NATIONWIDE STUDY OF THE STREAMFLOW DATA PROGRAM

During 1970 the Geological Survey conducted a study to evaluate the surface-water data collection program. Objectives were formulated, specific goals were set, a massive analysis of available data was made to determine the extent to which the present system enables the goals to be met, alternatives were considered for meeting the remaining goals, and finally, specific elements were identified for inclusion in the future program. The results of the evaluation will be used in planning the future streamflow data program. Less productive elements in the present program can be weeded out, and the effort devoted to more critically needed water data. The study provides the groundwork for redirection of efforts towards a more efficient system for satisfying present and future needs.     

Wastewater effects on a waterhyacinth marsh and adjacent impoundment

A waterhyacinth (Eichhornia crassipes) marsh occupying two-thirds of the basin of a small Florida impoundment has received sewage effluent for nearly 20 years. Water from the marsh flows into an area that is maintained free of waterhyacinths, and is discharged through wells at the far end of the impoundment. A water budget for the basin was estimated, and phosphorus concentrations were measured monthly at three stations in the marsh and at the discharge wells in the lake. Productivity levels were measured monthly where the marsh joins the lake and at the discharge wells. Only 16% of the phosphorus that enters the basin is stored. Gross primary productivity levels in the open-water areas are very high (22 gO₂m²day), but high respiration rates appear to keep the lake in steady-state.     

Cadaver decomposition in terrestrial ecosystems

A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems.     

Reducing hazard vulnerability: towards a common approach between disaster risk reduction and climate adaptation

Over the past few decades, four distinct and largely independent research and policy communities--disaster risk reduction, climate change adaptation, environmental management and poverty reduction--have been actively engaged in reducing socio-economic vulnerability to natural hazards. However, despite the significant efforts of these communities, the vulnerability of many individuals and communities to natural hazards continues to increase considerably. In particular, it is hydro-meteorological hazards that affect an increasing number of people and cause increasingly large economic losses. Arising from the realisation that these four communities have been largely working in isolation and enjoyed only limited success in reducing vulnerability, there is an emerging perceived need to strengthen significantly collaboration and to facilitate learning and information exchange between them. This article examines key communalities and differences between the climate change adaptation and disaster risk reduction communities, and proposes three exercises that would help to structure a multi-community dialogue and learning process.