During the late winter days, we successfully finished the collection of increment cores from the numbered sample trees as a part of the research tasks related to the monitoring of the improved groundwater management. By measurement of the annual tree ring widths on the cores taken with an increment borer, our aims are to prove the benefits of the LIFE Action on the growth and health condition of the common alder and pedunculate oak stands.

An important objective of the sampling design was to carry it out before the spring sap flow begin to alleviate this way the risk of any long lasting damages and infections to trees because of the drilled wounds on the stem. In addition to the proper timing, bored holes were treated with fungicidal sealer gel, usually used on garden trees after pruning.