Dendrology (Ancient Greek: δένδρον, dendron, "tree"; and Ancient Greek: -λογία, -logia, science of or study of) or xylology (Ancient Greek: ξύλον, ksulon, "wood") is the science and study of wooded plants (trees, shrubs, and lianas), specifically, their taxonomic classifications. There is no sharp boundary between plant taxonomy and dendrology; however, woody plants not only belong to many different plant families, but these families may be made up of both woody and non-woody members. Some families include only a few woody species. Dendrology, as a discipline of industrial forestry, tends to focus on identification of economically useful woody plants and their taxonomic interrelationships. As an academic course of study, dendrology will include all woody plants, native and non-native, that occur in a region. A related discipline is the study of sylvics, which focuses on the autecology of genera and species.
Dendrology is often confused with botany. However, botany is the study of all types of general plants, while dendrology studies only woody plants. Dendrology may be considered a subcategory of botany that specializes in the characterization and identification of woody plants.
The 774–775 carbon-14 spike is an observed increase of 1.2% in the concentration of carbon-14 isotope in tree rings dated to the years 774 or 775 AD, which is about 20 times as high as the normal background rate of variation. It was discovered during a study of Japanese cedar trees, with the year of occurrence determined through dendrochronology. A surge in beryllium isotope 10Be, detected in Antarctic ice cores, has also been associated with the 774–775 event.The event appears to have been global, with the same carbon-14 signal found in tree rings from Germany, Russia, the United States, and New Zealand.
The signal exhibits a sharp increase of ≈1.2% followed by a slow decline (see Figure 1), which is typical for an instant production of carbon-14 in the atmosphere, indicating that the event was short in duration. The globally averaged production of carbon-14 for this event is calculated as Q = (1.1 – 1.5) × 108 atoms/cm2.993–994 carbon-14 spike
The 993–994 carbon-14 spike was a rapid increase in carbon-14 content from tree rings, and followed the 774–775 carbon-14 spike. This event is also confirmed by a sharp increase of beryllium-10 and hence considered as solar-origin. It may have come from a massive solar storm as a series of auroral observations are known to be observed in late 992.Akshuat dendropark
Akshuat dendropark (Russian: Акшуатский дендропарк) is a natural monument (Protected areas of Ulyanovsk Oblast)Bernhard Adalbert Emil Koehne
Bernhard Adalbert Emil Koehne (February 12, 1848 – October 12, 1918) was a German botanist and dendrologist born near Striegau, a town known today as Strzegom, Poland.
Koehne was a professor of botany in Berlin and was a leading authority of the plant family Lythraceae. In Adolf Engler's treatise Das Pflanzenreich ("The Plant Kingdom"), he was author of the chapter on Lythraceae. He also made important contributions involving Lythraceae to Engler and Karl Prantl's Die Natürlichen Pflanzenfamilien ("The Natural Plant Families"), as well as to Karl Friedrich Philipp von Martius' Flora Brasiliensis.
Another noted written effort by Koehne was the 1893 Deutsche Dendrologie ("German Dendrology"). The plant genus Koehneola (family Asteraceae) is named in his honor.Bog-wood
Bog-wood, also known as abonos and morta, especially amongst pipe smokers, is a material from trees that have been buried in peat bogs and preserved from decay by the acidic and anaerobic bog conditions, sometimes for hundreds or even thousands of years. The wood is usually stained brown by tannins dissolved in the acidic water. Bog-wood represents the early stages in the fossilisation of wood, with further stages ultimately forming jet, lignite and coal over a period of many millions of years. Bog-wood may come from any tree species naturally growing near or in bogs, including oak (Quercus – "bog oak"), pine (Pinus), yew (Taxus), swamp cypress (Taxodium) and kauri (Agathis). Bog-wood is often removed from fields and placed in clearance cairns. It is a rare form of timber that is claimed to be "comparable to some of the world's most expensive tropical hardwoods".Dendrochronology
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".Dendrometry
Dendrometry is the branch of botany that is concerned with the measurement of the various dimensions of trees, such as their diameter, size, shape, age, overall volume, thickness of the bark, etc., as well as the statistical properties of tree stands, including measures of central tendency and dispersion of these quantities, wood density, or yearly growth, for instance.
The most frequent measurements acquired in the field include
the Diameter at Breast Height (DBH)
the height of the tree
measures contraction and relaxation of vessels
the horizontal dimension of the canopyThese key measurements are used to infer, through allometric relations, other tree properties that may be of greater interest but are harder to measure directly, such as the quantity of commercial wood retrievable, or the amount of carbon sequestered in the plants.Dendropyrochronology
Dendropyrochronology is the science of using tree-ring dating to study and reconstruct the history of wild fires. It is a subfield of dendrochronology, along with dendroclimatology and dendroarchaeology.Divergence problem
The divergence problem is an anomaly from the field of dendroclimatology, the study of past climate through observations of old trees, primarily the properties of their annual growth rings. It is the disagreement between the temperatures measured by the thermometers (instrumental temperatures) and the temperatures reconstructed from the latewood densities or, in some cases, widths of tree rings in the far northern forests.
While the thermometer records indicate a substantial late 20th century warming trend, many tree rings from such sites do not display a corresponding change in their maximum latewood density. In some studies this issue has also been found with tree ring width. A temperature trend extracted from tree rings alone would not show any substantial warming since the 1950s. The temperature graphs calculated in these two ways thus "diverge" from one another, which is the origin of the term.International Tree-Ring Data Bank
The International Tree-Ring Data Bank (ITRDB) is a data repository for tree ring measurements that has been maintained since 1990 by the United States' National Oceanic and Atmospheric Administration Paleoclimatology Program and World Data Center for Paleoclimatology. The ITRDB was initially established by Hal Fritts through the Laboratory of Tree-Ring Research at the University of Arizona through a grant from the US National Science Foundation after the First International Workshop on Dendrochronology in 1974. The ITRDB accepts all tree ring data with sufficient metadata to be uploaded, but was founded with a focus on tree ring measurements intended for climatic studies. Specific information is required for uploading data to the data base, such as the raw tree ring measurements, an indication of the type of measurement (full ring widths, earlywood, latewood), and the location, but the types of data and the rules for accuracy and precision of the primary data, tree-ring width measurements, are decided by the dendrochronologists who are contributing the data rather than by the NOAA or another governing organization.Kaldenkirchen Sequoia Farm
The Kaldenkirchen Sequoia Farm (German: Sequoiafarm Kaldenkirchen) is a German arboretum that has been used as a biological institute for many years. Part of the protected area in the city of Nettetal, it is situated in the "Kaldenkirchen Grenzwald" (forest bordering Germany and the Netherlands). Nettetal lies in the Lower Rhine region of Germany.Leopold Dippel
Georg Heinrich Leopold Dippel (4 August 1827 – 4 March 1914) was a German botanist. He was the son of a royal Bavarian forester, Carl Friedrich Peter Dippel, and Sussanna Purpus. He attended schools is Kaiserslautern and Zweibrücken. From 1845, he studied at the Academy of Forestry in Aschaffenburg, until he graduated in 1848. During his time there he was a member of the Munich Corps Hubertia fraternity. He continued his studies in Jena under the tutelage of Matthias Jacob Schleiden. Under him, he learned more extensively about botany and pioneered his work in microscopy and his research on the structure of plant's bodies. From July 1869, he worked at the Technische Universität Darmstadt, as a Professor of Botany and Zoology, Botany, and Cellular Histology. His interests turned towards Dendrology at this point. He brought many foreign trees and shrubs, mostly collected by his first cousin Carl Albert Purpus in North America and Mexico, and sent them to Germany. He was the rector of the Technical University of Darmstadt from 1870–71 and the Dean of the Chemical-Technical School from 1882-87. He retired at the end of the summer semester in 1896.List of botany journals
The following is a list of botanical scientific journals.Rhizome
In botany and dendrology, a rhizome (, from Ancient Greek: rhízōma "mass of roots", from rhizóō "cause to strike root") is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow horizontally. The rhizome also retains the ability to allow new shoots to grow upwards.A rhizome is the main stem of the plant. A stolon is similar to a rhizome, but a stolon sprouts from an existing stem, has long internodes, and generates new shoots at the end, such as in the strawberry plant. In general, rhizomes have short internodes, send out roots from the bottom of the nodes, and generate new upward-growing shoots from the top of the nodes.
A stem tuber is a thickened part of a rhizome or stolon that has been enlarged for use as a storage organ. In general, a tuber is high in starch, e.g. the potato, which is a modified stolon. The term "tuber" is often used imprecisely and is sometimes applied to plants with rhizomes.
If a rhizome is separated each piece may be able to give rise to a new plant. The plant uses the rhizome to store starches, proteins, and other nutrients. These nutrients become useful for the plant when new shoots must be formed or when the plant dies back for the winter. This is a process known as vegetative reproduction and is used by farmers and gardeners to propagate certain plants. This also allows for lateral spread of grasses like bamboo and bunch grasses. Examples of plants that are propagated this way include hops, asparagus, ginger, irises, lily of the valley, cannas, and sympodial orchids. Some rhizomes which are used directly in cooking include ginger, turmeric, galangal, fingerroot, and lotus.
Stored rhizomes are subject to bacterial and fungal infections, making them unsuitable for replanting and greatly diminishing stocks. However, rhizomes can also be produced artificially from tissue cultures. The ability to easily grow rhizomes from tissue cultures leads to better stocks for replanting and greater yields. The plant hormones ethylene and jasmonic acid have been found to help induce and regulate the growth of rhizomes, specifically in rhubarb. Ethylene that was applied externally was found to affect internal ethylene levels, allowing easy manipulations of ethylene concentrations. Knowledge of how to use these hormones to induce rhizome growth could help farmers and biologists producing plants grown from rhizomes more easily cultivate and grow better plants.
Some plants have rhizomes that grow above ground or that lie at the soil surface, including some Iris species, and ferns, whose spreading stems are rhizomes. Plants with underground rhizomes include gingers, bamboo, the Venus flytrap, Chinese lantern, western poison-oak, hops, and Alstroemeria, and the weeds Johnson grass, Bermuda grass, and purple nut sedge. Rhizomes generally form a single layer, but in giant horsetails, can be multi-tiered.Many rhizomes have culinary value, and some, such as zhe'ergen, are commonly consumed raw.Silvology
Silvology (Latin, silva or sylva, "forests and woods"; and Ancient Greek: -λογία, -logia, "science of or study of") is the biological science of studying forests and woods, incorporating the understanding of natural forest ecosystems, and the effects and development of silvicultural practices. The term compliments silviculture, which deals with the art and practice of forest management.Silvology is seen as a single science for forestry and was first used by Roeloff Oldeman. It integrates the study of forests and forest ecology, dealing with single tree autecology and natural forest ecology.Southern Forestry Conclave
The Southern Forestry Conclave is an annual competition among students from 15 southern forestry schools in a variety of physical and technical events. It typically involves more than 250 contestants. Traditional physical events include archery, axe throwing, pole climbing, log rolling, bow sawing, log birling, and cross-cut saw competition. Technical events include dendrology, timber volume estimation, photogrammetry, wood identification, and others. Scores from individual events are combined to determine the overall winning school of each year's conclave, which is a highly sought honor. The Forestry Conclave is hosted by the participating schools on a rotating basis and is sponsored by the Association of Southern Forestry Clubs.The Conclave promotes spirited competition among the forestry students representing their respective schools and clubs, and participation in the Conclave helps students develop high standards and professionalism. Planning the Conclave requires considerable cooperation among the participating forestry clubs for it to be successful.Strážnice
Strážnice (German: Straßnitz) is a town in Hodonín District, South Moravian Region, Czech Republic. It has a population of 5,829 (2006 est.). It is located in Slovácko microregion.
Items from the Neolithic Linear Pottery culture have been found in the area.The Strážnice Castle – originally a water castle – was founded in the second half of the 13th century, later rebuilt in Renaissance style. Positioned at the river Morava, it served as a guarding point on Hungarian border. Nowadays, the National Institute of Folk Culture resides here. There is a permanent exposition of "Folk instruments of the Czech Republic" and the Castle library. The castle is surrounded by an informal park with the longest plane alley in Central Europe founded in the first half of the 19th century. Amphitheatres, a summer cinema, lakes, a dendrology path with educational boards and many benches are located in the park. The Jewish cemetery in Sadova street holds about 1100 gravestones, the oldest ones dating back to 17th century. The synagogue rebuilt in early 20th century has been recently renovated in mid-2008 and is an adjunct to the local museum. Most of the Straznice Jews were deported to their deaths in the Holocaust but many of the houses in the old ghetto still stand.
The roads leading to neighbouring towns of Veselí nad Moravou and Skalica are flanked by massive early-16th century bastions.Timeline of dendrochronology timestamp events
A Timeline of dendrochronology timestamped events.Woody plant
A woody plant is a plant that produces wood as its structural tissue. Woody plants are usually either trees, shrubs, or lianas. These are usually perennial plants whose stems and larger roots are reinforced with wood produced from secondary xylem. The main stem, larger branches, and roots of these plants are usually covered by a layer of bark. Wood is a structural cellular adaptation that allows woody plants to grow from above ground stems year after year, thus making some woody plants the largest and tallest terrestrial plants.
Wood is primarily composed of xylem cells with cell walls made of cellulose and lignin. Xylem is a vascular tissue which moves water and nutrients from the roots to the leaves. Most woody plants form new layers of woody tissue each year, and so increase their stem diameter from year to year, with new wood deposited on the inner side of a vascular cambium layer located immediately beneath the bark. However, in some monocotyledons such as palms and dracaenas, the wood is formed in bundles scattered through the interior of the trunk.Woody herbs are herbaceous plants that develop hard woody stems. They include such plants as Uraria picta and certain species in family Polygonaceae. These herbs are not truly woody but have hard densely packed stem tissue. Other herbaceous plants have woody stems called a caudex, which is a thickened stem base often found in plants that grow in alpine or dry environments.
Under specific conditions, woody plants may decay or may in time become petrified wood.
The symbol for a woody plant, based on Species Plantarum by Linnaeus is , which is also the astronomical symbol for the planet Saturn.