Claudia Guidi has received the EGU Outstanding Student Poster (OSP) Award for her presentation “Changes in SOC stocks and fractions after natural afforestation of alpine grasslands“.
Who is Claudia?
Claudia is a PhD student at the University of Copenhagen, Denmark and at Fondazione Edmund Mach, Italy. She obtained her MSc degree in Agricultural Sciences at the University of Pisa and at the Scuola Superiore Sant’Anna, Pisa, where she was holder of a full scholarship.
Soil organic carbon changes after forest expansion on mountain grasslands
In the Alps and Mediterranean mountains, forest area is currently increasing, due to an abandonment of agricultural marginal areas. Land-use change can induce significant alterations in soil organic carbon (SOC) stocks, causing C sequestration or CO2 release, having therefore an impact on global warming. While an accumulation of SOC in the forest floor is common after woody expansion on grassland, the impact on the mineral soil is still unclear.
With our research activity, we want to identify potential changes in soil organic carbon, looking both to the stock of organic carbon in soil and to the different fractions which compose the total organic carbon.
To achieve this goal, we compared four land uses (managed grassland, abandoned grassland, natural afforestation and a reference forest), located in a pre-Alpine area in Trentino (Italy). To assess changes in SOC stocks, we sampled soils to a maximum depth of 30 cm and we determined bulk density, stoniness, root biomass and organic carbon content.
In order to detect changes in the different SOC fractions, we performed an aggregate size fractionation and a size-density fractionation procedure.
Our preliminary result shows no significant change in total soil organic carbon stocks among land uses, but an overall improvement in soil aggregation in forested sites compared to grassland ones.
SOC becomes stored mainly in large macroaggregates following afforestation: this can be probabily due to a different rooting system between grassland and forest ecosytems.
Moreover first results of size-density fractionation suggest that with grassland afforestation there is there is a shift from stable to more labile SOC pool, such as an increase of carbon stored in the particulate organic matter fraction.
Our results underline the importance of fractionation analysis to identify changes in soil organic carbon with land use change. No change in total organic carbon does not mean that there is not modification in organic carbon. The organic carbon can be allocated to different fractions, therefore becoming more or less stable against disturbance.
You can contact Claudia at:
- E-mail: firstname.lastname@example.org
- Sustainable Agro-ecosystems and Bioresources Department, IASMA Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige, Italy