Vulnerabilities - Terrestrial biodiversity

Climate change will probably increase the total number of Finnish flora and fauna. However, some species characteristic to Finland, like relict cold water fish and other reminders of the ice age, may become extinct (6).

A warmer climate may create preconditions for the distribution of several species of flora and fauna to extend hundreds of kilometres to the north. … The increase in temperature, carbon dioxide concentration and precipitation caused by climate change will boost the growth of trees in the boreal forest belt, and the timberline is expected to move north. Climate change will lead to changes in soil and vegetation. The climatic zone suitable for boreal vegetation is expected to move 150–550 km farther north during this century. However, boreal vegetation cannot migrate at such a rapid pace, at least not naturally, because the natural rate of migration for trees is only 20–200 km a century (1).

As the climate changes, species currently found in Southern Finland will migrate to Northern Finland, and new species will spread to Southern Finland from regions south of the country. Broadleaved trees, birch in particular, will become more common in forests, and the timberline will rise. … The timberline might shift 20 – 200m upward, depending, inter alia, on the natural migration speed of trees. … Arctic species that have adapted themselves to the coldest conditions of Northern Finland will recede and their areas of distribution will become smaller. The overall number of species found in Finland is expected to increase (1).

Climate change will increase the productivity of northern ecosystems. This will be an advantage to agricultural production and forestry. Increased productivity is both an advantage and disadvantage in terms of biodiversity. Original ecosystems will change and many species will decline. Abnormal weather conditions and the improved living conditions of pests and diseases will increase the risk of plant and forest damage, and impose uncertainty on productivity forecasts (1).

Climate change and higher regional temperatures, in particular, will influence the timing of the reproduction of animals and plants, the length of the growing season and/or the migration/movement of animals, the distribution of species and sizes of populations, as well as the appearance of pests and diseases. Climate change, together with impacts of human activities and spreading of invasive alien species, will probably restrict the ability of many indigenous species to migrate and survive in fragmented habitats (1).

The most threatened species include those with poor tolerance to climate change, those with restricted possibilities for geographical expansion (such as species in mountain-tops, islands, and capes or species under other restrictive physical factors) or those with small populations. According to the most recent studies, the threat of becoming extinct by 2050 concerns approximately one third of the species, at most, in evaluated areas (20% of the land area of the Earth), and many of these species live in the tropical zone. The cause of this threat is not only climate change but also the destruction of habitats by humans (1).

Northern ecosystems are less rich in terms of their biodiversity and number of species compared to many more southern areas. Their adaptive capacity is poorer and their structure and biodiversity is simpler, so their buffer capacity is lower than that of southern ecosystems with a multitude of species (1).

Tundra

The concurrent increase in the productivity of the tundra, probably due to longer and warmer growing seasons, will in the long run cause northern boreal forests to invade the tundra, while boreal forests at the southern ecotone are likely to retreat due to increasing drought, insects and more prevalent fires (4). Since the rate of loss at the southern ecotone due to relatively fast processes such as fire is likely to be higher than the rate of gain at the northern ecotone due to the slow growth conditions, the overall effect of these two processes for the boreal forests is likely to be negative during the transient phase, i.e. until a new equilibrium between climate and vegetation is established. However, in equilibrium a general increase in deciduous vegetation at the expense of evergreen vegetation is predicted at all latitudes (5).

Vulnerabilities - Animals

The adaptive capacity of animals has clear genetic limits. If a change takes place too fast, not all animals will be able to adapt themselves. Adaptation will probably become more difficult for animals as extreme climatic events become more common and unpredictable (1).

The game resources of Finland are quite rich; there are 34 mammal and 26 bird game species. By far the most important is elk, the annual number of animals hunted is around 60,000–70,000 and the meat value totals some EUR 40 million. Because the winter population is around 120,000, the harvest plays a major role in elk population dynamics. Elk is not only a valuable game animal but it causes considerable forest damages and traffic accidents. The elk will mainly benefit from a warming climate and thinning snow cover. Thus, food will be more easily available and the management of the population will become even more important than today. Several game birds and small mammals are also likely to find the future winter climate comfortable and their populations might increase, and the large annual variations attenuate (2).

Vulnerabilities - Fresh water and wetlands biodiversity

Changes in the northernmost Finland will affect the occurrence of permafrost in palsa mires. The extent of palsa has lessened greatly during the past few decades. The defrosting of palsa and the diminishing of water moulds increases the coverage of vegetation but reduces the populations of birds and insect groups that benefit from the palsa mires. Overall, the total number of species living in Finland is more likely to increase than decrease as a consequence of climate change. At the same time, however, some species characteristic to Finland, like relict cold water fish and other reminders of the Ice Age, may become extinct (2).

The peatlands in Finland suffer from climate change. On the other hand, the peatlands are a source of greenhouse gasses as well. Originally one third of the land area of Finland was covered in peatlands; half of this has been drained for agriculture, converted to forestry or cut for fuel. 20% of the country’s greenhouse gas emissions are due to combustion and disturbance of peat. There is a positive feedback loop between draining, harvesting and combustion that releases CO2, which causes global warming that leads to further drying of peatlands (3).

Increasing temperatures and runoff into aquatic environments, and the resulting changes in nutrient loads, may have a profound impact on e.g. phytoplankton and zooplankton, benthic fauna, fish stocks and the number of species. The spring peak of phytoplankton in lakes will occur earlier and will be considerably more pronounced than today (6).

Vulnerabilities - Marine biodiversity

Baltic Sea

The Baltic Sea today suffers from eutrophication and from dead bottom zones due to (10)

1. excessive nutrient loads from land,
2. limited water exchange with the world ocean and
3. perhaps other drivers like global warming. 

The impact of excessive nutrient loads is the most important driver. Without elevated nutrient concentrations, hypoxia would not have occurred during the twentieth and twenty-first centuries (13). 

Model simulations (10) suggest that global sea level rise will cause increases in

1. frequency and magnitude of saltwater inflows,
2. salinity and phosphate concentrations in the Baltic Sea as a direct or indirect consequence of increased cross sections in the Danish straits, and will contribute to 
3. increased hypoxia and anoxia amplifying the previously reported future impacts of increased external nutrient loads due to increased runoff, reduced oxygen flux from the atmosphere to the ocean and intensified internal nutrient cycling due to increased water temperatures in future climate (11). 

Although sea level rise will cause more intense inflows of high saline, oxygen-rich water, hypoxic bottom areas will increase because of increased stratification (10). 

The combined impact of changing nutrient loads from land and changing climate during the 21st century for the Baltic Sea region has been assessed, for a moderate (RCP 4.5) and high-end scenario (RCP 8.5) of climate change (12). The scientists found in almost all scenario simulations, with differing nutrient inputs, reduced eutrophication and improved ecological state compared to the reference period 1976-2005. This result is a long-lasting consequence of ongoing nutrient load reductions since the 1980s. Only in case of combined high-end nutrient load and climate scenarios, eutrophication is reinforced. Effects of changing climate, within the range of considered greenhouse gas emission scenarios, are smaller than effects of considered nutrient load changes, in particular under low nutrient conditions. Hence, nutrient load reductions following the Baltic Sea Action Plan will lead to improved environmental conditions independently of future climate change (12).

Vulnerabilities - Interaction climate change and other factors

Some 10% of the animal and plant species in Finland are endangered. Over one third of these species live in forests, while 28% live in man-made, cultivated habitats. For most of the endangered species, anticipated climate change is not the main threat; their habitats are undergoing harmful changes due to land use change and other direct anthropogenic factors (2).

Adaptation strategies - Terrestrial biodiversity

Sufficient networks of protected areas that are representative in terms of conservation biology, with ecological interconnections and protection zones, will support the maintenance of biodiversity and provide plants and animals with channels for spreading and migration. At present there is not yet enough information on the adaptive capacity of ecosystems, flora and fauna expressing biodiversity with regard to climate change (1).

Finland has launched or is preparing guidelines and national strategies for several vulnerabilities with respect to biodiversity, such as ecological corridors between protection areas and, where necessary, other valuable nature areas, invasive alien species, (the reconstruction and restoration of) mires and peatlands, and valuable forest habitats (6).

Conservation of grassland butterflies

The potential impacts of climate change on semi-natural grassland biodiversity in Finland and potential adaptation options have been considered by focusing on grassland butterflies as a key indicator species (7). The areas that are suitable for grassland butterflies will shift due to climate change. Failure to track this shift will result in overall negative impacts on grassland butterflies.

Traditionally managed semi-natural grasslands are one of the most species-rich habitats in Europe, and their preservation is crucial for the protection of biodiversity (8). The maintenance of these grasslands and their biota is threatened due to their drastic decline caused by changes in agricultural practices (9). The current extent of semi-natural grasslands in Finland is much lower than the minimum level estimated to ensure the survival of butterfly species.

There are different options to enhance the adaptation of grassland biodiversity in Finland under a changing climate. Short-term options are measures taken by farmers who get paid to conserve grassland biodiversity. These measures include buffer strips along waterways, management of traditional biotopes, wider buffer zones along waterways and environmental fallow. Longer-term options include dispersal corridors and translocation of species. Dispersal corridors are designed to enhance species’ range expansion to new, currently unoccupied areas by linking present-day populations to alternative locations that are projected to become climatically suitable in the future. Translocation of species (also referred to as assisted colonization or assisted migration) refers to actively moving species to climatically suitable areas (7).

Currently there are several barriers to the success of the longer-term options. The current extent of semi-natural grasslands is too low to provide a secure passage from current to future suitable areas for the selected butterfly species; at present the longer-term option of dispersal corridors is insufficient to adapt Finnish grassland biodiversity to climate change. This implies a potential need to increase the amount of semi-natural (grazed or mowed) managed grasslands in Finland. The alternative longer-term option of species translocations is also limited by the general difficulty of finding sufficiently large and good quality recipient sites as well as by insufficient knowledge of species’ exact habitat requirements (7).

Besides, climate change scenarios and the effects on biodiversity are highly uncertain. One should plan a portfolio of sites or corridors that could be effective over the range of possible projected futures and outcomes. However, this has resource implications. It suggests that a more sensible option would be to move towards an iterative adaptive management framework that includes monitoring, learning and changing management strategies as the evidence emerges (7). 

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Finland.

1. Marttila et al.(2005)
2. Ministry of the Environment of Finland (2006)
3. Anderson (ed.) (2007)
4. Denman et al. (2007); Fischlin et al. (2007), in: Fischlin (ed.) (2009)
5. Fischlin (ed.) (2009)
6. Ministry of the Environment and Statistics Finland (2009)
7. Tainio et al. (2016)
8. PykäläĪ (2000); Kivinen et al. (2008); Kleijn et al. (2011), all in: Tainio et al. (2016)
9. Wenzel et al. (2006); Polus et al. (2007), both in: Tainio et al. (2016)
10. Meier et al. (2017)
11. Meier et al. (2011), in: Meier et al. (2017)
12. Saraiva et al. (2019)
13. Meier et al. (2019)