A method for monitoring deposited matter in forest ecosystems.

Systematic and elaborate multidisciplinary research of pedunculate oak and common hornbeam began in the Forest Research Institute in Jastrebarsko in 1991. That led to a development of a method for monitoring deposition in forest ecosystems which is now closely related to the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forest. Several forest communities on the territory of Croatia were monitored for Cl-, SO4(2-)-S, NH4(+)-N, NO3(-)-N, Na+, K+, Ca2+, and Mg2+ using that method. Samples were collected by funnels (bulks). Plastic lysimeters were placed in the soil at the depth of 10 cm or beneath the humus layer. They served to collect liquid that seeped into the soil (seepage). Sampling was carried out once a month or once in three months. The results show that the monitored forest ecosystems absorbed more deposited particles (wet and dry sedimentation) than control areas.