Global distribution of Pistacia with focus on the Mediterranean species – remote sensing and GIS analyses

Environmental conditions are the limiting factors for vegetation development. It is hypothesized that changes in global distribution of plant species over geological periods reflects the climatic changes over time. This relationship is potentially useful in prediction of the most suitable areas for forestation. Changing climate can force sufficient plant species to migrate into more suitable areas, therefore global or regional climate change episodes are consequently followed by various distribution patterns of flora. Forests play an integral part in carbon and water cycles, they provide timber, food and other products, and they are home to a vast diversity of plants, animals and microorganisms. Forests occur in a wide range of climatic conditions, thus it is challenging to predict how the vulnerability of trees to changes in water availability and temperature compares between different biomes. The focus in this study is on the genus Pistacia and the Mediterranean forest species P. atlantica, P. lentiscus, P. terebinthus and P. palaestina. Geographically distinctive species of the genus occur in between 4 ° S - 50 ° N latitudinal belt. Unique regional division of groups of species is a viable feature to investigate the global environmental variations and migratory pathways of plants as well as to characterize regional climate and changes of wooded lands. The regional distribution of species of the genus extrapolated into the global scale in relation to different climate zones was done by analysis of remote sensing and Geo-statistics. Geostatistical with corresponding spatial and climate analyses showed limited distribution centers of the genus by various environmental parameters. Probability distributions, result of Global distribution models using climate, landscape and soil parameters in the present, past and future periods showed migration pathways according to the climate change, contributing to the process of reforestation and conservation of Pistacia genus. Additionally, biochemical composition of leaf and bark of the trees appeared to be an appropriate variable for species classification in phylogenetic clusters. There was high correlation between the first derivative of the spectral reflectance of specific portions of the reflectance spectrum and biochemical content in the plants. Also, variation within the phenology cycle appeared to be a significant factor for classification of species when up-scaling the data from hyper-spectral to multispectral resolution. They showed not only distinctive classes of the different species but also phylogenetic patterns.