Herbchronology

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Root cross section (30 mm) of Penstemon venustus. Lignified tissue is stained reddish using Phloroglucinol/HCL. Black markers denote annual ring borders. Individual collected at the Wallowa Mts., Oregon, USA (2003) Root cross-section of Penstemon venustus.jpg
Root cross section (30 μm) of Penstemon venustus . Lignified tissue is stained reddish using Phloroglucinol/HCL. Black markers denote annual ring borders. Individual collected at the Wallowa Mts., Oregon, USA (2003)
Root cross section (30 mm) of Cirsium spinosissimum. Lignified tissue is stained reddish using Phloroglucinol/HCL. Black markers denote annual ring borders. Individual collected in the Churfirsten Mountain range, Switzerland (2002) Root cross-section of Cirsium spinosissimum.jpg
Root cross section (30 μm) of Cirsium spinosissimum . Lignified tissue is stained reddish using Phloroglucinol/HCL. Black markers denote annual ring borders. Individual collected in the Churfirsten Mountain range, Switzerland (2002)
Root cross section (30 mm) of Silene vulgaris. Lignified tissue is stained reddish using Phloroglucinol/HCL. Black markers denote annual ring borders. Individual collected at Davos, Switzerland (2003) Root cross-section of Silene vulgaris.jpg
Root cross section (30 μm) of Silene vulgaris . Lignified tissue is stained reddish using Phloroglucinol/HCL. Black markers denote annual ring borders. Individual collected at Davos, Switzerland (2003)

Herbchronology is the analysis of annual growth rings (or simply annual rings) in the secondary root xylem of perennial herbaceous plants. While leaves and stems of perennial herbs die down at the end of the growing season the root often persists for many years or even the entire life. [1] Perennial herb species belonging to the dicotyledon group (also known as perennial forbs) are characterized by secondary growth, which shows as a new growth ring added each year to persistent roots. About two thirds of all perennial dicotyledonous herb species with a persistent root that grow in the strongly seasonal zone of the northern hemisphere show at least fairly clear annual growth rings. [1]

Contents

Counting of annual growth rings can be used to determine the age of a perennial herb similarly as it is done in trees using dendrochronology. [2] This way it was found that some perennial herbs live up to 50 years and more. [3] [4]

History

The term herb-chronology is referring to dendrochronology because of the similarity of the structures investigated. The term was introduced in the late 1990s, [5] however, the existence of annual rings in perennial herbs was already observed in earlier times by several researchers. [6] [7] [8]

Annual growth rings

Like trees and woody plants, perennial herbs have a growth zone called vascular cambium between the root bark and the root xylem. The vascular cambium ring is active during growing season and produces a new layer of xylem tissue or growth ring every year. This addition of a new lateral layer each year is called secondary growth and is exactly the same as in woody plants. Each individual growth ring consists of earlywood tissue that is formed at the beginning of the growing season and latewood tissue formed in summer and fall. Earlywood tissue is characterized by wide vessels or denser arrangement of vessels, whereas latewood tissue shows narrower vessels and/or lower vessel density. [1] [2]

Annual growth rings in herbs are usually only visible by means of a microscope and a specific staining method. Ring-like patterns visible in root cross-sections by the naked eye may be "false rings". [9]

The width of an annual growth ring depends on conditions during its formation: in a favorable year, a ring is wider, and in a less favorable year it is narrower. [10]

Applications

Herbchronology is used in many fields of ecological and biological research, for instance in community ecology, population biology, plant ecology and invasion biology.

Herbchronology is used as a tool to estimate plant age. This may be relevant information to determine :

Herbchronology allows to assess long-term annual growth rates of a perennial herbaceous plant without having to monitor it. This may be relevant information to assess …

Related Research Articles

<span class="mw-page-title-main">Wood</span> Fibrous material from trees or other plants

Wood is a structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fiber.

<span class="mw-page-title-main">Dendrochronology</span> Method of dating based on the analysis of patterns of tree rings

Dendrochronology is the scientific method of dating tree rings to the exact year they were formed in a tree. As well as dating them, this can give data for dendroclimatology, the study of climate and atmospheric conditions during different periods in history from the wood of old trees. Dendrochronology derives from the Ancient Greek dendron, meaning "tree", khronos, meaning "time", and -logia, "the study of".

<span class="mw-page-title-main">Xylem</span> Water transport tissue in vascular plants

Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of the xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word xylem is derived from the Ancient Greek word ξύλον (xylon), meaning "wood"; the best-known xylem tissue is wood, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858.

<span class="mw-page-title-main">Root</span> Basal organ of a vascular plant

In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the surface of the soil, but roots can also be aerial or aerating, that is, growing up above the ground or especially above water.

<span class="mw-page-title-main">Phloem</span> Sugar transport tissue in vascular plants

Phloem is the living tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as photosynthates, in particular the sugar sucrose, to the rest of the plant. This transport process is called translocation. In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Ancient Greek word φλοιός (phloiós), meaning "bark". The term was introduced by Carl Nägeli in 1858. Different types of phloem can be distinguished. The early phloem formed in the growth apices is called protophloem. Protophloem eventually becomes obliterated once it connects to the durable phloem in mature organs, the metaphloem. Further, secondary phloem is formed during the thickening of stem structures.

<span class="mw-page-title-main">Bark (botany)</span> Outermost layers of stems and roots of woody plants

Bark is the outermost layer of stems and roots of woody plants. Plants with bark include trees, woody vines, and shrubs. Bark refers to all the tissues outside the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner bark, which in older stems is living tissue, includes the innermost layer of the periderm. The outer bark on older stems includes the dead tissue on the surface of the stems, along with parts of the outermost periderm and all the tissues on the outer side of the periderm. The outer bark on trees which lies external to the living periderm is also called the rhytidome.

<span class="mw-page-title-main">Vascular cambium</span> Main growth tissue in the stems, roots of plants

The vascular cambium is the main growth tissue in the stems and roots of many plants, specifically in dicots such as buttercups and oak trees, gymnosperms such as pine trees, as well as in certain other vascular plants. It produces secondary xylem inwards, towards the pith, and secondary phloem outwards, towards the bark.

<span class="mw-page-title-main">Herbaceous plant</span> Plant that has no persistent woody stem above ground

Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials.

<span class="mw-page-title-main">Perennial plant</span> Plant that lives for more than two years

A perennial plant or simply perennial is a plant that lives more than two years. The term is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widely used to distinguish plants with little or no woody growth from trees and shrubs, which are also technically perennials.

The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants.

<span class="mw-page-title-main">Vessel element</span> Component of Xylem

A vessel element or vessel member is one of the cell types found in xylem, the water conducting tissue of plants. Vessel elements are found in angiosperms but absent from gymnosperms such as conifers. Vessel elements are the main feature distinguishing the "hardwood" of angiosperms from the "softwood" of conifers.

<span class="mw-page-title-main">Secondary growth</span> Type of growth in plants

In botany, secondary growth is the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips of stems and roots, causing them to elongate, and gives rise to primary tissue. Secondary growth occurs in most seed plants, but monocots usually lack secondary growth. If they do have secondary growth, it differs from the typical pattern of other seed plants.

Important structures in plant development are buds, shoots, roots, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born, it has all its body parts and from that point will only grow larger and more mature. However, both plants and animals pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification.

<span class="mw-page-title-main">Lepidodendrales</span> Extinct order of vascular tree-like plants

Lepidodendrales or arborescent lycophytes are an extinct order of primitive, vascular, heterosporous, arborescent (tree-like) plants belonging to Lycopodiopsida. Members of Lepidodendrales are the best understood of the fossil lycopsids due to the vast diversity of Lepidodendrales specimens and the diversity in which they were preserved; the extensive distribution of Lepidodendrales specimens as well as their well-preservedness lends paleobotanists exceptionally detailed knowledge of the coal-swamp giants’ reproductive biology, vegetative development, and role in their paleoecosystem. The defining characteristics of the Lepidodendrales are their secondary xylem, extensive periderm development, three-zoned cortex, rootlike appendages known as stigmarian rootlets arranged in a spiralling pattern, and megasporangium each containing a single functional megaspore that germinates inside the sporangium. Many of these different plant organs have been assigned both generic and specific names as relatively few have been found organically attached to each other. Some specimens have been discovered which indicate heights of 40 and even 50 meters and diameters of over 2 meters at the base. The massive trunks of some species branched profusely, producing large crowns of leafy twigs; though some leaves were up to 1 meter long, most were much shorter, and when leaves dropped from branches their conspicuous leaf bases remained on the surface of branches. Strobili could be found at the tips of distal branches or in an area at the top of the main trunk. The underground organs of Lepidodendrales typically consisted of dichotomizing axes bearing helically arranged, lateral appendages serving an equivalent function to roots. Sometimes called "giant club mosses", they are believed to be more closely related to extant quillworts based on xylem, although fossil specimens of extinct Selaginellales from the Late Carboniferous also had secondary xylem.

<span class="mw-page-title-main">Woody plant</span> Plant that produces wood and has a hard stem

A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposed to herbaceous plants that die back to the ground until spring.

<span class="mw-page-title-main">Plant stem</span> Structural axis of a vascular plant

A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, photosynthesis takes place here, stores nutrients, and produces new living tissue. The stem can also be called halm or haulm or culms.

<i>Rorippa austriaca</i> Species of flowering plant

Rorippa austriaca is a species of flowering plant in the family Brassicaceae known by the common names Austrian yellow-cress and Austrian fieldcress. It is native to parts of Europe and Asia, and it is known in North America as an introduced species and sometimes a noxious weed. It can grow in disturbed habitat, such as roadsides, and in very wet habitat such as mudflats. It is a perennial herb growing upright to erect, reaching a maximum height near one meter. The branching stem bears hairless blue-green lance-shaped leaves up to 10 centimeters long. The bases of the upper leaves clasp the stem. The inflorescence is a raceme at the top of the stem and the ends of stem branches. The mustardlike flowers have small yellow petals. The fruit is a plump silique a few millimeters long, but many plants do not fruit and seed production is rare. Reproduction in this species is more often vegetative, the plants concentrating their growth in belowground tissue and spreading clonally. The root system of the plant is particularly aggressive, sending up many new plants as it spreads.

<span class="mw-page-title-main">Cambium</span> Layer of plant tissue with cells for growth

A cambium, in plants, is a tissue layer that provides partially undifferentiated cells for plant growth. It is found in the area between xylem and phloem. A cambium can also be defined as a cellular plant tissue from which phloem, xylem, or cork grows by division, resulting in secondary thickening. It forms parallel rows of cells, which result in secondary tissues.

Fritz Hans Schweingruber was a Swiss dendrochronologist and emeritus professor.

<span class="mw-page-title-main">Karl Gustav Sanio</span>

Karl Gustav Sanio was a Prussian botanist and served as a professor of botany at the University of Königsberg. He observed patterns in the growth of plant vasculature and wrote several articles on the organization of wood and cambium. He examined patterns in the size distribution of the xylem vessels in five statements known as Sanio's laws was also among the first to describe the formation of compression wood by conifers.

References

  1. 1 2 3 Dietz H, Schweingruber FH (2002). "Annual rings in native and introduced forbs of lower Michigan, USA". Canadian Journal of Botany. 80 (6): 642–649. doi:10.1139/b02-048.
  2. 1 2 von Arx G, Dietz H (2006). "Growth rings in the roots of temperate forbs are robust annual markers". Plant Biology. 8 (2): 224–233. doi:10.1055/s-2005-873051. PMID   16547867. S2CID   17849550.
  3. Schweingruber FH, Poschlod P (2005). "Growth rings in herbs and shrubs: life span, age determination and stem anatomy". Forest Snow and Landscape Research. Bern: Haupt: 195–415. ISSN   1424-5108.
  4. 1 2 3 von Arx G, Edwards PJ, Dietz H (2006). "Evidence for life history changes in high altitude populations of three perennial forbs". Ecology. 87 (3): 665–674. doi:10.1890/05-1041. PMID   16602296. S2CID   26567998.
  5. 1 2 Dietz H, Ullmann I (1998). "Ecological application of 'Herbchronology': Comparative stand age structure analyses of the invasive plant Bunias orientalis L.". Annals of Botany. 82 (4): 471–480. doi:10.1006/anbo.1998.0706.
  6. Petersen HE (1908). "Diapensiaceae". Meddelelser Am Gronland. 36: 141–154.
  7. Zoller H (1949). "Beitrag zur Altersbestimmung von Pflanzen aus der Walliser Felsensteppe". Bericht über das Geobotanische Forschungsinstitut Rübel in Zürich: 61–68.
  8. Bakshi TS, Coupland RT (1960). "Vegetative propagation in Linaria vulgaris". Journal of Botany. 38 (2): 243–249. doi:10.1139/b60-022.
  9. Werner PA (1978). "On the determination of age in Liatris aspera using cross-sections of corms: implications for past demographic studies". The American Naturalist. 112 (988): 1113–1120. doi:10.1086/283350.
  10. 1 2 Dietz H, von Arx G (2005). "Climatic fluctuation causes large-scale synchronous variation in radial increments of the main roots of northern hemisphere forbs". Ecology. 86: 327–333. doi:10.1890/04-0801.
  11. Dietz H (2002). "Plant invasion patches - reconstructing pattern and process by means of herb-chronology". Biological Invasions. 4 (3): 211–222. doi:10.1023/a:1020971509871.
  12. Moloney KA, Knaus F, Dietz H (2009). "Evidence for a shift in life-history strategy during the secondary phase of a plant invasion". Biological Invasions. 11 (3): 625–634. doi:10.1007/s10530-008-9277-3.