Ecological approach to resource survey and planning for environmentally significant Areas: The ABC method

A resource survey and planning method for parks, reserves, and other environmentally significant areas (ESAs) is presented in the context of a holistic balanced approach to land use and environmental management. This method provides a framework for the acquisition, analysis, presentation, and application of diverse ecological data pertinent to land use planning and resource management within ESAs. Through the independent analysis and subsequent integration of abiotic, biotic, and cultural or ABC information, land areas within an ESA are identified in terms of their relative environmental significance and environmental constraints. The former term encompasses wildlife, historic, and other resource values, while the latter term reflects biophysical hazards and sensitivities, and land use conflicts. The method thus calls for a matching of an ESA's distinctive attributes with appropriate land use and institutional arrancements through an analysis of available acts, regulations, agencies, and other conservation and land use management mechanisms. The method culminates with a management proposal showing proposed park or reserve allocations, buffer areas, or other land use controls aimed at preserving an ESA's special ecological qualities, while providing for resource development. The authors suggest that all resource management decisions affecting ESA's should be governed by a philosophical stance that recognizes a spectrum of broad land use types, ranging from preservation to extractive use and rehabilitation.     

Fostering Sustainability in Headwaters Country: Using Bioregional and Social Capital Strategies in Support of Sustainability

Many of Canada's ex-urban and rural areas face a daunting array of sustainability challenges. In developing effective sustainability strategies, these areas must rely heavily upon local resources and capacities and existing social capital. Part of the solution for these areas may lie in multi-stakeholder collaborative approaches built on sustainability principles and strategies. These include the engagement and mobilization of civil society networks; the cultivation of strategic partnerships among key stakeholders in civil society, the private sector and government; and long-term local programmes of research, education and advocacy that are supportive of sustainability. This article describes and analyses a Canadian case study—Dufferin County, part of the Headwaters Country region in southern Ontario—in which a multi-stakeholder, civil society based approach to fostering sustainability is currently unfolding. The ideological and theoretical underpinnings of the initiative are explored, key process-oriented and substantive challenges to the approach are analysed and action research strategies are discussed.     

Assessment of older drivers: relationships among on-road errors, medical conditions and test outcome

PROBLEM: It is essential that driver licensing authorities have a valid and reliable system for evaluating older drivers' continuing competency; road tests are usually required as part of such a system. This study sought to find information about the nature of driving errors made during license review tests, and about relationships between error type and test outcome for older drivers. METHOD: Data from licensing authority files from 533 road tests during a 12-month period were analyzed; medical and other referral information was included. Average driver age was 76 years. Performance scores were generated for intersection negotiation, lane changing, low speed manoeuvres, positioning and speed control, safety margin, and car control. RESULTS: Logistic regression analysis showed that test outcome was well predicted by a subset of driving performance scores; adding driver age to the model explained very little variance. Age alone was strongly associated with outcome. Relationships between referral information and test outcome are also reported. IMPACT: Results highlight several factors relevant to the development of more valid and reliable road tests for older drivers.     

Nitrogen removal and nitrate leaching for two perennial,sod-based forage systems receiving dairy effluent

In northern Florida, year-round forage systems are used in dairy effluent sprayfields to reduce nitrate leaching. Our purpose was to quantify forage N removal and monitor nitrate N (NO3(-)-N) concentration below the rooting zone for two perennial, sod-based, triple-cropping systems over four 12-mo cycles (1996-2000). The soil is an excessively drained Kershaw sand (thermic, uncoated Typic Quartzip-samment). Effluent N rates were 500, 690, and 910 kg ha(-1) per cycle. Differences in N removal between a corn (Zea mays L.)-bermudagrass (Cynodon spp.)-rye (Secale cereale L.) system (CBR) and corn-perennial peanut (Arachis glabrata Benth.)-rye system (CPR) were primarily related to the performance of the perennial forages. Nitrogen removal of corn (125-170 kg ha(-1)) and rye (62-90 kg ha(-1)) was relatively stable between systems and among cycles. The greatest N removal was measured for CBR in the first cycle (408 kg ha(-1)), with the bermudagrass removing an average of 191 kg N ha(-1). In later cycles, N removal for bermudagrass declined because dry matter (DM) yield declined. Yield and N removal of perennial peanut increased over the four cycles. Nitrate N concentrations below the rooting zone were lower for CBR than CPR in the first two cycles, but differences were inconsistent in the latter two. The CBR system maintained low NO3(-)-N leaching in the first cycle when the bermudagrass was the most productive; however, it was not a sustainable system for long-term prevention of NO3(-)-N leaching due to declining bermudagrass yield in subsequent cycles. For CPR, effluent N rates > or = 500 kg ha(-1) yr(-1) have the potential to negatively affect ground water quality.     

The diversity of naturally produced organohalogens

More than 3800 organohalogen compounds, mainly containing chlorine or bromine but a few with iodine and fluorine, are produced by living organisms or are formed during natural abiogenic processes, such as volcanoes, forest fires, and other geothermal processes. The oceans are the single largest source of biogenic organohalogens, which are biosynthesized by myriad seaweeds, sponges, corals, tunicates, bacteria, and other marine life. Terrestrial plants, fungi, lichen, bacteria, insects, some higher animals, and even humans also account for a diverse collection of organohalogens.     

Principles and issues in radiological ecological risk assessment

This paper provides a bridge between the fields of ecological risk assessment (ERA) and radioecology by presenting key biota dose assessment issues identified in the US Department of Energy's Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota in a manner consistent with the US Environmental Protection Agency's framework for ERA. Current radiological ERA methods and data are intended for use in protecting natural populations of biota, rather than individual members of a population. Potentially susceptible receptors include vertebrates and terrestrial plants. One must ensure that all media, radionuclides (including short-lived radioactive decay products), types of radiations (i.e., alpha particles, electrons, and photons), and pathways (i.e., internal and external contamination) are combined in each exposure scenario. The relative biological effectiveness of alpha particles with respect to deterministic effects must also be considered. Expected safe levels of exposure are available for the protection of natural populations of aquatic biota (10 mGy d(-1)) and terrestrial plants (10 mGy d(-1)) and animals (1 mGy d(-1)) and are appropriate for use in all radiological ERA tiers, provided that appropriate exposure assumptions are used. Caution must be exercised (and a thorough justification provided) if more restrictive limits are selected, to ensure that the supporting data are of high quality, reproducible, and clearly relevant to the protection of natural populations.     

LAW,HYDROLOGY, AND SURFACE-WATER SUPPLY IN THE UPPER COLORADO RIVER BASIN1

ABSTRACT: Law and hydrology are inextricably woven together in the pattern of water resource development in the west. The former attempts to allocate a limited and valuable resource as the latter tries to define the limits of the resource. In the past an inadequate data base has made hydrologic estimates difficult and political factors have pushed the law into possibly conflicting commitments in the Colorado River Basin. Through the use of tree-ring research, hydrologists have produced a more definitive data base and placed water allocations such as the Colorado River Compact of 1922 in a clearer long-term perspective. This data base leads to the conclusion that the surface-water supply is about 13.5 million acre-feet per year. This hydrologic limit must be apportioned within an existing legal framework - the “Law of the River.” As development approaches the resource limit in the Upper Colorado River Basin, lawyers and hydrologists must act in concert toward the equitable solution of allocation and reallocation problems.     

Using flue gas desulfurization gypsum to remove dissolved phosphorus from agricultural drainage waters

High levels of accumulated phosphorus (P) in soils of the Delmarva Peninsula are a major source of dissolved P entering drainage ditches that empty into the Chesapeake Bay. The objective of this study was to design, construct, and monitor a within-ditch filter to remove dissolved P, thereby protecting receiving waters against P losses from upstream areas. In April 2007, 110 Mg of flue gas desulfurization (FGD) gypsum, a low-cost coal combustion product, was used as the reactive ingredient in a ditch filter. The ditch filter was monitored from 2007 to 2010, during which time 29 storm-induced flow events were characterized. For storm-induced flow, the event mean concentration efficiency for total dissolved P (TDP) removal for water passing through the gypsum bed was 73 ± 27% confidence interval (α = 0.05). The removal efficiency for storm-induced flow by the summation of load method was 65 ± 27% confidence interval (α = 0.05). Although chemically effective, the maximum observed hydraulic conductivity of FGD gypsum was 4 L s(-1), but it decreased over time to <1 L s(-1). When bypass flow and base flow were taken into consideration, the ditch filter removed approximately 22% of the TDP load over the 3.6-yr monitoring period. Due to maintenance and clean-out requirements, we conclude that ditch filtration using FGD gypsum is not practical at a farm scale. However, we propose an alternate design consisting of FGD gypsum-filled trenches parallel to the ditch to intercept and treat groundwater before it enters the ditch.