Characterization of plant communities: Mentha, Origanum and
Thymus plants in the central easter region of Portugal
Nunes, M.J. (1); Matos, A. (1); Malho, S. (1) & Caldeira, R. (1)
(1)
Escola Superior Agrária de Castelo Branco. Quinta da Sra. de Mércoles. Apartado 119.
6001-909 Castelo Branco. Portugal. Tel: +351 272 33 99 00. Fax: +351 272 33 99 01.
E-mail: [email protected]
The main aim of the present work was the characterisation of plant communities
including the genera Mentha, Origanum and Thymus, in different places of the counties
of Penamacor and Idanha-a-Nova, in the central eastern region of Portugal.
The field sampling was stratified because the areas were sought bearing in mind
the likely abundance of the above mentioned species. Five floristic inventories of each
smaller area within the two counties under study were drawn up. The inventory
methodology used with abundance-dominance indices was developed by BraunBlanquet.
The inventory of the plant communities were compiled using the Global Position
System (GPS). The data was analysed using the software package Geographic
Information System (SIG) ArcView 3.2. The results obtained were used to draw a map
of the inventories location was drawn.
A cluster analysis was made, with SPSS 10.0 for Windows. This software package
groups the species in different communities and characterises them according to
dissimilarity degrees (distance). This was shown in a dendogram. The results obtained
in the 86 floristic inventories were use (CANOCO for Windows 4.0) to determine
species distribution in relation to environmental factors. That is, a multivariate
ordination analysis consisting of the canonical correspondence analysis (CCA) was
made.
After the cluster analysis ten different type of plant communities were defined.
It was observed, using multivariate ordination analysis, that both habitat and
Potassium (K2O) values are the environmental factors which influence species
distribution the most.
Keywords: Classification, plant communities, Mentha, Ordination, Origanum and
Thymus.
Maria Raquel Bento Rainho Caldeira
Escola Superior Agrária de Castelo Branco
Quinta da Senhora de Mércoles
Apartado 119
6001-909 Castelo Branco
Tel: 00351272339900
Fax:00351272339900
e-mail: [email protected]