DE MARCO, ANNA

MEOLA A.

RANUCCI S.

VIRZO, AMALIA

English

Archivio della ricerca - Università degli studi di Napoli Federico II

Geophysical Research Abstracts, Vol. 8, 03057, 2006SRef-ID: 1607-7962/gra/EGU06-A-03057© European Geosciences Union 2006Decomposition of leaf litter of Phillyrea angustifolia L.and mixed aboveground litter of herbaceous speciesfrom a mediterranean maquis.A. De Marco, S. Ranucci, A. Meola, A. Virzo De SantoDip. Biologia strutturale e funzionale, Università degli Studi di Napoli Federico II,Complesso Universitario Monte S.Angelo, Via Cinthia, 80126, Napoli-ItalyFax:+39081679233; E-mail: ademarco@unina.itThe Mediterranean shrubland is a mosaic of vegetation types mainly related to fire dis-turbance. The mosaic of shrub and clearings may show different pattern of decompo-sition due to different litter chemical composition as well as to different microclimaticand edaphic conditions.In the low maquis of Castel Volturno Nature Reserve (Southern Italy)Phillyrea angus-tifolia L. is one of the most abundant shrub species while the clearings are covered byannual herbs (Phleum subulatum, Medicago minima, M. litoralis, Melilotus neapoli-tana, Aetheorriza bulbosa, Petrorragia saxifraga, P. velutina, Briza maxima, Dactylishispanica). In this study, decomposition of leaf litter ofPhillyrea angustifoliaL., andof mixed aboveground litter of herbaceous species from the clearings was determinedas weight loss, during 215 days of incubation. In order to highlight the influence oflitter quality the study was performed in laboratory microcosms at 25˚C under notlimiting moisture condition, for. Brown leaves ofPhillyrea angustifoliawere sampledat abscission from the shrubs (between May and July) by shaking the branches; in theclearings aboveground plant material was collected at the end of the vegetative pe-riod (July), in randomized quadrates of 20x20 cm. Microcosms (glass pots, Ø: 12cm;volume: 550 ml) were filled with 5 cm of soil sampled under shrubs of Phillyrea andunder herbaceous plants, respectively; about 10 g of litter were placed on the soil ineach microcosm. Clearings-soil showed values of fungal and microbial biomass loweras compared to shrub-soil. Soil respiration, metabolic quotient (qCO2) and coefficientof endogenous mineralization (CEM) were significantly higher in clearings-soil ascompared to shrub-soil. Clearings-soil was also poorer in Fe, Zn, Cu, Cr, Ni and Pb ascompared to shrub-soil. Herbaceous litter was richer in lignin, cellulose, K, Fe, Mn,Cu, Pb, Cr, Ni and Cd as compared to leaf litter of Phillyrea. Comparing the patternof decomposition, it was evident that litter of clearings decomposed more rapidly thanlitter of Phillyrea. At the end of the study period accumulated mass loss reached 58.4%and 32.5 % of the initial mass, respectively in herbaceous and shrub litter. At any de-composition stage, water holding capacity of herbaceous litter was significantly higheras compared to the litter of Phillyrea, and a significant positive correlation was foundbetween water holding capacity and accumulated litter mass loss. In the herbaceous lit-ter, the absolute amount of lignin decreased since the beginning of the decompositionand a significant negative correlation was found between absolute amount of ligninand accumulated litter mass loss. In the litter ofPhillyrea angustifolia, an increase ofthe absolute amount of lignin occurred during decomposition. Mn, Cu, Fe, K, Cr, Niand Pb were accumulated during decomposition in litter of Phillyrea, while celluloseand Mg were released. In herbaceous litter, cellulose and Mg were accumulated whilethe other elements were released.The data suggest that in the late stage of decomposition, the two types of litter, leaflitter of Phillyrea angustifoliaand aboveground litter of herbaceous species, are char-acterized by a different degree of recalcitrancy. In particular the litter of Phillyrea isricher of recalcitrant organic matter (lignin) as compared to herbaceous litter. This isconsistent with the higher metabolic activity measured in the clearing-soil as com-pared to shrub-soil.

Decomposition of leaf litter of Phillyrea angustifolia L. and mixed aboveground litter of herbaceous species from a mediterranean maquis.

https://www.iris.unina.it/bitstream/11588/343694/1/EGU06-J-03057.pdf

Decomposition of leaf litter of Phillyrea angustifolia L. and mixed aboveground litter of herbaceous species from a mediterranean maquis.

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