Identifying the largest individual sample value from a two-way composite sampling design

Composite sampling techniques for identifying the largest individual sample value seem to be cost effective when the composite samples are internally homogeneous. However, since it is not always possible to form homogeneous composite samples, these methods can lead to higher costs than expected. In this paper we propose a two-way composite sampling design as a way to improve on the cost effectiveness of the methods available to identify the largest individual sample value.     

Phylogenetic relationships within the Octocorallia (Cnidaria: Anthozoa) based on nuclear 18S rRNA sequences

We determined the nuclear 18S rRNA sequences for 41 species of octocorals and used these to address the validity of the historical ordinal divisions and the current subordinal divisions within the subclass Octocorallia. We also explored the phylogenetic affinities of the species Dendrobrachia paucispina, which was originally classified in the order Antipatharia (subclass Ceriantipatharia) although polyp structure indicates it belongs in the subclass Octocorallia. Trees constructed using maximum likelihood techniques are incongruent with the current and historical taxonomy of the Octocorallia. There appeared to be three major clades of octocorals. The first clade included most, but not all, pennatulaceans as a monophyletic group. The second clade contained 21 species, representing all major octocoral groups other than pennatulaceans. The third clade contained members from three suborders of the Alcyonacea and one member of the Pennatulacea. These data could not be used to distinguish the branching order of the three major clades. The species D. paucispina had a close affinity with the genera Corallium and Paragorgia (Alcyonacea: Scleraxonia), although its morphology suggests it is more similar to the genus Chrysogorgia (Alcyonacea: Calcaxonia). The morphological character of dimorphism (the presence of both autozooids and siphonozooids within a single colony) corresponded loosely with the topology of the most likely trees, and a single origin of dimorphism could not be rejected. Despite sampling from the majority of families within the Octocorallia, many of the relationships within this group remain ambiguous. Received: 16 June 2000 / Accepted: 14 September 2000     

A Systematic Test of an Enterprise Strategy for Community-Based Biodiversity Conservation

Abstract: A commonly held belief is that if people can benefit financially from enterprises that depend on nearby forests, reefs, and other natural habitats, then they will take action to conserve and sustainably use them. The Biodiversity Conservation Network brought together conservation and development organizations and local communities to systematically test this hypothesis across 39 conservation project sites in Asia and the Pacific. Each project implemented one or more community-based enterprises such as setting up an ecotourism lodge, distilling essential oils from wild plant roots, producing jams and jellies from forest fruits, harvesting timber, or collecting marine samples to test for pharmaceutical compounds. Each project team collected the biological, enterprise, and social data necessary to test the network's hypothesis. We present the results of this test. We found that a community-based enterprise strategy can lead to conservation, but only under limited conditions and never on its own. We summarize the specific conditions under which an enterprise strategy will and will not work in a decision chart that can be used by project managers to determine whether this strategy might make sense at their site. We also found that an enterprise strategy can be subsidized and still create a net gain that pays for conservation. Based on our experiences, we recommend developing "learning portfolios" that combine action and research to test other conservation strategies.     

High-frequency measurements reveal spatial and temporal patterns of dissolved organic matter in an urban water conveyance

Stormwater runoff in urban areas can contribute high concentrations of dissolved organic matter (DOM) to receiving waters, potentially causing impairment to the aquatic ecosystem of urban streams and downstream water bodies. Compositional changes in DOM due to storm events in forested, agricultural, and urban landscapes have been well studied, but in situ sensors have not been widely applied to monitor stormwater contributions in urbanized areas, leaving the spatial and temporal characteristics of DOM within these systems poorly understood. We deployed fluorescent DOM (FDOM) sensors at upstream and downstream locations within a study reach to characterize the spatial and temporal changes in DOM quantity and sources within an urban water conveyance that receives stormwater runoff. Baseflow FDOM decreased over the summer season as seasonal flows upstream transported less DOM. FDOM fluctuated diurnally, the amplitude of which also declined as the summer season progressed. During storms, FDOM concentrations were rapidly elevated to values orders of magnitude greater than baseflow measurements, with greater concentrations at the downstream monitoring site, revealing high contributions from stormwater outfalls between the two locations. Observations from custom, in situ fluorometers resembled results obtained using laboratory methods for identifying DOM source material and indicated that DOM transitioned to a more microbially derived composition as the summer season progressed, while stormwater contributions contributed DOM from terrestrial sources. Deployment of a mobile sensing platform during varying flow conditions captured spatial changes in DOM concentration and composition and revealed contributions of DOM from outfalls during stormflows that would have otherwise been unobserved.     

Spatial distribution of metals within the liver acinus and their perturbation by PCB126

Animal studies show that exposure to the environmental pollutant 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) causes alterations in hepatic metals as measured in acid-digested volume-adjusted tissue. These studies lack the detail of the spatial distribution within the liver. Here we use X-ray fluorescence microscopy (XFM) to assess the spatial distribution of trace elements within liver tissue. Liver samples from male Sprague Dawley rats, treated either with vehicle or PCB126, were formalin fixed and paraffin embedded. Serial sections were prepared for traditional H&E staining or placed on silicon nitride windows for XFM. With XFM, metal gradients between the portal triad and the central vein were seen, especially with copper and iron. These gradients change with exposure to PCB126, even reverse. This is the first report of how micronutrients vary spatially within the liver and how they change in response to toxicant exposure. In addition, high concentrations of zinc clusters were discovered in the extracellular space. PCB126 treatment did not affect their presence, but did alter their elemental makeup suggesting a more general biological function. Further work is needed to properly evaluate the gradients and their alterations as well as classify the zinc clusters to determine their role in liver function and zinc homeostasis.     

Pastoralists in a changing environment: The competition for grazing land in and around the W Biosphere Reserve,Benin Republic

Pastoralists face increasing competition for land with crop farmers and nature in and around the W Biosphere Reserve (WBR) in Benin. Our aim was to describe and analyse land use changes in order to understand their drivers, and to describe and analyse the viewpoints of relevant stakeholders in order to understand the competition for land. To this end, remote sensing data, regional statistics, and survey data were collected. We found that crop land expansion around the WBR was the direct driver of decrease of the grazing land area. Population growth and rising demand for food crops, and government support to the cotton sector were indirect drivers of grazing land reduction. Furthermore, competing claims on land among users arose from the complex interaction of crop expansion, presence of WBR and the way it is governed, the lack of support to pastoralists, and the increasing shift of pastoralists’ lifestyle into one of settled crop farmers. Pastoralism is under threat and its survival depends on the successful implementation of policies to support pastoralists and protect grazing lands.     

Bird on the wire: Landscape planning considering costs and benefits for bird populations coexisting with power lines

Power-line grids are increasingly expanding worldwide, as well as their negative impacts on avifauna, namely the direct mortality through collision and electrocution, the reduction of breeding performance, and the barrier effect. On the other hand, some bird species can apparently benefit from the presence of power lines, for example perching for hunting purposes or nesting on electricity towers. In this perspective essay, we reviewed the scientific literature on both costs and benefits for avifauna coexisting with power lines. Overall, we detected a generalized lack of studies focusing on these costs or benefits at a population level. We suggest that a switch in research approach to a larger spatio-temporal scale would greatly improve our knowledge about the actual effects of power lines on bird populations. This research approach would facilitate suitable landscape planning encompassing both mitigation of costs and promotion of benefits for bird populations coexisting with power lines. For example, the strategic route planning of electricity infrastructures would limit collision risk or barrier effects for threatened bird populations. Concurrently, this strategic route planning would promote the range expansion of threatened populations of other bird species, by providing nesting structures in treeless but potentially suitable landscapes. We suggest establishing a collaborative dialogue among the scientific community, governments, and electricity companies, with the aim to produce a win–win scenario in which both biodiversity conservation and infrastructure development are integrated in a common strategy.     

Exploring dynamism of cultural ecosystems services through a review of environmental education research

The field of cultural ecosystem services (CES) explores the non-material benefits that ecosystems provide to people. Human perceptions and valuations change, for many reasons and in many ways; research on CES, however, rarely accounts for this dynamism. In an almost entirely separate academic world, research on environmental education (EE) explores how EE programming affects peoples’ attitudes and values toward the natural world. In this review of 119 EE research publications, we explore whether CES (and the adjacent concept of relational values) can be dynamic. We approach this via two lines of inquiry that explore whether EE may instigate this change. First, we investigate whether the EE community measures (and tries to affect) CES-related outcomes. Second, we ask: Has EE research detected changes in CES-related outcomes? We find the EE programs measure many CES outcomes (e.g., aesthetic appreciation, social connectedness), and that in most cases studies observe increases in these outcomes after EE experiences.     

Source characterization and risk of exposure to atmospheric polychlorinated biphenyls (PCBs) in Ghana

With recent evidence that persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) are emerging in environmental media in some developing countries that otherwise have sparing production and usage history, it has become important to identify such contemporary source factors of PCBs and the risks this may pose, in line with the global consensus on POP management and elimination. The present study investigated contaminations from atmospheric PCBs in Ghana, deciphered source factors, and accessed risk of exposure to dioxin-like PCBs (DL-PCBs). Atmospheric PCBs were monitored by deployment of PUF-disk passive air samplers (PAS) at several sites across Ghana for 56 days. Atmospheric ∑₁₉₀PCB concentration in Ghana ranged from 0.28 ng/m³ in Kumasi to 4.64 ng/m³ at Agbogbloshie, a suburb in Accra noted for informal electronic waste (e-waste) recycling activities. As high as 11.10 ng/m³ of PCB concentration was measured in plumes from uncontrolled open burning of e-wastes at Agbogbloshie. Applying statistical source characterization tools, it emerged that e-wastes were a major contributor to the environmental burden of atmospheric PCBs in Ghana. The risk of DL-PCB toxicity via inhalation in the Agbogbloshie area was 4.2 pg TEQ/day, within similar order of magnitude of an estimated risk of 3.85 pg TEQ/day faced by e-waste workers working averagely for 8 h per day. It is suggested that elimination of e-waste sites would help to significantly reduce PCB-related toxicity issues in Ghana.

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