Powerline right-of-way management and flower-visiting insects: How vegetation management can promote pollinator diversity.

Loss in the availability of early successional habitat is a threat to pollinator populations. Given that powerline rights-of-way (ROW) must be managed to maintain early successional habitat, preventing vegetation from interfering with electrical lines, they have the potential to provide conservation benefits for wild pollinators. Moreover, it is possible to provide conservation benefits with no additional cost to land managers. We surveyed flower-visiting insects over two years in different vegetation management treatments in a long-term research ROW to determine which best promoted pollinator abundance and species richness. We found that the ROW had stabilized in an early successional state soon after its establishment and that this early successional state could be maintained with low levels of periodic maintenance. We collected a high diversity of flower-visiting insects (126 bee species and 179 non-bee morphospecies) in six ROW plots. Higher levels of herbicide application had a negative effect on bee species richness, but low levels of herbicide application were compatible with a high abundance and species richness of flower-visiting insects, including several rare species. Moreover, this effect was seen only in the bee community, and not in non-bee flower-visiting insects. Our results suggest further research into the conservation value of ROW for pollinators is warranted. We demonstrate that there is substantial potential for pollinator conservation in ROW, compatible with low-cost vegetation management.

An examination of endoparasites and fecal testosterone levels in flying squirrels (Glaucomys spp.) using high performance liquid chromatography-ultra-violet (HPLC-UV).

The immuno-competence hypothesis proposes that higher levels of testosterone increases the susceptibility to parasitism. Here we examined the testosterone levels in two species of flying squirrels (Glaucomys): one known to regularly host a nematode species (Strongyloides robustus) without ill effects (G. volans) and a closely related species that is considered negatively affected by the parasite. We quantified fecal testosterone levels in northern and southern flying squirrels (G. sabrinus, G. volans) with high-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV), and compared levels to endoparasites detected in individual squirrels. Qualitatively, we found highest levels of testosterone in male northern flying squirrels infected with Strongyloides robustus. This analytical approach represents an alternative and equally reliable method to using enzyme-linked immunosorbent assay (ELISA), for detecting and quantifying fecal testosterone levels.

Sustainable Remediation of Legacy Mine Drainage: A Case Study of the Flight 93 National Memorial.

Pollution from mining activities is a global environmental concern, not limited to areas of current resource extraction, but including a broader geographic area of historic (legacy) and abandoned mines. The pollution of surface waters from acid mine drainage is a persistent problem and requires a holistic and sustainable approach to addressing the spatial and temporal complexity of mining-specific problems. In this paper, we focus on the environmental, socio-economic, and legal challenges associated with the concurrent activities to remediate a coal mine site and to develop a national memorial following a catastrophic event. We provide a conceptual construct of a socio-ecological system defined at several spatial, temporal, and organizational scales and a critical synthesis of the technical and social learning processes necessary to achieving sustainable environmental remediation. Our case study is an example of a multi-disciplinary management approach, whereby collaborative interaction of stakeholders, the emergence of functional linkages for information exchange, and mediation led to scientifically informed decision making, creative management solutions, and ultimately environmental policy change.

Using ecological indicators and a decision support system for integrated ecological assessment at two national park units in the mid-Atlantic region, USA.

We implemented an integrated ecological assessment using a GIS-based decision support system model for Upper Delaware Scenic and Recreational River (UPDE) and Delaware Water Gap National Recreation Area (DEWA)-national park units with the mid-Atlantic region of the United States. Our assessment examined a variety of aquatic and terrestrial indicators of ecosystem components that reflect the parks' conservation purpose and reference condition. Our assessment compared these indicators to ecological thresholds to determine the condition of park watersheds. Selected indicators included chemical and physical measures of water quality, biologic indicators of water quality, and landscape condition measures. For the chemical and physical measures of water quality, we used a water quality index and each of its nine components to assess the condition of water quality in each watershed. For biologic measures of water quality, we used the Ephemeroptera, Plecoptera, Trichoptera aquatic macroinvertebrate index and, secondarily, the Hilsenhoff aquatic macroinvertebrate index. Finally, for the landscape condition measures of our model, we used percent forest and percent impervious surface. Based on our overall assessment, UPDE and DEWA watersheds had an ecological assessment score of 0.433 on a -1 to 1 fuzzy logic scale. This score indicates that, in general, the natural resource condition within watersheds at these parks is healthy or ecologically unimpaired; however, we had only partial data for many of our indicators. Our model is iterative and new data may be incorporated as they become available. These natural parks are located within a rapidly urbanizing landscape-we recommend that natural resource managers remain vigilant to surrounding land uses that may adversely affect natural resources within the parks.

The potential role of strongyloides robustus on parasite-mediated competition between two species of flying squirrels (Glaucomys).

There is growing evidence that populations of the northern flying squirrel (Glaucomys sabrinus) are declining in the eastern United States, perhaps due to competition with the southern flying squirrel (Glaucomys volans). Potential causes include parasite-mediated or apparent competition from the shared intestinal nematode, Strongyloides robustus, which has been shown to detrimentally affect the northern flying squirrel but not the southern flying squirrel. To investigate this hypothesis, we conducted a preliminary study on the parasite community of both flying squirrel species from sites in Pennsylvania where the two species occur sympatrically and where G. sabrinus is now considered endangered at the state level. We compared these parasite communities with those from northern flying squirrels from northern New York where the southern flying squirrel is absent. We found eight species of gastrointestinal parasites (Pterygodermatites peromysci, Lemuricola sciuri, Syphacia thompsoni, Syphacia spp., Capillaria spp., Citellinema bifurcatum, Strogyloides robustus, and an unidentifiable cestode species) in both species of flying squirrels examined for our study. The parasite-mediated competition hypothesis was partially supported. For example, in Pennsylvania, S. robustus was overdispersed in southern flying squirrels, such that a small proportion of the hosts carried a large proportion of the worm population. In addition, we found S. robustus to be present in northern flying squirrels when the species were sympatric, but not where southern flying squirrels were absent in New York. However, there was no association between S. robustus and the body condition of flying squirrels. We detected a potential parasite community interaction, as S. robustus abundance was positively associated with P. peromysci.

Natural resource assessment: an approach to science based planning in national parks.

We conducted a natural resource assessment at two national parks, New River Gorge National River and Shenandoah National Park, to help meet the goals of the Natural Resource Challenge--a program to help strengthen natural resource management at national parks. We met this challenge by synthesizing and interpreting natural resource information for planning purposes and we identified information gaps and natural significance of resources. We identified a variety of natural resources at both parks as being globally and/or nationally significant, including large expanses of unfragmented, mixed-mesophytic forests that qualify for wilderness protection, rare plant communities, diverse assemblages of neotropical migratory birds and salamanders, and outstanding aquatic recreational resources. In addition, these parks function, in part, as ecological reserves for plants in and wildlife. With these significant natural resources in mind, we also developed a suite of natural resource management recommendations in light of increasing threats from within and outside park boundaries. We hope that our approach can provide a blueprint for natural resource conservation at publically owned lands.

Developing a monitoring program for invertebrates: guidelines and a case study.

Invertebrates provide the majority of ecosystem services; thus, it is important that they be inventoried, monitored, and protected. Nevertheless, inventories, monitoring, and management generally focus on vertebrates and flowering plants. Consequently, there are few guidelines or case studies for invertebrates. We present a procedure for developing a monitoring program for species-rich invertebrates that entails (1) characterizing the community; (2) identifying surrogates for biodiversity; and (3) establishing efficient methods to monitor surrogates and any ecologically important or sensitive taxa. We used these procedures, biodiversity-based statistical advances, and a survey of arthropods to develop a monitoring plan for the forests of Shenandoah National Park, Virginia (U.S.A.). Our case study revealed that mixed hardwood and hemlock forests had significantly different compositions of arthropods in their soil and understory strata. Of the 10 orders tested Coleoptera and Hymenoptera were the only two to pass most of the five surrogate tests, and their combination improved predictions of overall arthropod diversity. Because arthropods represent the majority of macroscopic species in most ecosystems, the ability of this assemblage to predict overall arthropod diversity makes it a powerful surrogate. Of the 11 collecting methods used, the beat-sheet method was the most efficient for monitoring this surrogate assemblage. To complement this coarse-filter approach to monitoring at-risk, invasive, or other important taxa (fine filter), we used ordination analyses to match 66 taxa with the methods that most effectively sampled them. Our methods serve as a model for developing an invertebrate monitoring plan and should facilitate linking such monitoring with ecosystem functions and management.