The above mentioned concepts of individual authors create a wide range of terms and thus a clear differentiation of individual forest stands in common practice is impossible (especially when everybody uses their own resources). To unify the terminology, it seems practical to maintain a three-point scale of forest stands. Such scale enables distinguishing main past influences that have changed or may change the function of the dynamics of the studied community. From the perspective of content, the concepts of Málek, Míchal and Podrázský et al. gradually converge. For permanent application, we consider important to harmonize the content and concepts with terms and their content used in comparable areas of the Europe. Our terms are in content similar to those from abroad, with the only exception of the term “near-natural forest”. When compared with English and German literature, this term cannot be differentiated from the term “natural forest” since what we translate as e.g. potential natural vegetation or the degree of naturalness is in English and German terms derived from “nature – natural” or “die Natur – natürlich”. As such, we suggest terms original – natural – near natural forest as the most suitable. They can be briefly defined:

a) Original forest or virgin forest – loosely defined as a forest more or less unaffected by humans where tree species composition and spatial structure correspond to habitat, i.e. potential natural vegetation. We can mark as original forests also those that were influenced by humans in the past but the intervention did not affect natural developmental trajectory and the traces of such intervention are not obvious – e.g. selective cutting of individual trees more than 100 years ago, removal of dead trees from the forest edges more than 50 years ago etc. The term virgin forest can be identified with the term original forest. However, it is important to point out that this term is widely used in relation with some stands that are in fact natural or near-natural forests – e.g. “Mionší virgin forest”, “Rýchorský virgin forest” etc. We are not able to force general public stop using this traditional and popular labelling so this term should be used really carefully. Equivalents in foreign languages: English: original forest, virgin forest, primary forest; German: der Urwald.

b) Natural forest – forest formed by natural processes but influenced by human activities in the past (namely selective cutting and grazing, not planting or sowing). The species composition as well as spatial and age structure predominantly correspond to habitat; they may differ in some places due to e.g. spontaneous development that occurred in altered conditions (e.g. after grubbing in the Middle Ages and subsequent long-term spontaneous development, long-term influence of higher numbers of game etc.). Equivalents in foreign languages: English: natural forest; German: der Naturwald.

c) Near-natural forest – forest whose composition largely corresponds to habitat but the spatial structure is simpler than in the original forest. These forests were formed under the human influence and their status could have been achieved intentionally. Their development was influenced in a long term and the traces of such influence is still present (removal of dead wood, logging, thinning etc.). Equivalents in foreign languages: English: near-natural forest; German: der naturnahe Wald.

For all three terms we can use a general term “natural forests” as the word “natural” has traditionally been used in a broader sense and in conjunction such as “degree of naturalness”, etc.

Degree of naturalness

The term degree of naturalness is predominantly used to express the degree of forest stand conservation. It is an internationally used term which is related to “natural forest”, which corresponds to derivative terms such as “potential natural vegetation” (in German die potentielle natürliche Vegetation). Equivalents in foreign languages: English: degree of naturalness; German: die Natürlichkeitstuffe.

To be left to natural/spontaneous development

In connection with the dynamics of natural forests which were dropped from direct human intervention, the term “natural development” is very often used. We believe that this term corresponds to steady development of natural forests without both direct and indirect human influences. Especially indirect human impacts affect forests in different forms and intensity everywhere and it is very difficult to classify them in any way. Thus it is preferable to use the term spontaneous development when talking about forest development without direct human intervention (i.e. mainly education and restoration). This term sums up both spontaneous influence of natural forces on relationships within individual components of the forest geobiocoenosis and a certain degree of human influence in the past together with indirect influence in present (e.g. high numbers of game or lingering air pollution, etc.). E.g. we cannot call natural development a situation where forest dynamics (even though it is in a natural forest) is significantly impaired by excessive number of hoofed game (as a result of human activities) which effectively blocks natural regeneration of the forest. The term spontaneous development can be used as a synonym. Equivalents in foreign languages: English: spontaneous development; German: die spontan Entwicklung.