thesis

Influenze ambientali sull'accrescimento radiale nella quercia da sughero

Abstract

The purpose of this study is to contribute to the knowledge of the effects of the climatic trends on the cork oak system and to furnish a base of prediction models related to the wood growth. The area of the study is located in the centre of Sardinia. The area covers an overall surface of 9 Km2 for the statistic analysis and of 25 Km2 for the simulation. We have collected the measures of trees with diameter at breast height between 15 and 30 cm. The statistic analysis has concerned: 1) the classification of the statistic variables; 2) the treatment of the satellite images MODIS for the extraction of space- temporal variables related to temperatures at ground level, the water content and the mass vegetation; 3) the definition of the samples with a high possibility of error; 4) Annealing simulation for the optimization of the model and of data. Finally we have create one prediction model for a vast area. The Pearson correlation of show that the average increases of a sample group of trees are tightly tied to thermometric trend. The analysis with geo-statistics technique has brought to verify that there is a clear correlation with the content of water, with the daytime temperature, and with the biomass. While the increases, on the other hand, are negatively correlated with the night-temperatures and the EVI. The results of the simulations have brought, finally, to the possibility to build prediction maps with annual, biennial and cumulative scale

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