The Impact of Salvage Logging on Deadwood Decomposition and Forest Regeneration: A Case Study in Tatra National Park, Slovakia

In November 2004, a severe windstorm destroyed large portions of the spruce-dominated forests in the Tatra National Park (northern Slovakia). This study focused on the status of deadwood and its influence on post-disturbance forest regeneration 18 years after the destruction. Since some disturbed areas were salvaged and others were not, we could compare the situations between these two management approaches. Therefore, 40 research sites (20 salvaged and 20 unsalvaged) were analyzed; each contained four satellite plots, i.e., circle-like areas with a radius of 3 m. We measured the diameter of deadwood and its decay status (classes 1-5) and recorded the sizes (stem base diameter and height) as well as species of young trees. Our results showed that while salvage conditions and contact with soil stimulated deadwood decomposition, the diameter of logs was not a significant factor. The highest decay class (3.83) was found in deadwood in salvaged areas and touching the soil, while the lowest decay class (3.10) was found in deadwood in unsalvaged areas and in the case of logs not touching the soil. Although carbon content (based on the percentage of wood mass) did not change with the decay class, wood density decreased sharply with decay, and deadwood moisture increased. We also found that the different post-disturbance management strategies influenced forest regeneration. Significantly higher tree diversity was observed in salvaged sites (5.40 species per plot) compared to unsalvaged sites (3.85 species per plot). At the same time, while sites with logging were predominantly covered by broadleaved species, those without logging were typically dominated by Norway spruce (Picea abies L. Karst). Our findings suggest that although salvage logging reduced the carbon and total water content in deadwood, it can promote tree species diversity. Therefore, the currently prevailing opinion about the exclusively negative effects of salvage logging on the forest environment should be accepted with caution, and local conditions must be considered before making broad judgments.