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Forests regulate climate, as carbon, water and nutrient fluxes are modified by physiological processes of vegetation and soil. Forests also provide renewable raw material, food, and recreational possibilities. Rapid climate warming projected for the boreal zone may change the provision of these ecosystem services. We demonstrate model based estimates of present and future ecosystem services related to carbon cycling of boreal forests. The services were derived from biophysical variables calculated by two dynamic models. Future changes in the biophysical variables were driven by climate change scenarios obtained as results of a sample of global climate models downscaled for Finland, assuming three future pathways of radiative forcing. We introduce continuous monitoring on phenology to be used in model parametrization through a webcam network with automated image processing features. In our analysis, climate change impacts on key boreal forest ecosystem services are both beneficial and detrimental. Our results indicate an increase in annual forest growth of about 60% and an increase in annual carbon sink of roughly 40% from the reference period (1981–2010) to the end of the century. The vegetation active period was projected to start about 3 weeks earlier and end ten days later by the end of the century compared to currently. We found a risk for increasing drought, and a decrease in the number of soil frost days. Our results show a considerable uncertainty in future provision of boreal forest ecosystem services.

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1. Temperature and many other physical and chemical factors affecting CO 2 production in lake sediments vary significantly both seasonally and spatially. The effects of temperature and sediment properties on benthic CO 2 production were studied in in situ and in vitro experiments in the boreal oligotrophic Lake Pääjärvi, southern Finland. 2. In in situ experiments, temperature of the water overlying the shallow littoral sediment varied seasonally between 0.5 and 15.7°C, but in deep water ( ‡20 m) the range was only 1.1-6.6°C. The same exponential model (r 2 = 0.70) described the temperature dependence at 1.2, 10 and 20 m depths. At 2.5 and 5 m depths, however, the slopes of the two regression models (r 2 = 0.94) were identical but the intercept values were different. Sediment properties (wet, dry, mineral and organic mass) varied seasonally and with depth, but they did not explain a significantly larger proportion of variation in the CO 2 output rate than temperature. 3. In in vitro experiments, there was a clear and uniform exponential dependence of CO 2 production on temperature, with a 2.7-fold increase per 10°C temperature rise. The temperature response (slope of regression) was always the same, but the basic value of CO 2 production (intercept) varied, indicating that other factors also contributed to the benthic CO 2 output rate. 4. The annual CO 2 production of the sediment in Lake Pääjärvi averaged 62 g CO 2 m )2 , the shallow littoral at 0-3 m depth releasing 114 g CO 2 m )2 and deep profundal (>15 m) 30 g CO 2 m )2 . On the whole lake basis, the shallow littoral at 0-3 m depth accounted for 53% and the sediment area in contact with the summer epilimnion (down to a depth c. 10 m) 75% of the estimated total annual CO 2 output of the lake sediment, respectively. Of the annual production, 83% was released during the spring and summer. 5. Using the temperature-CO 2 production equations and climate change scenarios we estimated that climatic warming might increase littoral benthic CO 2 production in summer by nearly 30% from the period 1961-90 to the period 2071-2100.