Porto Conte, IT

Site location and background
The Italian site is located in the Peninsula of Capo Caccia at NW Sardinia, within the Nature Reserve Porto Conte Capo Caccia (40°36'N 8°9'E). The Nature Reserve covers approximately 1200 ha between the coast line (a cliff with a maximum height of 300 m a.s.l) and Monte Timidone (a 360 m tall hill).

 Roofs and view at Capo Caccia

The most frequent geologic substrate of the area is represented by Mesozoic rocks with calcareous outcrops with dolomites. The most common soils are Luvi and Litosoils, neutral, with depth hardly exceeding 20-30 cm.

The climate is semi-arid with a remarkable water deficit from May through September and a mean annual rainfall amount of 640 mm. The mean annual temperature value is 16.8 °C. Maximum and minimum air temperatures result milder due to sea vicinity (10 °C in January and 24 °C in August). Even winter season can be dry and temperature not so low to determine vegetation break.

Four different vegetation types can be easily identified: a quite recent forestation area of Pine (Pinus pinea and Pinus halepensis), the Mediterranean macchia, a Quercus ilex forest and the garigue, located near the cliff and dominated by small bushes and tiny herbaceous plants growing between emerging rocks.

The experimental site is located in a typical Mediterranean gariga, a short shrubland formation re-colonizing soil after disturbance (fires, cutting, grazing). The nine experimental plots (25 m2 each) are located in a firebreak strip realised in 1973 and cleared regularly by controlled fire until 1990. In 1991 and 1992, the firebreak strip was cleared mechanically and from 1993 a natural recolonization process started without any other disturbance.

The plots are now covered by a sclerophyllous vegetation with a 1 m maximum height, including semideciduous shrub species as Cistus monspeliensis, Dorycnium pentaphyllum and Helichrysum italicum (more scattered Cistus incanus, Daphne gnidium and others); evergreen scattered shrubs as Pistacia lentiscus and Rosmarinus officinalis; herbaceous plants as Carlina spp., Asphodelus spp., Brachipodium ramosus, Ammoidespusilla and othres. The degree of vegetation cover is about 80% of the plot surface.

Climate change manipulations
The experimental design consists of a warming treatment and a drought treatment. The microclimatic manipulation is obtained by covering automatically the plots during night by an IR-reflective material (warming) or during rain events by a plastic material (drought). The nine experimental plots were installed in June 2001. The site is unique in Europe for the study of the impacts of climate changes on the semi-arid Mediterranean coastal environment.

Research activities and research ideas
The research activities in Porto Conte are in the frame of ecology in a wide sense: from plant ecophysiology to soil biology. Data on plant phenology, community growth and structure, plant water relations, plant and soil nutrient status, soil processes and CO2 effluxes on a different time basis (weekly, monthly, seasonally) are currently collected. Furthermore,  air temperature, soil temperature and water content are continuously monitored on a half-hour basis in each plot since the starting of the infrastructure (summer 2001).

The results obtained until now showed a high resilience of this type of community to the climate drivers (temperature and drought), partly because it is already adapted to extreme values but also associated to the avoidance of the stressful summer season, thanks to the semideciduous habit. Nevertheless, an anticipation of the summer drought period produced sensible changes on the community functions. On the other hand, the long-term adaptation to the new simulated climate conditions remain an open question that could be the objective of new research activities in this infrastructure.

Specific hot questions are related to the litter decomposition during the drought period, change and functioning of soil microbial community during the hot and drought summer, changes on the vegetation succession under climate alteration, soil structure and erosion.

Other facilities offered
The Laboratories of Forest Ecophysiology of the Department of Forest Environment and Resources (DISAFRI) of the University of Tuscia (Viterbo, Italy), has developed a large experience in the fields of tree and forest ecophysiology, forest-atmosphere exchanges, plant-soil interactions, impacts of climate changes and forest management on productivity and ecological processes of native forest ecosystems and plantations forestry.

The laboratory has also a wide array of scientific instrumentations for measuring:

  • leaf gas exchanges (Li-Cor 6400, USA; CMS 400 Walz, D; ADC-LCA4, UK)
  • soil CO2 effluxes (Li-8110, USA; PP-Systems, UK)
  • in vivo leaf fluorescence (PAM 101 e PAM 2000 Walz, D)
  • C & N elemental determinations (Thermo, USA)
  • plant water status (Corvallis, USA, Skye UK)
  • microenvironment measurements (Campbell, Skye, Decagon)
  • anopy attributes as LAI and light quality (Ceptometer Decagon, USA; LAI-2000 Li-Cor, USA; Red-Fared sensor Skye, UK).

Moreover, the laboratory is equipped with vacuum pumps, large growth chambers, freezer (-20 °C) and ultra freezer (-80 °C), ultra precise balance and typical consumables for chemistry and biology.

An additional laboratory is already available for the preparation of samples (vegetable and soil), by electronic controlled mortar and grinding.

The on-site team
The on-site team for Porto Conte includes Prof. Paolo De Angelis, Dr. Giovanbattista De Dato and the PhD students Gabriele Guidolotti and Dario Liberati.

For more information
Please, contact Paolo De Angelis - email pda@unitus.it Dept. of Forest Environment and Resources DISAFRI, University of Tuscia, Via San Camillo de Lellis, 01100 Viterbo, Italy. Tel. +39 0761 357 292; Fax +39 0761 357 389.

Team at Capo Caccia