Questioning the ecosystem services argument for biodiversity conservation

One of the central justifications for the conservation of biodiversity is the notion that species diversity is essential for the maintenance of ecosystem services. However, an important observation overlooked by proponents of this argument is that most ecosystem services are provided not by whole ecosystems, but by any group of species that fulfils certain basic functional criteria. Distinguishing between services that are resilient in response to species decline, and those that are not, is a far less challenging task than identifying the precise influence on ecosystem functioning of rare species. Conservationists have been almost unanimous in their failure to acknowledge this distinction between resilient and sensitive ecosystem services. Not only does this threaten the credibility of conservation science, but also increases the likelihood that natural area management becomes hijacked by the demand that ecosystem service provision be made the dominant management criteria.     

A review and a framework for the integration of biodiversity monitoring at the habitat level

The monitoring of biodiversity at the level of habitats is becoming widespread in Europe and elsewhere as countries establish national habitat monitoring systems and various organisations initiate regional and local schemes. Parallel to this growth, it is increasingly important to address biodiversity changes on large spatial (e.g. continental) and temporal (e.g. decade-long) scales, which requires the integration of currently ongoing monitoring efforts. Here we review habitat monitoring and develop a framework for integrating data or activities across habitat monitoring schemes. We first identify three basic properties of monitoring activities: spatial aspect (explicitly spatial vs. non-spatial), documentation of spatial variation (field mapping vs. remote sensing) and coverage of habitats (all habitats or specific habitats in an area), and six classes of monitoring schemes based on these properties. Then we explore tasks essential for integrating schemes both within and across the major classes. Finally, we evaluate the need and potential for integration of currently existing schemes by drawing on data collected on European habitat monitoring in the EuMon project. Our results suggest a dire need for integration if we are to measure biodiversity changes across large spatial and temporal scales regarding the 2010 target and beyond. We also make recommendations for an integrated pan-European habitat monitoring scheme. Such a scheme should be based on remote sensing to record changes in land cover and habitat types over large scales, with complementary field mapping using unified methodology to provide ground truthing and to monitor small-scale changes, at least in habitat types of conservation importance.     

Linking biodiversity to ecosystem function: implications for conservation ecology

We evaluate the empirical and theoretical support for the hypothesis that a large proportion of native species richness is required to maximize ecosystem stability and sustain function. This assessment is important for conservation strategies because sustenance of ecosystem functions has been used as an argument for the conservation of species. If ecosystem functions are sustained at relatively low species richness, then arguing for the conservation of ecosystem function, no matter how important in its own right, does not strongly argue for the conservation of species. Additionally, for this to be a strong conservation argument the link between species diversity and ecosystem functions of value to the human community must be clear. We review the empirical literature to quantify the support for two hypotheses: (1) species richness is positively correlated with ecosystem function, and (2) ecosystem functions do not saturate at low species richness relative to the observed or experimental diversity. Few empirical studies demonstrate improved function at high levels of species richness. Second, we analyze recent theoretical models in order to estimate the level of species richness required to maintain ecosystem function. Again we find that, within a single trophic level, most mathematical models predict saturation of ecosystem function at a low proportion of local species richness. We also analyze a theoretical model linking species number to ecosystem stability. This model predicts that species richness beyond the first few species does not typically increase ecosystem stability. One reason that high species richness may not contribute significantly to function or stability is that most communities are characterized by strong dominance such that a few species provide the vast majority of the community biomass. Rapid turnover of species may rescue the concept that diversity leads to maximum function and stability. The role of turnover in ecosystem function and stability has not been investigated. Despite the recent rush to embrace the linkage between biodiversity and ecosystem function, we find little support for the hypothesis that there is a strong dependence of ecosystem function on the full complement of diversity within sites. Given this observation, the conservation community should take a cautious view of endorsing this linkage as a model to promote conservation goals. Received: 2 September 1999 / Accepted: 26 October 1999     

Capturing biodiversity: selecting priority areas for conservation using different criteria

International treaties call for the protection of biodiversity in all its manifestations, including ecosystem and species diversities. The selection of most priority area networks focuses, however, primarily on species richness and occurrence. The effectiveness of this approach in capturing higher order manifestations of biodiversity, that is ecosystem and environmental diversity patterns, remains poorly understood. Using a case study of birds and environmental data from South Africa and Lesotho, we test how complementary networks that maximise species diversity perform with regard to their representation of ecosystem and environmental diversity, and vice versa. We compare these results to the performance of the existing reserve network. We conclude that focusing on any single biodiversity component alone is insufficient to protect other components. We offer explanations for this in terms of the autocorrelation of species diversity in environmental space.     

A comparison of some population density sampling techniques for biodiversity, conservation, and environmental impact studies

Twelve terrestrial and marine studies were conducted at various sites in Malaysia, Brazil, and the United States between April 1999 and February 2004. These data were analyzed using five density estimate techniques for stationary (non-motile) organisms including Stratified Random Sampling, Point-Center Quarter, Third Nearest Object, Weinberg, and Strong. The Strong method gave the most accurate density estimates of stationary animals and plants. Stratified Random Sampling ranked second best and the Third Nearest Object the third best. Belt or strip transects may be preferable but can be restrictive in some situations because of logistics and associated time constraints. Straight line measurements on reefs were 3–27% more accurate than reef slack line and reef contour measurements. Most study areas measured with the standardized Morisita index of dispersion were moderately aggregated. Results from the Third Nearest Object and Point-Center Quarter techniques indicate that the addition of more data to establish a density correction factor does not necessarily give more accurate estimates of density.     

Optimal investment for enhancing social concern about biodiversity conservation: A dynamic approach

To maintain biodiversity conservation areas, we need to invest in activities, such as monitoring the condition of the ecosystem, preventing illegal exploitation, and removing harmful alien species. These require a constant supply of resources, the level of which is determined by the concern of the society about biodiversity conservation. In this paper, we study the optimal fraction of the resources to invest in activities for enhancing the social concern y(t) by environmental education, museum displays, publications, and media exposure. We search for the strategy that maximizes the time-integral of the quality of the conservation area x(t) with temporal discounting. Analyses based on dynamic programming and Pontryagin’s maximum principle show that the optimal control consists of two phases: (1) in the first phase, the social concern level approaches to the final optimal value y^∗, (2) in the second phase, resources are allocated to both activities, and the social concern level is kept constant y(t)=y^∗. If the social concern starts from a low initial level, the optimal path includes a period in which the quality of the conservation area declines temporarily, because all the resources are invested to enhance the social concern. When the support rate increases with the quality of the conservation area itself x(t) as well as with the level of social concern y(t), both variables may increase simultaneously in the second phase. We discuss the implication of the results to good management of biodiversity conservation areas.     

A collaborative GIS method for integrating local and technical knowledge in establishing biodiversity conservation priorities

Methods for establishing biodiversity conservation priorities are urgently required, as the number of species and habitats that are threatened increases relative to the material resources available for their conservation. The identification of priority areas demands the integration of biophysical data on ecosystems together with social data on human pressures and planning opportunities. But comprehensive and reliable data are rarely available to demarcate where the need for action is most urgent and where the benefits of conservation strategies can be maximized. Strategic conservation initiatives cannot wait for the creation of comprehensive databases. In order to fill the missing data gaps, the combined knowledge of local and technical experts can be used. This study presents a collaborative geographic information system (GIS) method for integrating the knowledge of local and technical experts with existing spatial environmental data to establish priority areas for biodiversity conservation. Procedures for structuring and framing the discussions, establishing assessment criteria, integrating knowledge with data, and building consensus are incorporated into the method. The method provides a novel cooperative mechanism to aid spatial knowledge management and inclusive biodiversity planning.     

Information as a regulatory instrument to price biodiversity benefits: certification and ecolabeling policy practices

In this paper we address the issue of market failure arising from the non-existence of (market) prices for biodiversity, and also present and discuss alternative policies to cope with it. Particular attention is given to certification and ecolabeling of policies. First, we critically survey the role of certification and ecolabeling as an information provision instrument. Second, we provide a comprehensive view on basic foundations and crucial issues that underpin the design of a certification and ecolabeling policy. Finally, we present some case studies to draw some lessons from current certification and ecolabeling policy practices.     

Assessing New Zealand fern diversity from spatial predictions of species assemblages

The utility of explicit spatial predictions for biodiversity assessment is investigated with New Zealand fern flora. Distributions of 43 species were modelled from climatic and landform variables and predicted across New Zealand using generalised additive models (GAM). An original package of functions called generalised regression analysis and spatial prediction (GRASP) was developed to perform the analyses. On average, for the 43 models, the contributions of environmental variables indicate that mean annual temperature is the most important factor at this broad regional scale. Both annual solar radiation and its seasonality had higher correlations than temperature seasonality. Measures of water availability such as ratio of rainfall to potential evapotranspiration, air saturation deficit and soil water deficit presented significant contributions. Lithology was a better predictor than slope and drainage. These results are similar to those obtained from analyses of the distributions of New Zealand tree species and are consistent with the hypothesis that both tree and fern diversity are highest on sites conducive to high productivity. In order to identify hotspots of fern diversity, spatial predictions of individual species were summed up. The resulting map gave a very similar result to the direct prediction of their corresponding richness (number of species by plot out of 43 spp.). As a consequence, and where individual species models were not all available, the number of species within different species assemblages was directly modelled. Predicted richness hotspots of total species (out of 122 spp.), selected species (out of 43 and 21 spp.) and common species (out of 23 spp.) present very similar spatial patterns and are highly correlated. Richness of uncommon species (out of 39 spp.) was also accurately predicted, but presented a different spatial pattern. The number of rare species (out of 60 spp.) was not correctly modelled. Even though the lack of data for rare species clearly limits the application of this approach, fern community composition of more common species can be partially reconstructed from individual species predictions. This case study offers therefore a consistent approach not only for biodiversity hotspots identification, but also for setting targets to biodiversity assessment and restoration programs.     

Linking political and scientifically derived targets for global biodiversity conservation: implications for the expansion of the global network of protected areas

Despite the global network of protected areas covers 12% of the world's land surface, its performance is still unsatisfactory. Although political and scientifically sound conservation targets usually portray different pictures of the task ahead, we show that in terms of priority areas for expanding the global network of reserves, there is much agreement between the political targets of the Convention on Biological Diversity (CBD), and the scientifically derived goals endorsed by international conservation organizations. Here we analyse four global databases to identify priority areas for fulfilling the CBD target of representing 10% of every ecological region within protected areas, and compare the distribution of priority regions for fulfilling that political target, with the distribution of the priority areas for global biodiversity conservation identified by Conservation International, the WWF, and the Wildlife Conservation Society on scientific basis. For 63% (549) of the world's terrestrial ecoregions the CBD 10% target is still not met; fulfilling it requires protecting another 4.6% of the Earth's land surface (6,239,894 km²). Yet, at least 78% of the priority regions for fulfilling that target lay within priority regions for the main global conservation strategies. By pursuing the political target set by the CBD much ancillary gains in terms of other global conservation objectives can be obtained.     

A new analytical method for wildlife habitat conservation planning on a city scale using the classification of physiologically homogeneous areas

Kyoto has a tradition of positively protecting scenic landscapes. However, a question has arisen about the effectiveness of the present legislative system on biodiversity conservation because most laws aim to essentially preserve the aesthetic value of the landscape. It is necessary to identify gaps in the present conservation system to develop an effective conservation policy for the city. The authors propose a practical method of analysis for wildlife habitat conservation planning without wildlife distribution information, which is the usual situation in many cities, and discuss the usefulness and limitations of the method by applying it to Kyoto. The proposed method relies on both of the following two assumptions: (1) the physical properties of the environment are closely related to the potential vegetation communities and (2) the conservation or restoration of rare or extinct vegetation communities ensures diverse wildlife habitats, contributing to biodiversity enhancement in a region. Thus it should be deemed a supplementary analysis to other types of analyses employing endangered, umbrella and/or flagship species in the planning process. A unique aspect of the method is to evaluate land potential, which is important for long-term conservation planning and the determination of target vegetation communities in restoration projects. In Kyoto, this revealed that the candidates for vegetation communities, prioritized for conservation and restoration, were appropriate. Moreover, identifying physiotopes corresponding with none of the existing vegetation communities was another advantage providing useful information for restoration planning. However, it was considered that a filtering process, with auxiliary information about the trend of vegetation communities over time, was necessary after applying the proposed method.     

Models for forest ecosystem management: a European perspective

BACKGROUND: Forest management in Europe is committed to sustainability. In the face of climate change and accompanying risks, however, planning in order to achieve this aim becomes increasingly challenging, underlining the need for new and innovative methods. Models potentially integrate a wide range of system knowledge and present scenarios of variables important for any management decision. In the past, however, model development has mainly focused on specific purposes whereas today we are increasingly aware of the need for the whole range of information that can be provided by models. It is therefore assumed helpful to review the various approaches that are available for specific tasks and to discuss how they can be used for future management strategies. SCOPE: Here we develop a concept for the role of models in forest ecosystem management based on historical analyses. Five paradigms of forest management are identified: (1) multiple uses, (2) dominant use, (3) environmentally sensitive multiple uses, (4) full ecosystem approach and (5) eco-regional perspective. An overview of model approaches is given that is dedicated to this purpose and to developments of different kinds of approaches. It is discussed how these models can contribute to goal setting, decision support and development of guidelines for forestry operations. Furthermore, it is shown how scenario analysis, including stand and landscape visualization, can be used to depict alternatives, make long-term consequences of different options transparent, and ease participation of different stakeholder groups and education. CONCLUSIONS: In our opinion, the current challenge of forest ecosystem management in Europe is to integrate system knowledge from different temporal and spatial scales and from various disciplines. For this purpose, using a set of models with different focus that can be selected from a kind of toolbox according to particular needs is more promising than developing one overarching model, covering ecological, production and landscape issues equally well.     

Integrating multiple wilderness values into a decision-making model for Denali National Park and Preserve

Decisions about how to manage wilderness recreation in Denali National Park and Preserve require managers to integrate a diverse set of public values, a process that typically involves balancing tradeoffs among multiple and often competing values. While decisions about how to manage wilderness are often contentious, previous research suggests that if managers are able to predict public support for various management alternatives the decisions become more tractable. This study develops a decision-making model that integrates social, resource, and managerial values associated with the Denali wilderness experience. Specifically, stated choice analysis is used to evaluate the choices overnight wilderness visitors make when faced with hypothetical tradeoffs among the conditions of social, resource, and management attributes of the Denali wilderness. Study findings offer an empirical approach for predicting and evaluating the likelihood of public support for Denali wilderness management alternatives.