Influence of climate and forest management on damage risk by the pine weevil Hylobius abietis in northern Sweden

• Published in: Silva Fennica
• Main Authors: Nordlander G, Mason EG, Hjelm K, Nordenhem H, Hellqvist C
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: clear-cut age; conifer seedling; damage prediction; reforestation; soil scarification; temperature sum; warmer climate; Fields of Research::30 - Agricultural; veterinary and food sciences::3007 - Forestry sciences::300704 - Forest health and pathology; veterinary and food sciences::3007 - Forestry sciences::300707 - Forestry management and environment; Field of Research::05 - Environmental Sciences::0501 - Ecological Applications::050101 - Ecological Impacts of Climate Change; Duff; Northern Sweden
• Online Access: http://hdl.handle.net/10092/15254; https://doi.org/10.14214/sf.7751

The pine weevil Hylobius abietis (L.) is an economically important pest insect that kills high proportions of conifer seedlings in reforestation areas. It is present in conifer forests all over Europe but weevil abundance and risk for damage varies considerably between areas. This study aimed to obtain a useful model for predicting damage risks by analyzing survey data from 292 regular forest plantations in northern Sweden. A model of pine weevil attack was constructed using various site characteristics, including both climatic factors and factors related to forest management activities. The optimal model was rather imprecise but showed that the risk of pine weevil attack can be predicted approximatively with three principal variables: 1) the proportion of seedlings expected to be planted in mineral soil rather than soil covered with duff and debris, 2) age of clear-cut at the time of planting, and 3) calculated temperature sum at the location. The model was constructed using long-run average temperature sums for epoch 2010, and so effects of climate change can be inferred from the model by adjustment to future epochs. Increased damage risks with a warmer climate are strongly indicated by the model. Effects of a warmer climate on the geographical distribution and abundance of the pine weevil are also discussed. The new tool to better estimate the risk of damage should provide a basis for foresters in their choice of countermeasures against pine weevil damage in northern Europe.