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The Relative Importance Of Patch Area And Perimeter–Area Ratio To Grassland Breeding Birds, Christopher J. Helzer, Dennis E. Jelinski

School of Natural Resources: Faculty Publications

Habitat fragmentation has been implicated as a major cause of population decline in grassland birds. We tested the hypothesis that a combination of area and shape determines the use of grassland patches by breeding birds. We compared both species richness and individual species presence in 45 wet meadow grasslands in the floodplain of the central Platte River, Nebraska. Bird data were collected through the use of belt transects and supplemented by walking and listening outside transects. Our data supported our primary hypothesis that perimeter–area ratio, which reflects both the area and shape of a patch, is the strongest predictor of …

The Effects Of Urbanization And Human Disturbance Upon Plant Community Structure And Bird Species Richness, Diversity, And Abundance In A Natural Forested Area (Forest Park) In Portland, Oregon, Nancy Ellen Broshot

Dissertations and Theses

The effects of urbanization and continual human disturbance on the plant and avian communities of Forest Park and forested lands surrounding Portland, Oregon, were studied. I examined characteristics of plant and avian communities at 25 sites, 24 which were in Forest Park and surrounding areas and one which was in the Ancient Forest Preserve (old-growth stand) northwest of Forest Park. Data were analyzed using multiple regression, ANOV A, and Bonferonni/Dunn. Seven variables were selected representing different urbanization gradients. An additional covariable coded for the old-growth stand, allowing it to be used as a control.

Many tree variables, especially those related …

Inventory Of The Central Mixed-Grass Prairie Ecoregion Of Kansas And Nebraska, Hillary Loring, Mike Bullerman, Kelly Kindscher

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

An inventory of potential high quality mixed-grass prairie ranches and large properties within the Central Mixed-Grass Prairie Ecoregion of Kansas and Nebraska was conducted in the spring and summer of 1999. Emphasis during the inventory was placed on identification of relatively intact landscapes. Significant ranches within those untilled landscapes were visited. An interview of the owners or managers of those properties was coupled with a survey of the vegetation. Assessments of quality were based on species composition, continuity of ground cover, observations of livestock impact, and viability of the community types present.

The objectives of this study were to:

1) …