%0 Journal Article %T The effects of post-pasture woody plant colonization on soil and aboveground litter carbon and nitrogen along a bioclimatic transect %A La Mantia T %A Gristina L %A Rivaldo E %A Pasta S %J iForest : Biogeosciences and Forestry %D 2013 %I Italian Society of Silviculture and Forest Ecology (SISEF) %R 10.3832/ifor0811-006 %X We investigated the effects of woody plant colonization of abandoned pastures on soil and litter organic carbon (C) stocks and nitrogen (N) content along a bioclimatic transect in a semi-arid environment (Sicily, Italy). Soil samples were taken in three successional stages (grazed pasture, shrubland, forest) within each of three bioclimates (supramediterranean - ˇ°supraˇ±, mesomediterranean - ˇ°mesoˇ±, thermomediterranean - ˇ°thermoˇ±). Organic C and N in litter and soil (0-10 cm and 10-30 cm depth) were determined, as well as soil bulk density. Especially at 0-10 cm depth, changes in C and N contents along successional stages differed among bioclimates. Soil organic carbon (SOC) stock decreased from pasture to shrubland and increased from shrubland to forest in ˇ°supraˇ±, increased from pasture to shrubland and then remained stable in ˇ°thermoˇ±, and was stable in ˇ°mesoˇ±. Soil C/N ratio decreased with succession in ˇ°supraˇ±, showed no significant trend in ˇ°mesoˇ±, and increased with succession in ˇ°thermoˇ±. Litter C stock increased with succession in ˇ°mesoˇ±, increased from pasture to shrubland and decreased from shrubland to forest in ˇ°thermoˇ±, and increased from pasture to shrubland and then remained stable in ˇ°supraˇ±. Litter C/N ratio increased in ˇ°thermoˇ± and ˇ°supraˇ± from pasture to shrubland and from shrubland to forest, but did not change significantly with succession in ˇ°mesoˇ±. The different trends in SOC among bioclimates may be caused by changes in the importance of litter input, litter decay rate and mineralization. Successional changes in ˇ°mesoˇ± and ˇ°supraˇ± appeared to be most affected by litter quality, while those in ˇ°thermoˇ± appeared to be strongly influenced by limited litter decay due to low soil moisture and high temperature. %K SOC Change %K C/N Ratio %K Secondary Succession %K Mediterranean %U http://www.sisef.it/iforest/contents/?id=ifor0811-006