Transcript Document
Forest damage in a changing climate Anna Maria Jönsson and Lars Bärring Dept. of Physical Geography and Ecosystem Analysi Geobiosphere Science Centre, Lund University Forest damage in a changing climate Predisposing factors Climate change, Tree species and Provenances Forest management, Nutrient availability, Air pollution Triggering factors Weather events exceeding tree acclimatization capacity Often causing visible damage Contributing factors Attacks by pests and pathogens Often the cause of mortality Extreme weather event ≠ Extreme situation for the tree Acclimatization The ability to adjust to changing weather conditions Tolerate non-optimal conditions Threshold values could be more important than extreme values Affected by Seasonality Intensity Duration Frequency Combination Example Spring backlashes Flooding Dry spells Wind storms Spring frost followed by drought Tree nutrient availability decomposition, weathering, mycorrhiza, leakage Photosynthesis: growth - repair - defence - respiration NPP +10-20% CO2 Climate change temperature dry spells during summer flooding episodes storm frequency Pests and Pathogens Tree damage frost damage drought stress root oxygen deficiency wind throw, root damage Ongoing activities within ENSEMBLES related to task 6.2.2, 6.2.3, 6.2.5 and 6.2.10 1) Spring backlash index: Frost damage projections SBI has been calculated for Sweden, is currently applied to European conditions using the PRUDENCE dataset, and will use ENSEMBLES RCM data. A Frost hardiness and damage sub-module is incorporated to the vegetation model LPJ-GUESS. 2) Modelling the temperature dependent development of the spruce bark beetle Ips typographus The model has been applied to south Swedish conditions, and will be applied for Northern European spruce forests using ENSEMBLES RCM data. Start of dehardening in Norway spruce 5 consecutive days with a mean temperature above 5°C Scenario A2 Scenario B2 1961-1990 1 2 3 4 5 month Climate data: HadRM3 Frost events after the start of dehardening over 30-years Control period 0 100 200 Number of events Scenario B2 - Control Scenario A2 - Control -75 0 75 Difference Temperature dependent annual cycle of Ips typographus Egg development Spring swarming > Summer swarming? Egg development? Winter mortality Almost 100% for not completely developed bark beetles Development of Ips typographus in Växjö Spring swarm Completed development Scenario A2 Scenario B2 1961-1990 April May June July August September Temperature dependent summer swarming of Ips typographus 1961-1990 1981-2010 2011-2040 Data from RCA3 Scenario A2 2041-2070 2071-2100