Geology topics

Ned H. Euliss

Publications and source records attributed to Ned H. Euliss.

39 records · Page 3Linked to original sources

USGS1996

Water-level fluctuation in wetlands as a function of landscape condition in the prairie pothole region

We evaluated water-level fluctuation (maximum water depth - minimum water depth/catchment size) in 12 temporary, 12 seasonal, and 12 semipermanent wetlands equally distributed among landscapes dominated by tilled agricultural lands and landscapes dominated by grassland. Water levels fluctuated an average of 14.14 cm in wetlands within tilled agricultural landscapes, while water levels in wetlands within grassland landscapes fluctuated an average of only 4.27 cm. Tillage reduces the natural capacity of catch meets to mitigate surface flow into wetland basins during precipitation events, resulting in greater water-level fluctuations in wetlands with tilled catchments. In addition, water levels in temporary and seasonal wetlands fluctuated an average of 13.74 cm and 11.82 cm, respectively, while water levels in semipermanent wetlands fluctuated only 2.77 cm. Semipermanent wetlands receive a larger proportion of their water as input from ground water than do either temporary or seasonal wetlands. This input of water from the ground has a stabilizing effect on water-levels of semipermanent wetlands. Increases in water-level fluctuation due to tillage or due to alteration of ground-water hydrology may ultimately affect the composition of a wetland's flora and fauna. In this paper, we also describe an inexpensive device for determining absolute maximum and minimum water levels in wetlands.

Wetlands↗

USGS1992

A new device for collection of interstitial water from wetland sediments

A sampler for collection of interstitial water from wetland sediments is described. It differs from other sampling devices because it does not have to be filled with solution to facilitate diffusion, it does not have to be removed from the wetland to collect samples, and it can be used to draw repeated samples over time from identical locations. The device facilitates “in situ” measurement of a wide range of abiotic parameters such as electrical conductivity, redox potential, and pH in wetland sediments. The device has application in ecological investigations of sediment-borne wildlife diseases, studies of benthic invertebrates, measurement of nutrient exchange, and other aspects of wetland ecology.

Wetlands Ecology and Management↗

USGS1987

Feeding ecology of northern pintails and green-winged teal wintering in California

The feeding ecology of northern pintails (Anas acuta) and green-winged teal (A. crecca) was examined from October through February 1979-81 in 4 major seasonal marsh types in the Central Valley, California. The esophagi of 262 pintails contained 72.3% plant seeds and 27.7% animal matter. The esophagi of 173 green-winged teal contained 62.3% plant seeds and 37.6% animal matter. Swamp timothy (Heleochloa schoenoides) caryopses, chironomid midge larvae, and common barnyardgrass (Echinochloa crusgalli) caryopses formed >50% of the diet of both species. Both species were highly opportunistic and generally shifted their food habits seasonally to the most available foods. Animal matter increased seasonally in the diets of both and formed about 60% of the foods eaten during January and February compared to only about 8% in October and 17% in December. Both species used open water marsh habitats almost exclusively in daytime but they used densely vegetated marshes almost exclusively at night. Management recommendations based on the food habits and habitat use patterns of pintails and green-winged teal are offered.

Journal of Wildlife Management↗