Land Management Restrictions and Options for Change in Perpetual Conservation Easements

Conservation organizations rely on conservation easements for diverse purposes, including protection of species and natural communities, working forests, and open space. This research investigated how perpetual conservation easements incorporated property rights, responsibilities, and options for change over time in land management. We compared 34 conservation easements held by one federal, three state, and four nonprofit organizations in Wisconsin. They incorporated six mechanisms for ongoing land management decision-making: management plans (74 %), modifications to permitted landowner uses with discretionary consent (65 %), amendment clauses (53 %), easement holder rights to conduct land management (50 %), reference to laws or policies as compliance terms (47 %), and conditional use permits (12 %). Easements with purposes to protect species and natural communities had more ecological monitoring rights, organizational control over land management, and mechanisms for change than easements with general open space purposes. Forestry purposes were associated with mechanisms for change but not necessarily with ecological monitoring rights or organizational control over land management. The Natural Resources Conservation Service-Wetland Reserve Program had a particularly consistent approach with high control over land use and some discretion to modify uses through permits. Conservation staff perceived a need to respond to changing social and ecological conditions but were divided on whether climate change was likely to negatively impact their conservation easements. Many conservation easements involved significant constraints on easement holders’ options for altering land management to achieve conservation purposes over time. This study suggests the need for greater attention to easement drafting, monitoring, and ongoing decision processes to ensure the public benefits of land conservation in changing landscapes.     

Effects of VOCs on herbaceous plants in an open-top chamber experiment

A selection of herbaceous plants representing the ground flora around a typical chemical installation in the UK was exposed continuously for 7 weeks to a mixture of six VOCs (acetone, acetonitrile, dichloromethane, ethanol, methyl t-butyl ether and toluene) in open-top chambers. Exposure concentrations were based on predictions of atmospheric dispersion from a single source, at a distance of approximately 2 km. The effects of continuous exposure, representing a worst-case, were measured in terms of uncontrolled water loss from leaves, leaf wettability, chlorophyll content and fluorescence, dry matter production and detailed observations of changes in plant growth and phenology. There were significant effects of VOC exposure on seed production, leaf water content and photosynthetic efficiency in some plant species. Such effects may be detectable in vegetation close to major industrial point sources of VOCs, or as a result of an accidental release of material during manufacture or transport. Some of the species tested e.g. birdsfoot trefoil (Lotus corniculatus L.) seem to be promising as potential bioindicators for VOCs, but there may be other even more sensitive species waiting to be discovered. However, the most obvious and conveniently measured response to VOCexposure in the birdsfoot trefoil (premature senescence i.e. advanced timing of seed pod production) could easily be confused in the field with climatic influences. It is also uncertain at this stage whether any of the effects observed would lead to longer term ecological changes in natural plant communities, through biased competition between sensitive and more tolerant species.     

Preliminary comparison of landscape pattern-normalized difference vegetation index (NDVI) relationships to Central Plains stream conditions

We explored relationships of water quality parameters with landscape pattern metrics (LPMs), land use-land cover (LULC) proportions, and the advanced very high resolution radiometer (AVHRR) normalized difference vegetation index (NDVI) or NDVI-derived metrics. Stream sites (271) in Nebraska, Kansas, and Missouri were sampled for water quality parameters, the index of biotic integrity, and a habitat index in either 1994 or 1995. Although a combination of LPMs (interspersion and juxtaposition index, patch density, and percent forest) within Ozark Highlands watersheds explained >60% of the variation in levels of nitrite-nitrate nitrogen and conductivity, in most cases the LPMs were not significantly correlated with the stream data. Several problems using landscape pattern metrics were noted: small watersheds having only one or two patches, collinearity with LULC data, and counterintuitive or inconsistent results that resulted from basic differences in land use-land cover patterns among ecoregions or from other factors determining water quality. The amount of variation explained in water quality parameters using multiple regression models that combined LULC and LPMs was generally lower than that from NDVI or vegetation phenology metrics derived from time-series NDVI data. A comparison of LPMs and NDVI indicated that NDVI had greater promise for monitoring landscapes for stream conditions within the study area.     

POTENTIAL EFFECTS OF DEVELOPMENT ON FLOW CHARACTERISTICS OF TWO NEW JERSEY STREAMS1

ABSTRACT: Parts of the Raritan River basin in central New Jersey have undergone increasing development over the last several decades. The increasing population relies on the region's ground water and surface water sources for its residential, commercial, and industrial water supply. Urbanization, regionalized wastewater-treatment facilities, stream channel alterations, and interbasin transfers of water can all affect water availability. This pilot study was conducted to determine whether significant trends exist in the base-flow and overland-runoff characteristics of streams in two subbasins with different percentages of urban/built-up land (Anderson et at., 1976). Changes in flow characteristics that could indicate future reductions in safe water yield of the Raritan River basin were examined. Flow and flow variability of the steams draining these two subbasins have increased over time. Many of the flow measures studied experienced pronounced trend shifts about 1960. The cause of these changes cannot be readily determined from the data, nor is it clear whether the increased flow variability lies outside the natural range of flow variability of the streams draining the subbasins.     

The built environment — The case against conservation

Summary In considering the total range of the built environment in the U.K. a case against present attitudes to conservation is presented. Particular reference is made to urban structures. Comparisons are drawn with past conditions and the natural environment. Future dangers of such a policy are detailed.Architect and planner with considerable experience in UK and USA.     

Differences in the importance of work outcomes between full-time and part-time hospital employees

This study examined differences in the importance of work outcomes between full-time and part-time hospital employees in a sample drawn from five western hospitals (N = 1,876). Work status was operationalized by classifying respondents into four categories based on hours worked per week. Exploratory factor analysis showed that work outcomes may be classified as extrinsic (pay and fringe benefits) and instrinsic (being informed about the job, participating in decision-making, and doing the job well). Confirmatory factor analyses demonstrated that this two-factor structure fits the data well for all four work status categories although the factor loadings differed across categories. Multivariate analyses of variance and covariance indicated that statistically significant differences in the importance of extrinsic and intrinsic outcomes exist for full-time and part-time employees and that these differences persist when various social and demographic variables are held constant. Employees who work fewer hours per week tend to assign less importance to the work outcomes measured in this study. The results suggest that theoretical models of variables such as job satisfaction should take into account work status differences in the importance of work-related outcomes. In addition, managers may find that workers respond to different reward structures depending on the degree of their involvement in the organization.     

Sequential sampling: A cost-effective approach for monitoring benthic macroinvertebrates in environmental impact assessments

Sequential sampling is a method for monitoring benthic macroinvertebrates that can significantly reduce the number of samples required to reach a decision, and consequently, decrease the cost of benthic sampling in environmental impact assessments.Rather than depending on a fixed number of samples, this analysis cumulatively compares measured parameter values (for example, density, community diversity) from individual samples, with thresholds that are based on specified degrees of precision.In addition to reducing sample size, a monitoring program based on sequential sampling can provide clear-cut decisions as to whethera priori-defined changes in the measured parameter(s) have or have not occurred. As examples, sequential sampling programs have been developed to evaluate the impact of geothermal energy development on benthic macroinvertebrate diversity at The Geysers, California, and for monitoring the impact of crude oil contamination on chironomid midge [Cricotopus bicinctus (Meigen) andC. mackenziensis Oliver] population densities in the Trail River, Northwest Territories, Canada.     

Project appraisal and planning for overdeveloped countries: II. Shadow pricing under uncertainty

In the uncertainty that surrounds the future availability of nonrenewable natural resources and the efficacy of technological advance, the economic costing of resources should be undertaken probabilistically. While optimistic assumptions entail little change from the costing procedures used in conventional cost-benefit analysis, even moderately pessimistic assumptions lead to a much increased cost for nonrenewable resources. These lead in turn to a reappraisal of the value of investment and of the cost ascribed to other factors of production. Even when optimistic assumptions are deemed the more plausible, a utility-maximizing evaluation may still give more emphasis to pessimism.     

Automatic sorting of zooplankton by isopycnic sedimentation in gradients of silica: Performance of a “Rho Spectrometer”

The embryonic and larval stages of the quahog clam Mercenaria sp. were exposed to the water-soluble fractions (WSFs) of 6 oils and the effects on survival and growth rate of the various stages were noted. Kuwait crude oil was the least toxic on initial exposure to both stages, having LC₅₀ values in excess of 10 ppm after continuous exposure to the WSF for up to 6 days. However, at 10 days, Kuwait was slightly more toxic than southern Louisiana crude oil, with both oils having LC₅₀ values near 2 ppm. Florida Jay crude oil was much more toxic, with an LC₅₀ of less than 1 ppm at 48 h and less than 0.2 ppm at 10 days. Two refined oils, No. 2 fuel oil and Bunker C, had LC₅₀ values of 1 to 2 ppm after 48 h, while used crankcase motor oil, the most toxic oil tested, had LC₅₀ values of 0.10 ppm or less at all exposure times. Larvae surviving exposure to water-soluble fractions of the various oils often grew at slower rates than the controls.