Forest damage in a changing climate

Anna Maria Jönsson and Lars BärringDept. of Physical Geography and Ecosystem Analysis

Geobiosphere Science Centre, Lund University

Predisposing factors Climate change, Tree species and ProvenancesForest management, Nutrient availability, Air pollution

Triggering factors Weather events exceeding tree acclimatization capacityOften causing visible damage

Contributing factors Attacks by pests and pathogensOften the cause of mortality

Forest damage in a changing climate

Extreme weather event ≠ Extreme situation for the tree

Acclimatization

The ability to adjust to changing weather conditionsTolerate non-optimal conditionsThreshold values could be more important than extreme values

Affected by ExampleSeasonality Spring backlashesIntensity FloodingDuration Dry spellsFrequency Wind stormsCombination Spring frost followed by drought

Tree nutrient availability decomposition, weathering, mycorrhiza, leakage

Climate changetemperaturedry spells during summerflooding episodesstorm frequency

Tree damagefrost damagedrought stressroot oxygen deficiencywind throw, root damage

CO2 Pests and Pathogens

Photosynthesis: growth - repair - defence - respiration NPP+10-20%

Ongoing activities within ENSEMBLESrelated 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

1961-1990

Scenario B2

Scenario A2

1 2 3 4 5 month

Climate data: HadRM3

Frost events after the start of dehardening over 30-years

Control period Scenario B2 - Control Scenario A2 - Control

0 100 200

Number of events -75 0 75

Difference

Temperature dependent annual cycle of Ips typographus

Spring swarming

Egg development Summer swarming?

Winter mortalityAlmost 100% for not completely

developed bark beetles

Egg development?

>

April May June July August September

1961-1990

Scenario B2

Scenario A2

Spring swarm Completed development

Development of Ips typographus in Växjö

Temperature dependent summer swarming of Ips typographus

1961-1990 1981-2010 2011-2040

2041-2070 2071-2100

Data from RCA3Scenario A2