In a global perspective, climate change is estimated to have modest effects on forestry production in the short and long term (IPCC, 2007a). However, forestry can be affected by climate change in several ways. A number of climate change impacts on forestry are broached in this toolkit, i.e. increased risk of forest fire in Europe (Camia et al., 2008; van der Linden and Mithchell, 2009), increased net primary production (Bergh et al., 2010) and altered forest cover (EEA, 2008).
The summary of the impacts on forestry are presented in Table 1. For further details about the each subsection and specific studies, click on the links below the table. For tips on how to interpret the information in the table see the Swedish example on the right.
Table 1. Climate change impacts on forestry in the BalticClimate countries – a summary of general outlooks for the found impact scenarios interpreted from different scientific studies
(↑↑ Considerable increase; ↑ Slight increase; ↓↓ Considerable decrease; ↓ Slight decrease; ○ No or insignificant change; ~ Outcome very uncertain; ~↑ Outcome uncertain, increase tendency; ~↓ Outcome uncertain, decrease tendency; ─ Not included in the analysis)
Climate change impacts on:
|Forest fire danger||↑||↑||↑||↑||↑||↑||↑↑|
|Frost events after budburst||↑||○||↑↑||↑↑||↑↑||↑↑||↓↓|
|Spruce bark beetle attacks||↑↑||↑↑||↑↑||↑↑||↑↑||↑↑||↑↑|
|Net primary production of trees||↑↑||─||─||─||─||─||─|
|Net primary production||↑↑||↑↑||↑||↑||↑||↑||↓|
• Forest cover (Europe)
• Forest fire danger (Europe)
• Forest fire risk (Northern Europe)
• Forest damage (frost events after budburst and spruce bark beetle attacks) (Europe)
• Net primary production of trees (Sweden)
• Net primary production (Europe)
The EEA report (2008) included a study by Casalegno et al. (2007) who modelled the actual and future dominant forest categories and estimated the shift in vegetation for the period 2000-2100 under NCAR-CCM3 A1B climate scenario. A Classification Tree Analysis model was used to estimate the actual and future distribution of the ten most dominant European forest categories. The Classification Tree Analysis model relates observed forest categories and environmental predictor surface maps. Forest field observations were derived from the Forest Focus database.
The projected changes of forest categories 2100 compared to 2000 for the BSR are most apparent for Sweden, Finland, and Germany (Figure 1). Sweden is projected to have an upward shift of the hemiboreal, nemoral coniferous, mixed broadleaved from the southern part of Sweden to the middle part of Sweden. Finland’s southern half is projected to go from boreal forest to hemiboreal, nemoral coniferous, mixed broadleaved. Eastern Germany’s boreal regions are projected to have disappeared in 2100. The forests in Estonia, Latvia and Lithuania are not projected to change noteworthy. A general projection of forest cover for the BSR is illustrated in Table 2, interpreted from the results in EEA (2008).
Figure 1. Forest coverage of the 10 most dominant forest categories in Europe in 2000 and 2100 (Map 5.43 in EEA (2008)) (click to enlarge)
The study by Camia et al. (2008) projects three monthly fire danger levels 2071-2100 compared to 1961-1990 in Europe for the A2 emission scenario. Daily high resolution data from the HIRHAM model, derived from the PRUDENCE data archive (PRUDENCE, 2001-2004), was used. The three winter months were not included since fire danger is negligible at that time of the year.
Camia et al. (2008) stated that their result confirms an enlargement of the fire prone area and lengthening of the fire season in Europe. Although, the modelled map of fire weather index (FWI) and seasonal severity rating (SSR) show no significant changes for the BSR (Figure 2). The result for the BSR showed no changes in FWI and SSR in spring (March, April, May). In summer and fall (June-July-Aug and Sept-Oct-Nov, respectively) there are some small changes. The SSR increases in parts of Sweden and Germany from 0 to 0.5 on the SSR scale. The FWI in Germany and southern parts of Finland and Sweden are projected increase in the future; some regions currently about 0 - 5 on the FWI scale are projected to have a FWI of 5 - 7.5 in the future. A general projection of future forest fire danger for the BSR is illustrated in Table 3, interpreted from the results in EEA (2008).
An assessment of forest fire danger related to climate change has been conducted by the means of the Finnish Forest Fire Index (FFI) (van der Linden and Mitchell, 2009). The FFI is based on the surface layer volumetric moisture. The index ranges from 1 to 6 where 5 and higher corresponds to very high forest fire risk. The SRES A2 and B2 climate scenarios were simulated for the 21st century with the SMHI-RCA for Finland, Sweden and the Baltic region, focusing on the fire season; April-Sept. Sixteen sites were selected for statistical analyses to obtain a regional as well as temporal variation in fire risk. The number of days with a FFI value above 4 and 5 were evaluated for the sites but also for the entire region using gridded data. The result for the A2 scenario showed that the days with very high risk of fire are anticipated to almost double during the 21st century (Figure 3). The B2 scenario is projected to give slightly less increase in days with very high risk. The northernmost stations are estimated to have the largest increase.
Figure 3. Number of days with very high risk of forest fire in Northern Europe during the 21st century. Results for latitudinal zones are averages from station data (Fig. 9.16 in van der Linden and Mitchell (2009))
Spruce is particularly vulnerable to two weather related events (van der Linden and Mitchell, 2009). Firstly, frost damage after bud burst and secondly, spruce-bark-beetle attacks following storm damage. These specific weather related events could increase with climate change. A warmer climate leads to earlier onset of the vegetation processes; though, the early budburst increases the risk of frost damage during long nights and cold air outbreaks. Wind storm damage produces sufficient breeding substrates which can lead to large bark beetle outbreaks and consecutively kill millions of trees. Higher temperatures also allow for rapid development of the new generation of beetles. Higher temperatures with climate change can therefore lead to higher frequency of late summer swarming, generating a second generation of beetles in southern Scandinavia. The forest damage due to low temperature and pests has been estimated based on climate projections from SMHI-RCA3 driven by seven Global Climate Models (van der Linden and Mitchell, 2009).
The estimation for 2011-2040 indicates an increase in number of frost events after onset of the vegetation process in Sweden, Estonia, Latvia and Lithuania (Figure 4). For the period 2070-2098 the number of events is projected to increase even more, also southern Finland and Russia are projected to have increased events during this period. The southernmost part of Sweden, however, is projected to have decreased number of events during 2070-2098. Germany is projected to have a decreased number of events for 2011-2040 and during 2070-2098 the decrease in events is projected to be even greater. A general projection of future forest damage for the BSR is illustrated in Table 4 and Table 5, interpreted from the results in van der Linden and Mitchell (2009).
Figure 4. Projected changes in frequency of number of frost events after budburst for the periods 2011-2040 and 2070-2098 compared to 1961-1990 (Fig. 9.17 in van der Linden and Mitchell (2009))
The swarming frequency of first generation spruce-bark-beetle is projected to increase in many parts of the BSR with about 0 to 5 years for the 2011-2040 period and about 0 to 20 years for 2070-2098, both compared to 1961-1990 (Figure 5). The change in second generation swarming is projected to increase for Germany and Lithuania with about 5 years 2011-2040. During 2070-2098 the increased frequency of second generation swarming is projected to be about 5-17 years for Estonia, Latvia, Lithuania, Russia, Germany and Southernmost Sweden.
Figure 5. Projected changes in swarming frequency of the first and second generation of spruce bark beetle for the periods 2011-2040 and 2070-2098 compared to 1961-1990 (Fig. 9.18 in van der Linden and Mitchell (2009))
Bergh et al. (2010) calculated the climate change (temperature and CO2 increase) affect on net primary production (NPP) of trees in Sweden. A forest production process-based growth model, called BIOMASS, for five different species was used to perform this projection. Production changes for three of the species are shown in Figure 6. The regional RCA3 model was used together with global driving variables from ECHAM4/OPYC3 to get transient dynamic regional climate scenarios. The simulations were based on the emission scenarios A2 and B2; however, only A2 simulations for 2071-2100 compared to 1961-1990 are shown in Figure 6. The figure illustrate that Scots pine, Norway spruce and Silver birch, have a relative increase in NPP 2071-2100 compared to 1961-1990 varying from 15 to 45% dependent on region and species. The highest relative increase, 42-45 %, is projected for Norway spruce and Silver birch in the very northeastern parts of Sweden. In the south of Sweden, scots pine is projected to have the highest increase, about 30 to 40%. A general projection of the future net primary production in the BSR is illustrated in Table 6, interpreted from the results in Bergh et al. (2010).
Figure 6. Changes in NPP (%) for Scots pine, Norway spruce and Silver birch under A2 scenario 2071-2100 compared to 1961-1990 (Fig. 2 in Bergh et al. (2010))
A study by Fronzek and Carter (2007) estimated the future net primary production (NPP) by using the Miami Model to compute the impacts of seven regional circulation models (RCM) (HIRHAM, HadRM3H, CHRM, CLM, REMO, RCAO, and RACMO2) climate scenarios (Figure 7). The RCMs were driven by the HadAM3H-A2 simulation.
The results for the BSR generally predict increased NPP for the period 2071-2100 compared to the baseline. The highest projected NPP for the BSR is found in the north of Sweden and Finland; >40 % increase. Central Sweden and Finland are estimated to have 20 to 40% increased NPP. Southern Sweden and Finland and just about the rest of the BSR are modelled to have an increased NPP in the range of 0 to 20%. Conversely, this does not include most areas of Germany where the NPP is simulated to decrease in the range of -20 to 0%. A general projection of future net primary production in the BSR is illustrated in Table 7, interpreted from the results in Fronzek and Carter (2007).
Figure 7. Modelled baseline (1961-1990) (a) and change in net primary production between baseline and 2071-2100 for seven RCM-based climate scenarios (b) (Fig. 5 in Fronzek and Carter (2007))
Look at the impacts on other sectors: