Evaluation of Bayesian networks for modelling habitat suitability and management of a protected area

To be effective, management of protected areas should be based on the best available evidence, including the scientific literature and expert knowledge. However, lack of such evidence in a suitable form to support decision-making may hinder effective management. Here we examine the use of Bayesian networks to support the management of protected areas, through the development of habitat suitability models for eight species of conservation concern. Bayesian networks were constructed on the basis of the scientific literature and expert knowledge, and were then tested using results from a field survey. Models of all species demonstrated very high discrimination between presence and absence sites, as indicated by AUC values >0.8, with values >0.9 obtained for four species, and Kappa values in the range of 0.4–0.9. The Bayesian networks were then used to examine the impact of different management interventions on habitat suitability of each species, including tree cutting, grazing and burning. Species differed in terms of their sensitivity to different management interventions, and model output provided evidence of both negative and positive interactions between types of intervention. These results highlight the trade-offs that must often be made when undertaking conservation management, and demonstrate the value of Bayesian networks in helping to make such trade-offs explicit. The identification of management impacts through analysis of available evidence also demonstrates the value of Bayesian networks for supporting evidence-based approaches to protected area management.     

Measuring impact of protected area management interventions: current and future use of the Global Database of Protected Area Management Effectiveness

Protected areas (PAs) are at the forefront of conservation efforts, and yet despite considerable progress towards the global target of having 17% of the world''s land area within protected areas by 2020, biodiversity continues to decline. The discrepancy between increasing PA coverage and negative biodiversity trends has resulted in renewed efforts to enhance PA effectiveness. The global conservation community has conducted thousands of assessments of protected area management effectiveness (PAME), and interest in the use of these data to help measure the conservation impact of PA management interventions is high. Here, we summarize the status of PAME assessment, review the published evidence for a link between PAME assessment results and the conservation impacts of PAs, and discuss the limitations and future use of PAME data in measuring the impact of PA management interventions on conservation outcomes. We conclude that PAME data, while designed as a tool for local adaptive management, may also help to provide insights into the impact of PA management interventions from the local-to-global scale. However, the subjective and ordinal characteristics of the data present significant limitations for their application in rigorous scientific impact evaluations, a problem that should be recognized and mitigated where possible.     

The role of modelling in resource management within the livelihood-conservation nexus: A socio-ecological systems approach to Sand Forest harvesting,Northern KwaZulu-Natal

Divergences between community livelihoods and conservation efforts often result in changes to the access and use of natural capital in affected areas, negatively affecting the respective livelihoods. New tools and interdisciplinary approaches are more frequently required for solving these conflicts. In this paper, the socio-ecological systems (SES) perspective along with Bayesian Belief Networks (BBNs) have been used to model the interdependencies that exist within the livelihood-conservation nexus to determine if this method can improve synergy between community livelihood requirements and conservation targets in an era of unsustainable decline of natural resources, using the livelihood-conservation nexus of informal Sand Forest harvesting in Northern KwaZulu-Natal as a case study. Results suggest BBNs have great potential for use in socio-ecological and resource management studies concerning the livelihood-conservation nexus. The results of the sensitivity analysis of the BBN showed that employment and income are the greatest socio-economic drivers in terms of Sand Forest harvesting, while preference (i.e. behaviour) for energy sources and building materials has the greatest overall influence on Sand Forest usage. The BBN scenario comparison further demonstrated the influence of preference (i.e. behaviour) on the SES. Finally, the conservation effectiveness assessment using the BBN showed the significant contribution of accessibility and availability of Sand Forest (i.e. conservation) to the system. Information provided by the BBN allowed for suitable areas for conservation to be identified given conservation targets and the utilisation needs of the communities (i.e. greater synergy), through the mapping of two livelihood management approaches (i.e. community conservation and formal conservation). The results of mapping the different management objectives have shown that community conservation is more suitable for moving the system towards synergy and should be considered for a Sand Forest resource management approach to compliment any conservation planning.     

Quantifying the Short-Term Costs of Conservation Interventions for Fishers at Lake Alaotra,Madagascar

Artisanal fisheries are a key source of food and income for millions of people, but if poorly managed, fishing can have declining returns as well as impacts on biodiversity. Management interventions such as spatial and temporal closures can improve fishery sustainability and reduce environmental degradation, but may carry substantial short-term costs for fishers. The Lake Alaotra wetland in Madagascar supports a commercially important artisanal fishery and provides habitat for a Critically Endangered primate and other endemic wildlife of conservation importance. Using detailed data from more than 1,600 fisher catches, we used linear mixed effects models to explore and quantify relationships between catch weight, effort, and spatial and temporal restrictions to identify drivers of fisher behaviour and quantify the potential effect of fishing restrictions on catch. We found that restricted area interventions and fishery closures would generate direct short-term costs through reduced catch and income, and these costs vary between groups of fishers using different gear. Our results show that conservation interventions can have uneven impacts on local people with different fishing strategies. This information can be used to formulate management strategies that minimise the adverse impacts of interventions, increase local support and compliance, and therefore maximise conservation effectiveness.     

Simulation of management and soil interactions impacting SOC dynamics in sugarcane using the CENTURY Model

Newer methods of management and harvesting of sugarcane are being considered to improve soil and water conservation in Brazil. Our aim in this study was to evaluate soil C dynamics under sugarcane cultivation as influenced by the use of conservation management, using measurements from four different management systems and land use histories, i.e. conventional management with preharvest burning, no burning with residue retention and two systems without burning plus additional organic amendments. Field sites also differed in terms of soil texture. We compared field measurements of soil C stocks, ¹³C and microbial biomass with simulated results from the Century ecosystem model for each of the sites and management histories. We also did long-term simulations of the management treatments and sites to approximate steady-state SOC levels, to explore potential management-induced differences in SOC stocks and interactions with soil texture. The model accurately represented treatment and site differences for total SOC stocks, in which SOC stocks were strongly affected by both rates of organic matter input to soil and soil clay content. However, the model tended to underestimate the relative contribution of sugarcane-derived C to total SOC for sites with high residue and external organic matter amendments. Measured microbial biomass C across the sites was closely aligned with relative amounts of organic matter input but did not appear to be strongly affected by soil texture, whereas the model predicted that both texture and organic matter input rate would impact microbial biomass C. Long-term simulations of the conservation management alternatives suggested that SOC stocks could be maintained at or above levels in the original native Cerradão vegetation, whereas conventional practices using residue burning would result in a reduction of SOC to ca. 60% of native levels. Our results support the use of the CENTURY model as an aid to assess the impacts of different soil management practices on SOC stocks under sugarcane in Brazil.     

The influence of different aspects of grouse moorland management on nontarget bird assemblages

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Impacts of species-led conservation on ecosystem services of wetlands: understanding co-benefits and tradeoffs

Biodiversity conservation organisations have recently begun to consider a wider ecosystem services context for their activities. While the literature suggests the potential of ‘win–win’ situations where biodiversity conservation and the delivery of ecosystem services overlap, empirical evidence is wanting. Here we explore the role that species-led management for the benefit of biodiversity in cultural landscapes can play in the delivery of wider ecosystem services. We use UK lowland wetlands as a case study and show how successful delivery of species-led conservation through management interventions relies on practices that can affect greenhouse gas fluxes, water quality and regulation, and cultural benefits. In these wetlands, livestock grazing has potentially large effects on water and greenhouse gas related services, but there is little scope to alter management without compromising species objectives. Likewise, there is little potential to alter reedbed management without compromising conservation objectives. There is some potential to alter woodland and scrub management, but this would likely have limited influence due to the relatively small area over which such management is practiced. The management of water levels potentially has large effects on provision of several services and there does appear to be some scope to align this objective with biodiversity objectives. A comprehensive understanding of the net costs and benefits to society of these interventions will require fine-grained research integrating ecological, economic and social science research. However, a less analytic understanding of the potential costs and benefits can highlight ways by which land management principally to achieve biodiversity conservation objectives might be modified to enhance delivery of other ecosystem services.     

Direct and indirect interactions with vegetation shape crocodylian ecology at multiple scales

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Contracting Tasmanian montane grasslands within a forest matrix is consistent with cessation of Aboriginal fire management

The persistence of treeless grasslands and sedgelands within a matrix of eucalypt and rainforest vegetation in the montane plateaux of northern Tasmania has long puzzled ecologists. Historical sources suggest that Tasmanian Aborigines were burning these treeless patches and models seeking to explain their maintenance generally include fire, soil properties and Aboriginal landscape burning. We aimed to provide a new historical perspective of the dynamics of the vegetation mosaics of Surrey Hills and Paradise Plains in north‐west and north‐east Tasmania, respectively, and used vegetation surveys and soil sampling to explore the role of vegetation and soils in these dynamics. Sequences of historical maps (1832 and 1903) and aerial photography showed that many treeless patches have persisted in the landscape since European settlement and that forests have rapidly expanded into the treeless patches since the early 1950s. Stand structure and floristic data described an expanding forest dominated by Leptospermum, which is consistent with vegetation succession models for the region. Soils under expanding forest boundaries did not have higher soil nitrogen or phosphorus than those under stable boundaries, signalling a lack of edaphic limitation to forest expansion. The magnitude of forest expansion at Paradise Plains (granite), Surrey Hills (basalt) and south‐west Tasmania (quartzite) appears to follow a nutrient availability gradient and this hypothesis is backed by differences in soil phosphorus capital between the three systems. Given that existing vegetation boundaries in northern Tasmania do not coincide with soil nutrient gradients, we suggest that treeless vegetation was maintained by Aboriginal landscape burning and that the recent contraction of treeless vegetation is related to the breakdown of these fire regimes following European settlement. The observed rates of forest expansion could result in a substantial loss of these grasslands if sustained through this century and therefore our work supports the continuation of prescribed burning to maintain this high conservation value ecosystem.     

Altered ignition catchments threaten a hyperdiverse fire‐dependent ecosystem

Human activities affect fire in many ways, often unintentionally or with considerable time‐lags before they manifest themselves. Anticipating these changes is critical, so that insidious impacts on ecosystems, their biodiversity and associated goods and services can be avoided, mitigated or managed. Here we explore the impact of anthropogenic land cover change on fire and biodiversity in adjacent ecosystems on the hyperdiverse Cape Peninsula, South Africa. We develop a conceptual framework based on the notion of an ignition catchment, or the spatial extent and temporal range where an ignition is likely to result in a site burning. We apply this concept using fire models to estimate spatial changes in burn probability between historical and current land cover. This change layer was used to predict the observed record of fires and forest encroachment into fire‐dependent Fynbos ecosystems in Table Mountain National Park. Urban expansion has created anthropogenic fire shadows that are modifying fire return intervals, facilitating a state shift to low‐diversity, non‐flammable forest at the expense of hyperdiverse, flammable Fynbos ecosystems. Despite occurring in a conservation area, these ecosystems are undergoing a hidden collapse and desperately require management intervention. Anthropogenic fire shadows can be caused by many human activities and are likely to be a universal phenomenon, not only contributing to the observed global decline in fire activity but also causing extreme fires in ecosystems where there is no shift to a less flammable state and flammable fuels accumulate. The ignition catchment framework is highly flexible and allows detection or prediction of changes in the fire regime, the threat this poses for ecosystems or fire risk and areas where management interventions and/or monitoring are required. Identifying anthropogenic impacts on ignition catchments is key for both understanding global impacts of humans on fire and guiding management of human‐altered landscapes for desirable outcomes.     

How good are Bayesian belief networks for environmental management? A test with data from an agricultural river catchment

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Mycorrhizal infection indicates the suitability of different management treatments for nature conservation in calcareous grassland

The vegetation composition of calcareous grasslands in Central Europe is mainly determined by the applied management treatments and the nutrient status of the ecosystems, but these factors cannot clearly be separated. Recently several authors reported a shift in growth-limiting plant nutrients from nitrogen to phosphate. Therefore, we tested the interaction between management and plant available phosphate in a long-term experiment in Southern Germany with different management treatments applied to calcareous grassland. We measured mycorrhization rates, which are assumed to be high at low phosphate availability, to explore the interaction between management, phosphate availability and vegetation composition. By correlating mycorrhization rates to vegetation and soil data we found that treatments involving nutrient removal show a greater degree of mycorrhization than treatments leading to nutrient enrichment. According to decreasing suitability for grassland conservation, the six different management treatments could be ranked as mowing, followed by mulching (twice a year, once a year and every second year), burning and undisturbed succession. It was shown, that mycorrhizal infection rates (1) can be used to evaluate different management treatments for their suitability to conserve the initial vegetation composition, and (2) may provide information about the processes of adaptation to the current management, namely to differences in plant available phosphate. However, as discussed for the undisturbed succession treatment, it might not be sufficient to look at the degree of mycorrhization only. These are related to phosphate availability, but to detect adaptation processes to management, the degree of mycorrhization should be analysed together with plant’s internal nutrient relocation patterns.     

中国重大生态工程近40年生态成效整合分析

我国持续推进实施了系列大规模重大生态工程,科学评估工程取得的成效对于及时掌握工程实际效果是否符合预期目标、针对性地改进优化工程管理措施、促进生态保护修复目标的实现等具有重要意义。通过文献整合分析,从生态系统质量、功能和生物多样性等方面综合评估我国10项重大生态工程的生态成效,辨析取得成效的驱动因素贡献差异并总结成效评估产生不确定性的原因。结果表明:工程在国土绿化、碳固定、土壤保持、水源涵养、生物多样性保护等方面产生了良好生态效益,促进工程区植被覆盖度增加(0.19%-26%),生物量(-13%-187%)、固碳量(-7.41%-200%)、土壤保持量(-26.91%-151.52%)、水源涵养量(-64.66%-80.24%)、物种丰富度(-16%-441%)、均匀度指数(-6%-28%)和多样性指数(-5%-315%)总体也呈增加趋势(多年变化率中值>0)。但在部分区域也引起了生物量下降、土壤保持能力降低、水文效益减弱、生物多样性损失等问题。生态工程与气候变化的相对贡献率比值在0.06-3.60之间,贡献大小存在明显的空间分异并且产生交互耦合作用,多因素耦合作用分解机制仍有待研究。评估对象、数据、尺度、基准、方法及驱动因素拆解差异使得评估结果不确定性极大,相关研究需要重点关注评估基准和尺度的选择、多源数据的融合及同化、工程评估技术体系的改进,综合考虑区域地带性差异、工程措施适宜性和有效性、生态系统服务权衡、驱动因素贡献空间分异等以调整优化工程措施。     

Review: Prospects and limitations of prescribed burning as a management tool in European grasslands

Grassland managers and scientists are increasingly interested in cost-effective alternative ways of grassland biodiversity conservation. Prescribed burning is a promising management tool which should be integrated in the planning of management efforts. In addition, small-scale prescribed burning is an effective fire suppression strategy to decrease the serious negative impacts of uncontrolled burnings on ecosystems and human life. Prescribed burning forms an integral part of the North-American grassland management practice, while in Europe it is rarely applied, despite the fact that uncontrolled burning occurs frequently in some regions. Our goal was to evaluate the use of prescribed burning as a promising but neglected management tool in European grasslands. We found that European studies on prescribed burning of grasslands are scarce and we conclude that annual burning is usually not an appropriate option for the conservation of species-rich grasslands. We reviewed burning studies from North-America to identify findings which might be adapted to the European grassland conservation strategy. In North-America, contrary to Europe, the application of burning is fine tuned in terms of frequency and timing, and usually combined with other restoration measures (grazing or seed sowing). Thus, we conclude that with the application of carefully designed prescribed burning, multiple conservation goals, e.g. invasion control and enhancing landscape-level heterogeneity, can be linked with an effective fire suppression strategy. We emphasize that for the application of prescribed burning in Europe, the general findings of carefully designed case studies should be combined with the practical knowledge of conservation managers concerning the local application circumstances to reach specific management objectives.     

Offshore renewable energy and nature conservation: the case of marine tidal turbines in Northern Ireland

The global demand for renewable energy continues to increase rapidly and with it the necessity to develop and test new technologies to deliver the power. Offshore renewable energy sources that harness wind, wave or tidal power are of major interest. Technological advances in these directions have not been matched by a clear understanding of the environmental impacts of the new devices, with most existing research concentrated on the impacts of offshore wind farms. Decisions often continue to be made without the support of a clear evidence base. Here we use an underwater tidal turbine, SeaGen, constructed and operated within the Strangford Lough marine protected area in Northern Ireland, as a case study to explore the potential impacts of the turbine as points of concern and argumentation in the decision-making processes. We use information obtained from official documents and one-to-one interviews with the main stakeholders. Our results demonstrate that during the construction and operation of the turbine the perceptions and views of different stakeholders sometimes disagreed but were often surprisingly similar in relation to both likelihood and intensity of the potential impacts of the turbine on marine biodiversity, ecosystem services and human well-being in general. The overall consensus of views was refined and evolved under an adaptive management approach over the 10 years of the discussions and decision-making processes. The results are discussed in relation to cumulative gains in knowledge, future arrays of many underwater turbines and multiple use of oceans within social ecological systems to maintain the conservation of marine biodiversity.     

A Long-Term Experimental Case Study of the Ecological Effectiveness and Cost Effectiveness of Invasive Plant Management in Achieving Conservation Goals: Bitou Bush Control in Booderee National Park in Eastern Australia

Invasive plant management is often justified in terms of conservation goals, yet progress is rarely assessed against these broader goals, instead focussing on short-term reductions of the invader as a measure of success. Key questions commonly remain unanswered including whether invader removal reverses invader impacts and whether management itself has negative ecosystem impacts. We addressed these knowledge gaps using a seven year experimental investigation of Bitou Bush, Chrysanthemoides monilifera subsp. rotundata. Our case study took advantage of the realities of applied management interventions for Bitou Bush to assess whether it is a driver or passenger of environmental change, and quantified conservation benefits relative to management costs of different treatment regimes. Among treatments examined, spraying with herbicide followed by burning and subsequent re-spraying (spray-fire-spray) proved the most effective for reducing the number of individuals and cover of Bitou Bush. Other treatment regimes (e.g. fire followed by spraying, or two fires in succession) were less effective or even exacerbated Bitou Bush invasion. The spray-fire-spray regime did not increase susceptibility of treated areas to re-invasion by Bitou Bush or other exotic species. This regime significantly reduced plant species richness and cover, but these effects were short-lived. The spray-fire-spray regime was the most cost-effective approach to controlling a highly invasive species and facilitating restoration of native plant species richness to levels characteristic of uninvaded sites. We provide a decision tree to guide management, where recommended actions depend on the outcome of post-treatment monitoring and performance against objectives. Critical to success is avoiding partial treatments and treatment sequences that may exacerbate invasive species impacts. We also show the value of taking advantage of unplanned events, such as wildfires, to achieve management objectives at reduced cost.     

Marine protected areas can be useful but are not a silver bullet for kelp conservation

Kelp forests are among the most valuable ecosystems on Earth, but they are increasingly being degraded and lost due to a range of human-related stressors, leading to recent calls for their improved management and conservation. One of the primary tools to conserve marine species and biodiversity is the establishment of marine protected areas (MPAs). International commitments to protect 30% of the world's ecosystems are gaining momentum, offering a promising avenue to secure kelp forests into the Anthropocene. However, a clear understanding of the efficacy of MPAs for conserving kelp forests in a changing ocean is lacking. In this perspective, we question whether strengthened global protection will create meaningful conservation outcomes for kelp forests. We explore the benefits of MPAs for kelp conservation under a suite of different stressors, focusing on empirical evidence from protected kelp forests. We show that MPAs can be effective against some drivers of kelp loss (e.g., overgrazing, kelp harvesting), particularly when they are maintained in the long-term and enforced as no-take areas. There is also some evidence that MPAs can reduce impacts of climate change through building resilience in multi-stressor situations. However, MPAs also often fail to provide protection against ocean warming, marine heatwaves, coastal darkening, and pollution, which have emerged as dominant drivers of kelp forest loss globally. Although well-enforced MPAs should remain an important tool to protect kelp forests, successful kelp conservation will require implementing an additional suite of management solutions that target these accelerating threats.     

Mid- and late-Holocene vegetation history,climate and human impact in the forest-steppe ecotone of European Russia: new data and a regional synthesis

Appropriate management of contemporary environments requires knowledge of their long-term history. We use palaeoecological data to explore how contemporary forest-steppe environments have been shaped by climate change and human impacts through the Holocene using the western Mid-Russian Upland as a case-study. Our paper presents new reconstructions of Mid- and Late Holocene climate, vegetation dynamics and local environmental change based on pollen, plant macrofossil and testate amoeba records from a site at Selikhovo (Mid-Russian Upland, Russia). Eutrophic fen vegetation dominated by Phragmites australis developed around 6800 cal year BP and has been resilient to episodes of local burning and variable input of mineral material through the Holocene. New and previously-published data show that the boundary between broadleaf forest and steppe occupied a similar position to present during the period 7000–4800 cal year BP, despite a warmer and drier climate, but shifted to the south following climate cooling and an increase in precipitation from 4800–2500 cal year BP. A subsequent decline in woodland cover was caused by both climate change and human impacts, with human activity becoming increasingly significant over the last two millennia. Prior to major human disturbance (about 1700 cal year BP) the landscape was dominated by mixed broadleaf-pine forests with some spruce covering about 60 % of the study area. Our results emphasize the variability of steppe-forest habitats over long time periods and the need to consider human impacts and climate change when setting targets for habitat conservation.     

Hidden effects of forest management practices: responses of a soil stored seed bank to logging and repeated prescribed fire

Forest management practices have the potential to impact upon native vegetation. Most studies focus on the effects of management on the above‐ground vegetation communities, with little attention given to the soil stored seed bank. Here we examine the soil stored seed bank of a long‐term experimental site in south‐eastern Australia, which has experienced timber harvesting and repeated prescribed burning over a 20‐year period. At each of 213 long‐term vegetation measurement plots, 3.5 kg of soil was collected and germinated in a glasshouse over a period of 2 years. Comparisons were made between the experimental treatments considering differences in species richness, abundance and community composition of the understorey seed bank. Logged sites had a higher diversity and abundance of seedlings compared with unlogged sites, which is consistent with observed changes in standing vegetation within 10 years following logging. Prescribed burning resulted in a lower diversity and abundance of seedlings, which contrasts with the increase in species diversity observed in response to frequent fire in standing vegetation. Individual taxa that declined in the seed bank in response to frequent fire were all taxa for which germination is enhanced by exposure to smoke. Contrary to expectations, these did not exhibit a corresponding decline as standing plants. While management actions above ground are having minor impacts, greater effects were seen in the soil stored seed bank.