Ramsar Wetlands of International Importance–improving conservation outcomes

The Ramsar Convention (or the Convention on Wetlands), signed in 1971, was one of the first international conservation agreements, promoting global wise use of wetlands. It has three primary objectives: national designation and management of wetlands of international importance; general wise use of wetlands; and international cooperation. We examined lessons learnt for improving wetland conservation after Ramsar’s nearly five decades of operation. The number of wetlands in the Ramsar Site Network has grown over time (2,391 Ramsar Sites, 2.5 million km2, as at 2020-06-09) but unevenly around the world, with decreasing rate of growth in recent decades. Ramsar Sites are concentrated in countries with a high Gross Domestic Product and human pressure (e.g., western Europe) but, in contrast, Ramsar Sites with the largest wetland extent are in central-west Africa and South America. We identified three key challenges for improving effectiveness of the Ramsar Site Network: increasing number of sites and wetland area, improved representation (functional, geographical and biological); and effective management and reporting. Increasing the number of sites and area in the Ramsar network could benefit from targets, implemented at national scales. Knowledge of representativeness is inadequate, requiring analyses of functional ecotypes, geographical and biological representativeness. Finally, most countries have inadequate management planning and reporting on the ecological character of their Ramsar Sites, requiring more focused attention on a vision and objectives, with regular reporting of key indicators to guide management. There are increasing opportunities to rigorously track ecological character, utilizing new tools and available indicators (e.g., remote sensing). It is critical that the world protect its wetlands, with an effective Ramsar Convention or the Convention on Wetlands at the core

Status of Wetlands in Northern Australia

Compared to southern Australia it is generally considered that wetlands in northern Australia are generally 'intact' and possibly close to 'pristine'. With the exception of a few specific areas we accept the comparison, but baulk at making a categorical statement that supports the\ud impression that northern wetlands are in good condition. Without getting into an esoteric debate about concepts we provide an analysis of pressures on northern wetlands and point to major concerns for the future. We do this by assessing the extent of wetland inventory information and recommend that a coordinated approach using standardised protocols and core data is needed to complete the picture and make this available to users. Further, ecological assessment, including structured risk assessment of pressures is urgently needed. This not only provides a considered base for management actions but also for further\ud prioritisation of research effort. We then identify major research topics that need to be addressed. \ud \ud Our analysis is essentially based on the biophysical features of northern wetlands. These are valuable and in some instances well known and protected. However, in order to conserve and ensure wise use of wetlands we contend that this approach is insufficient. We propose that a stronger emphasis be placed on sustainable use of the goods and services which wetlands provide humans. The challenge in doing this is to demonstrate through research activities that the provision of these goods and services is dependent on the maintenance of wetland habitats and their species. The case for doing this is illustrated through a framework relating goods and services to ecosystem components and thence to pressures that could degrade these, including the emerging pressures of globalisation of trade and global climate change, and the research required to understand these sufficiently well to support management responses

The aging effect in Au-Cd alloys: A Mössbauer spectroscopy study

The martensite aging effect, observed in a number of alloy systems and through which fundamental properties for particular materials are altered by aging in the martensite state, has attracted considerable interest in recent years. It is important to understand and control the effect, particularly in shape-memory alloys for which stability of properties is fundamental to applications. The most likely model, at least for the Au-Cd system in which it bas been most critically tested, is the “symmetry conforming short-range order” (SC-SRO) model first proposed by Ren and Otsuka. $^{197}$Au Mössbauer spectroscopy offers the possibility to observe the nature of defects associated with the gold sites. The spectra for single crystal and polycrystalline Au-Cd in both the “aged martensite" and “quenched austenite” conditions are presented and discussed. While some uncertainty in interpretation of the spectra remains, particularly in relation to any quadruple splitting to be expected from either Au atoms on Cd-nearest-neighbour sites or the martensite lattice distortion, the best single-line fits provide evidence for two defect types

Une étude de l’hydrologie des zones humides et la fourniture de services écosystémiques : la zone humide de GaMampa, Afrique du Sud

International audienceThe GaMampa wetland is typical of many small wetlands in the Limpopo River basin. These wetlands support the livelihoods of many poor people through agriculture for both food production and income from the sale of crops. They also contribute to livelihoods through the provision of natural food products and medicines, as well as materials for construction and handicrafts. The wetlands are complex and vulnerable ecosystems, fulfilling important environmental functions that benefit both local and downstream stakeholders. Conversion of a wetland to agriculture therefore has potential impacts not just within the wetland itself, but also downstream. In this paper we report the findings of an integrated study, comprising both hydrological and socioeconomic investigations of the GaMampa wetland in South Africa. The GaMampa wetland comprises less than 1% of the Mohlapitsi catchment and an even smaller portion of the Olifants River catchment; a major tributary of the Limpopo. Yet hydrological records show that the Mohlapitsi River contributes up to 16% of the dry season flow in the Olifants River. This has perpetuated the belief that, regardless of its small size, the GaMampa wetland provides an important regulating service, contributing significantly to the Mohlapitsi and Olifants River flows. The contribution of the GaMampa wetland to dry season flow in the Mohlapitsi River and the impact of wetland conversion to agriculture on its hydrological functioning were investigated. The economic analyses showed that the total net financial value of the wetland equates to an average of US$211 per household of which agriculture comprises 38$ dont 38% correspondent à l’agriculture. Les analyses hydrologiques ont montré que la rivière Mohlapitsi contribue en moyenne pour 16% au débit de la rivière Olifants en saison sèche. Cependant, la zone humide contribue à 12% au plus de l’augmentation du débit observé en saison sèche sur la portion de la rivière sur laquelle la zone humide est située. Le reste de l’augmentation provient de l’eau souterraine qui coule au travers de la zone humide. Par ailleurs, malgré la conversion de 50% de la zone humide en terres agricoles depuis 2001, il n’y a pas eu de réduction statistiquement significative du débit de saison sèche de la rivière Mohlapitsi. Ces résultats soulignent combien il est important de comprendre la nature de la gamme complète de services fournis par une zone humide, afin de prendre des décisions éclairées pour une gestion appropriée