REGESOL: a diagnostic tool for forest soil improvement by liming.

In the 1980s, the acid rain phenomenon and the risk of forest decline revived the problems of forest soil fertility. To understand the phenomenon and to rectify it, research scientists used old fertilizationimprovement trials installed in the 1970s and new calcium and/or magnesium trials were set-up. Today, these trials form the liming-fertilization network. In parallel, to study the biogeochemical cycles and the mineral element inputs and outputs of forest ecosystems in depth, these experimental sites have been highly instrumented and monitored intensively and at present are integrated into SOERE F-ORE-T. The liming-fertilization network, linked with studies of biogeochemical cycles, has resulted in great improvements in our knowledge about the restoration of mineral fertility by liming in deteriorated forest ecosystems.