Protected forest ecosystems, (national parks, nature parks, strict reserves …) are of great importance for the development of basic and applied natural scienceswhile their references are essential for evaluation of the effectiveness of forest management. Principally,in these forest ecosystems methodologies for forest development monitoring on permanent trial plots should be developed with the purpose of gaining insight into relationship between the stand structure and, for example, environmental factors, the regeneration process, the intensity of the damage and the danger of the various biotic factors spreadingwith corresponding analyses. The study of such forests provides us with opportunities for better understanding of the causes and consequences of various phenomena together with amplecomparisons with managed forests. Certainly, we should not ignore the extremely important component of this kind of knowledge in terms of educationaland promotional value, especially if information boards for visitors are taken into account.

The main characteristic of forests present in NP “Krka” derive from two forest ecosystems. The first, eumediterranean part, consists of mixed forests of holm oak and black ash, while the second one, sub-Mediterranean, consists of oak and hornbeamforests. Previous studies have been carried out on the two most characteristic areas in terms of forest ecosystems: (i) in the old preserved pubescent oak high forest -in the area of STINICA, and (ii) in the area Mackovic (locating and monitoring the health status of older oaktrees). Research encompassed the standsstructure, the number of young growth (seedlings and saplings), shrubs and tree vegetation by species and origin (seed-stump) and the health status of the trees. The need of further monitoring of health status, growth and development of these stands, abundance and survival of young pubescent and holm oak plants will indicate the direction of the development of forest ecosystems in this area.

The third characteristic regionencompasses areas around Skardinski Buk, Roški Slap and Manojlovac waterfalls. The region is characterized by swamp vegetation, riparian forests of alder and narrow leafed ash to be exact, which appear in fragments along the river Krka, most often as an extension of the vegetation of reeds.

The main objectives of the research will be focused on the description of representative forest ecosystemsstructures, trends in growth and development, identification and description of forest communities (list of characteristic species), the risk of spread and occurrence of various infections, as well as protection measures in order to preserve the biodiversity of the park. In addition, the research will encompass application of the method of visual assessment of tree health and methods of determining the static safety by measuring the resistance in the trunk using the resistograph.