Storm damage does not pose a threat to the long-term conservation of Switzerland's forests; rather it contributes to forest renewal and promotes biodiversity. These are the findings of the study by the Swiss Agency for the Environment, Forests and Landscapes (SAEFL) on the storm nicknamed Lothar, which swept across Switzerland and her neighbouring states on 26 December 1999. The storm was not a disaster, either ecologically or economically.
Despite the storm damage forests were able to exercise their protective function over part of the affected areas, and in most places their regenerative ability remained good. The SAEFL recommends that near-natural (mixed) forests be promoted to ensure that in future Switzerland's forests are better able to withstand the impact of storms. Measures following a storm must focus first and foremost on the forests' protective function, particularly in areas where the risk of consequential damage (mainly due to the bark beetle) is intolerable or where people or materials assets are directly at risk from natural hazards. From an economic and ecological point of view it is also advisable to leave most of the wood brought down by a storm on the ground as even fallen trees have a protective function.