. The good examples of management are given from Chinese and British experiences, where planted forests are begin to be managed to meet multifunctional objectives, including biodiversity, recreation, and landscape values (Mason and Zhu 2013). The most successful silvicultural practices given are introduction of complementary species for increasing the diversity, and the use of thinning to create a more open and varied stand structure. The good practices of transformation of the old monospecific pine plantations to more diverse, resistant, and resilient forest systems include thinning to facilitate the establishment of late successional trees and shrubs, enrichment planting by development of a network of small islets strategically placed inside pine plantations, and properly managed as seed sources for colonization of more valuable hardwood tree species (Villar-Salvador 2016).
Integrated decision-making and multi-stakeholder approaches
Effective organizational and personal capacity
Recognizing value of goods and services
Enabling environment for investment
Recognition of the role of the market
Recognition and maintenance of social and cultural values
Maintenance of environmental sustainability and forest health
Conservation of biological diversity
Management of landscapes
In order to improve management of planted forests, the new-generation plantations platform was launched by WWF in 2007, which encourages well-managed planted forests in the right places to conserve biodiversity and meet human needs (Silva et al. 2018). There are four key principles identified, agreeing that plantations should (Silva et al. 2018): (1) Maintain ecosystem integrity, (2) protect and enhance high conservation values, (3) be developed through effective stakeholder involvement processes, and (4) contribute to economic growth and employment.
Planted Forests and Species and Genetic Diversity
The existence of species diversity not only increase the resilience and sustainability of established forest, but also increase their productivity. There are evidences that biomass production increases with species richness in a wide range of wild taxa and ecosystems (Duffy et al. 2017). Mixing tree species upon planting increase the number of ecological niche, decrease the risks of failure associated with biotic and abiotic factors (Larjavaara 2008), and increase growth rate and improve wood quality (Tani et al. 2006; Pelleri et al. 2013). Different species use site resources in different ways, resulting with reduced competition and improved utilization of site potential (Ivetić and Devetaković 2017).
The issue of planted forests effect on biodiversity is complex and any assessment of this effect should consider biodiversity status of planting site and neighboring landscape before establishing of planted forest, as well as the likely alternative for land-use options for the site (Carnus et al. 2006). Many evidences shows planted forests as a valuable habitat for various species, including threatened and endangered ones (Brockerhoff et al. 2008), and thus contributing to biodiversity conservation. Evidences from Britain’s Biodiversity Assessment Project shows that planted forests of non-native conifers can provide suitable habitat for a wide range of native flora and fauna (Humphrey et al. 2001), with over 2000 species recorded, including large percent of invertebrates. In the same study, native forests were considerably richer in species only in some groups such as vascular plants and lichens.
Similar to biodiversity, there is no single and simple answer on question on genetic diversity in planted forests. It is obvious that in forest plantations, there is no genetic variation within a monoclonal stand. However, in clonal forestry compared to other types of planted forests, level of genetic diversity is easier to control. The number of clones or genotypes used in the establishment of plantations should balance genetic gain and loss of genetic diversity, with larger number of clones needed for slow-growing species (Ivetić et al. 2016). In many cases, planted forests are established with use of planting material of unknown origin, and this practice can result in both decrease and increase of genetic diversity in the new population, depending on several variables with effective size of the seed source population, provenancing, and seed collection strategy as the most important. In review of 34 papers comparing genetic diversity in natural forests versus various regeneration methods of 24 tree species examined by the range of markers (Ivetić and Devetaković 2017), in most cases there were no significant differences in genetic diversity between natural and planted forests, followed by an almost equal number of cases with decreased and increased level of genetic diversity.
Planted Forests and Invasive Species
One of concerns related to planted forests is use of non-native tree species which can be invasive. The rationale of introduction of new genes (species and provenances) during establishment of planted forests lies in evidences of higher productivity of non-local provenances (Schmidtling and Myszewski 2003; Ivetić et al. 2005; Krakowski and Stoehr 2009) and non-native species (Heryati et al. 2011; Kawaletz et al. 2013; Guo and Ren 2014b; Kjær et al. 2014; Ivetić 2017) compared to local (native) populations at a specific site. In addition, the non-native species can be used to fulfill some specific market demands. Often controversial and vigorously debated use of non-native species is reasonable for providing the short-term benefits to ecosystem function and facilitation of introduction of late-successional native species (Stilinović 1991; Thomas et al. 2014; Jacobs et al. 2015). On the other side, in many parts of the world, non-native tree species are among the most conspicuous and damaging invasive alien plants (Brundu and Richardson 2016). However, not all of them are coming from the planted forests. FAO FRA 2015 shows that, at global level, only 18–19% of planted forests are of introduced species, which dominates at southern hemisphere (Payn et al. 2015).
Many of the issues related to non-native tree species invasiveness can be resolved by appropriate management and silviculture practices, as well as with development and implementation of appropriate policies. The good example is a Code of Conduct on Planted Forest and Invasive Alien Trees, facilitated by the Council of Europe (Brundu and Richardson 2016).
Planted Forests: Future Perspectives
In uncertain future, planted forests will face the challenges of population pressure, extreme weather, and climate events, as well as forest health issues connected with changes in distribution of pests and pathogens. These challenges are not the same over the globe. The forest health risks are most likely in Europe and North America, the population pressure in Asia and Africa, and the climate and extreme weather risks are most likely in Europe, North America, Asia, Oceania, the Caribbean, and Central and South America (Payn et al. 2015). The right responses to these challenges are increase of production (to meet population pressure), development and implementation of climate adaption strategies (to mitigate climate and extreme weather risks), and improvement of the planted forests health through tree breeding and pest control strategies (to mitigate forest health risks).
- AEBIOM – European Biomass Association (2012) European bioenergy outlook 2012. Brussels. http://www.aebiom.org
- Brundu G, Richardson DM (2016) Planted forests and invasive alien trees in Europe: a code for managing existing and future plantings to mitigate the risk of negative impacts from invasions. In: Daehler CC, van Kleunen M, Pyšek P, Richardson DM (eds) Proceedings of 13th international EMAPi conference, Waikoloa. NeoBiota 30:5–47. https://doi.org/10.3897/neobiota.30.7015CrossRefGoogle Scholar
- Carle J, Holmgren P (2003) Definitions related to planted forests. In: UNFF intercessional expert meeting on the role of planted forests in sustainable forest management, Wellington, New Zealand, pp 329–343Google Scholar
- Carle J, Holmgren P (2008) Peter Wood from planted forests: a global outlook 2005–2030. For Prod J 58:6–18Google Scholar
- Carnus JM, Parrotta JA, Brockerhoff EG, Arbez M, Jactel H, Kremer A, Lamb D, O’Hara K, Walters BB (2006) Planted forests and biodiversity. J Forest 104(2):65–77Google Scholar
- Crowther TW, Glick HB, Covey KR, Bettigole C, Maynard DS, Thomas SM, Smith JR, Hintler G, Duguid MC, Amatulli G, Tuanmu MN, Jetz W, Salas C, Stam C, Piotto D, Tavani R, Green S, Bruce G, Williams SJ, Wiser SK, Huber MO, Hengeveld GM, Nabuurs GJ, Tikhonova E, Borchardt P, Li CF, Powrie LW, Fischer M, Hemp A, Homeier J, Cho P, Vibrans AC, Umunay PM, Piao SL, Rowe CW, Ashton MS, Crane PR, Bradford MA (2015) Mapping tree density at a global scale. Nature 525(7568):201–205. https://doi.org/10.1038/nature14967CrossRefGoogle Scholar
- Cubbage F (2003) Sustainable forest management, forest certification, tree improvement, and forest biotechnology. In: McKinley CR (ed) Proceedings of the 27th southern forest tree improvement conference, Oklahoma State University, USA, pp 6–15Google Scholar
- FAO (1982) Forestry paper 30: tropical forest resource, by J.P. Lanly. 120 pagesGoogle Scholar
- FAO (1995) FAO forestry paper 124: forest resources assessment 1990 – global synthesis. http://www.fao.org/docrep/007/v5695e/v5695e00.htm
- FAO (2000) FAO forestry paper 140: global forest resources assessment 2000. http://www.fao.org/docrep/004/Y1997E/y1997e08.htm#bm08
- FAO (2006a) Global planted forests thematic study: results and analysis. In: Del Lugo A, Ball J, Carle J (eds) Planted forests and trees working paper 38. Rome (also available at www.fao.org/forestry/site/10368/en)
- FAO (2006b) FAO forestry paper 147 global forest resources assessment 2005 progress towards sustainable forest management. Food and Agriculture Organization of the United Nations, Rome. 350 pagesGoogle Scholar
- FAO (2010a) FAO forestry paper 163: global forest resources assessment 2010 main report. Food and Agriculture Organization of the United Nations, Rome. 378 pagesGoogle Scholar
- FAO (2010b) Planted forests in sustainable forest management. A statement of principles. http://www.fao.org/docrep/012/al248e/al248e00.pdf
- FAO (2012) Forest resources assessment working paper 180: FRA 2015 terms and definitions. Food and Agriculture Organization of the United Nations, Rome. 36 pagesGoogle Scholar
- FAO (2015) Global forest resources assessment 2015 desk reference. Food and Agriculture Organization of the United Nations, Rome. 244 pagesGoogle Scholar
- FAO (2018) Forest resources assessment working paper 188: terms and definitions FRA 2020. Food and Agriculture Organization of the United Nations, Rome. 26 pagesGoogle Scholar
- FAO. http://www.fao.org/forestry/plantedforests/en/. Last accessed 10 July 2018
- Humphrey JW, Ferris R, Peace AJ, Jukes MR (2001) Biodiversity in planted forests. Forest research annual report and accounts 2000–2001. The Stationery Office, EdinburghGoogle Scholar
- ICPF (2013) Planted forests are a vital resource for future green economies. Summary report of the 3rd international congress on planted forests. http://www.fao.org/forestry/37902-083cc16479b4b28d8d4873338b79bef41.pdf. Accessed 17 Aug 2016
- INDUFOR (2012) FSC current and future plantations. A12-06869. 4 Oct 2012Google Scholar
- Ivetić V (2017) The use of exotic tree species in Serbia: what we have learned so far? In: Löf M (ed) Program and book of abstracts of the IUFRO 3rd restoring forest: regeneration and ecosystem function for the future. Lund. 12–14 September 2017. Report 51. Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Alnarp, p 76Google Scholar
- Ivetić V, Vilotić D (2014) The role of plantation forestry in sustainable development. Bull Fac Forestry Spec Ed: 157–180Google Scholar
- Ivetić V, Isajev V, Šijačić-Nikolić M (2005) Results of fourteen year’s old Norway spruce provenance test in Serbia. Proceedings of symposium forest and sustainable development, Brasov, pp 65–71Google Scholar
- Jürgensen C, Kollert W, Lebedys A (2014) Assessment of industrial roundwood production from planted forests. FAO planted forests and trees working paper FP/48/E. Rome. Available at: http://www.fao.org/forestry/plantedforests/67508@170537/en/
- Mason WL, Zhu JJ (2013) Silviculture of planted forests managed for multi-functional objectives: lessons from Chinese and British experiences. In: Fenning T (ed) Challenges and opportunities for the world’s forests in the 21st century. Springer, Dordrecht, pp 37–54Google Scholar
- Pelleri F, Ravagni S, Bianchetto E, Bidini C (2013) Comparing growth rate in a mixed plantation (walnut, poplar and nurse trees) with different planting designs: results from an experimental plantation in northern Italy. Ann Silvicultural Res 37(1):13–21Google Scholar
- Schmidtling RC, Myszewski JH (2003) Effect of large-scale movement of loblolly pine seed on genetic integrity of the species in its natural range. In: Beaulieu J (ed) Proceedings of the symposium of the North American forest commission, forest genetic resources and silviculture working groups, and the International Union of Forest Research Organizations (IUFRO), September 21, Quebec City, pp 43–48Google Scholar
- Sedjo R, Botkin D (1997) Using forest plantations to spare natural forests. Environment 39(10):14–20Google Scholar
- Stilinović S (1991) Afforestation. Naučna knjiga, Belgrade. University book. 274 p. [In Serbian]Google Scholar