HABIT-CHANGE. Managing Spruce Forests Under Climate Change

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1 HABIT-CHANGE Managing Spruce Forests Under Climate Change HABIT-CHANGE is evaluating, enhancing and adapting the management and conservation strategies in protected areas of Central and Eastern Europe. The activities are aimed to respond pro-actively to current effects of climate change and to foster preparedness for likely future impacts. The acronym HABIT-CHANGE not only stands for changes of habitats, but also for the necessary adaptation of our own habits in conserving biodiversity. Results for the management of spruce dominated forests and their ecosystems will be published in this leaflet. It will illustrate climate change effects and management options in regard to Natura 2000 management. This project is implemented through the CENTRAL EUROPE Programme co-financed by the ERDF

2 HABIT-CHANGE Forest Habitats and Climate Change Climate change is already affecting Europes biodiversity. Altered water regimes or other abiotic conditions are likely to change the character of habitats and ecosystems. The timing of seasonal events like the first flowering date for plants and breeding date of birds has changed and species are shifting their geographic distribution northwards or to higher altitudes. Projected future climate trends indicate a further acceleration of changes in timing and in distribution of species and ecosystems, and intensify overall biodiversity loss. Even though mitigation of climate change is of utmost importance, also the management of Europes natural capital and heritage needs to be adapted to climate change or its impacts will lead to the degradation of habitats, the extinction of species and the loss of ecosystem services that are essential for human well-being. This is especially true for protected areas and Natura 2000 sites. Natura 2000 is aimed at achieving and maintaining a good conservation status of protected species and habitats by protecting and managing selected areas of community interest. Present forest stands represent the result of both - natural conditions and human activity. The influence of ecological factors on forest growth and structure has been in focus of environmental research since decades. Changing climate conditions as in the course of global climate change involve disturbances of the current equilibrium and thus, induce new adaptation processes of forest ecosystems. However, adaptation processes are restricted by both natural and cultural boundaries. Locally available species inventory, genetic and site diversity or species-specific ecological needs, respectively are decisive for a consequent adaptation potential. Additionally, adaptive processes cannot perform freely due to major anthropogenic induced aspects of air pollution and of European land-use, particularly the fragmentation of landscapes and a lack of habitat connectivity. Inherently forests are characterised by a long regeneration cycle and cannot adapt rapidly to environmental changes. IPCC (2007): FOURTH ASSESSMENT REPORT (AR4) The project HABIT-CHANGE has evaluated how management of individual sites can be adapted to climate change. The partners of the HABIT- CHANGE project recommend several actions on EU level to foster adaptation to climate change in conservation planning, protected area management and land-use policies. The proposed recommendations build on the projects experience in the implementation of climate adapted management in Natura 2000 sites of Central and Eastern Europe and draws on a number of recent strategic initiatives in the field of climate adaptation and biodiversity conservation. The projected changes in climate are likely to affect the forest ecosystems by both direct effects (e.g. physiological impairment or damage) and indirect effects, such as forest fires or pests. A number of long-term climate trends regarding seasonal temperature and precipitation patterns might be compensated by ecological adaptation processes, such as changes in species composition, age structure as well as modifications of physiological processes of individual plants. Other changes such as a prolonged vegetation period may equally result in enhanced vitality and growth rates. Particular thermophile species could even benefit to a large extent from warmer and dryer conditions

3 Nonetheless, current forest stands with its established species composition are adapted to current soil and climate conditions and the projected pace and magnitude of changing climate conditions is likely to exceed the adaptive capabilities of many forest stands in its current constitution. In particular expected changes of the frequency, magnitude or duration of extreme events such as drought, heat waves, heavy precipitation, wet snow loads or storm events can trigger the ecological functionality of certain plant types, development stages or individuals and thus, modify the ecological characteristics of forest stands fundamentally. Information on potential vulnerability of particular species can be obtained by the application of climate envelopes. This characterisation of climatically suitable conditions can be combined with species distribution data in order to derive species distribution models and generate maps of potential current and future species distribution. Calculated potential shifts of spatial distribution (dispersion, aggregation) and suitable area (enlargement, reduction) can help to identify relevant areas characterised by habitat gain or loss and thus, facilitate provident planning and controlling processes. It becomes obvious, that the projected climatic conditions may become critical especially for the azonal and spruce-dominated forest habitat types. In terms of the assessment of habitat sensitivity towards climate change, a qualitative method was applied in HABIT-CHANGE. The approach aims for the classification of the sensitivity of several habitat types under consideration of pressures (land use, eutrophication), regenerability, spatial distribution, invasion of alien species, dependency on ground water and overflow as well as conservation status. According to the biogeographical distribution of habitats and the respective ground water availability, flooding conditions and climatic pressures, different sensitivity levels were identified. As expected, especially alluvial forests, bog woodlands and ravine forests, were classified as highly sensitive habitats. Above all, the montane to alpine acidophilous spruce forest habitat type (Vaccinio-Piceetea-FFH-type 9410) shows the highest level of sensitivity to climate change. Natura 2000 Natura 2000 is the key instrument to protect biodiversity in the European Union. It is an ecological network of protected areas, set up to ensure the survival of Europe's most valuable species and habitats. Natura 2000 is based on the 1979 Birds Directive and the 1992 Habitats Directive. The green infrastructure provides safeguards for numerous ecosystem services and ensures that Europe's natural systems remain healthy and resilient. Forests represent about one third of the reported protected areas of the flora and fauna directive, Natura 2000 in Europe. Among those, there are three rare types of forest habitats in the zone of temperate conifer forests. Germany has a great responsibility on obtaining two of these three natural forest types

4 Natura 2000 habitat types in Europe (in Germany & in Thuringia) Forest Habitat Types and Spruce Forests of Natura 2000 Mountainous to subalpine natural or close-tonature spruce forests (Vaccinio-Piceetea) of the high and also the low mountain ranges, have also been reported as habitat by Thuringia. Here two subtypes are distinguished: the subalpine spruce forest in the Alps and the hercynian spruce forest of the highlands above 750m above sea level. Naturally the Vaccinio-Piceetea includes wide locational amplitude of silicate to calcareous soils, cold air dominated hydrophilic to xerophilic vegetation types. It is limited to mountainous to sub-alpine locations in the natural range of spruce, mostly poor soils and characterised by the dominance of spruce. Nonnatural spruce plantation forests outside the natural range of spruce forests do not represent those habitats and are excluded. Besides Spruce (Picea abies Karst.) also Silver Fir (Abies alba Mill.), Sycamore Maple (Acer pseudoplatanus L.), White Birch (Betula pubescens Ehrh.) and Rowan (Sorbus aucuparia L.) can be found. attribute requirement best rating `A worst rating `C habitat structure different stages of forest development > 3 different stages (distribut. patches) only 1 large & uniform patch Conserva$on Status The reported conservation status (rating) as the result of criteria for habitat structure, species composition and observed impairments in Germany were given by the official habitat type descriptions and the recommended evaluation matrix as provided by the German federal Working Group for Conservation (LANA) and the Conference of Forest Directors (FCK). Those spruce habitats reported by Thuringia, never reach the best conservation status "A" and are only represented on 40% of the reported area by the state "B". Even without considering the added pressure climate change, the habitat types of Vaccinio-Piceetea have to be improved by an adapted and continuous habitat management to secure sustainable existence. habitat specific species stock & species composition impairment biotope & overmature trees thick deadwood typical tree & herb layer, oriented on natural vegetation damages on forest soil, water balance, vegetation & structure occurrence of nonhabitat specific invasive species habitat fragmentation & disturbances 6 units per ha > 3 units per ha lying & standing 90% of the layer area non-existent nonobserved without disturbances, pathways & streets < 1 unit per ha 1 unit per ha lying or standing 70% of the layer area existent on > 33% of the habitat observed on > 50% of the habitat > 25m per ha fixated forest pathways & streets - 3 -

5 Implica$ons of Climate Change for Acidophilous Picea Forests Depending on the climate change characteristics and the habitat type, three different classes of climate-induced effects and a number of corresponding impacts could be identified: (1) large-area disturbances, e.g. caused by storm, pests or fire resulting in: homogeneous habitat structures, failure and lack of particular structural elements, drastic changes of habitat-specific species inventory and composition, significant impairments of forest soils, water balance and vegetation. (2) small-scale and scattered damages in forest stands (species or structure specific (a)- biotic implications, e.g. caused by insects, frost or heatwaves, lightning stroke) involving: heterogeneous habitat structure and stronger presence of particular structural elements, commonly easy to compensate selective loss of habitat-specific species inventory, various small-scale impairments, that can be rapidly restored. (3) gradual shifts of climate conditions, e.g. increasing temperature, increasing vegetation periods, decreasing climatic water balances leading to: at most marginally improved habitat structures, stand- or habitat-specific changes in terms of species inventory, especially regarding the: 91D0 & 91E0 in case of a malfunctioning water regime (but not yet expected), 9410 on moderately moist mesotrophic, highly skeletal silicate soils, in case climate change favors European Beech and Silver Fir (transition towards 9110), 9110 on eutrophic sites, in case milder climatic conditions support the occurrence of European Ash, Sycamore Maple and Elm (towards 9130). halting and rapidly compensated impairments on a small-scale. Predicted survival probability (red = low, green = very high) for key species of the habitat types Luzulo-Fagetum, Asperulo-Fagetum and Vaccinio-Piceetea for the Biosphere Reserve Vessertal-Thuringian Forest, Germany using specific soil conditions and SRES -A1B, ECHAM5 and WETTREG-regionalisation. Remarkably, large-scale disturbances as currently approved by process-oriented conservation management, encompass a risk of devaluation for the habitat type quality. In particular the criterias biotope and over mature trees and thick deadwood can be affected by those climate-induced effects (e.g. loss or uniformly dimensioned deadwood types). In Thuringia there is actually a high vulnerability for the montane acidophilous spruce forests habitat type (9410), arising from a potentially intensified dispersion of beech and sycamore maple. Additionally, this habitat type is exposed to storm events, especially in mountain ridges and adjacent to treeless bog areas. In the long term, climate change and corresponding impacts can involve changes in habitat structure, species composition and thus, conservation status and spatial distribution of reported forest habitats. These findings should be considered for the development of climate change-integrated conservation strategies

6 Climate Change Adapted Management Climate change considerably influences forest ecosystems through potential alterations of temperature and precipitation regimes as well as the intensification and frequency of disturbances. A prolonged vegetation period may result in enhanced vitality and growth rates. Particular thermophile species could benefit to a large extent from warmer and dryer conditions. Higher CO 2 concentrations in the atmosphere could have a certain fertilization effect and affect tree growth. However, negative impacts of climate change on Natura 2000 habitats could outweigh and therefore advocate a customised management. General recommendations for the establishment of near-natural forests should be developed to promote pro-active climate-driven forest adaptation. Azonal and spruce-dominated forest habitat types are likely subject to particularly drastic changes associated with climate change. Options for adaptation by management mainly involve the restoration and creation of highly structured forest stands in favour of the forest habitat types 9410 according to storm events or wet snow loads. Vast areas of poorly structured spruce monocultures still need to be converted into diverse, highly structured mixed stands. In this context, structured forest edges, spatial diversity and small patches of different forest development phases also have to be created and promoted. The ecological gradient of the mixed mountain forest of the montane zone can be ensured by the anticipatory creation or promotion of site-adapted tree species and structures. On the other hand the climate-induced spreading of the European beech into the ridge areas of the forest area may threaten the typical species composition of the acidophilous Picea forests of the montane zone (9410). The positive effects of an active management in favour of spruce and supplementary intermixed montane species could quickly be offset by disturbances. Potential forest conversion areas located near protected areas need to be assessed with respect to options for habitat development, connectivity and landscape permeability. Nevertheless, the concept of near-natural climate plastic forest management always needs to be firmly supported by site-adapted game management, a modern concept for managing deadwood as well as nesting, cavity and biotope trees, the thoughtful use of forest machinery and minimal impairments by other pressures and impacts such as pollution, land consumption and biotope fragmentation. Nico Frischbier, Ingolf Profft, Fritz Richter, Nils Feske Service and Competence Centre of ThüringenForst-Institution under public law (SuK) Jägerstraße 1, DE Gotha (Germany) Judith Stagl, Fred Hattermann, Martin Gutsch Potsdam Institute for Climate Impact Research (PIK), Telegrafenberg A62, DE Potsdam (Germany) Click for more information: