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W.H. Pyle

Publications and source records attributed to W.H. Pyle.

4 recordsLinked to original sources
USGS2007

Effects of habitat management treatments on plant community composition and biomass in a Montane wetland

Grazing and burning are commonly applied practices that can impact the diversity and biomass of wetland plant communities. We evaluated the vegetative response of wetlands and adjacent upland grasslands to four treatment regimes (continuous idle, fall prescribed burning followed by idle, annual fall cattle grazing, and rotation of summer grazing and idle) commonly used by the U.S. Fish and Wildlife Service. Our study area was Grays Lake, a large, montane wetland in southeastern Idaho that is bordered by extensive wet meadows. We identified seven plant cover types, representing the transition from dry meadow to deep wetland habitats: mixed deep marsh, spikerush slough, Baltic rush ( Juncus balticus ), moist meadow, alkali, mesic meadow, and dry meadow. We compared changes in community composition and total aboveground biomass of each plant cover type between 1998, when all units had been idled for three years, and 1999 (1 yr post-treatment) and 2000 (2 yr post-treatment). Analysis using non-metric multidimensional scaling indicated that compositional changes varied among cover types, treatments, and years following treatment. Treatment-related changes in community composition were greatest in mixed deep marsh, Baltic rush, and mesic meadow. In mixed deep marsh and Baltic rush, grazing and associated trampling contributed to changes in the plant community toward more open water and aquatic species and lower dominance of Baltic rush; grazing and trampling also seemed to contribute to increased cover in mesic meadow. Changing hydrological conditions, from multiple years of high water to increasing drought, was an important factor influencing community composition and may have interacted with management treatments. Biomass differed among treatments and between years within cover types. In the wettest cover types, fall burning and grazing rotation treatments had greater negative impact on biomass than the idle treatment, but in drier cover types, summer grazing stimulated biomass production. Our results illustrate the spatial and temporal complexity of the transition between dry meadow and wetland habitats, and variable interactions among plant communities, treatments, and annual wetland conditions.

Idaho↗
USGS2004

Nesting ecology of waterbirds at Grays Lake, Idaho

Montane wetlands provide valuable habitat for nesting waterfowl and other waterbirds in the western United States, but relatively little information is available about the nesting ecology of their waterbird communities. We describe the general nesting ecology of breeding waterbirds at a large, shallow montane wetland in southeast Idaho during 1997-2000. Habitats included upland grasslands and intermittently to semipermanently flooded wetland habitats. We located a total of 1207 nests of 23 bird species: eared grebe (Podiceps nigricollis), Canada goose (Branta canadensis), mallard (Anas platyrhynchos), gadwall (A. strepera), American wigeon (A. americana), green-winged teal (A. crecca), blue-winged teal (A. discors), cinnamon teal (A. cyanoptera), northern shoveler (A. clypeata), northern pintail (A. acuta), redhead (Aythya americana), canvasback (A. valisineria), lesser scaup (A. affinis), ruddy duck (Oxyuris jamaicensis), northern harrier (Circus cyaneus), American coot (Fulica americana), Virginia rail (Rallus limicola), greater sandhill crane (Grus canadensis tabida), American avocet (Recurvirostra americana), long-billed curlew (Numenius americanus), Wilsons snipe (Gallinago delicta), Wilsons phalarope (Phalaropus tricolor), and short-eared owl (Asio flammeus). Most nests were initiated in May-early June and were terminated (hatched or destroyed) by the third week of June. Mean daily survival rate (DSR) for Canada goose nests was 0.954 0.005 (SE) (n = 127 nests), equivalent to Mayfield nest success of 21%. Mean DSR for dabbling duck nests over all four years was 0.938 0.006 (n = 141), equivalent to Mayfield nest success of 11%. For all other species where we found >10 nests each year (eared grebe, redhead, canvasback, coot, sandhill crane, American avocet, and Wilsons snipe), >50% of nests found hatched at least one young. Success rates for geese, cranes, and ducks were lower than reported for Grays Lake during 1949-1951 and lower than most other wetlands in the region.

Western North American Naturalist↗
USGS2002

Evaluation of management practices in wetland meadows at Grays Lake National Wildlife Refuge, Idaho, 1997-2000

We assessed the relative values of 4 management practices (idle, late season grazing, fall prescribed burning, and rotation of idle and summer grazing) to biotic resources of the grassland-wetland meadow ecosystem at Grays Lake during 1997-2000. Three replicates of each treatment were randomly assigned to 12 experimental units that bordered the deep emergent marsh. Biotic factors examined included the breeding bird community and abundance, nesting activity and nest success, small mammal abundance, plant community, and annual plant biomass production. Fall burns achieved treatment objectives, removing most residual vegetation across a range of cover types. Objectives for grazing treatments were mostly attained; however, vegetation use levels were insufficient for consistent attainment of treatment objectives. Savannah sparrow, American coot, Canada goose, sandhill crane, mallard, and yellow-headed blackbird were the most common bird species present. Densities of 2 bird species (savannah sparrow and red-winged blackbird) were related to year effect only. The effect of unit on densities of redhead, lesser scaup, ruddy duck, sora, long-billed curlew, and common snipe likely reflects habitat differences among units. Densities of 6 species (eared grebe, canvasback, American coot, American avocet, willet, and common yellowthroat) were related to both year and unit effects. Treatment affected densities of 6 of the 29 species examined (mallard, northern shoveler, cinnamon teal, blue-winged teal, American crow, and yellow-headed blackbird); we found no common trend in response to treatments among those species. Overall, idled habitat did not stand out to be a valuable treatment, whereas grazing tended to have positive responses for a number of species. Burning was more likely to result in reduced bird densities than other treatments. We also describe the distribution of species observations among 8 different habitat types. Of the 23 nesting species sampled in the experimental units, the most common were American coot, sandhill crane, Canada goose, American avocet, mallard, and cinnamon teal. Daily survival rates (DSRs) of dabbling duck nests (all species pooled) were negatively affected by fall grazing. We detected no effects of treatments on DSRs of Canada geese or sandhill crane nests. DSRs for sandhill crane nests were higher in 1998 than in 1999 or 2000 and were slightly higher than that in 1997. DSRs for coot nests were affected by both year and treatment; within-treatment differences among years were extensive, In 1998, when all units were idled, DSRs for coot nests were higher in units assigned to idle treatment than those assigned to fall-grazed or rotation treatment. DSRs for coot nests did not differ among treatment blocks in 1997 (all units idled) or 1999 (first year after treatments). We speculate that compaction of residual vegetation by snowpack reduced any differences between idle and treated units and thus lessened the value of idle habitat for most nesting birds. Nesting densities and nest success rates of Canada geese, dabbling ducks, and sandhill cranes were lower those that reported from Steel's (1952) study in 1949-1950, but differences in habitats and areas searched relative to our study make comparisons difficult. Nest success rates of sandhill cranes also were lower than those reported by Drewien (1973). Declines in nest success probably are related to changes in predator community. We captured 5 species of small mammals (meadow vole, montane vole, deer mouse, vagrant shrew, and ermine). Populations of meadow and montane voles irrupted in 1998 then crashed in spring 1999; the most marked changes were in montane vole numbers. Capture rates of ermine and observation rates for striped skunks and raptors suggested a numerical response (higher recruitment) by these predators to higher prey abundance and possibly distributional shifts (movement into areas of more abundant microtines). We did not detect differences

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