Aplicação de uma análise de clusters na relação entre as temperaturas de fogo e libertação de solutos em algumas espécies Mediterrâneas

Abstract

The aim of this work is the application of a cluster analysis, to study the behaviour and variability of released solutes, Calcium (Ca), Magnesium (Mg), Sodium (Na), Potassium (K), Aluminium (Al), Manganese (Mn), Iron (Fe), Zinc (Zn), Silicium (SiO2), Phosphorous Pentoxide (P2O5), pH and electrical conductivity (EC) from the litter ash slurries of three Mediterranean species, Quercus suber (QS), Quercus robur (QR) and Pinus pinea (PP) throughout a temperature gradient (150º, 200º, 250º, 300º, 350º, 400º, 450º, 500º e 550ºC) in laboratory environment. The results showed the relation between temperatures is different for each species. Three groups were formed in each tree diagram, although the temperatures that compose the clusters are different from species to species. The first group was classified as being of reduced impact, the second of average impact and the third of higher impact. The temperatures present the most variable impact in PP litter and the less in QS litter. It can be observed that the variability and impacts in the produced ash slurries is more substantial and heterogeneous, after 400ºC in Q.S. and 350ºC in QR and PP especially evident in the last species. This variability on the behavior, could have implications on the impact of prescribed fire or wildland fire on water quality, that are higher and heterogeneous with rising temperatures of exposition.