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This is an ARMI Product. Glyphosate and its degradation product AMPA occur frequently and widely in U.S. soils, surface water, groundwater, and precipitation
Author: Battaglin W, Meyer M, Kuivila K, Dietze J | Date: 2014 | Outlet: Journal of the American Water Resources Association 50(2): 275-290. | Format: URL
Glyphosate use in the US increased from less than 5,000 to more than 80,000 metric tons per year between 1987 and 2007. Glyphosate is popular due to its ease of use on soybean, cotton and corn crops that are genetically modified to tolerate it, utility in no-till farming practices, utility in urban areas, and the perception that it has low toxicity and little mobility in the environment. This compilation is the largest and most comprehensive assessment of the environmental occurrence of glyphosate and AMPA in the US conducted to date, summarizing the results of 3,732 water and sediment and 1,018 quality-assurance samples collected between 2001 and 2010 from 38 States. Results indicate that glyphosate and AMPA are usually detected together, mobile, and occur widely in the environment. Glyphosate was detected without AMPA in only 2.3% of samples, whereas AMPA was detected without glyphosate in 17.9% of samples. Glyphosate and AMPA were detected frequently in soils and sediment, ditches and drains, precipitation, rivers, and streams; and less frequently in lakes, ponds, and wetlands; soil water; and groundwater. Concentrations of glyphosate were below levels of concern for humans or wildlife; however, pesticides are often detected in mixtures. Ecosystem effects of chronic low-level exposures to pesticide mixtures are uncertain. The environmental health risk of low-level detections of glyphosate, AMPA, and associated adjuvants and mixtures remain to be determined.

This is an ARMI Product. The effects of hydropattern and predator communities on amphibian occupancy
Authors: Amburgey S, Bailey L, Murphy M, Muths E, Funk W | Date: 2014-09-23 | Outlet: Canadian Journal of Zoology | Format: URL
Complex, interactive ecological constraints regulate species distributions, and understanding these factors is crucial for predicting species persistence. We used occupancy analysis, which corrects for imperfect detection, to test the importance of abiotic and biotic habitat and landscape factors on probability of occupancy by boreal chorus frog (Pseudacris maculata; Agassiz 1850) tadpoles. We hypothesized that hydropattern and predators are primarily important as they affect desiccation and predation risk and can interact in ways difficult to predict. We surveyed 62 wetland sites across an elevational gradient in Colorado, USA and modeled patterns in P. maculata occupancy. Tadpoles were most frequently present in intermediate hydropattern systems with lower desiccation risk and no predatory fish due to occasional drying. P. maculata occupancy had a strong negative relationship with fish presence while tadpoles, odonate larvae and tiger salamanders (Ambystoma mavortium; Baird 1850) frequently co-occurred. Dry seasonal conditions will likely result in fewer intermediate hydropattern ponds available for amphibian breeding. We hypothesize that this will force P. maculata to breed in habitats with fish. As habitats shrink, predators that co-occur with P. maculata are expected to concentrate in the remaining habitat and increase predation risk for developing tadpoles (assuming predators are similarly constricted in their habitat use as amphibians are).

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This is an ARMI Product. Potential reduction in terrestrial salamander ranges associated with Marcellus shale development
Authors: Brand, Adrianne B, Wiewel, Amber NM, Grant, Evan H Campbell | Outlet: Biological Conservation
Natural gas production from the Marcellus shale is rapidly increasing in the northeastern United States. Most of the endemic terrestrial salamander species in the region are classified as ‘globally secure’ by the IUCN, primarily because much of their ranges include state- and federally protected lands, which have been presumed to be free from habitat loss. However, the proposed and ongoing development of the Marcellus gas resources may result in significant range restrictions for these and other terrestrial forest salamanders. To begin to address the gaps in our knowledge of the direct impacts of shale gas development, we developed occurrence models for five species of terrestrial plethodontid salamanders found largely within the Marcellus shale play. We predicted future Marcellus shale development under several scenarios. Under scenarios of 10000, 20000, and 50000 new gas wells, we predict 4%, 8%, and 20% forest loss, respectively, within the play. Predictions of habitat loss vary among species, but in general, Plethodon electromorphus and P. wehrlei are predicted to lose the greatest proportion of forested habitat within their ranges if future Marcellus predictions are based on characteristics of the shale play. If predictions are based on current well locations, P. richmondi is predicted to lose the greatest proportion of habitat. Models showed high uncertainty in species’ ranges and emphasize the need for distribution data collected by widespread and repeated, randomized surveys.

This is an ARMI Product. Short-term occupancy and abundance dynamics of the Oregon Spotted Frog (Rana pretiosa) across its core range
Authors: Adams MJ, Pearl CA, McCreary B, Galvan SK | Date: 2014-11-03 | Outlet: U.S. Geological Survey Open-File Report 2014-1230 | Format: .PDF
The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating panel frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are decreasing in probability of both site occupancy and abundance. We did not find an association between the probability that Oregon spotted frogs disappear from a site (local extinction) and any of the variables hypothesized to affect Oregon spotted frog occupancy. This 4-year study provides baseline data, but the 4-year period was too short to draw firm conclusions about current (2014) trends. Further study is essential to understand how habitat changes and management practices relate to the status and trends of this species.

This is an ARMI Product. Indicators of the Statuses of Amphibian Populations and Their Potential for Exposure to Atrazine in Four Midwestern U.S. Conservation Areas
Authors: Sadinski W, Roth M, Hayes T, Jones P, Gallant A | Date: 2014-09-12 | Outlet: PLoS ONE 9(9): e107018. doi:10.1371/journal.pone.0107018 | Format: .PDF
Extensive corn production in the midwestern United States has physically eliminated or fragmented vast areas of historical amphibian habitat. Midwestern corn farmers also apply large quantities of fertilizers and herbicides, which can cause direct and indirect effects on amphibians. Limited field research regarding the statuses of midwestern amphibian populations near areas of corn production has left resource managers, conservation planners, and other stakeholders needing more information to improve conservation strategies and management plans. We repeatedly sampled amphibians in wetlands in four conservation areas along a gradient of proximity to corn production in Illinois, Iowa, Minnesota, and Wisconsin from 2002 to 2005 and estimated site occupancy. We measured frequencies of gross physical deformities in recent metamorphs and triazine concentrations in the water at breeding sites. We also measured trematode infection rates in kidneys of recently metamorphosed Lithobates pipiens collected from nine wetlands in 2003 and 2004. We detected all possible amphibian species in each study area. The amount of nearby row crops was limited in importance as a covariate for estimating site occupancy. We observed deformities in <5% of metamorphs sampled and proportions were not associated with triazine concentrations. Trematode infections were high in metamorphs from all sites we sampled, but not associated with site triazine concentrations, except perhaps for a subset of sites sampled in both years. We detected triazines more often and in higher concentrations in breeding wetlands closer to corn production. Triazine concentrations increased in floodplain wetlands as water levels rose after rainfall and were similar among lotic and lentic sites. Overall, our results suggest amphibian populations were not faring differently among these four conservation areas, regardless of their proximity to corn production, and that the ecological dynamics of atrazine exposure were complex.

emergent wetland vegetation at Tamarac National Wildlife Refuge
Mark Roth  
This is an ARMI Product. Detecting Emergence, Growth, and Senescence of Wetland Vegetation with Polarimetric Synthetic Aperture Radar (SAR) Data.
Authors: Gallant AL, Kaya SG, White L, Brisco B, Roth MF, Sadinski W, Rover J | Date: 2014-03-24 | Outlet: Water. 2014; 6(3):694-722 | Format: .PDF
Wetlands provide ecosystem goods and services vitally important to humans. Land managers and policymakers working to conserve wetlands require regularly updated information on the statuses of wetlands across the landscape. However, wetlands are challenging to map remotely with high accuracy and consistency. We investigated the use of multitemporal polarimetric synthetic aperture radar (SAR) data acquired with Canada’s Radarsat-2 system to track within-season changes in wetland vegetation and surface water. We speculated, a priori, how temporal and morphological traits of different types of wetland vegetation should respond over a growing season with respect to four energy-scattering mechanisms. We used ground-based monitoring data and other ancillary information to assess the limits and consistency of the SAR data for tracking seasonal changes in wetlands. We found the traits of different types of vertical emergent wetland vegetation were detected well with the SAR data and corresponded with our anticipated backscatter responses. We also found using data from Landsat’s optical/infrared sensors in conjunction with SAR data helped remove confusion of wetland features with upland grasslands. These results suggest SAR data can provide useful monitoring information on the statuses of wetlands over time.

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This is an ARMI Product. Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by
Authors: Smalling KL, Reeves R, Muths E, Vandever M, Battaglin WA, Hladik ML, Pierce CL | Date: 2014 | Outlet: Science of the Total Environment | Format: .PDF
Among the multiple stressors potentially affecting the presence of amphibians across agricultural landscapes, habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline. Conservation efforts have attempted to restore wetlands lost through landscape modifications with the aim of reducing contaminant loads in surface waters and providing quality habitat to wildlife. However, the benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the accumulation of pesticides in tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The herbicide atrazine was detected in 100% of the water samples and in some instances at concentrations high enough to potentially cause reproductive effects in leopard frogs. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought to cause lethality in frogs. Seventeen pesticides were detected in tissue samples with concentrations ranging from 0.08 to 1,500 µg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing conservation and management actions for these and similar wetlands in agriculturally dominated landscapes.

Common Toad
J Bosch  
This is an ARMI Product. Demography of common toads after local extirpation of
Authors: Bosch J, Fernandez-Beaskoetxez S, Scherer R D, Amburgey S M, Muths E | Date: 2014-09 | Outlet: Amphibia-Reptilia | Format: .PDF
Estimating demographic parameters like survival or recruitment provides insight into the state and trajectory of populations, but understanding the contexts influencing those parameters, including both biotic and abiotic factors, is particularly important for management and conservation. At a high elevation national park in Central Spain, common toads (Bufo bufo) are apparently taking advantage of the near-extirpation of the midwife toad (Alytes obstetricans), as colonizationinto new breeding ponds is evident.Within this scenario, we expected demographic parameters of common toad populations to be affected favorably by the putative release from competition. However, we found the population growth rate was negative in 4 of 5 years at the long-standing population; survival probability at the long-standing population and newly-colonized breeding ponds was lower than reported for other toads living at high elevations and the probability of recruitment was inadequate to compensate for the survival rate in maintaining a positive trajectory for either of the breeding ponds. We assessed weather covariates and disease for their contribution to the context thatmay be limiting the common toad’s successful use of the niche vacated by the midwife toad.

This is an ARMI Product. Partitioning the non-consumptive effects of predators on prey with complex life histories
Authors: Davenport M, Hossack BR, Lowe WH | Date: 2014-08 | Outlet: Oecologia 176:149–155
Non-consumptive effects (NCE) of predators on prey can be as strong as consumptive effects and may be driven by numerous mechanisms, including predator characteristics. Previous work has highlighted the importance of predator characteristics in predicting NCEs, but has not addressed how complex life histories of prey could mediate predator NCEs. We conducted a meta-analysis to compare the effects of predator gape limitation (gape-limited or not) and hunting mode (active or sit-and-pursue) on the activity, larval period, and size at metamorphosis on larval aquatic amphibians and invertebrates. Larval prey tended to reduce their activity and require more time to reach metamorphosis in the presence of all predator functional groups, but the responses did not differ from zero. Prey metamorphosed at smaller size in response to non-gape-limited, active predators, but counter to expectations, prey metamorphosed larger when confronted by non-gape-limited, sit-and-pursue predators. These results indicate NCEs on larval prey life history can be strongly influenced by predator functional characteristics. More broadly, our results suggest that understanding predator NCEs would benefit from greater consideration of how prey life-history attributes mediate population and community-level outcomes.

Figure 1 from this paper showing various placements and arrangements of PVC pipe to sample hylid frogs.
 
This is an ARMI Product. A review of pipe and bamboo artificial refugia as a sampling tool in anuran studies
Authors: Glorioso BM, Waddle JH | Outlet: Herpetological Conservation and Biology
Artificial pipe-like refugia have been used by researchers for more than 40 years in anuran studies, and captured 28 species, primarily (82%) hylid treefrogs. Early pipe-like refugia were made using cut pieces of bamboo in the tropical forests of Puerto Rico, but more recent studies have used synthetic pipes and have occurred primarily in the southeastern United States. Although some studies have addressed particular aspects of pipe design, the diverse characteristics of the refugia as well as their placement in the environment have varied greatly, making comparisons among studies difficult. Here, we summarize and evaluate information regarding pipe designs and placement, address potential concerns for researchers, and suggest studies necessary to better interpret the data gained from this technique in anuran studies.


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