DUCK NEST SURVIVAL IN THE MISSOURI COTEAU OF NORTH DAKOTA: LANDSCAPE EFFECTS AT MULTIPLE SPATIAL SCALES

2005 ◽  
Vol 15 (6) ◽  
pp. 2137-2149 ◽  
Author(s):  
Scott E. Stephens ◽  
Jay J. Rotella ◽  
Mark. S. Lindberg ◽  
Mark L. Taper ◽  
James K. Ringelman
2014 ◽  
Vol 29 (6) ◽  
pp. 989-1000 ◽  
Author(s):  
William S. Beatty ◽  
Elisabeth B. Webb ◽  
Dylan C. Kesler ◽  
Andrew H. Raedeke ◽  
Luke W. Naylor ◽  
...  

The Condor ◽  
2020 ◽  
Vol 122 (2) ◽  
Author(s):  
Cassandra G Skaggs ◽  
Kevin M Ringelman ◽  
Charles R Loesch ◽  
Michael L Szymanski ◽  
Frank C Rohwer ◽  
...  

Abstract Over the past decade, the United States has seen a rapid increase in oil and gas extraction from areas where resources were previously thought to be unrecoverable, particularly the Bakken shale formation in North Dakota. The Bakken overlaps with the Prairie Pothole Region, the most critical habitat in North America for breeding ducks, where oil and gas extraction through hydraulic fracturing has the potential to impact more than a million duck pairs in the United States alone. Here, we evaluated the effect of oil and gas development on nesting ducks in 2015–2017 across 5 counties in North Dakota. Using data from ~4,000 nests we found that nest survival was higher at sites composed of a higher percentage of grassland, and for nests found closer to major roads. We found no effect of any metric of oil and gas extraction activity on duck nest survival. Using survival-corrected estimates of nest density, we found higher densities of nests closer to roads, but lower nest densities at sites surrounded by more wells. Our top-ranked model indicated that nest density was predicted to decline by 14% relative to sites with no development, given the average number of wells (3.15 wells) within 1,500 m of a site. However, within a nesting field, we found no evidence that ducks were avoiding petroleum-related infrastructure at smaller spatial scales. Our results indicate mixed effects of oil and gas development on nesting waterfowl, and highlight both the resiliency of dabbing ducks to environmental change and the need for additional research on other aspects of duck breeding biology.


2019 ◽  
Vol 612 ◽  
pp. 29-42 ◽  
Author(s):  
NR Evensen ◽  
C Doropoulos ◽  
KM Morrow ◽  
CA Motti ◽  
PJ Mumby

2019 ◽  
Vol 79 (2) ◽  
pp. 314-322 ◽  
Author(s):  
F. Licciardello ◽  
R. Aiello ◽  
V. Alagna ◽  
M. Iovino ◽  
D. Ventura ◽  
...  

Abstract This study aims at defining a methodology to evaluate Ks reductions of gravel material constituting constructed wetland (CW) bed matrices. Several schemes and equations for the Lefranc's test were compared by using different gravel sizes and at multiple spatial scales. The falling-head test method was implemented by using two steel permeameters: one impervious (IMP) and one pervious (P) on one side. At laboratory scale, mean K values for a small size gravel (8–15 × 10−2 m) measured by the IMP and the P permeameters were equal to 19,466 m/d and 30,662 m/d, respectively. Mean Ks values for a big size gravel (10–25 × 10−2 m) measured by the IMP and the P permeameters were equal to 12,135 m/d and 20,866 m/d, respectively. Comparison of Ks values obtained by the two permeameters at laboratory scale as well as a sensitivity analysis and a calibration, lead to the modification of the standpipe equation, to evaluate also the temporal variation of the horizontal Ks. In particular, both permeameters allow the evaluation of the Ks decreasing after 4 years-operation and 1–1.5 years' operation of the plants at full scale (filled with the small size gravel) and at pilot scale (filled with the big size gravel), respectively.


2016 ◽  
Vol 15 (1) ◽  
pp. 96
Author(s):  
E. Iglesias-Rodríguez ◽  
M. E. Cruz ◽  
J. Bravo-Castillero ◽  
R. Guinovart-Díaz ◽  
R. Rodríguez-Ramos ◽  
...  

Heterogeneous media with multiple spatial scales are finding increased importance in engineering. An example might be a large scale, otherwise homogeneous medium filled with dispersed small-scale particles that form aggregate structures at an intermediate scale. The objective in this paper is to formulate the strong-form Fourier heat conduction equation for such media using the method of reiterated homogenization. The phases are assumed to have a perfect thermal contact at the interface. The ratio of two successive length scales of the medium is a constant small parameter ε. The method is an up-scaling procedure that writes the temperature field as an asymptotic multiple-scale expansion in powers of the small parameter ε . The technique leads to two pairs of local and homogenized equations, linked by effective coefficients. In this manner the medium behavior at the smallest scales is seen to affect the macroscale behavior, which is the main interest in engineering. To facilitate the physical understanding of the formulation, an analytical solution is obtained for the heat conduction equation in a functionally graded material (FGM). The approach presented here may serve as a basis for future efforts to numerically compute effective properties of heterogeneous media with multiple spatial scales.


2021 ◽  
Author(s):  
Ben L. Gilby ◽  
Andrew D. Olds ◽  
Christopher J. Brown ◽  
Rod M. Connolly ◽  
Christopher J. Henderson ◽  
...  

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