Phytosociology

various schools of phytosociology

the Swedish school of sociations (HULT 1881, SERNANDER, Uppsala: RIETZ 1920,1930,1954), still used nowadays in Fennoscandie.

the English school of predominance (SMITH 1898,1899, CHIP 1927, TANSLEY 1946).

the American school of the climax (LENIENT 1905,1916,1928) to which are attached the charts of the series of vegetation (Toulouse: GAUSSEN 1933), and documents for the chart of the vegetation of the Alps of OZENDA.

the school free-Switzerland sigmatist (Zurich, Montpellier SIGMA: BRAUN-BLANQUET 1913,1928,1951,1964) to which the charts of GUINOCHET (1956) and LEMEE (1959) are attached.

the Swiss school of the synusies (RÜBEL 1917, GAMS 1918).

the American school of the continuum (GLEASON 1926,1939, CURTIS & MAC INTOSH1951, CURTIS 1959, MAC INTOSH 1967,1968).

the Russian school of the phytogéocénoses (SUKACHEV 1929,1954, ALECHIN 1932,1935, LAVRENKO 1938).

the Estonian school unistrate (LIPPMAA 1931,1933,1934,1935).

the Belgian school of the groups socioecologic (Paul DUVIGNEAUD 1946), to which work of PASSARGE (1964) is attached.

the French school of the statistical ecological groups (Montpellier BOLETUS: GOUNOT 1969, GADROON 1967,1971, DAGET 1968).

the French school of phytosociology synusiale integrated (Lille, Neuchâtel: JULVE 1985, OF FOUCAULT 1985, WAISTCOAT 1985,2000, WAISTCOAT, OF FOUCAULT & JULVE 1991), which draws its roots in work of LIPPMAA, GAMS and BRAUN-BLANQUET.

These schools differ:

by their concepts, in particular of the basic units (association, sociation, individualistic concept…), chosen by a phytocenotic approach synusiale or,
by the different importance allotted to predominance, the constancy and the fidelity of the species, the stratification, the dynamics of the vegetable groupings,
by their techniques of ground (raised, quadrats of constant size, sampling randomly or stratified…),
by their methods of synthesis and modeling.

Floristic systematic phytosociology - sociology of the plants

Phytosociology exists because the plants, like all the living organisms, do not live in an isolated way. Indeed, the plant species live associated between them (and with animals, mushrooms, protists, bacteria…), according to several aspects:

an aspect known as static , joining together the parameters Abiotic S of the medium (light, heat, moisture…).
an aspect known as of succession , where the ecosystems (structured by vegetable groupings) follow one another in different stages to arrive to a homeostatic climax .
an aspect of interactions , which takes account of the many relations between species: biotic interactions (predation, parasitism, co-operation, mutualism, symbiosis, competition…), abiotic interactions (shade, intoxication, fertilization…).

It is Josias Braun-Blanquet which made prevail the floristic aspect rather than the shape (or aspect) of the plants, like principal criterion of determination of vegetable associations considered. According to his method, one considers samples of grounds to the uniform biotopes, where the species are distributed in a repetitive way. One then draws up a list semi-quantified of the species present on a surface seeming floristiquement homogeneous, higher than the minimal surface of the groupings considered. The choice of the form and the size of the zone raised depends on the type of vegetation considered. By surface floristiquement homogeneous, one understands a surface where the list of species does not vary, independently of the more or less aggregate distribution of the individuals.

One considers also the cover respective of the species according to two criteria:

abundance-predominance: surface occupied by each plant specie in proportion of the entire surface occupied by the whole of the plants of the raised zone,
sociability: are distribution of the individuals of each species present on the whole of the sample of ground - regularly dispersed, or appear according to a particular reason for distribution?

The second criterion tends to be nowadays abandoned.

The various taken botanical readings are then compared the ones with the others in order to determine their degrees of similarity: several species always finding whole in a certain biotope, one manages to incorporate several statements for finally forming phytosociological units homogeneous floristiquement. One can then compare the groups of statements with those of similar biotopes located in more distant, or close but entirely different areas.

Phytosociological classification of the vegetations

The phytosociologists of the 20th century built a system of hierarchical classification (syntaxinomy) similar to that of the traditional classification (idiotaxinomy). The vegetable associations form the basic unit, and are gathered by similarities in alliances. The closest alliances in their floristic structure are grouped in orders, themselves grouped in classes. Each level of this hierarchy is called " syntaxon" (by analogy with the Idiotaxons of the system of classification of the organizations).

A vegetable association is named starting from or of the names of kind of one or two characteristic species present, to which one adds a suffix (in fat below) different according to whether one speaks about a class, an order, an alliance or a vegetable association:

Class (suffix - etea ): Querco-Fag' etea (leafy forests of the moderate climates dominated by the Oaks and the Beech);

Order (suffix - etalia ): Fag etalia (leafy forests of the climates moderate cold with Hêtre, Fagus sylvatica );

Alliance (suffix - ion ): Fag ion (hêtraie and mountain close associations);

vegetable Association (suffix - etum ): Abi eto' - Fag' etum (hêtraie with fir trees of medium mountains).

The possible sub-units carry specific suffixes: - etosum for under-association, - enion for under-alliance, - enalia for the sub-order, - enea for the subclass.

Physiognomical classification of the vegetations

A different approach, based on the aspect of the vegetable groupings can also be carried out. One then considers above all the biological types of the dominant species in a given place. The unit considered here becomes the vegetable Formation, a concept formulated since 1838 by August Grisebach. The formations are inserted they also in a hierarchical system, illustrated here on three examples:

This model tends to being forsaken with the profit of the system of phytosociological classification itself, of floristic nature, because this last details the various species present rather than to refer mainly to the total aspect. Out, the knowledge of the species includes the knowledge of the aspect, whereas the reverse is not true.

Interest of phytosociology in ecology

Phytosociology is interested in the description but also in the ecological and botanical operation of the vegetations, on various scales (of the Synusie S with the zonal Biome S). The comparative analysis of the vegetable groupings met on the ground makes it possible to define abstract categories (for example vegetable associations).

Phytosociology makes it possible to study the abiotic relations of the vegetations with the Climat, the grounds and the local Géomorphologie as well as the biotic relations with the other vegetable communities, the animal communities and the human society. Thus, the recognition of the vegetable groupings reveals in a more precise way local ecological operations, the bioindication of the communities being the intersection of the ecological valences of all the species the component.

Cartography of the vegetations

The characterization of the vegetations rests on floristic inventories carried out according to precise standards. The objective being to describe the diversity of the world vegetations and to allow the comprehension of the functional bonds between the communities of plants and the natural environments or artificial.

The use of charts for the space representation of the phytosociological units allows a precise study of the ecological conditions of the medium and distribution of the plant species. According to the scale, one will choose the suitable level of unit of vegetation, and one will represent it on the charts: phytosociological or physiognomical charts, charts of the formations, the types of biotopes, the forest resources, the agronomic values, etc

Study of the indicators and the ecological groups

Phytosociology can be used for the bioindication. Certain plants are " indicators biologiques" certain types of grounds (acidiphile, limestone, wet, sandy, etc). According to the system introduced by Heinz Ellenberg, the ecological behavior of a botanical species is described by an indicator including/understanding from 9 to 12 classes for each paramount ecological factor. These indicators specify certain variables of the environment like the light, the temperature, the continentality, the moisture of the ground, the pH, the quantity of nutrients in the ground, salinity. By " indication biologique" one must hear several possible levels of bioindication: qualitative presence-absence, quantitative importance of the populations, hereditary physiological modifications, temporary physiological adaptations.

Phytosociology and dynamics of the vegetations

Under the concept of dynamics of the vegetations one gathers all the quantitative and qualitative modifications vegetable associations during time: seasonal modifications phenologic, multiannual fluctuations of the vegetation, cyclic modifications, due in particular to the invasions of parasites, the autogenous or alien successions (series of vegetation).

The use of the phytosociological method with various time intervals on the same site allows the analysis of the fluctuations or the evolution of the vegetation. This evolution can thereafter be explained by the effect of internal phenomena (autogenous) or external (aliens) to the ecosystem considered. These phenomena can find their origin in human actions, climate changes, cicatrizations, like afterwards after a fire, etc).

Classes of vegetations in France

There exist several classifications of the vegetations, which for some define phytosociological classes properly (categorization CATMINAT ), for others are based on these classifications by considering a broader categorization, like Corine Biotope , which “to take into account the importance of fauna and the role of the communities in façonnement of the landscape, and to grant a place suitable to the more anthropogenic or zoogenic types of habitat, built-in a broad proportion of references to physical shapes, integrated nonsignificant ecosystems and facies phytosociologiquement” .

Classes CATMINAT

As the article Phytosociologie synusiale indicates it, the typology CATMINAT (Catalog of the Natural environments) “is a permanent program setting for objective the description of the natural environments of the Metropolitan France and its margins, from a phytosociological synusiale and hierarchical point of view”. It defines 16 primary keys of determination which are declined in one or more secondary keys.

First keys of determination

01/: Oceanic and littoral marine water with watery vegetation primarily algale.

To reach the detail of the key of determination secondaries

02/: Maritime littoral with air vegetation, supporting salt, sometimes episodically submerged.

To reach the detail of the key of determination secondaries

03/: Continental with sublittorales, soft water with brackish, in tablecloths free and levelling, of the lakes, ponds, ponds, rivers and rivers, of natural origins or created by the man.

To reach the detail of the key of determination secondaries

04/: Wetlands more or less amphibious, of the edges of lakes, ponds, of rivers, various sources and depressions, with low herbaceous vegetation more or less scattered, not recovering completely the ground.

To reach the detail of the key of determination secondaries

05/: Wetlands, sometimes amphibious, of the edges of lakes, ponds, rivers, rivers, torrents, sources, depressions various, with high herbaceous vegetation (roselières, cariçaies, mégaphorbiaies), recovering generally completely the sol.
(see also the 06/" Tourbières" for trembling of colonization of the edges of boggy lakes) .

To reach the detail of the key of determination secondaries

06/: High peat bogs, peat bogs low and trembling, meadows tourbeuses.
(see also the 05/3.2.1 for the watery cariçaies, the cladiaies and roselières of the peats with neutral pH and the 14/4 and 14/5 for the moors with chaméphytes) .

To reach the detail of the key of determination secondaries

07/: More or less vertical walls of the walls and nonmarine rocks; fall.

To reach the detail of the key of determination secondaries

08/: Horizontal rock flagstones and more or less stabilized sands, zones with very surface grounds generally of low trophic level and supporting the dryness.

To reach the detail of the key of determination secondaries

09/: Lawns, steppes and hems developed on grounds rich in calcium, dry, rather surface and generally low in nitrogen.

To reach the detail of the key of determination secondaries

10: Lawns, hems and long-lived grasses of the forest cuts on acid grounds.

To reach the detail of the key of determination secondaries

11: Permanent lawns of the stages alpine to subalpine.

To reach the detail of the key of determination secondaries

12: Meadows eurosibériennes of the nitrogen rich person grounds fairly rich, undergoing varied husbandries (fertilization, amendment, mowing, pasture, fallow, sowing…).

To reach the detail of the key of determination secondaries

13: Cultures, waste lands, forest cuts with disturbed grounds, more or less ruderalized places, and natural zones of similar ecological natures (feet of cliffs, hems dune…). Trophic enrichment is related to the animals, with the actions of the man, the symbiotic nitrogen fixing, or active mineralization in the ground consecutive with the breaks and the increase of sheet of water.

To reach the detail of the key of determination secondaries

14: Moors and garrigues with woody hardy perennials (sub-shrubs chamephytic of a few decimetres height).

To reach the detail of the key of determination secondaries

15: Shrubby hedges, halliers, fruticées, maquis, matorrals, bushes, pre-coats and coats external and of forest cuts (shrubby edges), often linear but sometimes in space tablecloths, or more or less burst, made up of shrubs and shrubs.

To reach the detail of the key of determination secondaries

16: Arborescent vegetations and herbaceous intraforestières, of the forests, arborescent wood and thickets.

To reach the detail of the key of determination secondaries

The classes Corine Biotope

The article which to him is devoted recalls it, “ Corine Biotope is a typology of the natural habitats and semi-natural present on the European ground. The program led in 1991 to the proposal for an arborescent typology on six levels maximum, based on the description of the vegetation” . Hereafter, principal classes and scondaires.

Classes Corine primary educations and secondaries

1 - littoral and halophilous Habitats

11 - Seas and oceans
12 - Arm of the sea
13 - Estuaries and rivers tidales (subjected to tides)
14 - Vasières and sand banks without vegetations
15 - salted Marais, meadows salted (salt meadows), salted steppes and lined on gypsum
16 - Coastal dunes and sand beaches
17 - Pebble beaches
18 - maritime rock Côtes and cliffs
19 - Ilots, benches rock and reefs

2 - nonmarine Aquatic environments

21 - Lagoons
22 - stagnant Fresh water
23 - Stagnant water, brackish and salted
24 - Running water

3 - Moors, fruticées, lawns and meadows

31 - Landes and fruticées
32 - Fruticées sclerophyllous
33 - Phryganes
34 - dry calcicoles Pelouses and steppes
35 - dry silicicolous Pelouses
36 - alpine and subalpine Pelouses
37 - wet Meadows and mégaphorbiaies
38 - Meadows mésophiles

4 - Forests

41 - caducifoliées Forests
42 - Forests of conifers
43 - mixed Forests
44 - bordering Forests, very wet forests and thickets
45 - nonresinous Forests sempervirentes

5 - Peat bogs and marshes

51 - Peaty high
52 - Peaty of cover
53 - Vegetation of belt of the edges of water
54 - Low-marsh, peat bogs of transition and sources

6 - continental Rocks, fall and sands

61 - Falls
62 - exposed continental Cliffs and rocks
63 - Snows and eternal ices
64 - continental sandy Dunes
65 - Caves
66 - the Communities of the volcanic sites

8 - arable Lands and artificial landscapes.

81 - improved Meadows
82 - Cultures
83 - Orchards, thickets and plantations of trees
84 - Alignments of trees, hedges, glazing bar, scrap-metal, parks
85 - City parks and large gardens
86 - Cities, villages and industrial sites
87 - Grounds in waste land and waste grounds
88 - Mines and underpasses
89 - industrial Lagoons and tanks, channels

See too

:Category: Phytosociology

Phytosociologues

Bruno of Foucault
Emile Castle
Josias Braun-Blanquet
Heinz Ellenberg
Philippe Julve
François Waistcoat
Marcel Guinochet

External bonds

Introduction to phytosociology (Internet site of Tela Botanica)
Course of phytosociology - Part data analysis
" Écosystème" by Patrice Francour. A very good site of introduction on close ecology, phytosociology and concepts.
a synthetic page on the classification CATMINAT maintained by Philippe Julve.

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