Climatic Change DOI 10.1007/s10584-015-1330-5
Forestry professionals’ perceptions of climate change, impacts and adaptation strategies for forests in south-west Germany Rasoul Yousefpour & Marc Hanewinkel
Received: 30 July 2014 / Accepted: 12 January 2015 # Springer Science+Business Media Dordrecht 2015
Abstract Forestry professionals’ perceptions of the risks and uncertainties associated with climate change were investigated in a questionnaire survey in south-west Germany. The respondents were employed in forestry in either public or private forests or working for state authorities. They were specifically asked about the related impacts of climate change on forest ecosystems, adaptive forest management and the potential of forestry to mitigate climate change. A factor analysis of the responses revealed significant variables explaining the major part of the variance and the key variable groups were identified in a canonical analysis. The majority of respondents (72 %) said they were under-informed, but most (83 %) view climate change as a reality, human-caused, and a significant risk. These forestry professionals were particularly concerned about extreme hazards, water scarcity, and changes in climatic zones. They generally said the potential of forestry to mitigate climate change is low, and saw few realistic measures like increased harvesting to substitute fossil fuels and energy-intensive materials for mitigation. Despite the uncertainty involved, adaptation strategies like using better-adapted tree species and provenances were mainly perceived as helpful, and tools such as spatially-explicit maps with recommendations for adapted species and indices of biotic and abiotic risks as important. The forestry professionals reported obtaining their information about climate change from advanced forestry training, the media, and scientific literature. The findings of the study are discussed in the light of the ongoing debate on climate change in Germany and recommendations made, including periodically checking and improving forestry professionals’ knowledge about climate change.
Electronic supplementary material The online version of this article (doi:10.1007/s10584-015-1330-5) contains supplementary material, which is available to authorized users.
R. Yousefpour : M. Hanewinkel Chair of Forestry Economics and Forest Planning, University of Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany R. Yousefpour (*) Max-Planck-Institute for Meteorology, Bundesstr. 53, 20146 Hamburg, Germany e-mail:
[email protected] M. Hanewinkel Swiss Federal Institute for Forest, Snow & Landscape Research WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
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1 Introduction Climate change is expected to severely affect the tree of life in Europe (IPCC 2007; Thuiller et al. 2011). Forests and the important ecosystem services they provide (MEA 2003) are assumed to be particularly vulnerable to changes in climatic conditions (Bonan 2008). There is, however, often a marked discrepancy between scientist’s knowledge about climate change and that of local stakeholders (Crona et al. 2013). Perceptions of climate change are a subjective risk that is thought to play an increasingly important role in forest risk assessment (Williamson et al. 2005; Yousefpour et al. 2013). Climate affects where and how forests grow through spatiotemporal variation in environmental factors that include atmospheric temperature, precipitation, wind, and humidity. The current global warming may have negative impacts on forests and increase the overall risks to forestry-related activities. We understand Bimpact^ as a specific effect like increased temperature and altered precipitation pattern and the Brisk^ associated with this impact as a product of its probability of occurrence and some estimation of damage (Kaplan and Garrick 1980). Climate change particularly affects plant distribution and a range of major tree species and consequently the development of forests throughout the world (Heller and Zavaleta 2009; Seppälä et al. 2009; Thuiller et al. 2011). It is likely to affect the range of major tree species, the regime of abiotic (Blennow and Olofsson 2008) and biotic (Jactel et al. 2012) disturbances, as well as a the productivity of forests (Reyer et al. 2014). To ensure forests survive the expected environmental changes, several adaptation strategies have been proposed (Bolte et al. 2009a). For example conservation of forest structures assumes low adverse impacts of climate change and high stand resistance to climatic stress, whereas passive adaptation means stopping all management interventions and relying on spontaneous adaptation processes. For many intensively managed forests in Europe, active adaptation is recommended to cope with marked climate change e.g., introducing new tree species or genetically better adapted provenances of existing species, and changing the rotation time or the thinning regime (Bolte et al. 2009b). Various adaptation options in forestry have been investigated Lindner et al. (2010) showed that the adaptive capacity of both ecosystems and society have to be taken into account for successful adaptations. Seidl et al. (2011) developed a framework to assess vulnerability as a precondition for designing adaptation strategies. Yousefpour and Hanewinkel (2014) aimed to optimize strategies to adapt to and mitigate the effects of climate change on Norway spruce stands in Germany with the help of advanced heuristics. Applying Bayesian update approaches seems to be a promising way to actively adapt forest management over time to novel climatic conditions (Yousefpour et al. 2013). To successfully implement adaptation strategies, however, decision makers and forest owners have to be convinced that climate change may be a threat to their forests. Only then will they be prepared to take forward-looking measures to avoid negative consequences in the future, which poses a major challenge: Blennow and Persson (2009) found strength of belief and adaptive capacities to be crucial factors for explaining observed differences in adaptation among a group of private forest owners in Sweden. Similar results were obtained in a European study (Blennow et al. 2012), where personal strength of belief and perception of local effects of climate change were highly significantly explaining human responses to climate change. Yousefpour et al. (2012) reviewed studies on the integration of risk and uncertainty of climate change in adaptive forest management. They emphasised the non-stationary nature of this risk and the necessity of determining risk perception and the beliefs of decision-makers about the current climate to better adapt forest management.
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Informing decision makers about potential adaptation measures seems also to be crucial. In a review of the implementation of climate change adaptation measures in Europe, Kolström et al. (2011), concluded disseminating about suitable adaptation measures to all decision makers is essential for a successful adaptation. Here, forestry professionals can play a crucial role. They include people with professional training in forestry, working either as practitioners in local forest districts in direct contact with private forest owners or in state or local authorities (e.g., ministries, regional councils). Pregernig (2001), found that such professionals’ values tend to be extremely diverse and that different value types respond to policy measures in very specific ways. They act as intermediaries between local or state forest authorities and private and public forest owners and are involved in transferring policy measures such as climate adaptation strategies. It is therefore essential to know more about how this group perceives climate change, and their attitudes towards potential adaptation or mitigation measures. 1.1 Study goals We focused on a group of forestry professionals directly involved in forest decision-making processes to analyse their knowledge and perceptions about: a) climate change and associated risks in general; b) the impacts of climate change on forest ecosystems; c) the need to adapt forests to changing environmental conditions and, d) the potential of forest management activities to mitigate climate change. We therefore aimed to find out more about what forestry professionals in south-west Germany know about climate change and how it affects forest management, in order to develop the most appropriate recommendations for adaptive forest management and mitigation activities to cope with the adverse effects of climate change. Factor analysis was used to reveal the most significant drivers respondents thought as influential about the future of the forests. Canonical analysis was then applied to analyse the major groups of variables they believed would influence the future of the forest in positive or negative ways. This analysis should help to integrate the different opinions of forestry professionals in decision-making about forest management and to identify the best planning aids to support forest practitioners in adapting to climate change. This approach is in line with the methodology in Papageorgiou et al. (2005) and Crona et al. (2013) who used quantitative questionnaires to elicit the attitudes and perceptions of local people to improve forest management decision-making.
2 Methodology 2.1 Survey instrument The questionnaire included a combination of affirmative and negative question formats to keep respondents more alert, and less likely to routinely agree with a given statement (see Tables S1 – S4 - supplementary material). It was designed to elicit and analyse the perceptions of forestry professionals regarding: (1) (2) (3) (4)
the risk of climate change in general the main impacts of climate change on forest ecosystems the best silvicultural strategies to adapt forests to climate change the potential of forestry-related measures to mitigate climate change
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The questionnaire included 69 different questions (variables) and was divided into the four major parts (1) to (4). The potentially useful adaptation measures selected were based on the adaptation measures commonly discussed in Germany by the state forest services (Bolte et al. 2009a, b; Lindner et al. 2010). The last part of the questionnaire elicited the demographic characteristics of the respondents including official position, main duties and age. The software EpiData (EpiData 2009) was used to manage data and do a preliminary descriptive statistical analysis based on 262 valid responses. The questionnaires were distributed at four different advanced training events with 100–150 participants about the effects of climate change in south-west Germany. 2.2 Statistical analysis with principal axis factoring Thee responses to each multiple-choice question on the risk of climate change, impacts of climate change, especially on forest condition, and adaptation and mitigation strategies were analyzed to determine the percentage of each choice of a query chosen by the respondents from the entire responses to that query. The variables were mainly measured on a five point Likert-type scale (Vagias-Wade 2006) i.e., with five alternative responses for each query. We used the correlation matrix among the responses as independent and correlated variables and applied principal axis factoring to extract the main factors from the original correlation matrix (see detaled description of factor analysis in supplementary materials). Canonical analysis visualizes the relationships between a single criterion variable Bforest condition^ and a set of predictor variables derived from significant factors. Each significant factor has a coefficient greater than │0.3│ to define its load of variances and refers to a set of variables. For example, a first factor may involve response variables such as climate change, thinning, and fire risk. These variables directly affect the criterion variable Bforest condition^. These inter-connections between the factor variables and their direction and the criterion variable can best be illustrated in a bi-dimensional canonical analysis plot. The scree plot of derived factors was used to determine the numbers of factors including sufficient variance of responses to the entire set of questions. The scree plot shows the eigenvalues of factors in decreasing order and helps to select the set of factors sufficient for further analysis. Each eigenvalue corresponds to an axis, which accounts for a certain percentage of inertia, i.e., variance among the responses of the forest professionals surveyed. We applied a bi-dimensional visualization to show the links and directions between the significant outcomes of the analysis (factors 1,2,…) defined by a cluster of correlated variables with coefficients greater than │0.3│. This allowed us to measure the cumulative percentage of inertia for a given set of dimensions and determine the correlations among significant variables. We then identified the corresponding groups of variables distinguishing between contradictory groups and simplifying the interpretation of positive and negative correlations between the groups and the criterion variable Bforest condition^.
3 Results 3.1 Characteristics of respondents Nearly 80 % of our respondents work for the public forest service in south-west Germany, of whom almost 70 % (BPublic Forests^ - supplementary Fig. S1) are employed in forest offices (mainly as forest rangers or heads of forest offices) and roughly 10 % work for local or state authorities (ministry, regional council) within the forest service. Some of the respondents
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(14 %) work for private forests owners and are, directly involved in decision-making and active forest management. About 6 % of the respondents were forest scientists, or were employed by NGOs, nature conservation or protection authorities or wood businesses. 3.2 Respondents’ perception of climate change and its impacts Over 80 % of the respondents (218/262) perceived climate change as having anthropogenic origin while very few saw it as a natural phenomenon and 14 % believed that it may be a problem, but the consequences would be more apparent in developing countries than in Germany (supplementary Table S1 gives details about the responses to the general climate change questions). Most of the respondents (70 %) did not think the risk of climate change is very high and were divided about whether forestry can actively manage the negative effects of climate change or just react to the new conditions and climate. Most respondents (85 %) were convinced that long-term planning in forestry can help in dealing with climate change and its impacts and do not see it as a very limiting factor in long-term forestry planning (81 %) as they consider risk to be part of forestry practice (97 %) in general. The majority saw all negative impacts of climate change as challenging, in particular, extreme hazardous events and water scarcity (>60 % very challenging) and habitat loss for flora and fauna and changes in climatic zones as challenging. Increasing sea levels were perceived as a problem but only a third saw it as very challenging. Answers to the question about IPCC scenarios revealed that respondents were very pragmatic about the future projections of the IPCC scenarios, with over 20 % considering the worst scenario (A1) as very realistic (22 %) and nearly half as realistic. The alternative IPCC scenarios (A2, B1 and B2) were considered less likely, with B1, which projects the lowest increase in mean annual temperature (i.e., 1.5 °C), as least likely. 3.3 Effects of climate change on forests in south-west Germany Recognition of climate change impacts on forests was reasonably high among the responding forestry professionals (see supplementary Table S2). Most (80 %) were at least concerned about the effects (scale 2–5), and the majority found it a crucial concern (scale 3–4, 65 %). The three most disturbing impacts from least to most were considered to be: storm occurrence, frequency of arid years, and insect calamity, are recognized, while changes in the growth and productivity of the main tree species were thought to be the least crucial. The forest management strategy perceived to be the best to deal with the negative effects of climate change (98 %) was the selection of those tree species in the regeneration phase that are better adapted to the changing environmental conditions. Forest conversion by admixing broadleaves and transformation, to ensure an uneven-aged forest structure, and selecting seedlings according to provenances are other strategies thought to facilitate forest adaptation. Short rotation forestry, in contrast, was viewed as the least important management strategy. 3.4 Potential of forestry to mitigate the negative effects of climate change Most respondents thought the general potential to mitigate climate change (see supplementary Table S3) through forestry-related measures is low (58 %) or a very low (25 %). Approximately half considered it Brealistic^ to substitute fossil fuels and energy intensive materials e.g., concrete and aluminum through the increased utilization of harvesting remnants (i.e., timber that would have otherwise stayed in the forest) or pulpwood, and through higher harvesting levels and afforestation or found it to -a lower percentage- even Bvery realistic^. More than half of the respondents thought it is less realistic to mitigate climate change through
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storing carbon in forest stock and around a quarter thought alternative forestry systems, namely agroforestry and planting energy woods as pioneer crops or in the form of pre-plantations under the forest canopy are to some extent realistic (34 %, 24 %) compared with over a third who considered them less realistic. 3.5 Respondents’ knowledge about climate change and decision support tools for adaptation Around two thirds of the respondents reported obtaining and updating their knowledge about climate change mainly through advanced forestry training, the media or reading forestryrelated scientific literature (see supplementary Table S4). Most did not give the internet, colleagues and the general literature about climate change as their preferred sources of information. However, 72 % of respondents claimed they are under-informed about climate change and only 24 % are satisfied with the state of their knowledge on the subject. Planning aids in the form of maps and written material (e.g., recommendations) may assist forestry professionals in obtaining sufficient information about how to deal with climate change challenges. Site maps improving recommendations for adaptive species selection seem to be the most helpful planning aid (90 %), but maps illustrating species distributions and danger indices of diverse biotic and abiotic risks were also appreciated. Climate-sensitive forest growth models can assist forest decision-making to cope with climate change, as can an improved forest management planning enhanced by recommendations for adaptation activities. Respondents favored developing decision-support tools for adaptive forestry for a particular forest unit (i.e., a forest area belonging to regional or even local administrative entity) and for the most probable climate change scenario. Maps and graphs with spatially explicit information about the forest stand types in a local forest unit seem to be more helpful for forest professionals than numerous maps and graphs for a large spectrum of future climate states or extreme prognoses. 3.6 The most significant variables affecting forests according to the factor analysis of respondents’ replies The factor analysis was used to derive the most ‘efficient’ variables for each factor, i.e., those variables where the correlation coefficients for the regression of each factor on the variables were above 0.3. The scree plot of the eigenvalue of the factors (supplementary Fig. S2) shows that the first factor accounts for a great amount of variance. Factor 2 adds more information about the variables, but the rate of increase in eigenvalue then slows. We therefore focused on factors 1 and 2 as the reduced dimensions of the total response space and did not consider other factors because their eigenvalues were below 3 and added more complexity to the analysis. Factors 1 and 2 together consist of only 13 efficient variables (see supplementary Table S5) out of 69 potential variables from the questionnaires, which reduces the space of the analysis greatly. The matrix data (in supplementary Table S5) was used in a canonical analysis to visualize the bi-dimensional relationships among the most significant variables of factors 1 and 2 (Fig. 1). KMO measure of sampling adequacy and Bartlett’s test of sphericity were both significant (as can be seen in supplementary Table S6). KMO was 0.536 and Bartlett’s test shows a χ2 of 3046, with degrees of freedom of 1891 and p< 0.001, demonstrate that the results of the factor analysis are statistically significant (KMO>0.5 and p
