Nicholas Davidson

Global Biodiversity: Indicators of Recent Declines

Global Biodiversity Target Missed In 2002, the Convention on Biological Diversity (CBD) committed to a significant reduction in the rate of biodiversity loss by 2010. There has been widespread conjecture that this target has not been met. Butchart et al. (p. 1164, published online 29 April) analyzed over 30 indicators developed within the CBDs framework. These indicators include the condition or state of biodiversity (e.g., species numbers, population sizes), the pressures on biodiversity (e.g., deforestation), and the responses to maintain biodiversity (e.g., protected areas) and were assessed between about 1970 and 2005. Taken together, the results confirm that we have indeed failed to meet the 2010 targets. An analysis of 30 indicators shows that the Convention on Biological Diversity’s 2010 targets have not been met. In 2002, world leaders committed, through the Convention on Biological Diversity, to achieve a significant reduction in the rate of biodiversity loss by 2010. We compiled 31 indicators to report on progress toward this target. Most indicators of the state of biodiversity (covering species’ population trends, extinction risk, habitat extent and condition, and community composition) showed declines, with no significant recent reductions in rate, whereas indicators of pressures on biodiversity (including resource consumption, invasive alien species, nitrogen pollution, overexploitation, and climate change impacts) showed increases. Despite some local successes and increasing responses (including extent and biodiversity coverage of protected areas, sustainable forest management, policy responses to invasive alien species, and biodiversity-related aid), the rate of biodiversity loss does not appear to be slowing.

Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas

ABSTRACT The conservation and sustainable use of marine resources is a highlighted goal on a growing number of national and international policy agendas. Unfortunately, efforts to assess progress, as well as to strategically plan and prioritize new marine conservation measures, have been hampered by the lack of a detailed, comprehensive biogeographic system to classify the oceans. Here we report on a new global system for coastal and shelf areas: the Marine Ecoregions of the World, or MEOW, a nested system of 12 realms, 62 provinces, and 232 ecoregions. This system provides considerably better spatial resolution than earlier global systems, yet it preserves many common elements and can be cross-referenced to many regional biogeographic classifications. The designation of terrestrial ecoregions has revolutionized priority setting and planning for terrestrial conservation; we anticipate similar benefits from the use of a coherent and credible marine system.

How much wetland has the world lost? Long-term and recent trends in global wetland area

It has been frequently stated, but without provision of supporting evidence, that the world has lost 50% of its wetlands (or 50% since 1900 AD). This review of 189 reports of change in wetland area finds that the reported long-term loss of natural wetlands averages between 54–57% but loss may have been as high as 87% since 1700 AD. There has been a much (3.7 times) faster rate of wetland loss during the 20th and early 21st centuries, with a loss of 64–71% of wetlands since 1900 AD. Losses have been larger and faster for inland than coastal natural wetlands. Although the rate of wetland loss in Europe has slowed, and in North America has remained low since the 1980s, the rate has remained high in Asia, where large-scale and rapid conversion of coastal and inland natural wetlands is continuing. It is unclear whether the investment by national governments in the Ramsar Convention on Wetlands has influenced these rates of loss. There is a need to improve the knowledge of change in wetland areas worldwide, particularly for Africa, the Neotropics and Oceania, and to improve the consistency of data on change in wetland areas in published papers and reports.

Tracking Progress Toward the 2010 Biodiversity Target and Beyond

Biodiversity indicators used by policy-makers are underdeveloped and underinvested. In response to global declines in biodiversity, some 190 countries have pledged, under the Convention on Biological Diversity (CBD), to reduce the rate of biodiversity loss by 2010 (1, 2). Moreover, this target has recently been incorporated into the Millennium Development Goals in recognition of the impact of biodiversity loss on human well-being (3). Timely information on where and in what ways the target has or has not been met, as well as the likely direction of future trends, depends on a rigorous, relevant, and comprehensive suite of biodiversity indicators with which to track changes over time, to assess the impacts of policy and management responses, and to identify priorities for action. How far have we come in meeting these needs, and is it sufficient?

The Ramsar Convention and Ecosystem-Based Approaches to the Wise Use and Sustainable Development of Wetlands

In the context of continuing, and probably increasing, pressure on and loss of wetland resources and their capacity to deliver benefits to people around the world, we describe the development and evolution of the concept of “wise use of wetlands,” which was formally introduced with the text of the Ramsar Convention on Wetlands four decades ago. Since then, the Convention has supported and promoted the “wise use of wetlands” as the fundamental basis for efforts to stop and reverse the loss and degradation of wetlands worldwide. Contracting parties to the Convention commit themselves

Regime shifts, thresholds and multiple stable states in freshwater ecosystems; a critical appraisal of the evidence

The concepts of ecosystem regime shifts, thresholds and alternative or multiple stable states are used extensively in the ecological and environmental management literature. When applied to aquatic ecosystems, these terms are used inconsistently reflecting differing levels of supporting evidence among ecosystem types. Although many aquatic ecosystems around the world have become degraded, the magnitude and causes of changes, relative to the range of historical variability, are poorly known. A working group supported by the Australian Centre for Ecological Analysis and Synthesis (ACEAS) reviewed 135 papers on freshwater ecosystems to assess the evidence for pressure-induced non-linear changes in freshwater ecosystems; these papers used terms indicating sudden and non-linear change in their titles and key words, and so was a positively biased sample. We scrutinized papers for study context and methods, ecosystem characteristics and focus, types of pressures and ecological responses considered, and the type of change reported (i.e., gradual, non-linear, hysteretic or irreversible change). There was little empirical evidence for regime shifts and changes between multiple or alternative stable states in these studies although some shifts between turbid phytoplankton-dominated states and clear-water, macrophyte-dominated states were reported in shallow lakes in temperate climates. We found limited understanding of the subtleties of the relevant theoretical concepts and encountered few mechanistic studies that investigated or identified cause-and-effect relationships between ecological responses and nominal pressures. Our results mirror those of reviews for estuarine, nearshore and marine aquatic ecosystems, demonstrating that although the concepts of regime shifts and alternative stable states have become prominent in the scientific and management literature, their empirical underpinning is weak outside of a specific environmental setting. The application of these concepts in future research and management applications should include evidence on the mechanistic links between pressures and consequent ecological change. Explicit consideration should also be given to whether observed temporal dynamics represent variation along a continuum rather than categorically different states.

The Ramsar Convention

This chapter examines the Ramsar Convention on Wetlands, the global intergovernmental treaty that promotes wetland conservation worldwide. When one is studying or seeking to protect a particular wetland, it is important to look beyond the wetland’s delineated borders. As discussed in Chap. 1, the health of a wetland is influenced by its placement in the landscape, the ecosystem services it provides, and the activities that occur within its watershed (e.g., development, agriculture). Focusing solely on the wetland site may result in missing the bigger picture. Similarly, when studying wetland policies, it is instructive to look beyond domestic regimes (i.e., national and local laws and policies) and consider global wetland policies. Parties to the Ramsar Convention address this through three main pillars of implementation: the ‘wise use’ of all wetlands, the designation and management of Wetlands of International Importance (Ramsar Sites), and international cooperation on management of shared resources and sharing of knowledge and information.

Assessing wetland ecosystem services and poverty interlinkages: a general framework and case study

Abstract The wise use of wetlands is expected to contribute to ecological integrity, as well as to secure livelihoods, especially of communities dependent on their ecosystem services for sustenance. This paper provides a conceptual framework capable of examining the goals of wetland management, poverty reduction and sustainable livelihoods. The framework highlights ecological character as a social construct and, with the notion of wetlands as settings for human well-being, builds a concept for assessing the inter-linkages between ecosystem services and livelihoods. The value and broader applicability of our framework is then tested by applying it to a case study from India (Lake Chilika) to evaluate the degree to which the mutual goals of improving both human well-being and the ecological character of wetlands have been achieved. The case study maps changes in human well-being induced in the basin communities due to external vulnerability contexts, institutions and freedoms. It further assesses the response strategies in terms of their impacts on ecological character and poverty status. Editor Z.W. Kundzewicz; Guest editor M.C. Acreman Citation Kumar, R., Horwitz, P., Milton, R.G., Sellamuttu, S.S., Buckton, S.T., Davidson, N.C., Pattnaik, A.K., Zavagli, M. and Baker, C., 2011. Assessing wetland ecosystem services and poverty interlinkages: a general framework and case study. Hydrological Sciences Journal, 56 (8), 1602–1621.

Role of palaeoecology in describing the ecological character of wetlands

While it is acknowledged that changes in the condition of a wetland can be detected through contemporary monitoring programs, this paper explores the extent to which palaeoecological approaches can be used in concert with contemporary techniques to understand benchmark conditions, rates and direction of change. This is done within the context of the Ramsar Convention on Wetlands that addresses the conservation of internationally important wetlands and the wise use of all wetlands. Over time the Convention has adopted a considerable body of guidance on detecting, reporting and responding to change in ecological character. In recognition that there remain gaps in available guidance on ecological character the Convention has requested further advice on the determination of appropriate reference conditions for assessing change and establishing the range of natural variability of wetlands. As palaeoecological approaches provide a ready means of considering the trajectories of change, and the nature and drivers of change over time, they can assist in qualifying established ecological descriptions. They can also help understand the timing and nature of any departure from normal conditions, and provide early warnings of future change, especially when integrated with contemporary monitoring and modelling.

Policy considerations for managing wetlands under a changing climate

Drawing on the experience and lessons of wetland researchers and managers in Australia and New Zealand, we examined the implications of climate change for wetland policy and management, and identified potential adaptation responses and the information needed to support these. First, we considered wetland vulnerability to climate change, focusing on wetland exposure and sensitivity. We then outlined the existing policy context for dealing with climate change, with an emphasis on the Ramsar Convention on Wetlands. We then considered how the objectives and targets for wetland management can be set in the face of climate change, how management can be adapted to climate change given the uncertainties involved, and how we can monitor and evaluate wetland condition in the face of climate change. We concluded with a set of principles to guide adaptation of wetland conservation and management policy to climate change.