Forestry in numbers

Forests make up about one third of the area of the country. Most present-day forest stands were planted artificially and do not correspond to the original species composition of the forests. They consist mostly of single-species stands with a predominance of spruce and pine. The development of the contemporary landscape is affected primarily by secondary ecosystems. Original, natural ecosystems are scarce in the landscape (1).

The area of forests in the Czech Republic has been consistently increasing since the second half of the 20th century, especially as a consequence of long-term afforestation of unproductive agricultural land; the annual increase has been approx. 2000 ha in recent years. The Czech Republic is in 12th place in Europe in the percentage of forest area (1).

In recent years, afforestation has been characterized by an attempt to increase the share of broad-leaved species at the expense of coniferous species. In 2006, 75.1% of forest stands consisted in coniferous species (compared to 76.5% in 2000), with 23.9% broad-leaved species (compared to 22.3% in 2000) (1).

Vulnerabilities - Czech Republic

Forest pests and diseases

A greater frequency of occurrence of pests, especially bark beetles, leaf eating insects and sap-sucking insects is expected in the future. Species that have not yet been recorded in this country could spread. The stress burden will probably lead to an increased proportion of dry wood and thus greater occurrence of fungal diseases (1).

The decline of forest stands is a consequence of the mutual action of biotic and abiotic stress factors, which fundamentally affect the physiological function of the tree species and thus their state of health, including their susceptibility to fungal diseases and insect pests (1).

The increased air tem­perature can influence pest populations mainly by (30)

• prolonged vegetation season and availability of host plants,
• accelerated development of a single generation in multivoltine species,
• lower mor­tality rate during winter, and
• overall change in the pest development.

It is projected that severe re­gional heat waves may become more frequent in a changing climate, thereby increasing the spruce susceptibility to bark beetle attacks. In addition, forest stands damaged by wind are  especially important precursors to outbreaks as they quickly provide large quantities of optimal breeding material (31). Thus a projected increase in the windstorm frequency (32) could also escalate the bark beetle threat to forests in future.

Climate change is expected to influence the distribution and population dynamics of many insect pests, with potential severe impacts on forests. Spruce bark beetle is the most important forest insect pest in Europe whose development is strictly regulated by air temperature. From model studies (33) it was shown that while a two-generation regime dominated in the Czech Republic in the period 1961–1990, significant three-generation regime regions are projected to appear in the near future (2025–2050). In the distant future (2075–2100), the three-generation regime can be expected to occur over all existing coniferous stands in the Czech Republic. These studies are based on just one emission scenario, however (IPCC A1B scenario). Hence the distant future projections could be subjected to particularly large uncertainty (33).

Heat stress and droughts

Climate change in relation to anticipated threat to forests in the Czech Republic has been studied (for the IPCC A1B emission scenario) in relation to four elevation zones with specific potential forest vegetation (24):

• up to 350 m a.s.l. (oak dominance),
• 350–600 m a.s.l. (beech dominance),
• 600–900 m a.s.l. (beech-fir dominance),
• 900–1,100 m a.s.l. (spruce dominance).

It was found that the frequency of heat spells at lower elevations is expected to increase dramatically compared to higher elevations. In general, drought is presumed to become a key limiting factor at lower elevations, while increased temperature along with the prolonged vegetation season at higher elevations can be beneficial to forest vegetation. Consequently, northward progression of forest tree species and retraction of the species lower distribution range are a generic response pattern. Such impacts are presumed to be accompanied by changes in the distribution and population dynamics of pests and pathogens (34).

Climate change impacts on the growth and natural mortality of Norway spruce Picea abies, European beech Fagus sylvatica, and oak Quercus sp. have been estimated for Central Europe for the IPCC SRES A1B scenario for 2021–2050 and 2071–2100, compared with 1961–1990 (based on two global climate models and four regional climate models). Growth simulations indicated that climate change will substantially affect the growth of spruce and beech, but not of oak, in Central Europe. Growth of spruce and beech in their upper distribution ranges was projected to improve, while drought-induced production decline was projected at the species’ receding edges. The results indicate that oak production will either remain the same as in the reference period or will increase. Future production of beech seems uncertain and might decline, while spruce production is likely to increase (36).

Windstorm damage

Under the assumption that the wind climate will not change, the risk of windstorms for forestry between now and 2100 will increase in the Czech Republic due to an increase in the exposure of the amount of forest to windstorms (35).

Vulnerabilities - Overview

The increased vulnerability of forests (and people) with respect to climate change refers to several impacts (22,28):

• Forest cover: conversion of forests to non-woody energy plantations; accelerated deforestation and forest degradation; increased use of wood for domestic energy.
• Biodiversity: alteration of plant and animal distributions; loss of biodiversity; habitat invasions by non-native species; alteration of pollination systems; changes in plant dispersal and regeneration.
• Productivity: changes in forest growth and ecosystem biomass; changes in species/site relations; changes in ecosystem nitrogen dynamics.
• Health: increased mortality due to climate stresses; decreased health and vitality of forest ecosystems due to the cumulative impacts of multiple stressors; deteriorating health of forest-dependent peoples.
• Soils and water: changes in the seasonality and intensity of precipitation, altering the flow regimes of streams; changes in the salinity of coastal forest ecosystems; increased probability of severe droughts; increased terrain instability and soil erosion due to increased precipitation and melting of permafrost; more/earlier snow melt resulting in changes in the timing of peak flow and volume in streams. The capacity of the forest ecosystem to purify water is an important service, obviating the cost of expensive filtration plants.
• Carbon cycles: alteration of forest sinks and increased CO2 emissions from forested ecosystems due to changes in forest growth and productivity.
• Tangible benefits of forests for people: changes in tree cover; changes in socio-economic resilience; changes in availability of specific forest products (timber, non-timber wood products and fuel wood, wild foods, medicines, and other non-wood forest products).
• Intangible services provided by forests: changes in the incidence of conflicts between humans and wildlife; changes in the livelihoods of forest-dependent peoples (also a tangible benefit); changes in socio-economic resilience; changes in the cultural, religious and spiritual values associated with particular forests.

Productivity

Increasing CO2 concentration can affect tree growth through increased photosynthetic rates and through improved water-use efficiency. There will be complex interactions, however: forest growth rates may well be increased in some cases by rising levels of atmospheric CO2, but rising temperatures, higher evaporation rates and lower rainfall may lower growth rates in other cases (13).

Non-timber products

Increasingly there are concerns about the productivity of non-timber products such as medicines and foods. Relatively little information is available in the scientific literature about the sustainable management of such products, and even less is known about their vulnerability to climate change (22).

Vulnerabilities – Temperate forests in Europe

Present situation

In parts of Europe with temperate forests, annual mean temperatures are below 17°C but above 6°C, and annual precipitation is at least 500 mm and there is a markedly cool winter period (2). Temperate forests are dominated by broad-leaf species with smaller amounts of evergreen broad-leaf and needle-leaf species (3). Common species include the oaks, eucalypts, acacias, beeches, pines, and birches.

Many of the major factors that influence these forests are due to human activities, including land-use and landscape fragmentation, pollution, soil nutrients and chemistry, fire suppression, alteration to herbivore populations, species loss, alien invasive species, and now climate change (4).

Forest productivity has been increasing in western Europe (5). This is thought to be from increasing CO2 in the atmosphere (6), anthropogenic nitrogen deposition (7), warming temperatures (8), and associated longer growing seasons (9).

Trends

Most models predict continuing trends of modestly increasing forest productivity in Western Europe over this century (10). Projections for the time near the end of the next century generally suggest decreasing growth and a reduction in primary productivity enhancement as temperatures warm, CO2 saturation is reached for photosynthetic enhancement, and reduced summer precipitation all interact to decrease temperate zone primary productivity (11). The projected increased occurrence of pests, particularly in drought-stressed regions, also contributes to decreased long-term primary productivity in some regions of temperate forests  (12).

Sensitivity to increasing air pollution loads, particularly nitrogen deposition and tropospheric ozone, will impact large areas of the northern temperate forest over the next century. In the temperate domain, air pollution is expected to interact with climate change; while the fertilization effects from nitrogen deposition are still highly uncertain, pollutants such as ozone are known to diminish primary productivity (13).

Migration

The ranges of northern temperate forests are predicted to extend into the boreal forest range in the north and upward on mountains (14). The distribution of temperate broadleaved tree species is typically limited by low winter temperatures (15). Since the latter are projected to rise more rapidly than summer temperatures in Europe and North America, temperate broad-leaved tree species may profit and invade currently boreal areas more rapidly than other temperate species.

Carbon sinks/sources

Temperate forest regions in the highly productive forests of western Europe (16) are known to be robust carbon sinks, although increased temperature may reduce this effect through loss of carbon from soils (17). Weaker carbon sinks or even carbon losses are seen for temperate forests in areas prone to periodic drought, such as southern Europe (18).

Models suggest that the greatest climate change threat to temperate forest ecosystems is reduced summer precipitation, leading to increased frequency and severity of drought (19). This will probably be most prominent in temperate forest regions that have already been characterized as prone to drought stress, such as southern Europe. Drought-stricken forests are also more susceptible to opportunistic pests and fire (20). Together, these related effects can potentially change large areas of temperate forest ecosystems from carbon sinks to sources.

Benefits

Globally, based on both satellite and ground-based data, climatic changes seemed to have a generally positive impact on forest productivity since the middle of the 20th century, when water was not limiting (29).

Timber production in Europe

Climate change will probably increase timber production and reduce prices for wood products in Europe. For 2000–2050 a change of timber production in Europe is expected of -4 to +5%. For 2050–2100 an increase is expected of +2 to +13% (21).

Vulnerabilities – Carpathian forests

Forests provide a number of important ecosystem services to society. They provide timber and protect against floods, mudflows, and other natural hazards by regulating water flows. Another important service is the accumulation of carbon. The more carbon is accumulated in the trees of a forest, the more this forest contributes to the mitigation of climate change. Global warming will change the composition of forests, and this will affect the provision of ecosystem services (38). This is not just due to the direct impact of higher temperatures and changing precipitation patterns. In particular bark beetle infestations will also likely increase due to more favourable thermal conditions and higher susceptibility of host trees due to stronger drought stress (39).

The Carpathian forests as an example

The Carpathian forests are an example of forests where significant changes are expected in the composition of tree species, leading to a reduction of forest carbon sink capacity (40). These forests are the second largest mountain range in Europe predominantly covered with forests. They span seven countries (Czech Republic, Hungary, Poland, Romania, Serbia, Slovakia, and Ukraine). Because carbon sequestration is the most important climate regulating function in European temperate forests (41), the Carpathians play a key role in climate change mitigation for the region (37).

The future forest and carbon dynamics of the Carpathians was studied by means of a forest landscape model including interactions between vegetation, climate, and disturbance regimes (37). The study area was chosen in Ukraine, in the centre of these forests. Prevailing tree species in this area are European beech, sessile oak (at lower elevations), and Norway spruce and silver fir (at mid-high elevations. Pedunculated oak, European hornbeam, and sycamore maple are also very common for the study region (42).

The impacts of four different scenarios of climate change were studied: a low-end and a high-end scenario, and two intermediate scenarios (the so-called RCP2.6, RCP4.5, RCP6.0, and RCP8.5 scenarios). For these scenarios, projected temperature change between the period 1980-2005 and the period 2071-2095 was calculated. This temperature was then kept constant for 500 years since forest tree composition responds very slowly to climate change, although this response is faster due to natural disturbances such as bark beetle infestations (43). Predicted precipitation changes in this region are minor and thus considered negligible (44).

A significant reduction of stored carbon

The results show a change in species composition accompanied by a significant reduction of the amount of carbon that is stored in the trees above the ground, the so-called ‘aboveground live carbon’ (ALC). Projected changes after 500 years are such that between 2.1% (RCP2.6) and 14.0% (RCP8.5) less carbon is stored in trees above the ground. The additional impact of disturbances such as bark beetle infestations led to an additional reduction of 4.5% − 6.6% stored carbon (37).

This reduction is especially due to the contraction of spruce forests in favour of hornbeam- and maple-dominated forests, and an upward shift of beech- and fir-dominated forests. Soil water stress in response to increasing air temperatures is an important driver of these changes (45). These findings are consistent with previous studies on vegetation dynamics under climate change in Europe (46).

The study illustrates that a strong spruce decline under global warming in European forests may turn these forests into a carbon source and thus reinforce global warming.

Adaptation strategies

The optimum model for forestry from the standpoint of climate change, while respecting the precautionary principle, seems to consist in a structurally varied forest, managed by close to nature practices, preferring habitat-suitable tree species with high and stable production of wood material, managed mainly utilizing natural processes with minimization of energy inputs (1).

Measures that are already implemented are (1):

• increasing the adaptation potential of forests through species, genetic and age diversification of tree stands The aspect of species diversity is connected particularly with the reduction of spruce stands and the increase of the share of broad-leaved and fir trees. The number of broad-leaved trees in the natural composition of forests should be approximately three times their current quantity. The natural conditions in this country provide sufficient scope for implementation of this measure. … Forest differentiation thus reduces the risk of extensive decomposition of the forest and substantially contributes to stabilization of carbon stocks. …  At the present time, the Ministry of the Environment is preparing a methodical instruction for the management of richly structured forests in national parks;
• implementation of sounder management methods and elimination of pressure from game;
• reduction of the risk of increased populations of insect pests, vascular mycosis and especially root rot.

Measures that are planned are (1):

• promotion of species and ecotypes of more resistant forest tree species maintaining high, stable production of wood material;
• promotion of ecologically advantageous afforestation of agricultural land, particularly by stands of fast-growing tree species;
• prolonging the legal deadlines for afforestation and provision for tree stands in connection with the natural renewal of the forest;
• reducing degradation of the soil and increasing the amount of carbon bound in the soil;
• directing subsidy rules towards support for adaptation measures reducing the impacts of climate change.

Adaptation strategies - Forest management measures in general

Near-nature forest management and a move away from monocultures toward mixed forest types, in terms of both species and age classes, are advocated. In addition, natural or imitated natural regeneration is indicated as a method of maintaining genetic diversity, and subsequently reducing vulnerability. For management against extreme disturbances, improvements in fire detection and suppression techniques are recommended, as well as methods for combating pests and diseases. It is reported that through stricter quarantine and sanitary management, the impact of insects and diseases can be minimized. The establishment of migration corridors between forest reserves may aid in the autonomous colonization and migration of species in response to climate change (26).

Adaptation strategies - Carpathian forests

Foresighted management strategies are needed to facilitate vegetation adaptation to climate change, with the goal of stabilizing carbon storage and maintaining economic value of future Carpathian forests. The authors of this study recommend that managers consider fostering highly productive tree species where they are expected to be adaptable in the future, and facilitating the adaptation of forest vegetation to novel environmental conditions where disturbances are expected to increase significantly. Active measures, like planting of oak, beech, and fir at higher locations, may facilitate the adjustment process (37).

Adaptive management

The terms adaptation and adaptive management are often incorrectly used interchangeably. The former involves making adjustments in response to or in anticipation of climate change whereas the latter describes a management system that may be considered, in itself, to be an adaptation tactic (23). Adaptive management is a systematic process for continually improving management policies and practices by learning from the outcomes of operational programmes (24). It involves recognizing uncertainty and establishing methodologies to test hypotheses concerning those uncertainties; it uses management as a tool not only to change the system but to learn about the system (25).

Both the climate and forest ecosystems are constantly changing, and managers will need to adapt their strategies as the climate evolves over the long term. An option that might be appropriate today given expected changes over the next 20 years may no longer be appropriate in 20 years’ time. This will require a continuous programme of actions, monitoring and evaluation – the adaptive management approach described above (22).

There is a widespread assumption that the forest currently at a site is adapted to the current conditions, but this ignores the extent to which the climate has changed over the past 200–300 years, and the lag effects that occur in forests. As a result, replacement of a forest by one of the same composition may no longer be a suitable strategy (22).

Adaptation to climate change has started to be incorporated into all levels of governance, from forest management to international forest policy. Often these policies are not adopted solely in response to climate, and may occur in the absence of knowledge about longer-term climate change. They often serve more than one purpose, including food and fuel provision, shelter and minimizing erosion, as well as adapting to changing climatic conditions (26).

Socio-economic and political conditions have significant influences on vulnerability and adaptive capacity. Climate change projections are perceived by many forest managers as too uncertain to support long-term and potentially costly decisions that may be difficult to reverse. Similarly, uncertainty over future policy developments may also constrain action. Finance is a further barrier to implementing adaptation actions in the forest sector (27).

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 the Czech Republic.

1. Ministry of the Environment of the Czech Republic (2009)
2. Walter (1979), in: Fischlin (ed.) (2009)
3. Melillo et al. (1993), in: Fischlin (ed.) (2009)
4. Reich and Frelich (2002), in: Fischlin (ed.) (2009)
5. Carrer and Urbinati (2006), in: Fischlin (ed.) (2009)
6. Field et al. (2007b), in: Fischlin (ed.) (2009)
7. Hyvönen et al. (2007); Magnani et al. (2007), both in: Fischlin (ed.) (2009)
8. Marshall et al. (2008), in: Fischlin (ed.) (2009)
9. Chmielewski and Rötzer (2001); Parmesan (2006), both in: Fischlin (ed.) (2009)
10. Alcamo et al. (2007); Field et al. (2007b); Alo and Wang (2008), all in: Fischlin (ed.) (2009)
11. Lucht et al. (2006); Scholze et al. (2006); Alo and Wang (2008), all in: Fischlin (ed.) (2009)
12. Williams et al. (2000); Williams and Liebhold (2002); Logan and Powell (2001); Tran et al. (2007); Friedenberg et al. (2008), all in: Fischlin (ed.) (2009)
13. Fischlin (ed.) (2009)
14. Iverson and Prasad (2001); Ohlemüller et al. (2006); Fischlin et al. (2007); Golubyatnikov and Denisenko (2007), all in: Fischlin (ed.) (2009)
15. Perry et al. (2008), in: Fischlin (ed.) (2009)
16. Liski et al. (2002), in: Fischlin (ed.) (2009)
17. Piao et al. (2008), in: Fischlin (ed.) (2009)
18. Morales et al. (2007), in: Fischlin (ed.) (2009)
19. Christensen et al. (2007); Fischlin et al. (2007); Meehl et al. (2007); Schneider et al. (2007), all in: Fischlin (ed.) (2009)
20. Hanson and Weltzin (2000), in: Fischlin (ed.) (2009)
21. Karjalainen et al. (2003); Nabuurs et al. (2002); Perez-Garcia et al. (2002); Sohngen et al. (2001), in: Osman-Elasha and Parrotta (2009)
22. Innes (ed.) (2009)
23. Ogden and Innes (2007), in: Innes (ed.) (2009)
24. BCMOF (2006a), in: Innes (ed.) (2009)
25. Holling (1978); Lee (1993, 2001), all in: Innes (ed.) (2009)
26. Roberts (ed.) (2009)
27. Keskitalo (2008), in: Roberts (ed.) (2009)
28. Kirilenko and Sedjo (2007)
29. Boisvenue et al. (2006)
30. Porter et al. (1991), in: Hlásny et al. (2011)
31. Grodzki et al. (2006), in: Hlásny et al. (2011)
32. Giorgi and Coppola (2007), in: Hlásny et al. (2011)
33. Hlásny et al. (2011a)
34. Hlásny et al. (2011b)
35. Schelhaas et al. (2010)
36. Hlásny et al. (2011c)
37. Kruhlov et al. (2018)
38. Hlásny et al. (2016, 2017); Keeton et al. (2013), both in: Kruhlov et al. (2018)
39. Kautz et al. (2017); Netherer et al. (2015), both in: Kruhlov et al. (2018)
40. Bonan (2008), in: Kruhlov et al. (2018)
41. Naudts et al. (2016); Schwaab et al. (2015); Thom et al. (2017b), all in: Kruhlov et al. (2018)
42. Prots and Kagalo (2012), in: Kruhlov et al. (2018)
43. Thom et al. (2017a), in: Kruhlov et al. (2018)
44. Alder and Hostetler (2013), in: Kruhlov et al. (2018)
45. Shvidenko et al. (2017), in: Kruhlov et al. (2018)
46. Hanewinkel et al. (2013); Hickler et al. (2012); Thom et al. (2017a), all in: Kruhlov et al. (2018)