At present, thinning of forest stands is investigated in the Forestry and Game Management Research Institute in one working group transformed in 1995 into Department of Thinning.
Investigation of thinnings after 1990 is based on traditional methods and long-term experimental series together with contemporal requirements of forest practice. The experimental basis consisting mainly of experiments in spruce and pine stands is continually being completed by experiments in broad-leaved and mixed stands as well as in the stands of substitute tree species. Except of classic increment and production studies, attention
is paid to health condition of experimental stands and nutrient cycling in forest ecosystems. Ecological investigation on selected series is automatized using special stations NOEL. For data processing and evaluation as well as archivation, the database system was developed in FOXPRO 2.
The aim of investigation is to obtain the information on reaction of main forest tree species to thinning with respect to contemporal changes of growing conditions, caused especially by anthropogenic effects and climatic extremes.
Taking account the principles of the State Forest Policy, the research is oriented on:
- effect of thinning on other non-wood production functions of forests,
- thinning as a mean for changing of management system,
- effect of thinning on wood production function of forest.
Since 1995, the problems of thinning has been solved as a part of the project "Silviculture in ecotopes disturbed by human activities" (Subproject 04 "Tending of forest stands in ecotopes disturbed by human activities").
The results obtained by the investigation were used for formulating of thinning principles for the stands of main forest tree species in growing conditions afflicted by human activities. In 1996, the most important results were summarized in Foresters handbook "Stabilization of forest stands by thinning" (Slodičák 1996) and in 2000,
in concluding issue "Thinning principles for main forest tree species in conditions changed by human activities" was submitted (Slodičák 2000).