摘要:

Thiérache is a small natural region with a bocage and forest landscape which takes up the north-eastern corner of department Aisne. Forest vegetation has been studied according to the synusial phytosociological methodology. In this last part the author presents the phytosociological data for hygrophilous forests. Two arborescent associations, three schrubby associations and eight herbaceous associations with their synfloristic and synecological characteristics are described. The main phytocœnosis are then reconstructed.

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515393

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The author studies vicariance phenomena in mire vegetation between Hokkaido (Japan) and Europe. Tables of unpublished data are also shown.

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515394

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The stations and ecological indicatory value of the plant communityLandolphio—Lecaniodiscetum cupanioidishave been studied in the natural undergrowth of teak plantations of Djigbé forest in south Benin. The main results show that the association occures on reddish non hydromorphic clay soils slightly acidic to neutral (pH 6 to 7,3). Its soils are associated with low slopes (5% on the average). The association is linked to the stations presenting the largest risks of windthrow (30% on average), by reason of the shallow depth of the large roots (50 cm on the average). The main factor which controls the extent of the windthrow is the presence of clay horizon in the first 40 cm of the soil.

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515395

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The actual distribution of three nitrophilous therophytes,Chenopodium rubrum, Ch. glaucumandAtriplex prostrata, that are extending on the lower course of Loire and Allier, is presented. It is supplemented by an arrangement of floristical and ecological data taken from floras and herbarium specimen. The study reveals a connection between their multiplication and some soil parameters. At twenty ecologically similar study sites, distributed all along the two rivers, populations of the three species were investigated quantitatively and seven physicochemical parameters were mesured. Three soil parameters, pH, electric conductivity and carbonate show some correlations with the biomass of the three plants, both increasing from the upper to the lower parts. High values for electric conductivity in the lower part of the Loire river are interpreted as a strong sign for hypertrophication. The spread of these plants, reputed as indicators of eutrophication and water pollution, thus ecological degradation, is taken as a signal of alarm, which needs further supervision.

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515396

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The total species number (Sp) of a group of genera and the size (G) of this group are in a relation of the form Sp = S.Gc, where c is a constant (= 1,3) in chorologic or systematic groups. Frequency distribution of species numbers among endemic genera is hyperbolic with F = k/N (F = frequency, N = genus size, and k = number of monotypic genera). The values of k are a function of the area of the considered territory. The mean species number of disjunct genera is higher than that of endemic ones. Their frequency distribution is hyperbolic only for the greatest genera and shows a lack of small ones, this lack being more significant with the age of the areal connection break.

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515397

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The author presents a new crop weed association growing on limy soils in northern France. This association is characterized byFumaria densifloraandPapaver hybridum;these weed taxa are very little quoted in phytosociological reports and are particularly developped in northern France. This syntaxon belonging toStellarietea mediaecomes betweenKickxietum spuriaeKrus. & Vlieg.-type syntaxa, described from northern Europe, andAdonidetum-type syntaxa (Caucalido—Adonidetum flammeaeTx. andAdonido—Iberidetum amarae(All.) Tx.) from southern- or easternmore areas. Parallel variations have been brought to the fore between sub-associations presented here and those ofKickxietum spuriaeKrus. & Vlieg.

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515398

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515399

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515400

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:1253-8078    

DOI:10.1080/12538078.1999.10515392

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor