Vztah Mezi Obsahem Nízkomolekulárních Organických Kyselin v Půdách a Bohatostí Bylinného Patra Karpatských Bučin

Abstract

Low molecular mass organic acids (LMMOA) are a part of the carbon cycle, and represent an important component of the active organic carbon in soil. The aim of this study was to determine the content, speciation and behavior of LMMOA in soils under Carpathian beech forest with different herb vegetation (herb poor, herb rich), and to assess the relationship between herb vegetation cover and LMMOA. We hypothesize, that LMMOA can infl uence herb vegetation richness through their (LMMOA) ability to release nutrients in forests soils. Speciation of LMMOA, nutrition content (PO43-, Ca2+, K+) and element composition in aqueous extracts were determined by means of ion chromatography and inductively coupled plasma – optical emission spectrometry (ICPOES) respectively. Sorption characteristics were determined in BaCl2 extracts by ICP-OES. Active, exchangeable pH and DOC (dissolved organic carbon) were also determined. Elemental composition of parent rocks was assessed by means of X-ray fluorescence spectroscopy. It was found that, on herb poor localities with higher LMMOA contents, the elements complexation and their further transport into the deeper parts of soil profile happens. There is also an increased dissolution of alumosilicates. And conversly, lowercontents of LMMOA were determined on herb rich locality, leading to nutrients mobilization but not to their leaching. The soil sorption complex is not enriched by Al3+ as there is not increased weathering of aluminosilicates. The result of this study is a diagram showing the influence of LMMOA on vegetation cover richness.