Modeling distribution of Mediterranean beech forests and soil carbon stock under climate change scenarios

Climate change is forecasted to alter forest species distributions and the organic carbon cycle, particularly in the Mediterranean region. In this context, one of the most important carbon reservoirs, both in terms of living biomass and soil organic matter, is represented by beech forests, which are highly vulnerable to global warming. Accordingly, we investigated how the effects of climate change predicted for 2070 could affect both beech distribution and soil carbon stocks in Italy. In order to achieve this goal, we predicted beech distribution using state of the art ecological niche modeling, projecting its potential range under climate change scenarios. Moreover, a field survey was carried out to quantify the proportion of organic carbon in the first 5 cm of soil, which are the most sensitive to climate effects. The latter results were used to explore the relationship between organic carbon and ecogeographical variables, projecting this relationship onto the predicted beech distribution. Our outcomes showed a substantial reduction in beech distribution, especially at its southern range limits, along with a remarkable shift towards higher elevations and latitudes. The organic carbon in beech forests was significantly related to temperature seasonality and elevation, showing a decrease between 64.5 and 98.8% under different IPCC scenarios.