Micro-hotspot determination and buffer zone value for Odonata in a globally significant biosphere reserve

Reserves are frequently constrained in design and size by various financial, social or political factors. Maintenance of existing reserves must therefore rely on strategic management practices, and prioritization of conservation activities within them. Identification of global and regional hotspots have been effective for prioritizing conservation activities. Yet, identification of micro-hotspots, or overlapping areas of endemic and rare species that are under threat at the landscape scale, have largely been ignored. From a reserve management point of view, knowledge of critical micro-hotspots within a reserve, are focal points for directing cost effective, conservation initiatives, especially removal of invasive alien plants which are a major threat to biodiversity.Using diversity patterns of dragonfly assemblages, many endemic and threatened, within a biosphere reserve located in the core of a global biodiversity hotspot, we investigated the concept of micro-hotspots. As biosphere reserves contain zones with varying degrees of anthropogenic impact, we also investigated the value of buffer and transition zones for complementing the dragonfly fauna of the reserve core. We found a distinct micro-hotspot within the protected core zone which shows concordance for both endemism and species richness. We conclude that focused conservation actions to remove invasive alien plants within this micro-hotspot would help insure its continued integrity. Furthermore, while there is greater habitat degradation within the buffer and transition zones, they support many additional species, but not those necessarily endemic or threatened. The complementary value of buffer and transition zones therefore lies in increasing habitat heterogeneity and species richness of the whole reserve.     

Expanding protected areas beyond their terrestrial comfort zone: Identifying spatial options for river conservation

There has been very little consideration of freshwater ecosystems in identifying and designing protected areas. Recent studies suggest that protected areas hold enormous potential to conserve freshwater biodiversity if augmented with appropriate planning and management strategies. Recognizing this need, South Africa’s relevant government authority commissioned a spatial assessment to inform their national protected area expansion strategy. This study presents the freshwater component of the spatial assessment, aimed at identifying focus areas for expanding the national protected area system for the benefit of river biodiversity. Conservation objectives to guide the assessment aimed to improve representation of river biodiversity pattern and processes in both new and existing protected areas. Data to address these objectives were collated in a Geographic Information System (GIS) and a conservation planning algorithm was used as a means of integrating the multiple objectives in a spatially efficient manner. Representation of biodiversity pattern was based on achieving conservation targets for 222 river types and 47 freshwater fish endemic to South Africa. Options were also identified for representing coarse-scale biodiversity processes associated with free-flowing rivers and catchment-estuarine linkages. River reaches that, with only minor expansion of existing protected area boundaries, could be fully incorporated into the national protected area system were also identified. Based on this study, generic recommendations are made on how to locate, design and manage protected areas for river biodiversity: use appropriate planning units, incorporate both biodiversity pattern and process, improve planning and management of individual protected areas, incorporate a mixture of protection strategies, and embed planning into an ongoing research and implementation process.     

Spatial assessment of benefits of a coastal Mediterranean Marine Protected Area

Marine reserves are increasingly advocated not only as conservation but also as fisheries management tools to safeguard the decline of coastal fishing resources. Still, conclusive evidence of their functioning is lacking, amongst others due to the influence of spatio-temporal variations in fish populations and habitat heterogeneity which could hamper a sound data interpretation. We conducted a spatial analysis of the benefits of the Medes Island Marine Reserve by combining geostatistical and Geographic Information System (GIS) tools. Concurrently, we analysed effects of trends reflecting habitat heterogeneity and spatial structuring of data on spatial predictions of fish catch per unit effort (CPUE) and length. Predicted spatial patterns showed the complexity and simultaneous action of trend factors leading to mostly non-linear gradients in CPUE and length data. CPUE of total fish and CPUE and length of common pandora (Pagellus erythrinus) increased close to the Integral Reserve due to direct and indirect reserve effects. CPUE and length of striped red mullet (Mullus surmuletus) slightly increased also near the Integral Reserve, but distinct reserve effects could not be identified due to the strong influence of artificial reefs. We conclude that the spatial dimension of the Buffer Zone, where artisanal fisheries are allowed, permits in general protection only for target species, favouring a habitat with no discontinuities from the reserve outwards. Our spatial approach to assess reserve benefits provides major insights into complex systems like coastal marine reserves in the northwestern Mediterranean. In addition, it contributes to a crucial aspect of marine conservation, viz. the decision on the spatial dimension of protected areas.     

The importance of fine-scale savanna heterogeneity for reptiles and small mammals

Tropical savannas are an important reservoir of global biodiversity. Australia’s extensive savannas, although still largely intact, are experiencing substantial declines in terrestrial biodiversity due to a variety of interrelated effects of altered fire regimes, grazing and increases in invasive species. These disturbance processes are spatially variable, combine to increase landscape to local-scale landscape heterogeneity, but rarely result in well-defined patch boundaries. We quantified the importance of this heterogeneity for native reptile and small mammal species in a tropical savanna landscape of Queensland, Australia. We used high resolution remote sensing imagery (IKONOS) to map habitat pattern at a 4 m spatial resolution and at variable extents. We found that landscapes dominated by grass or bare ground had low reptile and small mammal diversity, while landscapes with a heterogeneous mix of grass, bare ground and trees had high species diversity and relative abundance of most species. Landscape heterogeneity may increase reptile and small mammal species richness by: (i) increasing the variety and abundance of foraging resources such as seeds and invertebrates; (ii) providing cover from predators and high summer temperatures; and (iii) increasing functional connectivity and dispersal success. The importance of these resources and processes varies among individual species and at different spatial scales, reiterating the need to consider habitat requirements of multiple species in landscape management and conservation planning.     

Conservation planning with dynamic threats: The role of spatial design and priority setting for species’ persistence

Conservation actions frequently need to be scheduled because both funding and implementation capacity are limited. Two approaches to scheduling are possible. Maximizing gain (MaxGain) which attempts to maximize representation with protected areas, or minimizing loss (MinLoss) which attempts to minimize total loss both inside and outside protected areas. Conservation planners also choose between setting priorities based solely on biodiversity pattern and considering surrogates for biodiversity processes such as connectivity. We address both biodiversity processes and habitat loss in a scheduling framework by comparing four different prioritization strategies defined by MaxGain and MinLoss applied to biodiversity patterns and processes to solve the dynamic area selection problem with variable area cost. We compared each strategy by estimating predicted species’ occurrences within a landscape after 20 years of incremental reservation and loss of habitat. By incorporating species-specific responses to fragmentation, we found that you could improve the performance of conservation strategies. MinLoss was the best approach for conserving both biodiversity pattern and process. However, due to the spatial autocorrelation of habitat loss, reserves selected with this approach tended to become more isolated through time; losing up to 40% of occurrences of edge-sensitive species. Additionally, because of the positive correlation between threats and land cost, reserve networks designed with this approach contained smaller and fewer reserves compared with networks designed with a MaxGain approach. We suggest a possible way to account for the negative effect of fragmentation by considering both local and neighbourhood vulnerability to habitat loss.     

Climate change meets habitat fragmentation: linking landscape and biogeographical scale levels in research and conservation

Climate change and habitat fragmentation are considered key pressures on biodiversity. In this paper we explore the potential synergetic effects between these factors. We argue that processes at two levels of spatial scale interact: the metapopulation level and the species range level. Current concepts of spatially dynamic metapopulations and species ranges are consistent, and integration improves our understanding of the interaction of landscape level and geographical range level processes. In landscape zones in which the degree of habitat fragmentation allows persistence, the shifting of ranges is inhibited, but not blocked. In areas where the spatial cohesion of the habitat is below the critical level of metapopulation persistence, the expansion of ranges will be blocked. An increased frequency of large-scale disturbances caused by extreme weather events will cause increasing gaps and an overall contraction of the distribution range, particularly in areas with relatively low levels of spatial cohesion. Taking into account the effects of climate change on metapopulations, habitat distribution and land use changes, future biodiversity research and conservation strategies are facing the challenge to re-orient their focus and scope by integrating spatially and conceptually more dynamic aspects at the landscape level.     

Effect of the landscape context on the density and persistence of a predator population in a protected area subject to environmental variability

Protected areas are the most important tool for the conservation of biodiversity. However, many species are area-demanding and their populations seldom meet their space requirements in reserves. In this context, the unprotected exterior becomes an important part of their home range, and variations in habitat quality of the surroundings of a protected area might affect the dynamics of populations. Using a spatially explicit simulation model, we studied the effect of the surrounding landscape of a protected area on the density and persistence of a predator population inhabiting inside the reserve in different conditions of environmental variability. We simulated individuals of a predator population, their herbivorous prey and a vegetative substrate in a landscape comprised of a square protected area and different types of habitat quality outside the reserve. We studied the combination of three substrate qualities of protected area (inside) with three of the landscape context and three levels of variability of productivity. Our results showed that there were strong effects of both the relative quality of the surrounding landscape and of the environmental variability on the density and persistence of the simulated population inside the protected area. More importantly, we showed that complex patterns emerge when spatial heterogeneity and temporal variability interact with population dynamics. Specifically, under high environmental variability, when the protected area had a high habitat quality, the highest population persistence was not attained when the exterior was also of high quality, but when the surroundings had an intermediate quality. The latter result suggests that, under the mentioned conditions, small enhancements in the quality of the matrix may have, for some species, better effects on increasing persistence in small reserves than large and costly enhancements.     

Are hotspots of evolutionary potential adequately protected in southern California?

Reserves are often designed to protect rare habitats, or “typical” exemplars of ecoregions and geomorphic provinces. This approach focuses on current patterns of organismal and ecosystem-level biodiversity, but typically ignores the evolutionary processes that control the gain and loss of biodiversity at these and other levels (e.g., genetic, ecological). In order to include evolutionary processes in conservation planning efforts, their spatial components must first be identified and mapped. We describe a GIS-based approach for explicitly mapping patterns of genetic divergence and diversity for multiple species (a “multi-species genetic landscape”). Using this approach, we analyzed mitochondrial DNA datasets from 21 vertebrate and invertebrate species in southern California to identify areas with common phylogeographic breaks and high intrapopulation diversity. The result is an evolutionary framework for southern California within which patterns of genetic diversity can be analyzed in the context of historical processes, future evolutionary potential and current reserve design. Our multi-species genetic landscapes pinpoint six hotspots where interpopulation genetic divergence is consistently high, five evolutionary hotspots within which genetic connectivity is high, and three hotspots where intrapopulation genetic diversity is high. These 14 hotspots can be grouped into eight geographic areas, of which five largely are unprotected at this time. The multi-species genetic landscape approach may provide an avenue to readily incorporate measures of evolutionary process into GIS-based systematic conservation assessment and land-use planning.     

Mapping community change in modified landscapes

Habitat loss is not randomly distributed across modified landscapes, yet spatial patterns of habitat cover are not routinely combined with biodiversity data when assessing or predicting the biodiversity impacts of land use change. Here, we convert point observations of more than 28,000 beetles from 851 species into a continuous biodiversity surface representing the similarity of ecological communities relative to that of pristine forest, effectively integrating on-the-ground biodiversity data with remotely sensed land cover data to predict the magnitude of community change in a modified landscape. We generated biodiversity surfaces for both present-day and pre-human landscapes to map spatial patterns of change in a diverse ecological community to calculate the combined biodiversity impacts of habitat loss and fragmentation that accounts for the exact spatial pattern of deforestation. Our spatially-explicit, landscape-scale index of community change shows how the fine-scale configuration of habitat loss sums across a landscape to determine changes in biodiversity at a larger spatial scale. After accounting for naturally occurring within-forest heterogeneity, we estimate that the conversion of 43% of forest to grassland in a 1300 km² landscape in New Zealand resulted in a 47% change to the beetle community.     

The effects of including marine ecological values in terrestrial reserve planning for a forest-nesting seabird

Theoretical advances in systematic reserve design aim to promote the efficient use of limited conservation resources and to increase the likelihood that reserve networks enhance the persistence of valued species and ecosystems. However, these methods have rarely been applied to species that rely on spatially disjunct habitats. We used the marbled murrelet, a seabird that requires old-growth forest in which to nest and high quality marine habitats in which to forage, as a case study to explore methods of incorporating multiple ecological values into single species spatial reserve design. Specifically, we used the cost function in MARXAN to include the ecological value of marine habitats while identifying spatial solutions for terrestrial nesting habitat reserves. Including marine values influenced terrestrial reserve designs most when terrestrial habitat targets were low and little or none of the target was represented in pre-existing protected areas. Our results suggest that including marine values in the planning process will influence marbled murrelet terrestrial reserve designs most where substantial terrestrial nesting habitat still exists, where new reserves are relatively unconstrained by pre-existing reserves, or when conservation resources only allow the protection of a small fraction of available habitat. This paper presents a novel framework for incorporating multiple measures of ecological value in the spatial reserve design process and should be particularly useful for species that rely on multiple habitats during their life cycle.     

Spatial structure of multispecies distributions in southern California, USA

Analysis of the spatial distribution of all species of conservation importance within a region is necessary to augment reserve selection strategies and habitat management in biodiversity conservation. In this study, we analyzed the spatial aggregation, spatial association, and vegetation types of point occurrence data collected from museum and herbaria records for rare, special concern, threatened, and endangered species of plants, reptiles, mammals, and birds in western Riverside County in southern California, USA. All taxa showed clumped distributions, with aggregation evident below 14 km for plants, 12 km for reptiles, 2 km for mammals, and 10 km for birds. In addition, all combinations of the different species groups showed high positive spatial association. The Santa Rosa Plateau exhibited the highest number of rare, special concern, threatened, and endangered species, and shrubland (coastal sage and chaparral) was the vegetation type inhabited by the most species. Local land use planning, zoning and reserve design should consider the spatial aggregation within and between species to determine the appropriate scale for conservation planning. The higher spatial association between species groups in this study may indicate interdependence between different species groups or shared habitat requirements. It is important to maintain diverse communities due to potential interdependence. The results of the study indicate that concentrating preservation efforts on areas with the highest number of species of concern and the restoration of native shrublands are the most appropriate actions for multiple species habitat conservation in this area.     

Modelling semi-natural habitat area on lowland farms in western Ireland

A significant policy objective is the need for protection of biodiversity not just within designated Natura 2000 sites, but also in areas that occur outside of these sites. However there is a lack of information on existing semi-natural habitat cover on EU farms, making it difficult to assess whether targets for halting the loss of agricultural biodiversity are being met. To achieve these targets, reliable yet easy-to-use methods are needed for accurately identifying priority areas for conservation actions and monitoring biodiversity on a large spatial scale.Remote sensing, farmland statistics and species data have been used in some EU countries to create maps to estimate the extent of semi-natural habitat cover but these are acknowledged as being too broad scale. In this study, we examined a method of fine-scale prediction of the spatial coverage of semi-natural habitats in lowland farms. A generalized additive model (GAM) was used to investigate the relationships between landscape and farm management variables and the lowland farmland habitat biodiversity on 32 farms outside of conservation designations, in a region of western Ireland. Semi-natural habitat cover on lowland farms could be predicted with a model using stocking density, soil diversity and river and stream length. It is proposed that this model could be used to predict the coverage of semi-natural habitats on farms in other regions of Ireland with similar land-use and landscape. A similar modelling approach could be adapted for application in other regions of Ireland and across Europe with different landscapes to predict semi-natural habitat coverage.     

Where to put things? Spatial land management to sustain biodiversity and economic returns

Expanding human population and economic growth have led to large-scale conversion of natural habitat to human-dominated landscapes with consequent large-scale declines in biodiversity. Conserving biodiversity, while at the same time meeting expanding human needs, is an issue of utmost importance. In this paper we develop a spatially explicit landscape-level model for analyzing the biological and economic consequences of alternative land-use patterns. The spatially explicit biological model incorporates habitat preferences, area requirements and dispersal ability between habitat patches for terrestrial vertebrate species to predict the likely number of species that will be sustained on the landscape. The spatially explicit economic model incorporates site characteristics and location to predict economic returns for a variety of potential land uses. We apply the model to search for efficient land-use patterns that maximize biodiversity conservation objectives for given levels of economic returns, and vice versa. We apply the model to the Willamette Basin, Oregon, USA. By thinking carefully about the arrangement of activities, we find land-use patterns that sustain high levels of biodiversity and economic returns. Compared to the 1990 land-use pattern, we show that both biodiversity conservation and the value of economic activity could be increased substantially.     

Evaluating cost-effectiveness of conservation management actions in an agricultural landscape on a regional scale

Agricultural landscapes are the dominating landscape types in many parts of the world. Land-use intensification and spatial homogeneity are major threats to biodiversity in these landscapes. Thus cost-effective strategies for species conservation in large-scale agricultural landscapes are required. Spatial optimisation methods can be applied to identify the most effective allocation of a given budget for conservation. However, the optimisation of spatial land-use patterns in real landscapes on a large spatial scale is often limited by computational power. In this paper, we present a simplifying methodology for analysing cost-effectiveness of management actions on a regional scale. A spatially explicit optimisation approach is employed to identify optimum agricultural land-use patterns with respect to an ecological-economic goal function. Based on the optimisation results for small scale landscape samples we derive a target- and site-specific cost-benefit function that can be applied to predict ecological improvement as a function of costs and local conditions on a large spatial scale. Thus, it is possible to identify areas where management actions for ecological improvement are most efficient with respect to a certain conservation goal. The fitted function is validated independently. In a case study, we analyse cost-effectiveness of management actions to enhance habitat suitability for three different target species. The approach is flexible and could be applied to a variety of other landscape planning problems dealing with the effective allocation of management measures.     

Administrative regions in conservation: Balancing local priorities with regional to global preferences in spatial planning

Site selection, reserve selection, and spatial conservation prioritization are terms that have been used for various algorithms and methods for the spatial allocation of conservation resources. Many of these methods start from the setting of targets or weights for different conservation features. Almost always there is only one set of targets or weights, thus implicitly assuming that priorities stay the same through the entire planning region. However, priorities for biodiversity governance could vary between regions. For example, priorities inside countries could be different from global priorities. Inside a country, different stakeholders could hold different priorities. Thus, priorities could vary between sub-regions while ecological processes, such as connectivity, cross borders without regard to administrative boundaries. Here we describe how it is possible to account for conservation priorities that vary between administrative sub-regions in conservation prioritization. We illustrate how assumptions about selection methods and feature weights can significantly influence the outcome mapping of conservation priority. We also show how placing high emphasis on local considerations reduces the cost-efficiency of the global conservation outcome. Analyses proposed here will be made publicly available in software (Zonation) capable for large-scale high-resolution conservation prioritization.     

黄河三角洲自然保护区土地利用格局空间优化模拟

空间优化模型能够实现多管理目标下的土地利用格局空间优化,为管理者制定保护政策提供参考。该文以黄河三角洲自然保护区为研究区域,基于保护区的多目标管理需求,设计了3种用于协调丹顶鹤生境保护和社区可持续发展的情景模式,并采用土地利用空间优化(land use pattern optimization,LUPO)模型,模拟实现了不同情景模式下的保护区土地利用格局空间优化配置。模拟结果表明:情景A通过将光滩和芦苇滩等转为丹顶鹤喜好的翅碱蓬滩涂和柽柳-翅碱蓬滩涂,实现使丹顶鹤适宜生境面积增加30%的生态效益目标,但年经济收益增幅仅为11%;情景B通过将农田、芦苇滩和光滩等转为年经济效益更高的虾池,使区域年经济效益增长54%,但丹顶鹤适宜生境面积变化较小,生境更为破碎化;情景C通过将光滩等转为翅碱蓬滩涂,将农田等转为虾池,分别使丹顶鹤适宜生境面积增加24%和区域年经济效益增长41.3%,是一种双赢方案。研究结果表明,该模型可用于保护区土地利用格局空间优化,协调物种保护和经济发展之间的平衡关系,但需对模型结构和参数进一步优化设计。     

Determinants of native avian richness in suburban remnant vegetation: Implications for conservation planning

While urban areas are increasingly recognized as having potential value for biodiversity conservation, the relationship between biodiversity and the structure and configuration of the urban landscape is poorly understood. In this study we surveyed birds in 39 remnant patches of native vegetation of various sizes (range 1-107 ha) embedded in the suburban matrix in Melbourne, Australia. The total richness of species within remnants was strongly associated with the size of remnants. Remnant-reliant species displayed a much stronger response to remnant area than matrix-tolerant species indicating the importance of large remnants in maintaining representative bird assemblages. Large remnants are important for other ecological groups of species including migratory species, ground foraging birds and canopy foraging birds. Other landscape (e.g. amount of riparian vegetation) and structural components (e.g. shrub cover) of remnants have a lesser role in determining the richness of individual remnants. This research provides conservation managers and planners with a hierarchical process to reserve design and management in order to conserve the highest richness of native species within urban areas. First of all, conservation efforts should preferentially focus on the retention of larger remnants of native vegetation. Second, where possible, riparian vegetation should be included within reserves or, where it is already present, should be carefully managed to ensure its integrity. Third, efforts should be focused at maintaining appropriate habitat and vegetation structure and complexity.     

Identifying and mapping biodiversity processes for conservation planning in islands: A case study in Réunion Island (Western Indian Ocean)

Over the last century, island biodiversity has become one of the most threatened in the world. Although many island conservation plans address biodiversity requirements at the species level, few plans address the spatial requirements of the biodiversity processes that underpin the persistence of these species. Using systematic conservation planning principles, we map the spatial components of biodiversity processes (SCBPs) and use these to design broad-scale conservation corridors for Réunion Island. Our method is based upon a literature review, expert knowledge, spatially explicit base data, conservation planning software, and spatial modelling. We combine a target-driven algorithm with least-cost path analyses to delineate optimal corridors for capturing key biodiversity processes while simultaneously considering biodiversity pattern targets, conservation opportunities, and future threats. We identify five SCBPs: the oceanic-terrestrial interface; riverine corridors; macrohabitat interfaces; the boundaries of isolated topographic units; and lowland-upland gradients. A large proportion of the SCBPs (81.3%) is currently untransformed, whereas 3% is irreversibly transformed by urbanisation and 15.7% is transformed but restorable. However, SCBPs are almost fully disrupted by urbanisation in the lowlands, thereby compromising functional corridors along full altitudinal gradients. This study is a contribution toward the reconciliation of conservation versus development objectives on Réunion Island but we believe that the delineation method is sufficiently general to be applied to other islands. Our results highlight the need for integrating marine, coastal and terrestrial conservation planning as a matter of urgency, given the rapid transformation of coastal areas on islands.     

Setting conservation targets under budgetary constraints

Target-based spatial prioritization is the default approach in conservation resource allocation. Here, we clarify a poorly known feature of target-based spatial prioritization that may lead to an unbalanced allocation of resources between species or other biodiversity features. Highest per-species resources will be allocated to species occurring in costly and otherwise species-poor locations, whereas smallest per-species resources will be allocated to species that occur in species-rich locations at low-cost areas. Uncertainty in information about processes determining distributions of biodiversity features may lead to uncertainty in target setting. This can be a problem if unnecessarily high targets emerge to consume excessive resources thus detracting from other conservation action. Difficulties might be encountered in particular when there are many features, targets are given simultaneously to multiple different types of biodiversity features, or components of features, or when there are interactions or correlations between features. Consequently, we recommend that the costs of targets for individual features could be evaluated to screen for such targets that consume a disproportionate fraction of available resources. Costs of targets can be evaluated by a variant of the replacement cost technique. We also find that commonly used reserve selection methods, minimum set coverage, maximum coverage, and utility maximization differ significantly in how they treat targets and their costs.     

Habitat-based conservation priorities for carabid beetles within the Picos de Europa National Park, northern Spain

Quick biodiversity studies on poorly studied taxa and areas are increasingly popular for setting conservation priorities over a wide range of spatial scales. However, the implementation of such studies is complicated by the variable extent to which the different criteria used in prioritisation are correlated to each other. Using methods of constrained ordination, we examined the species-habitat relationships of carabid beetles based on ground beetle assemblages from 22 sites in the Picos de Europa National Park, northern Spain. We found characteristic species assemblages for subalpine meadows, Genista shrublands, and pastures, whereas mown meadows, heathlands, beech and riparian woodlands were occupied by more habitat generalist species. Species associated with subalpine meadows and Genista shrublands tended to be mostly brachypterous and to have geographic ranges restricted to northern Spain. In contrast, we found no relationship between the degree of species' association with pastures and geographic range-wing size type. Although the species richness was higher in riparian woodlands and mown meadows, we suggest a higher conservation value for subalpine meadows and Genista shrublands across the landscape because they sustain characteristic assemblages dominated by species with restricted ranges and reduced powers of dispersal. Our study suggests that preserving areas in the landscape supporting higher biodiversity will not necessarily preserve those species potentially more susceptible to habitat loss and fragmentation. It also supports the feasibility of biodiversity studies based on multivariate techniques for setting conservation priorities over complex landscapes.