Question: The mosaic-cycle concept of forest dynamics dominates in Central Europe. According to this concept intermediate-scale disturbances only accelerate the forest break-up under existing cycles of forest development. Is such an approach correct, or should new developmental cycles be elaborated for intermediate-scale disturbances? Location: Near-natural Abies alba - Fagus sylvatica forests in the Świętokrzyski National Park in Central Poland. In these forests intermediate-scale disturbances occurred between 1970 and 1990. Methods: Data were collected twice in areas surrounding 212 permanent sample points (in 1994 and 2004). Two increment cores were taken from 259 sample Abies trees. The effect of intermediate-scale disturbances on radial increment of Abies was assessed. Probabilities of stand transition during a 10-year period between individual stages and phases of development of the mixed forest were calculated. The development stages and phases were arranged into hypothetical succession series of successive changes. Results: In 1994 70 stands and in 2004, 47 stands representing stages and phases containing the older generation formed by trees > 100-150 years were found. Also, in 1994 142 and in 2004, 165 stands representing stages and phases containing the younger generations only, formed by trees < 100-150 years, were recorded. Stages and phases containing only younger generations do not occur in the existing forest development cycle which does not consider the influence of intermediate-scale disturbances separately. Two developmental cycles, which take into account the presence of the older generation and the younger generations only (under conditions of the occurrence of intermediate-scale disturbances), are proposed. Conclusion: The mosaic-cycle concept of forest dynamics can be used to analyse the dynamics of Central European near-natural mixed-species forests, but new developmental cycles should be elaborated for intermediate-scale disturbances.
The Journal of Vegetation Science publishes original articles, short notes and review articles in the field of vegetation science, both methodological and theoretical studies, and descriptive and experimental studies of plant communities and plant populations. The Journal is the Official Organ of the International Association for Vegetation Science (IAVS).