The experimental watershed Bonis

The experimental watershed "Bonis" is located in the mountain area of Sila Greca (39°25'15''N, 16°12'38''W), Calabria, Italy, at an elevation ranging between 975 and 1300 m a.s.l.. Almost 93% of the total area (139 hectares) is covered by forest stands, dominated by about 50-years-old Calabrian pine (Pinus laricio Poiret) forests, whose origin is artificial and, secondarily, natural. Also small stands of chestnut (Castanea sativa Mill.) and riparian forests of common alder (Alnus glutinosa L.) are to be added.
The catchment is provided since 1984 with three mechanical, 20-minutes-span recording rain gauges. They are placed at the outlet (975 m a.s.l.) and at the watershed left side (1175 m a.s.l.) and right side (1258 m a.s.l.), respectively. At the outlet, there is also a runoff gauge.
Since 1994, in two sample plots covered by different density pine stands, investigations on rain interception, surface runoff and solid yield are carried out. Both plots are 150 m2 large, lies at the elevation of 1090 m a.s.l., have a slope of 30% and faces East.
Furthermore, experiments aiming at assessing the impact of different fire intensity have been conducted in 1999 in three 1000 m2 plots.
Recently, researches have been undertaken on the water use efficiency and the carbon balance in forest ecosystems in collaboration with the Dipartimento di Scienze dell'Ambiente Forestale e delle sue Risorse, University of Tuscia (Vt), and the IBAF-CNR of Porano (Tr). The following equipment have been installed:
1) tower for micrometeorological and ecophysiological measurements (height 24 m, width 1.2 x 2 m);
2) 4 solar panels (two 110W and two 70W);
3) 4 batterie (6V, 240Ah);
4) instruments for CO2 and H2O exchange measurements, including:
- fast answer gas analyser LiCor 7000 (LiCor, USA)
- sonic anemometer CSAT - 3 (Campbell, USA)
- 11 l min-1"brushless" pump (KNF, D)
5) Data Logger CR5000 (Campbell, USA), to record high frequency (10 Hz), eddy covariance and micrometeorological data;
6) micrometeorological sensors measuring:
- net radiation (Middleton, USA)
- photosynthetically active radiation (LiCor, USA)
- air temperature and humidity (Micros, Italy)
- two depths soil temperature (Micros, Italy)
- soil heat fluxes
- soil water content at 0-30 cm depth (CS615 Campbell, USA).
The station was installed at the end of May 2003 and started recordings on June, 1st 2003