Vulnerabilities - Hungary

Effects of decreasing precipitation, drought and extreme weather phenomena can unambiguously be traced in the Hungarian forests. Hungary is characterized by relatively low forest cover ratio and the high ratio of deciduous trees. Macro-climatic conditions have already created a critical situation for the stand-forming tree species over a substantial part of the country (mainly in the great lowland plains, called the ’Alföld’). A relatively small rise of the temperature and small decrease of precipitation can induce changes that are having an impact on the forest biocoenosis. Decisively degrading impacts are expected, which cannot be rectified by the natural self-regulating mechanisms and neither by the human interventions (30).

Presently game overpopulation causes serious damages to forests and this damage is 2-10 fold larger than that of the year 1971. The game stock might amplify the impacts of climate changes and therefore the populations of deer and wild boar should be decreased (30).

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

The ratio of forested land is rather low (18.9%). Although many tree species may benefit from a warming of about 1⁰C, further warming combined with water deficiency may lead to poorer growth and even dieback. The long life-cycle plants, such as hornbeam, sessile oak or Scots pine will probably suffer from water deficiency in summer because of increased assimilation activity and evapotranspiration (1).

The climate will be favourable for those plants that can tolerate summer droughts and demand or eventually tolerate precipitation surpluses in spring and winter, therefore the appearance of plant species of southern character, such as eastern hornbeam, Turkey oak, Hungarian oak is expected (1).

In the middle part of the Carpathian Basin, the continental climate zone may turn into typical steppe climate, therefore the extension of the regions covered by forest steppe would be larger in horizontal and vertical directions. The most disadvantageous climatic changes may be experienced by lowland coniferous stands as we already can see in the black pine forests of the Balaton hills (1).

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 (32). 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 (33).

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 (34). 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 (35), the Carpathians play a key role in climate change mitigation for the region (31).

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 (30). 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 (36).

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 (37). Predicted precipitation changes in this region are minor and thus considered negligible (38).

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 (31).

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 (39). These findings are consistent with previous studies on vegetation dynamics under climate change in Europe (40).

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

Hungary

Adaptation strategies might include (30):

• the mycorrhizal inoculation of seedlings;
• the further increase of tree species diversity with dryness-tolerant endemic Hungarian species;
• the protection of groundwater;
• halting of harmful anthropogenic strategies (such as drainage and stream regulation;
• the careful exploration of the sites selected for forestation;
• the selection of tree species that are suitable for all these purposes.

Forest plantation, forest regeneration, interrow cropping, grove planting, park planting, tree planting, wood utilisation, etc. are forestry techniques, which are likely to gain much importance on the long term and therefore it is desirable to assure the technical conditions that are needed for these approaches. The most urgent tasks are the provision of appropriate machinery for seedling production and for the forest planting and tending techniques (30).

Private forests play an increasing role in Hungary in the protection and expansion of forests (presently about 40% of the forests are owned privately and it is expected that those agricultural land owners who terminate plough-land cultivation will turn towards forestry). It is important to provide advisory services for private forest owners and to curtail the bureaucracy of the respective state administration (30).

Forest management should be prepared for securing appropriate watering and feeding of games and for avoiding game damages on both forested and agricultural land. Adaptation strategies of forest management must include the careful and sparing use of all available water resources of forest sites, with the main objective of the storage of water for watering of plants and animals and for water-game habitat preservation purposes. The habitat of small games can be favourably affected by grassing and the planting of forest strips, mosaic woodlots and groves, while forestation will increase the habitat of big games (30).

Forest management measures in general

The method of gradual regeneration should be a widely used application instead of clear cutting. This reforestation method could moderate all kinds of harmful effects on forests. In case of new forest plantations, we should select not only the indigenous ones, but also other species that can tolerate unfavourable conditions. This raises another problem: the issue of nature conservation, which is opposed to planting of non-indigenous trees.

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 (31).

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 Hungary.

1. Kellomäki et al. (2000)
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. Farago et al. (2010)
31. Kruhlov et al. (2018)
32. Hlásny et al. (2016, 2017); Keeton et al. (2013), both in: Kruhlov et al. (2018)
33. Kautz et al. (2017); Netherer et al. (2015), both in: Kruhlov et al. (2018)
34. Bonan (2008), in: Kruhlov et al. (2018)
35. Naudts et al. (2016); Schwaab et al. (2015); Thom et al. (2017b), all in: Kruhlov et al. (2018)
36. Prots and Kagalo (2012), in: Kruhlov et al. (2018)
37. Thom et al. (2017a), in: Kruhlov et al. (2018)
38. Alder and Hostetler (2013), in: Kruhlov et al. (2018)
39. Shvidenko et al. (2017), in: Kruhlov et al. (2018)
40. Hanewinkel et al. (2013); Hickler et al. (2012); Thom et al. (2017a), all in: Kruhlov et al. (2018)