In collaboration with French and Belgian researchers, I wrote an article on the evolution of Norway spruce vitality in the Ardennes (crown condition, radial growth, foliar nutrition) in relation with the temporal change in acid and eutrophying deposition. To reconstruct temporal trends, we put together different data sets, including data collected in level II plots of monitoring. I think it is a good example of what can be done with monitoring data. The article is available here:

Jonard et al. 2012 GCB.pdf