Author(s):
Capelo, J. 
; Mesquita, S. ; Costa, J.C. ; Arsénio, P. ; Neto, C. ; Monteiro-Henriques, T. ; Aguiar, C. ; Honrado, J. ; Espírito Santo, M.D. ; Lousã, M.
Date: 2007
Persistent ID: http://hdl.handle.net/10400.5/5401
Origin: Repositório da UTL
Subject(s): natural potential vegetation; phytosociology; expert-knowledge; GIS modelling; Portugal
Description
An attempt to obtain a consistent spatial model of natural potential vegetation
(NPV) for the mainland Portuguese territory is reported. Spatial modeling procedures
performed in a Geographic Information System (GIS) environment, aimed to operationalize
phytosociological expert-knowledge about the putative distribution of potential zona1
forest communities dominam in the Portuguese continental territories. The paradigm for
NPV assumed was that of RIVAS-MARTINE(1Z9 76) and RIVAS-MARTINEeZt al. (1999),
which presupposes, for a given territory, a univocal correspondence between a uniform
combination of bioclimatic stage and lithology' gi ven a biogeographical context, and a
unique successional sequence leading to a single climax community (i. e. a vegetation series
(VS)). Information issued from both literature and a team of phytosociologists possessing
detailed knowledge about Portuguese vegetation, namely about forests and its seria1 vegetation,
was acknowledged as a starting point for the construction of such a habitat-vegetation
correspondence model. First, a bioclimatic map concerning the "Worldwide Bioclimatic
Classification System" (WBCS) of RIVAS-MARTINE(1Z9 81 -2004), obtained by multivariate
grostatistical interpolation issuing from the work of MESQUITA(2 005), was set.
Severa1 partia1 matrices, one for each biogeographical Province, combined such habitat
statements to VS. Initial incoherence due to vagueness of statements led to an important
amount of both superimposition of VS and habitat gaps in the matrices. Further rearrangement
of the table according to known field distribution of VS by experts allowed
setting an approximate univocal correspondence VS-habitat. Finally, an intersection of
bioclimatic, lithology and biogeographic maps yielded over a thousand habitat combinations
to be associated each to a single VS through implementation of the matrices as a set
of rules. Again, inconsistencies were solved likewise, but this time by direct observation
of the map by experts. Keeping of phytosociological consistency and fidelity to information
on actual vegetation field distribution was always mandatory during the process
