Portugal - Atlas do Ambiente VII.8 - Laurissilva da Madeira

Summary

We present a general characacterization of the distribution area of laurissilva and some brief historical references, as well as data obtained by a study done at the laurissilva forest, in Madeira Island. This study was carried out by a team of researchers belonging to the following institutions : the Natural Park of Madeira, Botanic Garden of Madeira and Regional Directorate of the Environment, with support from Regional Directorate for The Forests. The field work was developed between December 1992 and May 1995. The metodology chosen was “the closest neighbour method “ which was considered the best for our purposes. The area covered with the laurissilva forest was defined with precision. Extremely important data was obtained such as density, dominance, frequency and weight of the various elements of the laurissilva floristic composition. In order to systematise the data collected the forest was subdivided in 18 different units, which boundaries were defined by relief lines or significant topographic features. There were collected 1,155 samples, from which one 176 are merely descriptive points. A qualitative analysis of this forest, was carried out at each of those points, using both the researchers expertise and the information collected during the field work. This enabled us to evaluate the conservation state of this formation. A final discussion of the main conclusions draws the attention to the necessity of intervention at specific areas, and points out the importance of