The Intensive Monitoring of Forest Ecosystems (ICP-Forests Level II network) consists currently in 14 monitoring plots representing important Spanish Forest Ecosystems distributed throughout the Spanish mainland showing the most common forest situations of each country and representing rare or endemic situations.

The plot 37 Ppr represents a Pinus pinaster forest located in the Castilian region. It is a 41 to 60 years old monoespecific regular forest. The tree layer covers one third of the plot area. Climatic gradient is Supramediterranean. The plot is located on siliceous sands. The soil is poor.