Strawberry tree biophysical units’ ecology to design provenance regions in Portugal using GIS tools

Abstract

Strawberry tree (Arbutus unedo L.) displays potential to be successfully businesslike cultured in several regions of Portugal and southern Europe, where it is well adapted to climate and soils. In Portugal, this species has been used by local populations for fruit consumption and spirit production, but remains largely a neglected crop. It has different possible commercial uses, since processed and fresh fruit production to ornamental, pharmaceutical and chemical applications, due to the phenolic acids and terpenoid compounds with strong antioxidant activity, vitamin C and tannin content. In addition, due to its pioneer status, it is valuable for land recovery and desertification avoidance, besides being fire resistant. Currently, the demand for improved plants has strongly increased. Under the project ARBUTUS (PTDC/AGR-FOR/3746/2012, Arbutus unedo plants and products quality improvement for the agro-forestry sector) 30 trees were selected, in 15 natural populations distributed throughout the country. The stands were ecologically characterized locally, using bioclimatology, lithology, topography, soil type, vegetation and wildfires records, as biophysical units. The data processed was the digital elevation model (DEM), the soil maps, the annual burnt areas since 1975, and the phytosociological and biogeographical maps. In parallel, the climatological data were collected (1981-2010) from various weather stations and bioclimatological indices maps, constructed by Monteiro-Henriques (2010), in order to calculate bioclimatic indices, using geostatistical tools. An exploratory multivariate statistical approach was performed with the collected information: principal component analysis (PCA) and hierarchical cluster analysis (HCA). The obtained information will be used for the provenance regions design in order to select plus trees and for tree species genetic improvement purposes, besides forest tree conservation programs design.