Natural zonal vegetation of the Azores Islands: characterization and potential distribution

Abstract

Aims: To present a statistically based classification of Azorean natural zonal vegetation; (2) to characterize
\nthe main features of this vegetation and (3) to present the first model of its potential distribution in the nine
\nAzorean Islands. Study area: Azores (São Miguel, Pico, Terceira and Flores islands). Methods: Information
\nfrom 139 plots set up in the best preserved vegetation patches was used. Ward’s agglomerative clustering method
\nwas applied in order to identify community types. Potential distribution of these community-level entities
\nwas modeled in relation to climatic predictors, using MAXENT. Results: Eight vegetation belts were identified:
\nErica-Morella Coastal Woodlands, Picconia-Morella Lowland Forests, Laurus Submontane Forests, Juniperus-
\nIlex Montane Forests, Juniperus Montane Woodlands, Calluna-Juniperus Altimontane Scrublands, Calluna-
\nErica Subalpine Scrublands and Calluna Alpine Scrublands. Modeling results suggest that
\nPicconia-Morella and Laurus forests (Laurel forests) are the potential dominant vegetation in the Azores. With
\nthe possible exception of Juniperus woodlands, Pico could have all vegetation types, in contrast with Santa
\nMaria, Graciosa and Corvo with only three. Conclusions: Most of Azorean natural vegetation has been transformed
\nor degraded by human action, with a greater impact on Laurel forests. The best preserved vegetation
\nbelts are located above 600 m a.s.l., including Juniperus-Ilex Forests and Juniperus Woodlands, perhaps the only
\nexample of island montane cloud forests existing outside the tropics. In the present work, for the first time we
\nused a statistical method to classify zonal vegetation, gave it a bioclimatic foundation and applied it to the whole
\narchipelago, thus defining and describing the main vegetation belts of the Azores. This work also gives the first
\npotential distribution maps of the zonal vegetation for each island. This information may be used for landscape
\nplanning and management, selection of sites and species for ecological restoration and evaluation of climate
\nchange effects.