Search

Simple Summary: The most important disturbances in European forests are windstorms and fire. In 2004, 12,000 ha of High Tatra Mts. (Slovakia) forests were seriously damaged by strong winds. Furthermore, in 2005 the area of 250 ha of not cleared forest from fallen wood biomass after windstorms was burned down. Our study brings an overview on the influences of irregular wind and fire disturbances and subsequently human activities upon the structure of thrips communities there, where eight study plots with different after-calamity management were chosen. There were two study plots that were affected by wind and subsequent management with the extraction of fallen wood biomass and influenced by fire that were characterized by low species richness. In comparison, not cleared habitats from fallen wood biomass with significantly higher species richness of thrips and higher values of diversity were characterized mainly by the presence of grass-living species Chirothrips manicatus and Limothrips denticornis. The meadow communities with longer development and higher values of diversity were inhabited by the species-rich community mainly with Thrips fuscipennis, T. brevicornis, T. flavus, and T. tabaci. Gradually, in the process of secondary succession these thrips assemblages will be probably replaced by the thrips of the shaded and long-term forests that are mainly composed of Oxythrips bicolor, O. ajugae, and Thrips pini. Strong winds, fire, and subsequent forest management impact arthropod communities. We monitored the diversity and changes in the community structure of forest thrips assemblages in the context of secondary succession and anthropogenic impact. There were eight study plots that were affected to varying degrees by the mentioned disturbances that were selected in the Central European spruce (Picea abies (L.) Karst.) forests in Slovakia. The soil photoeclectors were used to obtain thrips in the study plots during two vegetation seasons. The thrips assemblages and their attributes were analyzed by non-metric multidimensional scaling (NMDS). The significant changes in community structure, composition, stratification, species richness, and diversity of thrips assemblages that were caused by natural- (wind) and human-induced disturbance (forestry and fire) were observed in our research. Our analyses revealed a clear relationship between different thrips assemblages and impacted environment. Moreover, our results indicate that silvicolous thrips species may be useful for indicating changes and disturbances in forest ecological systems. [ABSTRACT FROM AUTHOR]

In November 2004 a large windstorm affected forests dominated by Norway spruce (Picea abies (L.) H. Karst, 1881) in the High Tatras National Park, Slovakia, and was followed by a wildfire (2005) and bark beetle outbreak. In this study we investigate temporal changes of breeding bird community (their species richness, density and diversity) as well as different nest-position guilds, in relation to disturbance type. Bird species composition was surveyed in two periods (2006 and 2007, and 2017 and 2018) using the point count method on four plots differing by disturbance type – undisturbed forest, unlogged windthrow, salvage logged windthrow and burnt salvage logged windthrow. A total of three visits per point and breeding season were performed at forty point count sites. We also assessed the successional shift in habitat characteristics between the two monitored periods. In total, 55 bird species and 2059 individuals were recorded on the plots during the study. We observed no effect of disturbance type on mean species richness, abundance and Simpson's diversity per point; however, those characteristics did significantly increase over the study duration. While differently disturbed points had previously differed in their (nest-position) guild number and diversity, the differences between them disappeared over time. We found different trajectories of temporal change in the composition of the species communities and guild diversity in relation to disturbance type, but in a similar direction. During the first period, the greater the initial differences in the severity of disturbance among the disturbance types, the greater the differences were in the composition of bird communities; however, the differences gradually diminished as the forests regenerated. Alterations in habitat structure caused by natural and anthropogenic disturbance and by subsequent succession were the most probable reasons for the altered bird communities and observed patterns of recovery. [ABSTRACT FROM AUTHOR]