Ecosystem Services Related to Carbon Cycling – Modeling Present and Future Impacts in Boreal Forests

Abstract

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.

Uncertainty sources in simulated ecosystem indicators of the 21st century climate change

“…8), also investigated by Ruosteenoja et al (2017). These effects are also detrimental for winter harvesting and wood quality, as suggested by Holmberg et al (2019). Manninen et al (2019) reported lengthened snow melting periods for some regions in Finland for 1982-2016.…”

Thermal seasons in northern Europe in projected future climate

“…In wild plants, the earlier onset of thermal springs does not necessarily increase the total annual growth, since water resources in the soil may then be depleted earlier, resulting in drought stress (Buermann et al, 2018). Even so, according to Holmberg et al (2019) warming is likely to increase the carbon sink in boreal forests; particularly the tree biomass (Sievänen et al, 2014). However, the long-lasting thermal autumns act to enhance the total ecosystem respiration more than photosynthesis, which turns the carbon balance more negative in that season (Vesala et al, 2010).…”

Bayesian methods applied for ecosystem model calibration and uncertainty source estimation

“…3), but the effect pales in comparison to the examined management actions. This underlines the importance of proper forest management for provisioning services (Snell et al, 2018;Holmberg et al, 2019). This is illustrated by the relative NEE pathways (Fig.…”

“…Assessment of uncertainties related to carbon budgets and growing season length together with water and snow conditions is important in estimating the forests ability to provide ecosystem services related to e.g. carbon sequestration, wood harvesting, maintaining habitats and promoting nature tourism (Snell et al, 2018;Holmberg et al, 2019).…”

“…ongitude-latitude grid, similarly to ; Holmberg et al (2019). The bias correction methods are described in Räisänen and Räty (2013); Räty et al (2014).…”