Natural regeneration of mountain spruce forests: 10 years after a bark-beetle outbreak

An extensive area of mountain spruce (Picea abies (L.) Karst.) forests in the Šumava National Park has been affected by a massive bark beetle (Ips typographus (L.)) outbreak since the middle of the 1990s. Parts of forests were left without interventions, while salvage logging was applied in other areas. The results indicated that a natural succession of mountain spruce forests after a bark beetle outbreak, if left without interventions, avoids a pioneer stage and direct recovery of the spruce forests is possible. Wind-dispersed pioneer species appeared temporarily in clear-cuts shortly after salvage logging, but their share in the whole regeneration was negligible after ten years. The height and age structure of spruce regeneration was reduced in clear-cuts. There was also a severe effect of salvage logging on ground layer vegetation compared to the bark-beetle outbreak itself