Biohemijski sastav stelje i njen uticaj na stvaranje organskog horizonta zemljišta u sladunovo-cerovoj šumi na planini Maljen

Abstract

This research focused on the biochemical composition of organic matter and its change during the process of decomposition in natural conditions of the local climatic community of Quercetum farnetto-cerris Rudski (1940) 1949 s.lat. The experiment was conducted on leaf fall of edificators in this forest, i.e. Hungarian and bitter oak and a combination of the two, material analysed at three time spans (following leaf fall, after six months and after one year). The aim of this research was to determine the value of each of the above mentioned edificators for the ecosystem functioning as well as their impact in the formation of soil organic horizon. In addition to biochemical content analysis, concentrations of C, N, C:N ratio and lignin:N ratios in organic matter were analyzed. In tandem with these examinations (at three time spans) concentrations of soil humus were also determined (0-10cm 10-20cm, and 20-30cm) aimed at comprehending their time distribution. It transpired that Hungarian oak organic matter had a more favourable ratio of readily-soluble matter and resistant matter, as opposed to the bitter oak organic matter. This fact directly influenced decomposition altitude of examined species: Hungarian oak (51.25%), Hungarian and bitter oak (48.33%) and bitter oak (28.52%). On the basis of an empirically obtained annual constant (k), Oslon decomposition model was designed to give a prognosis of decomposition to the state of almost complete mineralization. The humus time analysis in this community indicated degradation processes within.

Na osnovu obavljenih istraživanja mogu se izvesti sledeći zaključci. Postoji statistički potvrđena razlika u brzini razlaganja između organske materije sladuna i cera, kombinacije sladuna i cera i same organske materije cera. Relevantni parametri dekompozicije (C, N i odnos C:N) su potvrdili razliku u razlaganju. Organska materija sladuna imala je presudnu ulogu u metabolizmu ove zajednice u prvoj godini istraživanja, dok će organska materija cera (zahvaljujući svom rezistentnijem biohemijskom sastavu) imati presudnu ulogu u budućim fazama dekompozicije. Za skoro potpunu mineralizaciju (99%) organskog opada ove zajednice biće potrebno oko 7.7 godina. Organski otpad edifikatora ekosistema sladuna i cera razlaže se u opsegu karakterističnom sa listopadne šume umerene zone. Vremenska analiza količine humusa je ukazala na ozbiljnost degradacionih procesa u ovoj zajednici i na narušenost balansa između procesa mineralizacije i humifikacije organske materije zemljišta koja ce se u bliskoj budućnosti odraziti na produktivnost ovog šumskog staništa.