Phosphorus in Phoenix: a budget and spatial representation of phosphorus in an urban ecosystem

As urban environments dominate the landscape, we need to examine how limiting nutrients such as phosphorus (P) cycle in these novel ecosystems. Sustainable management of P resources is necessary to ensure global food security and to minimize freshwater pollution. We used a spatially explicit budget to quantify the pools and fluxes of P in the Greater Phoenix Area in Arizona, USA, using the boundaries of the Central Arizona-Phoenix Long-Term Ecological Research site. Inputs were dominated by direct imports of food and fertilizer for local agriculture, while most outputs were small, including water, crops, and material destined for recycling. Internally, fluxes were dominated by transfers of food and feed from local agriculture and the recycling of human and animal excretion. Spatial correction of P dynamics across the city showed that human density and associated infrastructure, especially asphalt, dominated the distribution of P pools across the landscape. Phosphorus fluxes were dominated by agricultural production, with agricultural soils accumulating P. Human features (infrastructure, technology, and waste management decisions) and biophysical characteristics (soil properties, water fluxes, and storage) mediated P dynamics in Phoenix. P cycling was most notably affected by water management practices that conserve and recycle water, preventing the loss of waterborne P from the ecosystem. P is not intentionally managed, and as a result, changes in land use and demographics, particularly increased urbanization and declining agriculture, may lead to increased losses of P from this system. We suggest that city managers should minimize cross-boundary fluxes of P to the city. Reduced P fluxes may be accomplished through more efficient recycling of waste, therefore decreasing dependence on external nonrenewable P resources and minimizing aquatic pollution. Our spatial approach and consideration of both pools and fluxes across a heterogeneous urban ecosystem increases the utility of nutrient budgets for city managers. Our budget explicitly links processes that affect P cycling across space with the management of other resources (e.g., water). A holistic management strategy that deliberately couples the management of P and other resources should be a priority for cities in achieving urban sustainability.     

An analysis of the problems of developing environmental education in Brazilian Federal protected areas

This paper describes the problems encountered in developing environmental education in Federal protected areas in Brazil. Results of a survey on the current status of environmental education in four categories of Federal protected areas; namely national parks, biological reserves, ecological stations and environmental protection areas, are described and discussed. The study suggests that the development of environmental education in protected areas in the country has several limitations: financial resources, lack of training, material resources and a lack of policy on environmental education. It also identifies that some of these problems seem to be inter-related with those of the National System of Conservation Units of the country which may result in a retarding of the development of environmental education in such areas.     

Sources and Distribution of Polychlorinated Terphenyls at a Major US Aeronautics Research Facility

O -deethylase (EROD) activity to a similar degree as PCB Aroclor 1254 and to a greater extent than PCT Aroclor 5460. The presence of high concentrations of PCTs contributed to the facility being included on the National Priorities List. It subsequently became the first US federal facility to sign a Federal Facility Agreement, identifying cleanup responsibilities, prior to formal listing.     

Responses of greening bean seedling leaves to nitrogen dioxide and nutrient nitrate supply

Phaseolus vulgaris cv. Kinghorn Wax seedlings grown in darkness at 25 degrees C for 7 days with half strength Hoagland's nutrient solution containing no nitrogen, were transferred to lit continuous stirred tank reactors (CSTRs) in atmospheres containing 0 or 0.3 ppm NO(2) and irrigated with a nutrient solution containing 0 or 5 mm nitrate as sole nitrogen source and allowed to grow for a period of up to 5 days in a 14 h photoperiod. Exposure to NO(2) increased total Kjeldahl nitrogen in the leaves. Further, the exposure to NO(2) increased chlorophyll content from day 3 onwards and inhibited the leaf dry weight substantially on days 4 and 5. The primary leaves of the seedlings exposed to 0.3 ppm NO(2) and supplied with nitrate accumulated some nitrite after 5 days of exposure. Some of the seedlings were returned from CSTRs to growth chambers and allowed to grow for a further period of 5 days in a 14 h photoperiod without NO(2). The growth which developed after the NO(2) exposure growth period, as measured by fresh and dry weights of the leaves, was significantly less in NO(2)-exposed plants than in nitrate-grown plants. The experiments demonstrate that the leaves of greening seedlings are able to assimilate NO(2) and that a reduction in leaf dry weight by prolonged NO(2) exposure in the presence of nutrient nitrate can be associated with nitrite accumulation, and that NO(2) has a carry-over effect beyond the duration of NO(2) exposure. It is apparent that NO(2) induces some durable biochemical or cytological aberration in the presence of nutrient nitrate, which adversely affects subsequent leaf growth.     

Beyond data management: how ecoinformatics can benefit environmental monitoring programs

We review ways in which the new discipline of ecoinformatics is changing how environmental monitoring data are managed, synthesized, and analyzed. Rapid improvements in information technology and strong interest in biodiversity and sustainable ecosystems are driving a vigorous phase of development in ecological databases. Emerging data standards and protocols enable these data to be shared in ways that have previously been difficult. We use the U.S. Environmental Protection Agency’s National Coastal Assessment (NCA) as an example. The NCA has collected biological, chemical, and physical data from thousands of stations around the U.S. coasts since 1990. NCA data that were collected primarily to assess the ecological condition of the U.S. coasts can be used in innovative ways, such as biogeographical studies to analyze species invasions. NCA application of ecoinformatics tools leads to new possibilities for integrating the hundreds of thousands of NCA species records with other databases to address broad-scale and long-term questions such as environmental impacts, global climate change, and species invasions.     

Regulatory risk control through mandatory occupational safety and health (OSH) certification and testing regimes (CTRs)

Governments make increasing use of private certification and testing infrastructures as an alternative for traditional regulatory arrangements in several areas including occupational safety and health (OSH).This research, commissioned by the Dutch Inspectorate for Work and Income (IWI), concerns an analysis of risk control of four certification and testing regimes (CTRs) in the Netherlands, three mandatory regimes and one non-mandatory regime. The aim was to create a better understanding of problems that may arise in the risk control through such regimes and to identify critical processes and factors that can affect the risk control process.The results of this research are reported in two papers in this special issue (see also Zwetsloot et al., this issue). This one presents an analysis of the risk control at the regulatory level, and its associated critical factors and processes. These critical factors are clustered in four essential processes: the regulatory choice for a CTR, the definition of requirements for the auditing or inspection regime, the certification and testing processes as such, and the processes needed for the self-correcting or learning capability of the CTR. Jointly, these factors and processes form a framework for both the design and the evaluation of such regimes. The case studies clearly demonstrate that these critical factors may undermine the effectiveness of such regulatory practices. We propose that a further development of our framework should be used in the (re)design process for proposed and existing CTRs, and in the process of independent evaluation of such regimes.     

Using a reverse auction to promote household level stormwater control

Phase II of the US Environmental Protection Agency's (USEPA) National Pollution Discharge Elimination System (NPDES) stormwater regulations requires communities smaller than 100 000 residents to meet new criteria for stormwater runoff reduction. In many cases these smaller communities have no established stormwater utility, and are investigating alternatives for complying with these new, sometimes expensive requirements. We note that it might be cost effective for some communities to encourage homeowners to control stormwater runoff at the parcel level instead of, or in conjunction with more traditional large, infrastructural best management practices (BMP). We go onto argue that in the absence of a strict regulatory cap, an auction is a cost-effective tool for implementing controls on stormwater runoff quantity at the parcel level. In this paper, we test the effectiveness of a procurement auction as the coordinating mechanism for encouraging installation of parcel-scale rain gardens and rain barrels within a small suburban watershed in the Midwest. The auction, which was conducted in spring 2007 and 2008, resulted in installation of 81 gardens and 165 barrels on 107 of the 350 eligible properties. Average cost per liter of runoff detention in both years was $0.36 for gardens and $0.59 for barrels. Interestingly, approximately 55% of the bids were for $0, suggesting that an educational campaign may result in substantial runoff mitigation if utilities paid for the installation of stormwater management practices. However, we found that an auction promoted more participation than education alone and at a cheaper per-unit control cost than a flat stormwater control payment plan. Overall, this study demonstrates that relatively minimal financial incentives can result in homeowners’ willingness-to-accept stormwater management practices on their property, thus opening an important avenue for retrofitting watersheds that are largely in private ownership.     

The aerobic soil degradation of spinosad ‐ a novel natural insect control agent

Abstract

Spinosad is a natural product with biological activity against a range of insects including lepidoptera. It is comprised of two major components namely spinosyns A and D. The degradation of spinosad in soil under aerobic conditions was investigated using two U.S. soils (a silt loam and a sandy loam) which were treated with either ¹⁴C‐spinosyn A or ‐spinosyn D at a 2X use rate of 0.4mg/kg soil for spinosyn A and 0.1mg/kg for spinosyn D. Further samples of soil were pre‐sterilised prior to treatment in order to establish whether spinosyns A and D degrade abiotically. Flasks of treated soil were incubated in the dark at 25°C for up to one year after treatment.

HPLC and LC‐MS of soil extracts confirmed that the major degradation product of spinosyn A was spinosyn B, resulting from demethylation on the forosamine sugar. Other dégradâtes were hydroxylation products of spinosyns A and B, with hydroxylation probably taking place on the aglycone portion of the molecule. Half lives were similar for both spinosyns and were in the range 9–17 days, with longer half lives in the pre‐sterilised soils (128–240 days) suggesting that degradation was largely microbial.