Dendrochronology

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Dendrochronology

 

Drill for dendrochronology sampling and growth ring counting

 

The growth rings of a tree at Bristol Zoo, England. Each ring represents one year; the outside rings, near the bark, are the youngest

 

Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed. As well as dating them this can give data for dendroclimatology, the study of climate and atmospheric conditions during different periods in history from wood. 

Dendrochronology is useful for determining the precise age of samples, especially those that are too recent for radiocarbon dating, which always produces a range rather than an exact date, to be very accurate. However, for a precise date of the death of the tree a full sample to the edge is needed, which most trimmed timber will not provide. It also gives data on the timing of events and rates of change in the environment (most prominently climate) and also in wood found in archaeology or works of art and architecture, such as old panel paintings. It is also used as a check in radiocarbon dating to calibrate radiocarbon ages.

New growth in trees occurs in a layer of cells near the bark. A tree's growth rate changes in a predictable pattern throughout the year in response to seasonal climate changes, resulting in visible growth rings. Each ring marks a complete cycle of seasons, or one year, in the tree's life. As of 2013, the oldest tree-ring measurements in the Northern Hemisphere are a floating sequence extending from about 12,580 to 13,900 years. Dendrochronology derives from Ancient Greek: δένδρον (dendron), meaning "tree", χρόνος (khronos), meaning "time", and -λογία (-logia), "the study of".

 

History

The Greek botanist Theophrastus (c. 371 – c. 287 BC) first mentioned that the wood of trees has rings. In his Trattato della Pittura (Treatise on Painting), Leonardo da Vinci (1452–1519) was the first person to mention that trees form rings annually and that their thickness is determined by the conditions under which they grew. In 1737, French investigators Henri-Louis Duhamel du Monceau and Georges-Louis Leclerc de Buffon examined the effect of growing conditions on the shape of tree rings. They found that in 1709, a severe winter produced a distinctly dark tree ring, which served as a reference for subsequent European naturalists. In the U.S., Alexander Catlin Twining (1801–1884) suggested in 1833 that patterns among tree rings could be used to synchronize the dendrochronologies of various trees and thereby to reconstruct past climates across entire regions. The English polymath Charles Babbage proposed using dendrochronology to date the remains of trees in peat bogs or even in geological strata (1835, 1838).

During the latter half of the nineteenth century, the scientific study of tree rings and the application of dendrochronology began. In 1859, the German-American Jacob Kuechler (1823–1893) used crossdating to examine oaks (Quercus stellata) in order to study the record of climate in western Texas. In 1866, the German botanist, entomologist, and forester Julius Ratzeburg (1801–1871) observed the effects on tree rings of defoliation caused by insect infestations. By 1882, this observation was already appearing in forestry textbooks. In the 1870s, the Dutch astronomer Jacobus C. Kapteyn (1851–1922) was using crossdating to reconstruct the climates of the Netherlands and Germany. In 1881, the Swiss-Austrian forester Arthur von Seckendorff-Gudent (1845–1886) was using crossdating. From 1869 to 1901, Robert Hartig (1839–1901), a German professor of forest pathology, wrote a series of papers on the anatomy and ecology of tree rings. In 1892, the Russian physicist Fedor Nikiforovich Shvedov (Фёдор Никифорович Шведов) (1841–1905) wrote that he had used patterns found in tree rings to predict droughts in 1882 and 1891.

During the first half of the twentieth century, the astronomer A. E. Douglass founded the Laboratory of Tree-Ring Research at the University of Arizona. Douglass sought to better understand cycles of sunspot activity and reasoned that changes in solar activity would affect climate patterns on earth, which would subsequently be recorded by tree-ring growth patterns (i.e., sunspots → climate → tree rings). 

Growth rings

Diagram of secondary growth in a tree showing idealised vertical and horizontal sections, a new layer of wood is added in each growing season, thickening the stem, existing branches and roots, to form a growth ring

 

Horizontal cross sections cut through the trunk of a tree can reveal growth rings, also referred to as tree rings or annual rings. Growth rings result from new growth in the vascular cambium, a layer of cells near the bark that botanists classify as a lateral meristem; this growth in diameter is known as secondary growth. Visible rings result from the change in growth speed through the seasons of the year; thus, critical for the title method, one ring generally marks the passage of one year in the life of the tree. Removal of the bark of the tree in a particular area may cause deformation of the rings as the plant overgrows the scar. 

The rings are more visible in trees which have grown in temperate zones, where the seasons differ more markedly. The inner portion of a growth ring forms early in the growing season, when growth is comparatively rapid (hence the wood is less dense) and is known as "early wood" (or "spring wood", or "late-spring wood"); the outer portion is the "late wood" (sometimes termed "summer wood", often being produced in the summer, though sometimes in the autumn) and is denser.

Pinus taeda cross section showing annual rings, Cheraw, South Carolina

 

Many trees in temperate zones produce one growth-ring each year, with the newest adjacent to the bark. Hence, for the entire period of a tree's life, a year-by-year record or ring pattern builds up that reflects the age of the tree and the climatic conditions in which the tree grew. Adequate moisture and a long growing season result in a wide ring, while a drought year may result in a very narrow one.

Direct reading of tree ring chronologies is a complex science, for several reasons. First, contrary to the single-ring-per-year paradigm, alternating poor and favorable conditions, such as mid-summer droughts, can result in several rings forming in a given year. In addition, particular tree-species may present "missing rings", and this influences the selection of trees for study of long time-spans. For instance, missing rings are rare in oak and elm trees.

Critical to the science, trees from the same region tend to develop the same patterns of ring widths for a given period of chronological study. Researchers can compare and match these patterns ring-for-ring with patterns from trees which have grown at the same time in the same geographical zone (and therefore under similar climatic conditions). When one can match these tree-ring patterns across successive trees in the same locale, in overlapping fashion, chronologies can be built up—both for entire geographical regions and for sub-regions. Moreover, wood from ancient structures with known chronologies can be matched to the tree-ring data (a technique called cross-dating), and the age of the wood can thereby be determined precisely. Dendrochronologists originally carried out cross-dating by visual inspection; more recently, they have harnessed computers to do the task, applying statistical techniques to assess the matching. To eliminate individual variations in tree-ring growth, dendrochronologists take the smoothed average of the tree-ring widths of multiple tree-samples to build up a ring history, a process termed replication. A tree-ring history whose beginning- and end-dates are not known is called a floating chronology. It can be anchored by cross-matching a section against another chronology (tree-ring history) whose dates are known.

A fully anchored and cross-matched chronology for oak and pine in central Europe extends back 12,460 years, and an oak chronology goes back 7,429 years in Ireland and 6,939 years in England. Comparison of radiocarbon and dendrochronological ages supports the consistency of these two independent dendrochronological sequences. Another fully anchored chronology that extends back 8500 years exists for the bristlecone pine in the Southwest US (White Mountains of California).

Dendrochronological equation

A typical form of the function of the wood ring width in accordance with the dendrochronological equation

 

A typical form of the function of the wood ring (in accordance with the dendrochronological equation) with an increase in the width of wood ring at initial stage

 

The dendrochronological equation defines the law of growth of tree rings. The equation was proposed by Russian biophysicist Alexandr N. Tetearing in his work "Theory of populations" in the form: 

${\displaystyle \Delta L(t)={\frac {1}{k_{v}\,\rho ^{\tfrac {1}{3}}}}\,{\frac {d{\big (}M^{\tfrac {1}{3}}(t){\big )}}{dt}},}$

where ${\displaystyle \Delta L}$ is width of annual ring, ${\displaystyle t}$ is time (in years), ${\displaystyle \rho }$ is density of wood, ${\displaystyle k_{v}}$ is some coefficient, ${\displaystyle M(t)}$ is function of mass growth of the tree.

With the neglection of natural sinusoidal oscillations in tree mass, the formula of the changes in the annual ring width is: 

${\displaystyle \Delta L(t)=-{\dfrac {c_{1}e^{-a_{1}t}+c_{2}e^{-a_{2}t}}{3k_{v}\rho ^{\tfrac {1}{3}}(c_{4}+c_{1}e^{-a_{1}t}+c_{2}e^{-a_{2}t})^{\tfrac {2}{3}}}}}$

There ${\displaystyle c_{1}}$, ${\displaystyle c_{2}}$, and ${\displaystyle c_{4}}$ are some coefficients, ${\displaystyle a_{1}}$ and ${\displaystyle a_{2}}$ are positive constants. 

The formula is useful for correct approximation of samples data before data normalization procedure.

The typical forms of the function ${\displaystyle \Delta L(t)}$ of annual growth of wood ring are shown in the figures.

Sampling and dating

Dendrochronology makes available specimens of once-living material accurately dated to a specific year. Dates are often represented as estimated calendar years B.P., for before present, where "present" refers to 1 January 1950.

Timber core samples are sampled and used to measure the width of annual growth rings; by taking samples from different sites within a particular region, researchers can build a comprehensive historical sequence. The techniques of dendrochronology are more consistent in areas where trees grew in marginal conditions such as aridity or semi-aridity where the ring growth is more sensitive to the environment, rather than in humid areas where tree-ring growth is more uniform (complacent). In addition, some genera of trees are more suitable than others for this type of analysis. For instance, the bristlecone pine is exceptionally long-lived and slow growing, and has been used extensively for chronologies; still-living and dead specimens of this species provide tree-ring patterns going back thousands of years, in some regions more than 10,000 years. Currently, the maximum span for fully anchored chronology is a little over 11,000 years B.P. 

In 2004 a new radiocarbon calibration curve, INTCAL04, was internationally ratified to provide calibrated dates back to 26,000 B.P. For the period back to 12,400 B.P., the radiocarbon dates are calibrated against dendrochronological dates.

Dendrochronology practice faces many obstacles, including the existence of species of ants that inhabit trees and extend their galleries into the wood, thus destroying ring structure. 

Reference sequences

European chronologies derived from wooden structures initially found it difficult to bridge the gap in the fourteenth century when there was a building hiatus, which coincided with the Black Death, however there do exist unbroken chronologies dating back to prehistoric times, for example the Danish chronology dating back to 352 BC.

Given a sample of wood, the variation of the tree-ring growths provides not only a match by year, it can also match location because the climate across a continent is not consistent. This makes it possible to determine the source of ships as well as smaller artifacts made from wood, but which were transported long distances, such as panels for paintings and ship timbers. 

Applications

Radiocarbon dating calibration

Dates from dendrochronology can be used as a calibration and check of radiocarbon dating.

 

Climatology

Dendroclimatology is the science of determining past climates from trees primarily from the properties of the annual tree rings. Other properties of the annual rings, such as maximum latewood density (MXD) have been shown to be better proxies than simple ring width. Using tree rings, scientists have estimated many local climates for hundreds to thousands of years previous.

Art history

Dendrochronology has become important to art historians in the dating of panel paintings. However, unlike analysis of samples from buildings, which are typically sent to a laboratory, wooden supports for paintings usually have to be measured in a museum conservation department, which places limitations on the techniques that can be used.

In addition to dating, dendrochronology can also provide information as to the source of the panel. Many Early Netherlandish paintings have turned out to be painted on panels of "Baltic oak" shipped from the Vistula region via ports of the Hanseatic League. Oak panels were used in a number of northern countries such as England, France and Germany. Wooden supports other than oak were rarely used by Netherlandish painters.

A portrait of Mary Queen of Scots, determined to date from the sixteenth century by dendrochronology

 

Since panels of seasoned wood were used, an uncertain number of years has to be allowed for seasoning when estimating dates. Panels were trimmed of the outer rings, and often each panel only uses a small part of the radius of the trunk. Consequently, dating studies usually result in a "terminus post quem" (earliest possible) date, and a tentative date for the arrival of a seasoned raw panel using assumptions as to these factors. As a result of establishing numerous sequences, it was possible to date 85–90% of the 250 paintings from the fourteenth to seventeenth century analysed between 1971 and 1982; by now a much greater number have been analysed. 

A portrait of Mary, Queen of Scots in the National Portrait Gallery, London was believed to be an eighteenth-century copy. However, dendrochronology revealed that the wood dated from the second half of the sixteenth century. It is now regarded as an original sixteenth-century painting by an unknown artist.

On the other hand, dendrochronology was applied to four paintings depicting the same subject, that of Christ expelling the money-lenders from the Temple. The results showed that the age of the wood was too late for any of them to have been painted by Hieronymus Bosch.

While dendrochronology has become an important tool for dating oak panels, it is not effective in dating the poplar panels often used by Italian painters because of the erratic growth rings in poplar.

The sixteenth century saw a gradual replacement of wooden panels by canvas as the support for paintings, which means the technique is less often applicable to later paintings. In addition, many panel paintings were transferred onto canvas or other supports during the nineteenth and twentieth centuries. 

Archaeology

The dating of buildings with wooden structures and components is also done by dendrochronology; dendroarchaeology is the term for the application of dendrochronology in archaeology. While archaeologists can date wood and when it was felled, it may be difficult to definitively determine the age of a building or structure in which the wood was used; the wood could have been reused from an older structure, may have been felled and left for many years before use, or could have been used to replace a damaged piece of wood. The dating of building via dendrochronology thus requires knowledge of the history of building technology. Many prehistoric forms of buildings used "posts" that were whole young tree trunks; where the bottom of the post has survived in the ground these can be especially useful for dating.

Examples:

• The Post Track and Sweet Track, boardwalks or timber trackways, in the Somerset levels, England, have been dated to 3838 BC and 3807 BC.
• Navan Fort where in Prehistoric Ireland a large structure was built with more than two hundred posts. The central oak post was felled in 95 BC.
• cliff dwellings of Native Americans in the arid U.S. Southwest.
• The Fairbanks House in Dedham, Massachusetts. While the house had long been claimed to have been built circa 1640 (and being the oldest wood-framed house in North America), core samples of wood taken from a summer beam confirmed the wood was from an oak tree felled in 1637–8, as wood was not seasoned before use in building at that time in New England. An additional sample from another beam yielded a date of 1641, thus confirming the house had been constructed starting in 1638 and finished sometime after 1641.
• The burial chamber of Gorm the Old, who died c. 958, was constructed from wood of timbers felled in 958.
• Veliky Novgorod, where, between the tenth and the fifteenth century, numerous consecutive layers of wooden log pavement have been placed over the accumulating dirt.
  

Related chronologies

Herbchronology is the analysis of annual growth rings (or simply annual rings) in the secondary root xylem of perennial herbaceous plants. Similar seasonal patterns also occur in ice cores and in varves (layers of sediment deposition in a lake, river, or sea bed). The deposition pattern in the core will vary for a frozen-over lake versus an ice-free lake, and with the fineness of the sediment. Sclerochronology is the study of algae deposits.

Some columnar cactus also exhibit similar seasonal patterns in the isotopes of carbon and oxygen in their spines (acanthochronology). These are used for dating in a manner similar to dendrochronology, and such techniques are used in combination with dendrochronology, to plug gaps and to extend the range of the seasonal data available to archaeologists and paleoclimatologists.

A similar technique is used to estimate the age of fish stocks through the analysis of growth rings in the otolith bones.

Forestry

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Forestry

 

Forestry work in Austria

 

Forestry is the science and craft of creating, managing, using, conserving, and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. The science of forestry has elements that belong to the biological, physical, social, political and managerial sciences.

Modern forestry generally embraces a broad range of concerns, in what is known as multiple-use management, including the provision of timber, fuel wood, wildlife habitat, natural water quality management, recreation, landscape and community protection, employment, aesthetically appealing landscapes, biodiversity management, watershed management, erosion control, and preserving forests as "sinks" for atmospheric carbon dioxide. A practitioner of forestry is known as a forester. Other common terms are: a verderer, or a silviculturalist. Silviculture is narrower than forestry, being concerned only with forest plants, but is often used synonymously with forestry.

Forest ecosystems have come to be seen as the most important component of the biosphere, and forestry has emerged as a vital applied science, craft, and technology. 

Forestry is an important economic segment in various industrial countries. For example, in Germany, forests cover nearly a third of the land area, wood is the most important renewable resource, and forestry supports more than a million jobs and about €181 billion of value to the German economy each year.

A deciduous beech forest in Slovenia

 

History

Background

The preindustrial age has been dubbed by Werner Sombart and others as the 'wooden age', as timber and firewood were the basic resources for energy, construction and housing. The development of modern forestry is closely connected with the rise of capitalism, economy as a science and varying notions of land use and property.

Roman Latifundiae, large agricultural estates, were quite successful in maintaining the large supply of wood that was necessary for the Roman Empire. Large deforestations came with respectively after the decline of the Romans. However already in the 5th century, monks in the then Byzantine Romagna on the Adriatic coast, were able to establish stone pine plantations to provide fuelwood and food. This was the beginning of the massive forest mentioned by Dante Alighieri in his 1308 poem Divine Comedy.

Similar sustainable formal forestry practices were developed by the Visigoths in the 7th century when, faced with the ever-increasing shortage of wood, they instituted a code concerned with the preservation of oak and pine forests. The use and management of many forest resources has a long history in China as well, dating back to the Han dynasty and taking place under the landowning gentry. A similar approach was used in Japan. It was also later written about by the Ming dynasty Chinese scholar Xu Guangqi (1562–1633).

In Europe, land usage rights in medieval and early modern times allowed different users to access forests and pastures. Plant litter and resin extraction were important, as pitch (resin) was essential for the caulking of ships, falking and hunting rights, firewood and building, timber gathering in wood pastures, and for grazing animals in forests. The notion of "commons" (German "Allmende") refers to the underlying traditional legal term of common land. The idea of enclosed private property came about during modern times. However, most hunting rights were retained by members of the nobility which preserved the right of the nobility to access and use common land for recreation, like fox hunting. 

Early modern forestry development

Timber harvesting in Finland

 

Exploitation of brushwood at the Golden Steinrueck, Vogelsberg

 

Hans Carl von Carlowitz, German miner

 

Systematic management of forests for a sustainable yield of timber began in Portugal in the 13th century when Afonso III of Portugal planted the Pinhal do Rei near Leiria to prevent coastal erosion and soil degradation, and as a sustainable source for timber used in naval construction. His successor Dom Dinis continued the practice and the forest exists still today.

Forest management also flourished in the German states in the 14th century, e.g. in Nuremberg, and in 16th-century Japan. Typically, a forest was divided into specific sections and mapped; the harvest of timber was planned with an eye to regeneration. As timber rafting allowed for connecting large continental forests, as in south western Germany, via Main, Neckar, Danube and Rhine with the coastal cities and states, early modern forestry and remote trading were closely connected. Large firs in the black forest were called „Holländer“, as they were traded to the Dutch ship yards. Large timber rafts on the Rhine were 200 to 400m in length, 40m in width and consisted of several thousand logs. The crew consisted of 400 to 500 men, including shelter, bakeries, ovens and livestock stables. Timber rafting infrastructure allowed for large interconnected networks all over continental Europe and is still of importance in Finland.

Starting with the sixteenth century, enhanced world maritime trade, a boom in housing construction in Europe and the success and further Berggeschrey (rushes) of the mining industry increased timber consumption sharply. The notion of 'Nachhaltigkeit', sustainability in forestry, is closely connected to the work of Hans Carl von Carlowitz (1645–1714), a mining administrator in Saxony. His book Sylvicultura oeconomica, oder haußwirthliche Nachricht und Naturmäßige Anweisung zur wilden Baum-Zucht (1713) was the first comprehensive treatise about sustainable yield forestry. In the UK, and, to an extent, in continental Europe, the enclosure movement and the clearances favored strictly enclosed private property. The Agrarian reformers, early economic writers and scientists tried to get rid of the traditional commons. At the time, an alleged tragedy of the commons together with fears of a Holznot, an imminent wood shortage played a watershed role in the controversies about cooperative land use patterns.

The practice of establishing tree plantations in the British Isles was promoted by John Evelyn, though it had already acquired some popularity. Louis XIV's minister Jean-Baptiste Colbert's oak Forest of Tronçais, planted for the future use of the French Navy, matured as expected in the mid-19th century: "Colbert had thought of everything except the steamship," Fernand Braudel observed. In parallel, schools of forestry were established beginning in the late 18th century in Hesse, Russia, Austria-Hungary, Sweden, France and elsewhere in Europe. 

Forest conservation and early globalization

During the late 19th and early 20th centuries, forest preservation programs were established in British India, the United States, and Europe. Many foresters were either from continental Europe (like Sir Dietrich Brandis), or educated there (like Gifford Pinchot). Sir Dietrich Brandis is considered the father of tropical forestry, European concepts and practices had to be adapted in tropical and semi arid climate zones. The development of plantation forestry was one of the (controversial) answers to the specific challenges in the tropical colonies. The enactment and evolution of forest laws and binding regulations occurred in most Western nations in the 20th century in response to growing conservation concerns and the increasing technological capacity of logging companies. Tropical forestry is a separate branch of forestry which deals mainly with equatorial forests that yield woods such as teak and mahogany. 

Mechanization

Forestry mechanization was always in close connection to metal working and the development of mechanical tools to cut and transport timber to its destination. Rafting belongs to the earliest means of transport. Steel saws came up in the 15th century. The 19th century widely increased the availability of steel for whipsaws and introduced Forest railways and railways in general for transport and as forestry customer. Further human induced changes, however, came since World War II, respectively in line with the "1950s syndrome". The first portable chainsaw was invented in 1918 in Canada, but large impact of mechanization in forestry started after World War II. Forestry harvesters are among the most recent developments. Although drones, planes, laser scanning, satellites and robots also play a part in forestry. 

Early journals which are still present

• Sylwan first published in 1820
• Schweizerische Zeitschrift für Forstwesen first published in 1850
• Erdészeti Lapok first published in 1862. (Hungary, 1862–present).
• The Indian Forester first published in 1875.
• Šumarski list (Forestry Review, Croatia) was published in 1877 by Croatian Forestry Society.
• Montes (Forestry, Spain) first published in 1877.
• Revista pădurilor (Journal of Forests, Romania, 1881–1882; 1886–present), the oldest extant magazine in Romania
• Forestry Quarterly, first published in 1902 by the New York State College of Forestry.
• Šumarstvo (Forestry, Serbia) first published in 1948 by the Ministry of Forestry of Democratic Federal Yugoslavia, and since 1951 by Organ of Society of Forestry Engineers and Technicians of the Republic of Serbia (succeeding the former Šumarski glasnik published from 1907 to 1921)
  

Forestry in the 21st century

A modern sawmill

 

Today a strong body of research exists regarding the management of forest ecosystems and the genetic improvement of tree species and varieties. Forestry studies also include the development of better methods for the planting, protecting, thinning, controlled burning, felling, extracting, and processing of timber. One of the applications of modern forestry is reforestation, in which trees are planted and tended in a given area. 

Trees provide numerous environmental, social and economic benefits for people. In many regions the forest industry is of major ecological, economic, and social importance, with the United States producing more timber than any other country in the world. Third-party certification systems that provide independent verification of sound forest stewardship and sustainable forestry have become commonplace in many areas since the 1990s. These certification systems developed as a response to criticism of some forestry practices, particularly deforestation in less-developed regions along with concerns over resource management in the developed world.

In topographically severe forested terrain, proper forestry is important for the prevention or minimization of serious soil erosion or even landslides. In areas with a high potential for landslides, forests can stabilize soils and prevent property damage or loss, human injury, or loss of life. 

Foresters

Foresters of the Austral University of Chile in the Valdivian forests of San Pablo de Tregua, Chile

 

Foresters work for the timber industry, government agencies, conservation groups, local authorities, urban parks boards, citizens' associations, and private landowners. The forestry profession includes a wide diversity of jobs, with educational requirements ranging from college bachelor's degrees to PhDs for highly specialized work. Industrial foresters plan forest regeneration starting with careful harvesting. Urban foresters manage trees in urban green spaces. Foresters work in tree nurseries growing seedlings for woodland creation or regeneration projects. Foresters improve tree genetics. Forest engineers develop new building systems. Professional foresters measure and model the growth of forests with tools like geographic information systems. Foresters may combat insect infestation, disease, forest and grassland wildfire, but increasingly allow these natural aspects of forest ecosystems to run their course when the likelihood of epidemics or risk of life or property are low. Increasingly, foresters participate in wildlife conservation planning and watershed protection. Foresters have been mainly concerned with timber management, especially reforestation, maintaining forests at prime conditions, and fire control.

Forestry plans

Foresters develop and implement forest management plans relying on mapped resource inventories showing an area's topographical features as well as its distribution of trees (by species) and other plant cover. Plans also include landowner objectives, roads, culverts, proximity to human habitation, water features and hydrological conditions, and soils information. Forest management plans typically include recommended silvicultural treatments and a timetable for their implementation. Application of digital maps in Geographic Informations systems (GIS) that extracts and integrates different information about forest terrains, soil type and tree covers, etc. using, e.g. laser scanning, enhances forest management plans in modern systems.

Forest management plans include recommendations to achieve the landowner's objectives and desired future condition for the property subject to ecological, financial, logistical (e.g. access to resources), and other constraints. On some properties, plans focus on producing quality wood products for processing or sale. Hence, tree species, quantity, and form, all central to the value of harvested products quality and quantity, tend to be important components of silvicultural plans.

Good management plans include consideration of future conditions of the stand after any recommended harvests treatments, including future treatments (particularly in intermediate stand treatments), and plans for natural or artificial regeneration after final harvests. 

The objectives of landowners and leaseholders influence plans for harvest and subsequent site treatment. In Britain, plans featuring "good forestry practice" must always consider the needs of other stakeholders such as nearby communities or rural residents living within or adjacent to woodland areas. Foresters consider tree felling and environmental legislation when developing plans. Plans instruct the sustainable harvesting and replacement of trees. They indicate whether road building or other forest engineering operations are required.

Agriculture and forest leaders are also trying to understand how the climate change legislation will affect what they do. The information gathered will provide the data that will determine the role of agriculture and forestry in a new climate change regulatory system.

Forestry as a science

Over the past centuries, forestry was regarded as a separate science. With the rise of ecology and environmental science, there has been a reordering in the applied sciences. In line with this view, forestry is a primary land-use science comparable with agriculture. Under these headings, the fundamentals behind the management of natural forests comes by way of natural ecology. Forests or tree plantations, those whose primary purpose is the extraction of forest products, are planned and managed utilizing a mix of ecological and agroecological principles.

Genetic diversity in forestry

The provenance of forest reproductive material used to plant forests has great influence on how the trees develop, hence why it is important to use forest reproductive material of good quality and of high genetic diversity.

The term, genetic diversity describe differences in DNA sequence between individuals as distinct from variation caused by environmental influences. The unique genetic composition of an individual (its genotype) will determine its performance (its phenotype) at a particular site.

Genetic diversity is needed to maintain the vitality of forests and to provide resilience to pests and diseases. Genetic diversity also ensures that forest trees can survive, adapt and evolve under changing environmental conditions. Furthermore, genetic diversity is the foundation of biological diversity at species and ecosystem levels. Forest genetic resources are therefore important to consider in forest management.

Genetic diversity in forests is threatened by forest fires, pests and diseases, habitat fragmentation, poor silvicultural practices and inappropriate use of forest reproductive material. Furthermore, the marginal populations of many tree species are facing new threats due to climate change.

Most countries in Europe have recommendations or guidelines for selecting species and provenances that can be used in a given site or zone.

Education

History of forestry education

The first dedicated forestry school was established by Georg Ludwig Hartig at Hungen in the Wetterau, Hesse, in 1787, though forestry had been taught earlier in central Europe, including at the University of Giessen, in Hesse-Darmstadt.

In Spain, the first forestry school was the Forest Engineering School of Madrid (Escuela Técnica Superior de Ingenieros de Montes), founded in 1844.

The first in North America, the Biltmore Forest School was established near Asheville, North Carolina, by Carl A. Schenck on September 1, 1898, on the grounds of George W. Vanderbilt's Biltmore Estate. Another early school was the New York State College of Forestry, established at Cornell University just a few weeks later, in September 1898. Early 19th century North American foresters went to Germany to study forestry. Some early German foresters also emigrated to North America.

In South America the first forestry school was established in Brazil, in Viçosa, Minas Gerais, in 1962, and moved the next year to become a faculty at the Federal University of Paraná, in Curitiba.

Forestry education today

Prescribed burning is used by foresters to reduce fuel loads

 

Today, forestry education typically includes training in general biology, ecology, botany, genetics, soil science, climatology, hydrology, economics and forest management. Education in the basics of sociology and political science is often considered an advantage. Professional skills in conflict resolution and communication are also important in training programs.

In India, forestry education is imparted in the agricultural universities and in Forest Research Institutes (deemed universities). Four year degree programmes are conducted in these universities at the undergraduate level. Masters and Doctorate degrees are also available in these universities. 

In the United States, postsecondary forestry education leading to a Bachelor's degree or Master's degree is accredited by the Society of American Foresters.

In Canada the Canadian Institute of Forestry awards silver rings to graduates from accredited university BSc programs, as well as college and technical programs.

In many European countries, training in forestry is made in accordance with requirements of the Bologna Process and the European Higher Education Area. 

The International Union of Forest Research Organizations is the only international organization that coordinates forest science efforts worldwide.