The Yatir Research site was set up in 2000 at the center of the Yatir Forest, a 2'800 ha afforestation system of mainly P. halepensis trees, and is located on the southern end of the Hebron mountain range and at the northern edge of the Negev desert (31° 20’ N; 35° 3’ E; elevation 600 to 850 meters above sea level). Most of the area was planted during the 1960s-1970s. The site is located in the transition zone between the semi-arid and arid Mediterranean climates. Average air temperature for January and July is 10 and 25°C, respectively. Mean annual potential ET is 1600 mm, and mean annual precipitation is 285 mm. Only winter precipitation occurs in this region, creating a distinctive wet season (winter, December to March) and an extended dry season (summer, June to October), with short transition periods between them: a wetting season (autumn) and a drying season (spring). Research in the site mainly focuses on ecophysiology and ecohydrology, energy, carbon and water budgets, influence of stand density (through manipulation experiments), boundary layer dynamics and ecosystem interactions with the climate.