Summary: | The seasonal variation and the soil texture effect were evaluated in the phenolic contents (FolinCiocalteu) of Quercus sideroxyla ( red oak) leaves as a parameter of the genus deterioration. Leaves of six trees from eight sites were sampled and their edaphic characteristics determined as soil texture: clayed (12,5%), lime-clayed (75%) and clay-sandy (12,5%). Soils and sites were unaltered during the four season collections. It was found in spring a notorious decrease in phenolic content of Quercus leaves followed by a substantial increase during summer. A high positive correlation was found between phenolic content of leaves and electric conductivity of clay-sandy soils, and also between soil moisture retention and phenolic content, independently of the soil texture.
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