Response of bird assemblages to windstorm and salvage logging — Insights from analyses of functional guild and indicator species

• Published in: Ecological indicators 2016-06, Vol.65, p.142-148
• Main Authors: Thorn, Simon, Werner, Sinja A.B., Wohlfahrt, Jürgen, Bässler, Claus, Seibold, Sebastian, Quillfeldt, Petra, Müller, Jörg
• Format: Article
• Language: English
• Subjects: Anthus; Anthus spinoletta; Biodiversity; birds; breeding; Breeding season; Coniferous forests; economic valuation; financial economics; forage; foraging; forest ecosystems; Forest management; forest stands; Harvesting; indicator species; insects; landscapes; Logging; national parks; Natural disturbance; nesting; Phoenicurus phoenicurus; salvage logging; shrublands; snags; species diversity; storms; trees
• ISSN: 1470-160X; 1872-7034
• DOI: 10.1016/j.ecolind.2015.06.033

•We investigated the effects of windthrow and salvage logging to bird assemblages.•Bird assemblages were predominantly altered by the consequences of the windstorm.•Windstorm altered bird assemblages from forest species towards open-land species.•Bird species richness after 3 years was reduced by post-storm logging.•Diverse logged and unlogged stands can increase bird diversity on a landscape scale. Natural disturbances, such as fire, windstorms and insect outbreaks, are important drivers of biodiversity in forest ecosystems, but at the same time cause large economic losses. Among the natural disturbances in Europe, windstorms cause the highest economic loss. After such storms, damaged forest stands are commonly salvage logged to restore economic value. However, such interventions could affect species assemblages of various taxonomic groups, including breeding birds. Despite these potential effects, investigations of the impacts of post-storm logging are largely lacking. We thus investigated assemblages of breeding birds in 21 logged and 21 unlogged windstorm-disturbed forest plots and 18 undisturbed, control forest plots using fixed-radius point-stop counts three, five and seven years after a windstorm within the Bavarian Forest National Park as part of the European Long-Term Ecosystem Research Network. We recorded 2100 bird individuals of 55 bird species. Bird assemblages were predominantly altered by the consequences of the windstorm and affected only to a minor degree by subsequent logging of storm-felled trees. Nevertheless, bird species richness was significantly reduced by post-storm logging within the first season. In general, the windstorm led to a shift in bird assemblage composition from typical forest species towards open- and shrub-land species. Assemblages of logged and unlogged disturbed plots consisted mainly of long-distance migrants and ground-foraging bird species, whereas assemblages of undisturbed control plots consisted of resident species that forage within vegetation. Both unlogged and logged storm-felled coniferous forest stands were inhabited by endangered or declining bird species, such as Water Pipit (Anthus spinoletta) on logged plots and Eurasian Redstart (Phoenicurus phoenicurus) on unlogged plots. Indicator species analyses suggested that species of unlogged storm disturbed plots depended on storm-created legacies, such as pits and snags, for foraging and nesting. Hence, we recommend reducing post-storm logging of these lega