Phytosociology

Phytosociology is the branch of science which deals with plant communities, their composition and development, and the relationships between the species within them.[1] A phytosociological system is a system for classifying these communities.

History

Rooted in phytogeography and as such considered sometimes a field of geobotany, phytosociology emerged simultaneously in Poland (Paczoski), France (Braun-Blanquet) and Sweden (Du Rietz), but hardly penetrated in Anglo-Saxon world, where prevailed the continuum concept of community, opposed to the concept of plant associations.[2]

The term "phytosociology" was coined in 1896 by Paczoski.[3]

Classificatory traditions

There are five classification schools in phytosociology:[4]

Overview

The aim of phytosociology is to achieve a sufficient empirical model of vegetation using plant taxa combinations that characterize univocally vegetation units. Vegetation units as understood by phytosociologists may express largely abstract vegetation concepts (e.g. the set of all hard-leaved evergreen forests of western Mediterranean area) or actual readily recognizable vegetation types (e.g. cork-oak oceanic forests on Pleistocene dunes with dense canopy in SW-Iberian Peninsula). Such conceptual units are called "syntaxa" (singular "syntaxon") and can be set in a hierarchy system called "synsystem" or syntaxonomic system. The act of creation, amelioration or adjusting the synsystem is called "syntaxonomy". Therefore, the syntaxonomic system is putatively a sufficient empirical representation of vegetation of a given territory. An International Code of Phytosociological Nomenclature, issuing the rules for naming "syntaxa" exists and its use has increased among vegetation scientists.[25]

Association model

The basic unit of syntaxonomy is the "association". The association is a conceptual model of a concrete phytocoenosis (the plant component of a biocoenosis). The association is defined by its characteristic combination of plant taxa, habitat features, physiognomy, biogeographical area, role in ecological succession, historical (e.g. history of use by humans) and paleo-biogeographical relationships. Associations with floristic and territorial affinities can be grouped in larger ecological conceptual units (i.e. syntaxa) called "alliances". Similar alliances may be grouped in "orders" and orders in vegetation "classes". The setting of syntaxa in such a hierarchy makes up the syntaxonomical system, or the reference model of the given vegetation and territory.

In spite of early attempts (e.g. Charles Flauhault in the late 19th century), this science started in Europe, with the Swiss botanist and ecologist Josias Braun-Blanquet (1884–1980).

Vegetation complexes

Nowadays, phytosociologists try to include higher levels of complexity in the perception of vegetation, namely by describing whole successional units (vegetation series) or, in general, vegetation complexes. These lie in the scope of Landscape Phytosociology. Other developments include the use of multivariate statistics for the definition of "syntaxa" and their environmental interpretation.

On the one hand, some authors consider phytosociology to be in the scope of contemporary vegetation science, a successful approach because of its highly descriptive and predictive powers, and its usefulness in nature management issues. On the other hand, there are numerous critics who have focused on several methodological limitations: the absence of statistical approaches, the complexity and non-stability of the nomenclatural system, the mistakes in the predictive models, and certain basic assumptions.

Habitat-type classification

Even if in continental Europe, a complete synsystem describing vegetation types has been developed and it is a basis for habitat-type classification (e.g. NATURA 2000 typology and habitat network), there are numerous scientific experts who do not have a positive opinion about the suitability for phytosociology to be the main geobotanical approach for managing vegetation systems. An important point of disagreement is the floristic-phytosociological assumption that the forest patches of the Mediterranean species of pines mainly derived from afforestations, non-stables and incidentals.

Data collections

Phytosociological data contain information collected in relevés (or plots) listing each species cover-abundance values and the measured environmental variables. This data is conveniently databanked in a program like TURBOVEG[26] allowing for editing, storage and export to other applications.

Data is usually classified and sorted using TWINSPAN[27] in host programs like JUICE to create realistic species-relevé associations. Further patterns are investigated using clustering and resemblance methods, and ordination techniques available in software packages like CANOCO[28] or the R-package vegan.[29]

See also

References

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  1. ↑ Oxford English Dictionary
  2. ↑ Decocq, G. (2016). Moving from Patterns to Processes: A Challenge for the Phytosociology of the Twenty-First Century? In: Box, E. O. (Ed.). Vegetation Structure and Function at Multiple Spatial, Temporal and Conceptual Scales. Springer. pp. 407-424, .
  3. ↑ Rabotnov TA. 1970-1979. Phytocoenology. In: The Great Soviet Encyclopedia, 3rd ed.
  4. ↑ Sharma, P. D. (2009). Ecology and Environment. Rastogi: Meerut, p. 140-142, .
  5. ↑ Humboldt, A. von & Bonpland, A. 1805. Essai sur la geographie des plantes. Accompagné d'un tableau physique des régions équinoxiales fondé sur des mesures exécutées, depuis le dixiéme degré de latitude boréale jusqu'au dixiéme degré de latitude australe, pendant les années 1799, 1800, 1801, 1802 et 1803. Paris: Schöll, .
  6. ↑ Humboldt, A. von (1806). Ideen zu einer Physiognomik der Gewächse. Tübingen: Cotta, . English translation as Ideas for a physiognomy of plants, pp. 210-352 in Views of nature: or Contemplations on the sublime phenomena of creation by E.C. Otté and Henry G. Bohn (1850). London: H.G. Bohn, .
  7. ↑ Rübel, E.F. (1922). Geobotanische Untersuchungsmethoden. Gebrüder Borntraeger, Berlin, .
  8. ↑ Rübel, E.F. (1930). Pflanzengesellschaften der Erde. Bern-Berlin: H. Huber, .
  9. ↑ Pavillard, J. (1927). Les Tendances Actuelles de la Phytosociologie. Arch. Bot. Bull. Mens. 6: 89–112.
  10. ↑ Schröter, C. & Kirchner, O. 1886–1902. Die Vegetation des Bodensees. Stettner, Lindau, DE, .
  11. ↑ Flahaut, C. & Schröter, C. (1910). Phytogeographische Nomenklatur. Berichte und Worschläge. IIIe Congrès International de Botanique, Bruxelles, 14–22 mai. Zürcher & Furrer, Zürich, CH.
  12. ↑ Braun-Blanquet, J. (1932). Plant sociology; the study of plant communities. New York and London, McGraw-Hill, .
  13. ↑ von Post, Hampus (1842). Några ord till Fäderneslandets yngre Botanister. Bot. Not. 1842: 97-107, .
  14. ↑ Hult, Ragnar (1881). Försök till analytisk behandling af växtformationerna ("Attempt at an analytic treatment of plant communities"). Meddelanden af Societas pro Fauna et Flora Fennica, 8, pp. 1–155. Doctoral dissertation (University of Helsinki). Full text.
  15. ↑ Fries, T.C.E. (1913). Botanische Untersuchungen im nördlichsten Schweden. Ein Beitrag zur Kenntnis der alpinen und subalpinen Vegetation in Torne Lappmark. Akademische Abhandlung. Vetenskapliga och praktiska undersökningar i Lappland. Flora och fauna Nº 2, p. 1-361, .
  16. ↑ Du Rietz, G.E. (1921). Zur methodologischen Grundlage der modernen Pflanzensoziologie. Akadem. Abh. Upsala (Thesis, Uppsala), 272 pp.
  17. ↑ Sukachev, V.N. (1929). Über einige Grundbegriffe in der Phytosoziologie. Ber. Deutsch. Bot. Gesell. 47: 296–312.
  18. ↑ Cowles, H. C. (1899). The ecological relations of the vegetation on the sand dunes of Lake Michigan. Bot. Gaz. (Chicago) 27: 95–117, 167–202, 281-308, 361-369; Dissertation, .
  19. ↑ Cowles, H. C. 1901. The physiographic ecology of Chicago and vicinity. Botanical Gazette 31: 73–108, 145–82.
  20. ↑ Cowles, H. C. 1901. Plant Societies of Chicago and Vicinity. Bulletin of the Geographic Society of Chicago. no. 2, .
  21. ↑ Clements, F.E. (1905). Research Methods in Ecology. Lincoln, Neb.,University Pub. Co., .
  22. ↑ Clements, F.E. 1916. Plant Succession. Publication 242, Carnegie Institute, Washington, DC.
  23. ↑ Clements, F.E. 1916. Nature and structure of the climax. Journal of Ecology 24: 252–284.
  24. ↑ Tansley, A.G. (Ed). 1911. Types of British Vegetation: by Members of the Central Committee for the Survey and Study of British Vegetation. Cambridge University Press. Cambridge, .
  25. ↑ Weber, H E; Moravec, J; Theurillat, J-P (Oct 2000). "International Code of Phytosociological Nomenclature". Journal of Vegetation Science. Uppsala, Sweden: Blackwell Publishing. 11 (5): 739–768. JSTOR 3236580.
  26. ↑ Hennekens SM, Schaminée JHJ (2001) TURBOVEG, a comprehensive data base management system for vegetation data. Journal of Vegetation Science 12: 589-591
  27. ↑ Hill MO (1979) TWINSPAN: A FORTRAN Programme for arranging multivariate data in an ordered two-way table by classification of the individuals and attributes. Ecology and Systematics, Cornell University, Ithaca, NY
  28. ↑ ter Braak CJF, Šmilauer P (2002) CANOCO Reference manual and CanoDraw for Windows User’s guide: Software for Canonical Community Ordination (version 4.5). Microcomputer Power, Ithaca, NY
  29. ↑ Oksanen, J. (2010) (March 11, 2010). "Multivariate Analysis of Ecological Communities in R: vegan tutorial" (PDF). Retrieved April 20, 2010. PDF
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