Figure 2From: Forest observational studies-an essential infrastructure for sustainable use of natural resourcesLocation of the permanent forest observational sites in the pine-oak forests of Durango and some statistics of the 429 (50 × 50m) fiel plots of the Durango observational of the 429 (50 × 50m) fiel plots of the Durango observational network. The number of tree species recorded within the plots vary from 1 to 13 (average 7).Back to article page