Phytosociology
Encyclopedia
Phytosociology is the branch of science which deals with plant communities, their composition and development, and the relationships between the species
within them. A phytosociological system is a system for classifying these communities. The term "phytosociology" was coined in 1896 by Józef Paczoski
.
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 forest
s 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.
). 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).
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.
Data is usually classified and sorted using TWINSPAN 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 or the R
-package vegan.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
within them. A phytosociological system is a system for classifying these communities. The term "phytosociology" was coined in 1896 by Józef Paczoski
Józef Paczoski
Józef Konrad Paczoski was an eminent Polish botanist, who coined the term "phytosociology" and was one of the founders of this branch of botany .- Early life :...
.
Overview
The aim of phytosociology is to achieve a sufficient empirical model of vegetationVegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
using plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
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 forest
Evergreen forest
An temperate evergreen forest is a forest consisting entirely or mainly of evergreen trees that retain green foliage all year round. Such forests exist in the tropics primarily as broadleaf evergreens, and in temperate and boreal latitudes primarily as coniferous evergreens.-Tropical evergreen...
s of western Mediterranean
Mediterranean Basin
In biogeography, the Mediterranean Basin refers to the lands around the Mediterranean Sea that have a Mediterranean climate, with mild, rainy winters and hot, dry summers, which supports characteristic Mediterranean forests, woodlands, and scrub vegetation...
area) or actual readily recognizable vegetation types (e.g. cork-oak oceanic forests on Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
dunes with dense canopy in SW-Iberian Peninsula
Iberian Peninsula
The Iberian Peninsula , sometimes called Iberia, is located in the extreme southwest of Europe and includes the modern-day sovereign states of Spain, Portugal and Andorra, as well as the British Overseas Territory of Gibraltar...
). 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.
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 biocoenosisBiocoenosis
A biocoenosis , coined by Karl Möbius in 1877, describes the interacting organisms living together in a habitat . This term is rarely used in English, as this concept has not been popularized in Anglophone countries...
). The association is defined by its characteristic combination of plant taxa, habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
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
Josias Braun-Blanquet
Josias Braun-Blanquet was an influential phytosociologist and botanist. Braun-Blanquet was born in Chur, Switzerland and died in Montpellier, France.-Phytosociology:...
(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 statisticsMultivariate statistics
Multivariate statistics is a form of statistics encompassing the simultaneous observation and analysis of more than one statistical variable. The application of multivariate statistics is multivariate analysis...
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 allowing for editing, storage and export to other applications.Data is usually classified and sorted using TWINSPAN in host programs like JUICE
Juice
Juice is the liquid that is naturally contained in fruit or vegetable tissue.Juice is prepared by mechanically squeezing or macerating fruit or vegetable flesh without the application of heat or solvents. For example, orange juice is the liquid extract of the fruit of the orange tree...
to create realistic species-relevé associations. Further patterns are investigated using clustering and resemblance methods, and ordination techniques
Ordination (statistics)
In multivariate analysis, ordination is a method complementary to data clustering, and used mainly in exploratory data analysis . Ordination orders objects that are characterized by values on multiple variables so that similar objects are near each other and dissimilar objects are farther from...
available in software packages like CANOCO or the R
R (programming language)
R is a programming language and software environment for statistical computing and graphics. The R language is widely used among statisticians for developing statistical software, and R is widely used for statistical software development and data analysis....
-package vegan.
See also
- António Rodrigo Pinto da SilvaAntónio Rodrigo Pinto da SilvaAntónio Rodrigo Pinto da Silva , often referred to as A.R. Pinto da Silva or P. Silva, was a Portuguese botanist who distinguished himself as a taxonomist and phytosociologist when he collaborated with Swiss botanist Josias Braun-Blanquet.His studies on taxonomy and floristic yielded a substantial...
- Victor WesthoffVictor WesthoffVictor Westhoff was a botanist at the Radboud University Nijmegen.Victor Westhoff published 700 scientific papers on phytosociology and conservation, as well as articles on classical music...
- Josias Braun-BlanquetJosias Braun-BlanquetJosias Braun-Blanquet was an influential phytosociologist and botanist. Braun-Blanquet was born in Chur, Switzerland and died in Montpellier, France.-Phytosociology:...
- Józef PaczoskiJózef PaczoskiJózef Konrad Paczoski was an eminent Polish botanist, who coined the term "phytosociology" and was one of the founders of this branch of botany .- Early life :...
- JUICE - program for phytosociologistsJuiceJuice is the liquid that is naturally contained in fruit or vegetable tissue.Juice is prepared by mechanically squeezing or macerating fruit or vegetable flesh without the application of heat or solvents. For example, orange juice is the liquid extract of the fruit of the orange tree...
- Plant community
- PhytogeographyPhytogeographyPhytogeography , also called geobotany, is the branch of biogeography that is concerned with the geographic distribution of plant species...
- BiogeographyBiogeographyBiogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
External links
- International Code of Phytosociological Nomenclature, 3rd edition
- Landscape disagreement with phytosociological theories
- Phytosociology Methods of Ecosystem Analysis, yale.edu
- Technical University of Braunschweig, Working Group for Vegetation Ecology and Experimental Plant Sociology, accessed 20 April 2010