Effects of soil-landscape features on organic carbon storage along soil profiles in a forest area of Calabria (southern Italy)

Carbon (C) storage in farest soils is of great importance both to farest ecosystems and to~ reduce C02 in atmosphere. Knowledge of spatial pattern of soil organic carbon (SOC) and itsintluencing factors in different soil-landscapes are essential far understanding global C cycle.The main objective of the study was assessing C stock at profile scale in a farest area ofCalabria region and analyzing the relationship between C stock and some soil-landscapefeatures. .~The present study was carried out within the project LIFE09 ENV /IT /078 "Managing farests1far multiple purposes: carbon, biodiversity and socio-economie wellbeing" (ManFor C.BD.).· The study area (33.2 hectares) was a farest beech located in the Biogenetic Nature Reserve"Marchesale" in Calabria (Serre Massif, southern Italy). It has a mean elevation of about 1,180m a.s.l. and is geologically characterized by Palaeozoic granitoid rocks deeply fractured,· weathered and frequently covered by a thick regolith and/ or colluvial deposits. Themorphology of the study area is dominated by a mountains landscape with deep, V-shaped· valleys and summit Paleosurfaces representing the remnants tlat or gentlyrsloping highlands,often sharply separated by steep slopes.Soils belong to Inceptisol and Entisol orders and are from very shallow to moderately deepwith chemical and physical properties mainly controlled by granitic parent rock. Twenty-sixsoil profiles were selected to be representative of all soil types and physiographic units of thestudy area. In the 26 profiles, each horizon was sampled and analyzed far some chemicalphysicalproperties (SOC, total nitrogen, bulk density, texture and pH). Moreover, the organichorizon (O) was sampled and SOC concentration was determined. Finally, the C stock alongthe soil profiles was calculated.SOC of minerai horizons ranged from 9.1 g kg-1to132.3 g kg-1 with a mean value of 49.5 g kg-1.In the O horizon, SOC ranged from 217.0 to 369.8 g kg-1 with a mean value of 281.4 g kg-1. Themean value of total C stock far all the profiles was 171.0 Mg ha-1. The mean C stock was 4.7 Mgha-1 far the organic horizons and 166.3 Mg ha-1 far the minerai horizons. Both soil types andlandscape features controlled C stock dynamic across the soil profile with higher valuesrecorded in tlat areas than on steep slopes. C stock was typically lower far Entisols located onconvex slope and relatively higher far Inceptisols, along slopes with concave morphology. Thesoil-landscape features of the study area represent a baseline to evaluate the horizontal andvertical variability of the C stock. Moreover, the results obtained might be further used for asustainable management of forest land, which in Calabria cover a great portion of the regi on.