Biodiversity is a commonly used term, which is not exactly defined yet. It is based partly on another term being used for much longer time, diversity. For example, species diversity concept is an exactly measurable value within a biocoenosis (Magurran 2004). There are two components of the diversity (i) species richness and (ii) equitability. The former is a number of species within community while the latter expresses a share of particular species. To maintain biodiversity, species and/or whole communities are protected from extinction. From this point of view, red lists and red books comprising of many organisms are important. They are compiled to include either larger (for higher plants in the Czech Republic see Grulich 2012) or smaller regions (for South Bohemia see Chán et al. 1999, for the Šumava Mts. see Procházka et Štech 2002, for the Jeseníky Mts. see Bureš 2013).
Forests represent the principal climax ecosystem in the central Europe (Chytrý 2012). They are thus in the focus of nature conservation. However, there are is lack of primaeval forests nowadays. The protected forest areas have been changed and/or reshaped due to long-term human intervention, which is a thing the nature conservationists have to cope with.
The Catalogue of Silviculture Measures to improve Forest Biodiversity in Protected Areas (hereinafter referred as the Catalogue) adds more information to knowledge base of forest management in protected areas. Although relationships between both biodiversity and forest management have been studied a lot (Forkner et al. 2006, Gram et al. 2003), there is a need to propose and use so-called "non-standard" silvicultural measures. Central-European forests of lower (and middle) altitudes developed under several thousands of years lasting human interventions. The result is for instance light-demanding oak forests, which can be considered semi-natural ecosystems (see Chytrý 2012). This is also in accordance with archaeological findings such as distribution of prehistoric human settlements (Semotanová, Cajthaml et al. 2014) and potential vegetation map (Neuhäuslová et al. 1998). The forests were managed in such a way that relatively frequent removals of "fine" biomass contributed to existence of thin stands allowing penetration of solar radiation through broken canopy where spontaneous regeneration was common. At that time, wood was harvested using a selection cut (Dreslerová 2012). Contemporary Czech forestry abandoned the old management approaches. We have full canopy forest stands disabling long-term or permanent life of the species that benefitted from almost forgotten management systems. To maintain or restore the high level of biodiversity, the return to "the old-fashioned silviculture measures" is needed. Such measures aim to break the crown canopy (reduce stocking) which contributes to create conditions emulating ecotones i.e. transition zones between forested and non-forested areas. It is known that ecotones are typical of increased diversity. For example, birds use the opportunity to nest and forage there (Gram et al. 2003).
As for middle and upper forested sites, there were almost no human interventions in prehistoric period. The important human impact and following change of tree species share and forest structure date back to Medieval Age. Leaving forests to their spontaneous development (Kindlmann et al. 2012) and near-natural management emulating the forest gap dynamics are considered specific measures at these sites. Protected forest including NATURA 2000 areas can be managed specifically in order to achieve the objectives of protection. These specific approaches are usually a part of the management plans in the protected areas. The Catalogue describes eight measures that are potentially applicable for planning the care of forest ecosystems in order to preserve/improve their biodiversity. However, it is not a complete list of all possible measures. There are applicability of measures in terms of species, ecosystems and natural processes conservation including impact on forest production, methods to be used and feedback to the measure users to evaluate impact on biodiversity.
The Catalogue content is divided into three types of forest management:
The Catalogue is based on several working procedures. The first one included an analysis of protected areas care plans. The analysis showed what measures were proposed or applied in the protected forests. Next procedures' effect on biodiversity was studied from available literature. The impact of applied measures was evaluated in so-called demonstration sites i.e. research plots, which were established in different parts within the Czech Republic (Matějka et al. 2016).