Réponses écotoxicologiques aux stress abiotiques induits par une pollution atmosphérique particulaire chez Pinus halepensis Mill. et Cupressus sempervirens L.

Abstract

This work focuses on the study of the potential impact attributed to the release of dust particles from a cement factory, on the metabolic mechanism of conifers, in five sampling stations, under natural conditions in the periphery of Constantine, in Algeria. Three biochemical parameters are selected : Chlorophylls and Proline and soluble Sugars contents. The selected species showed great sensitivity to continuous exposure. Qualitative analyzes by Raman spectroscopy and X-ray diffraction for dust samples collected on the needles are performed in order to identify the substances responsible for the observed changes. These characterization tools made it possible to determine locally the different phases present. The chemometric treatment of the spectral data was able to identify major products (CaCO3, K2CO3, C2S and C3S) and other minority products (TiO2 and CaO), most of them being cement derivatives. The SIMPLISMA method is used to extract spectra of pure compounds from the complex chemical species found in the mixture and associated concentration profiles. The particles constraints of the environment have a decisive influence on the situation of the trees, with highly significant variations in the metabolites content. The chlorophyll levels vary significantly between stations, the reduction observed at the station near the cement factory is 78,84% for Cupressus sempervirens and 90,84% for Pinus halepensis. Concerning Proline, the responses of plants are slightly variable. However, for the accumulation of soluble Sugars, the pollution constraints vary considerably and appear to be related to environmental conditions.