Påverkan från den förväntade klimatförändringen på tillväxten i norra Sveriges skogar : En litteraturanalys

Sammanfattning: This is a literature review of how the climate change affects the forest growth innorthern Sweden. The temperature will rise about 5 °C with the largest increase in thewinter season (December - February) and the CO2level in the atmosphere is expected tobe doubled. Precipitation patterns will change and increase with 25-35 % and theprecipitation will be in form of rain rather than snow. Today the forests in northernSweden are entirely dominated by coniferous stands. This may shift with the climatechange and results in a larger number of deciduous trees, preferably birch will becomestronger and grow better and faster. Since 1920, the volume growth in the forest hascontinuously increased. The growth season in the forest will be 30-43 days longer andgrowth during the growing season will generally be higher in the end of this century. Afaster growth will require greater and earlier thinning. This reduces the carbon storagein forests and reduces nutrient availability. An earlier beginning of growing season willenhance the risk of frost damage. A temperature that drops below freezing point afterthe initiation of growth will increase the risk of frost damage to the trees. A goodnutrient availability enhances growth, adding nutrients to the forests will be necessary,to a greater extent than today. The availability of nutrients is currently low. The greatestneed of nutrient is N followed by P, K, Ca and Mg. High nutrition availability canreduce frost damage. Climate change will both generate more timber from the forest andparts from thinning can be used for bioenergy. The acceleration of growth resultingfrom the combination of increased temperature, ricing CO2level in the atmosphere andincreased nitrogen in the soil gives an increase in growth rate of about 15 %.