Carbon flux and climate change effects on Capo Caccia karst ecosystem (Sardinia, Italy)

The assessment of carbon sequestration or release in the terrestrial ecosystems is crucial for understanding carbon cycling processes. Since carbon dioxide plays a key role in karst processes, it has to be taken into consideration when studying gas exchanges among atmosphere, biosphere, and geosphere. Even though karst areas have been recently used to determine the contributions of multiple carbon sink (dissolution) or source (deposition), geological processes have not been sufficiently addressed yet in global carbon cycle model. After a short summary on cave microclimatology, its atmosphere dynamic and subsurface-atmosphere-biosphere gas exchanges, this work illustrates Eddy Covariance tower and cave micrometeorological data with the purpose of assessing the correlation between meteorological variables and carbon dioxide concentration in the shrubland karst ecosystem of Capo Caccia (North-West Sardinia, Italy). The preliminary results show that the ecosystem physiological features depend not only on surface and soil environmental conditions but also on environmental forcing related to underground voids.