Combining qualitative and quantitative understanding for exploring cross-sectoral climate change impacts, adaptation and vulnerability in Europe

Climate change will affect all sectors of society and the environment at all scales, ranging from the continental to the national and local. Decision-makers and other interested citizens need to be able to access reliable science-based information to help them respond to the risks of climate change impacts and assess opportunities for adaptation. Participatory integrated assessment (IA) tools combine knowledge from diverse scientific disciplines, take account of the value and importance of stakeholder ‘lay insight’ and facilitate a two-way iterative process of exploration of ‘what if’s’ to enable decision-makers to test ideas and improve their understanding of the complex issues surrounding adaptation to climate change. This paper describes the conceptual design of a participatory IA tool, the CLIMSAVE IA Platform, based on a professionally facilitated stakeholder engagement process. The CLIMSAVE (climate change integrated methodology for cross-sectoral adaptation and vulnerability in Europe) Platform is a user-friendly, interactive web-based tool that allows stakeholders to assess climate change impacts and vulnerabilities for a range of sectors, including agriculture, forests, biodiversity, coasts, water resources and urban development. The linking of models for the different sectors enables stakeholders to see how their interactions could affect European landscape change. The relationship between choice, uncertainty and constraints is a key cross-cutting theme in the conduct of past participatory IA. Integrating scenario development processes with an interactive modelling platform is shown to allow the exploration of future uncertainty as a structural feature of such complex problems, encouraging stakeholders to explore adaptation choices within real-world constraints of future resource availability and environmental and institutional capacities, rather than seeking the ‘right’ answers.     

Integration, synthesis and climate change adaptation: a narrative based on coastal wetlands at the regional scale

The idea that integration and synthesis are critical for designing climate change adaptation and mitigation is well entrenched conceptually. Here, we review the concepts of adaptation, synthesis and integration and apply them to the case study of coastal wetlands in South East Queensland, Australia. The distribution and condition of coastal wetlands will change as climate changes. This will create conservation challenges and economic costs, but these can be minimised by drawing from a broad sectoral perspective in undertaking adaptation planning and by ensuring integration into policy. Our review indicates that adaptations to sea level rise that are focussed on wetland and biodiversity conservation are likely to have impacts for urbanisation patterns. Planning regulations that provide spatial buffering around wetlands may give rise to more compact urban forms that may lead to reductions in the cost of defence against sea level rise, reduce energy usage per person and provide more green space. However, more compact urban forms could exacerbate heat island effects and place greater burden on the economically disadvantaged as, for example, single-family homes become more expensive. Planning for climate change needs to balance these equity and cross-sectoral issues in order to reduce the likelihood of unforeseen negative consequences.     

Improving cross-sectoral climate change adaptation for coastal settlements: insights from South East Queensland,Australia

Climate change impacts affecting coastal areas, such as sea-level rise and storm surge events, are expected to have significant social, economic and environmental consequences worldwide. Ongoing population growth and development in highly urbanised coastal areas will exacerbate the predicted impacts on coastal settlements. Improving the adaptation potential of highly vulnerable coastal communities will require greater levels of planning and policy integration across sectors and scales. However, to date, there is little evidence in the literature which demonstrates how climate policy integration is being achieved. This paper contributes to this gap in knowledge by drawing on the example provided by the process of developing cross-sectoral climate change adaptation policies and programmes generated for three coastal settlement types as part of the South East Queensland Climate Adaptation Research Initiative (SEQCARI), a 3-year multi-sectoral study of climate change adaptation options for human settlements in South East Queensland, Australia. In doing so, we first investigate the benefits and challenges to cross-sectoral adaptation to address climate change broadly and in coastal areas. We then describe how cross-sectoral adaptation policies and programmes were generated and appraised involving the sectors of urban planning and management, coastal management, emergency management, human health and physical infrastructure as part of SEQCARI. The paper concludes by discussing key considerations that can inform the development and assessment of cross-sectoral climate change adaptation policies and programmes in highly urbanised coastal areas.     

Bringing it all together: researcher dialogue to improve synthesis in regional climate adaptation in South-East Queensland,Australia

The effectiveness of climate adaptation policies in one sector can be compromised or aided by policies developed in another sector. When the focus of adaptation is a single geographical region, this potential for interaction between sectoral policies is heightened due to spatial, political and functional proximities. This paper analyses interactions within three suites of climate adaptation options developed for Australia’s ‘South-East Queensland’ region relating to: (1) wetland migration, coastal infrastructure and planned retreat; (2) urban water security and energy demand; and (3) terrestrial biodiversity and agricultural viability. Using the concept of ‘institutional interplay’ to structure a process of dialogue amongst researchers, we identify a number of critical implementation requirements for successful regional-scale adaptation. There is a need for greater focus on neighbourhood or sub-regional scales of policy design and intervention, particularly for the coordination of adapted infrastructure and services to households. Policy-makers must also be more explicit in considering broader drivers of land-use change and economic adjustment likely to impact on proposed adaptations. In considering these issues, our paper also demonstrates a process for conducting cross-sectoral syntheses that can be employed in other regional-scale adaptation studies.     

中国生物多样性保护适应气候变化的对策

基于气候变化对生物多样性影响的总结分析,初步提出了我国生物多样性保护适应气候变化的对策。气候变化对生物物候、分布、迁移活动、群落结构、栖息地质量、生态系统和景观多样性都产生了一定影响,未来将产生更深刻的影响。我国生物多样性保护适应气候变化需要从物种有效保护、自然保护区规划与管理、灾害防御等方面进行。     

Building resilience to water scarcity in southern Spain: a case study of rice farming in Doñana protected wetlands

Agricultural water management needs to evolve in view of increased water scarcity, especially when farming and natural protected areas are closely linked. In the study site of Doñana (southern Spain), water is shared by rice producers and a world heritage biodiversity ecosystem. Our aim is to contribute to defining adaptation strategies that may build resilience to increasing water scarcity and minimize water conflicts among agricultural and natural systems. The analytical framework links a participatory process with quantitative methods to prioritize the adaptation options. Bottom-up proposed adaptation measures are evaluated by a multi-criteria analysis (MCA) that includes both socioeconomic criteria and criteria of the ecosystem services affected by the adaptation options. Criteria weights are estimated by three different methods—analytic hierarchy process, Likert scale and equal weights—that are then compared. Finally, scores from an MCA are input into an optimization model used to determine the optimal land-use distribution in order to maximize utility and land-use diversification according to different scenarios of funds and water availability. While our results show a spectrum of perceptions of priorities among stakeholders, there is one overriding theme that is to define a way to restore part of the rice fields to natural wetlands. These results hold true under the current climate scenario and even more so under an increased water scarcity scenario.     

Climate change adaptation and cross-sectoral policy coherence in southern Africa

To be effective, climate change adaptation needs to be mainstreamed across multiple sectors and greater policy coherence is essential. Using the cases of Malawi, Tanzania and Zambia, this paper investigates the extent of coherence in national policies across the water and agriculture sectors and to climate change adaptation goals outlined in national development plans. A two-pronged qualitative approach is applied using Qualitative Document Analysis of relevant policies and plans, combined with expert interviews from non-government actors in each country. Findings show that sector policies have differing degrees of coherence on climate change adaptation, currently being strongest in Zambia and weakest in Tanzania. We also identify that sectoral policies remain more coherent in addressing immediate-term disaster management issues of floods and droughts rather than longer-term strategies for climate adaptation. Coherence between sector and climate policies and strategies is strongest when the latter has been more recently developed. However to date, this has largely been achieved by repackaging of existing sectoral policy statements into climate policies drafted by external consultants to meet international reporting needs and not by the establishment of new connections between national sectoral planning processes. For more effective mainstreaming of climate change adaptation, governments need to actively embrace longer-term cross-sectoral planning through cross-Ministerial structures, such as initiated through Zambia’s Interim Climate Change Secretariat, to foster greater policy coherence and integrated adaptation planning.     

Using qualitative scenarios to understand regional environmental change in the Canadian North

This paper discusses the application of qualitative scenarios to understand community vulnerability and adaptation responses, based on a case study in the Slave River Delta region of the Northwest Territories, Canada. Three qualitative, graphic scenarios of possible alternative futures were developed, focusing on two main drivers: climate change and resource development. These were used as a focal point for discussions with a cross-section of residents from the community during focus groups, interviews and a community workshop. Significant overlap among the areas of perceived vulnerability is evident among scenarios, particularly in relation to traditional land use. However, each scenario also offers insights about specific challenges facing community members. Climate change was perceived to engender mostly negative livelihood impacts, whereas resource development was expected to trigger a mix of positive and negative impacts, both of which may be more dramatic than in the “climate change only” scenario. The scenarios were also used to identify adaptation options specific to individual drivers of change, as well as more universally applicable options. Identified adaptation options were generally aligned with five sectors—environment and natural resources, economy, community management and development, infrastructure and services, and information and training—which effectively offer a first step towards prioritization of “no regrets” measures. From an empirical perspective, while the scenarios highlighted the need for bottom-up measures, they also elucidated discussion about local agency in adaptation and enabled the examination of multi-dimensional impacts on different community sub-groups. An incongruity emerged between the suite of technically oriented adaptation options and more socially and behaviourally oriented barriers to implementation. Methodologically, the qualitative scenarios were flexible, socially inclusive and consistent with the Indigenous worldview; allowed the incorporation of different knowledge systems; addressed future community vulnerability and adaptation; and led to the identification of socially feasible and bottom-up adaptation outcomes. Despite some caveats regarding resource requirements for participatory scenario development, qualitative scenarios offer a versatile tool to address a range of vulnerability and adaptation issues in the context of other Indigenous communities.     

Costs and benefits of adapting spatial planning to climate change: lessons learned from a large-scale urban development project in the Netherlands

Climate change increases the vulnerability of low-lying coastal areas. Careful spatial planning can reduce this vulnerability, provided that decision-makers have insight into the costs and benefits of adaptation options. This paper addresses the question which adaptation options are suitable, from an economic perspective, to adapt spatial planning to climate change at a regional scale. We apply social cost–benefit analysis to assess the net benefits of adaptation options that deal with the impacts of climate change-induced extreme events. From the methods applied and results obtained, we also aim at learning lessons for assessing climate adaptation options. The case study area, the Zuidplaspolder, is a large-scale urban development project in the Netherlands. The costs as well as the primary and secondary benefits of adaptation options relating to spatial planning (e.g. flood-proof housing and adjusted infrastructure) are identified and where possible quantified. Our results show that three adaptation options are not efficient investments, as the investment costs exceed the benefits of avoided damages. When we focus on ‘climate proofing’ the total area of the Zuidplaspolder, when the costs and benefits of all the presented adaptation options are considered together, the total package has a positive net present value. The study shows that it is possible to anticipate climate change impacts and assess the costs and benefits of adjusting spatial planning. We have learned that scenario studies provide a useful tool but that decision-making under climate change uncertainty also requires insight into the probabilities of occurrence of weather extremes in the future.     

Climatic changes and their impact on socio-economic sectors in the Bhutan Himalayas: an implementation strategy

This paper contributes to an enhanced understanding of present climatic conditions, observed climate trends and regional climate vulnerability of the Bhutan Himalayas. Bhutan’s complex, often high-altitude terrain and the severe impact of the Indian summer monsoon leads to a strong exposure of the countries’ key economic sectors (agriculture, forestry, hydropower generation and tourism) to climatic changes. Climate change also threatens Bhutan’s vast biodiversity and increases the likelihood of natural hazards (e.g. glacier lake outburst floods, flash floods, droughts and forest fires). A better understanding of Bhutan’s climate and its variability, as well as observed and possible climate impacts, will help in improving the handling of regional social, economic and ecologic challenges not limited to the Himalayas. Only a few climatological studies exist for the eastern Himalayas. They mainly focus on adaptation to immediate threats by glacier lake outbursts. In contrast, this paper (1) investigates the average spatial and inner-annual diversity of the air temperature regime of Bhutan, based on local meteorological observations, (2) discusses past temperature variability, based on global datasets, and (3) relates effects of observed warming to water availability, hydropower development, natural hazards, forests, biodiversity, agriculture, human health and tourism in the Bhutan Himalayas. Results indicate a large spatial and temporal temperature variability within Bhutan and considerably increasing temperatures especially over recent decades. Implications of regional climatic changes on various socio-economic sectors and possible adaptation efforts are discussed.     

Agronomic adaptation strategies under climate change for winter durum wheat and tomato in southern Italy: irrigation and nitrogen fertilization

Agricultural crops are affected by climate change due to the relationship between crop development, growth, yield, CO₂ atmospheric concentration and climate conditions. In particular, the further reduction in existing limited water resources combined with an increase in temperature may result in higher impacts on agricultural crops in the Mediterranean area than in other regions. In this study, the cropping system models CERES-Wheat and CROPGRO-Tomato of the Decision Support System for Agrotechnology Transfer (DSSAT) were used to analyse the response of winter durum wheat (Triticum aestivum L.) and tomato (Lycopersicon esculentum Mill.) crops to climate change, irrigation and nitrogen fertilizer managements in one of most productive areas of Italy (i.e. Capitanata, Puglia). For this analysis, three climatic datasets were used: (1) a single dataset (50?km?×?50?km) provided by the JRC European centre for the period 1975–2005; two datasets from HadCM3 for the IPCC A2 GHG scenario for time slices with +2°C (centred over 2030–2060) and +5°C (centred over 2070–2099), respectively. All three datasets were used to generate synthetic climate series using a weather simulator (model LARS-WG). Adaptation strategies, such as irrigation and N fertilizer managements, have been investigated to either avoid or at least reduce the negative impacts induced by climate change impacts for both crops. Warmer temperatures were primarily shown to accelerate wheat and tomato phenology, thereby resulting in decreased total dry matter accumulation for both tomato and wheat under the +5°C future climate scenario. Under the +2°C scenario, dry matter accumulation and resulting yield were also reduced for tomato, whereas no negative yield effects were observed for winter durum wheat. In general, limiting the global mean temperature change of 2°C, the application of adaptation strategies (irrigation and nitrogen fertilization) showed a positive effect in minimizing the negative impacts of climate change on productivity of tomato cultivated in southern Italy.     

Downscaling nonclimatic drivers for surface water vulnerabilities in the Elbe river basin

Aggregated consideration of both climate and socio-economic change in a coarse spatial resolution is a central feature for scenario development in global change research. Downscaling of the supposed aggregated changes is a necessary prerequisite for the assessments of global change at the regional scale. The present paper describes the method and results of an approach to develop and to apply scenarios of socio-economic change at a sub-national level, which are consistent with global change scenarios. National and regional models of economic and demographic development are used to regionalise drivers of socio-economic change. Scenario results are subsequently applied in order to analyse the impacts of socio-economic and climatic changes on water management issues in the Elbe river basin. Starting from global IPCC-Emissions Scenarios and taking up their key points, we formulate two scenarios for the German and Czech parts of the Elbe catchment areas. We present a system of demographic and economic models, designed to consistently project socio-economic developments at a national and sub-national level and, thus, to quantitatively illustrate our scenarios. The results show that in a scenario that assumes continued globalisation and emphasis on economic growth, export orientation will result in a comparatively high share of manufacturing. Growth spreads from centres to peripheral regions. Still, at the national level, the increase in population and employment will be modest and create little additional pressure, but water stress will be considerably stronger on a regional basis, namely in metropolitan areas such as Prague, Berlin and Hamburg. In a scenario where economic goals are balanced with ecologic and social ones, growth is weaker and the weight of the service sector increases more rapidly, thus easing the driving forces for overall water demand and pollution. However, as in this scenario regional metropolitan centres develop at the cost of peripheral regions, regional development is more selective and the driving forces for potential water stress will diverge spatially.     

Adaptation options for marine industries and coastal communities using community structure and dynamics

Identifying effective adaptation strategies for coastal communities dependent on marine resources and impacted by climate change can be difficult due to the dynamic nature of marine ecosystems. The task is more difficult if current and predicted shifts in social and economic trends are considered. Information about social and economic change is often limited to qualitative data. A combination of qualitative and quantitative models provide the flexibility to allow the assessment of current and future ecological and socio-economic risks and can provide information on alternative adaptations. Here, we demonstrate how stakeholder input, qualitative models and Bayesian belief networks (BBNs) can provide semi-quantitative predictions, including uncertainty levels, for the assessment of climate and non-climate-driven change in a case study community. Issues are identified, including the need to increase the capacity of the community to cope with change. Adaptation strategies are identified that alter positive feedback cycles contributing to a continued decline in population, local employment and retail spending. For instance, the diversification of employment opportunities and the attraction of new residents of different ages would be beneficial in preventing further population decline. Some impacts of climate change can be combated through recreational bag or size limits and monitoring of popular range-shifted species that are currently unmanaged, to reduce the potential for excessive removal. Our results also demonstrate that combining BBNs and qualitative models can assist with the effective communication of information between stakeholders and researchers. Furthermore, the combination of techniques provides a dynamic, learning-based, semi-quantitative approach for the assessment of climate and socio-economic impacts and the identification of potential adaptation strategies.     

Sub-basin scale characterization of climate change vulnerability, impacts and adaptation in an Indian River basin

Knowledge of climate change vulnerability and impacts is a prerequisite for formulating locally relevant climate change adaptation policies. A participatory approach has been used in this study to determine climate change vulnerability, impacts and adaptation aspects for the Kangsabati River basin, India. The study approach involved engaging with stakeholders representing state (sub-national), district and community levels, through an interactive brainstorming method, to understand stakeholder perceptions regarding (a) local characteristics which influence vulnerability, (b) climate change impacts and (c) relevant adaptation options. The study reveals that vulnerability varies across upstream, midstream and downstream sections of the river basin. Suggested adaptation options, in this predominantly agricultural basin, are found to be applicable across spatial scales. Stakeholder perceptions, regarding vulnerability and impacts, vary with the level of interaction, academic background and type of experience. Interaction confirms the notion that stakeholders have inherent knowledge regarding adaptation, reveals their preferences and ability to think unconventionally. We discuss limitations of the approach while demonstrating its ability to deliver locally relevant and acceptable adaptation options, which could facilitate implementation. We conclude that engaging stakeholders at multiple levels was highly effective in assessing locally relevant aspects of climate change vulnerability, impacts and applicable adaptation options in the Kangsabati River basin. Based on this assessment, a sub-basin scale is recommended for evaluating these aspects, especially for water resources and agricultural systems, through multi-level stakeholder input.     

Climate proofing the Zuidplaspolder: a guiding model approach to climate adaptation

Climate change will have an impact on various sectors, such as housing, infrastructure, recreation and agriculture. Climate change may change spatial demands. For example, rising temperatures will increase the need for recreation areas, and areas could be assigned for water storage. There is a growing sense that, especially at the local scale, spatial planning has a key role in addressing the causes and impacts of climate change. This paper promotes an approach to help translate information on climate change impacts into a guiding model for adaptive spatial planning. We describe how guiding models can be used in designing integrated adaptation strategies. The concept of guiding models has been developed in the 1990s by Tjallingii to translate the principles of integrated water management in urban planning. We have integrated information about the present and future climate change and set up a climate adaptation guiding model approach. Making use of climate adaptation guiding models, spatial planners should be able to better cope with complexities of climate change impacts and be able to translate these to implications for spatial planning. The climate adaptation guiding model approach was first applied in the Zuidplaspolder case study, one of the first major attempts in the Netherlands to develop and implement an integrated adaptation strategy. This paper demonstrates how the construction of climate adaptation guiding models requires a participatory approach and how the use of climate adaptation guiding models can contribute to the information needs of spatial planners at the local scale, leading to an increasing sense of urgency and integrated adaptation planning process.     

New climate change information modifies frames and decisions of decision makers: an exploratory study in forest planning

Information helps decision makers to address and to decide about environmental problems. In the context of climate change adaptation, often knowledge is missing on how the available information from impact models affects the decision-making process. The main aim of this study was to explore the extent of ambiguity and how new climate change information influenced decision of forest planners. We investigated changes in decisions of planners about forestry actions representing species choice and forest tourism and expiry dates of these actions leading to environmental constraints in the provision of ecosystem services. Forest planners evaluated expiry dates using four forest ecosystem services: forest production, stand yield class, sequestered carbon, and potential tourism. Data were collected during workshops with eleven forest planners from three forest districts in Scotland. Presented climate change information modified the understanding and frames of planners about forestry actions assessed with accompanying expiry dates. Changes in the frames of planners often result in both earlier and later expiry dates. Ambiguity of planners was found to be dependent on diversity in frames and difficulty in evaluating multiple ecosystem services. These findings imply that due to ambiguity forest planners might find it hard to choose climate change adaptation measures and researchers can struggle to convince planners with new research findings.     

Ecosystem service provision,management systems and climate change in Valsaín forest,central Spain

This study addresses the impact of climate change and management approach on the provision of four ecosystem services (ES) (timber production, protection against gravitational hazards, carbon sequestration and biodiversity) in Valsaín forest in central Spain. The hybrid forest patch model PICUS v1.6 was used to simulate the development of 24 representative stand types over 100 years (2010–2110) in a full factorial simulation experiment combining three management regimes [“business as usual” management (BAU) and two alternatives to BAU (AM1 and AM2)], a no-management scenario (NOM) and six climate scenarios (historic climate represented by the period 1961–1990 and five transient climate change scenarios). Simulations indicated relatively small differences as regards the impact of the different management alternatives (BAU, AM1 and AM2) on the provision of ES as well as a clear improvement in biodiversity, protection and carbon storage under the no-management regime (NOM). Although timber production indicators were the most sensitive to climate change scenarios, biodiversity-related indicators responded fastest to the management regimes applied. Indicators of protection against rockfall and landslides were affected by both management and climate change. The results indicate substantial vulnerability of ES provisioning under the more extreme climate change scenarios at low elevations (1250 m). At higher elevations, the productivity of Scots pine stands may show a moderate decrease or increase, depending on the climate change scenario.     

Climate change adaptation and sustainable regional development: a case study for the Federal State of Brandenburg, Germany

Located in a relatively dry region and characterized by mainly sandy soils, the German Federal State of Brandenburg (surrounding the capital city of Berlin) is especially vulnerable to climate change impacts (e.g., summer droughts) and cascading effects on ecological systems (e.g., decreasing ground water tables, water stress, fire risk, productivity losses) with socioeconomic implications. Furthermore, a complex interplay of unemployment, rural exodus, and an aging population challenges this structurally weak region. We discuss adaptation measures that are either implemented or planned, as well as research into adaptation strategies to climate change for the sectors forestry, agriculture, and water management as well as in nature conservation in light of socioeconomic and ecological challenges and benefits. In doing so, we adopt a systemic view of Brandenburg where the sectors discussed are seen as subsystems embedded in a larger regional system. This at least partially holarchical approach enables the identification of conflicts between adaptation measures, but also of synergies among the sectors that pertain to successful adaptation to climate change. The insights gained ultimately highlight the need for cross-sectoral, adaptive management practices that jointly target a sustainable regional development.     

Knowledge and information needs of adaptation policy-makers: a European study

Across Europe, national governments have started to strategically plan adaptation to climate change. Making adaptation decisions is difficult in the light of uncertainties and the complexity of adaptation problems. Already large amounts of research results on climate impacts and adaptive measures are available, and more are produced and need to be mediated across the boundary between science and policy. Both researchers and policy-makers have started to intensify efforts to coproduce knowledge that is valuable to both communities, particularly in the context of climate change adaptation. In this paper, we present results from a study of adaptation governance and information needs, comparing eight European countries. We identify sources and means for the retrieval of information as well as gaps and problems with the knowledge provided by scientists and analyzed whether these appear to be contingent on the point in the policy-making cycle where countries are. We find that in this early phase of adaptation planning, the quality of the definition of needs, the way uncertainty is dealt with, and the quality of science–policy interaction are indeed contingent on the stage of adaptation planning, while information needs and sources are not. We conclude that a well-developed science–policy interface is of key importance for effective decision-making for adaptation.     

Modelling bark beetle disturbances in a large scale forest scenario model to assess climate change impacts and evaluate adaptive management strategies

To study potential consequences of climate-induced changes in the biotic disturbance regime at regional to national scale we integrated a model of Ips typographus (L. Scol. Col.) damages into the large-scale forest scenario model EFISCEN. A two-stage multivariate statistical meta-model was used to upscale stand level damages by bark beetles as simulated in the hybrid forest patch model PICUS v1.41. Comparing EFISCEN simulations including the new bark beetle disturbance module against a 15-year damage time series for Austria showed good agreement at province level (R2 between 0.496 and 0.802). A scenario analysis of climate change impacts on bark beetle-induced damages in Austria’s Norway spruce [Picea abies (L.) Karst.] forests resulted in a strong increase in damages (from 1.33 Mm3 a⁻¹, period 1990–2004, to 4.46 Mm3 a⁻¹, period 2095–2099). Studying two adaptive management strategies (species change) revealed a considerable time-lag between the start of adaptation measures and a decrease in simulated damages by bark beetles.