Geology and geomorphology control suspended sediment yield and modulate increases following timber harvest in temperate headwater streams
Bywater-Reyes, S., C. Segura, K.D. Bladon

In this study, we quantified the relevance of natural controls (e.g., geology, catchment physiography) on suspended sediment yield (SSY) in headwater streams managed for timber harvest. We collected and analyzed six years of data from 10 sites (five headwater sub-catchments and five watershed outlets) in the Trask River Watershed (western Oregon, United States).

DISCIPLINE: Hydrology & Water Quality    STUDY: Trask    TYPE: Journal Articles    TAGS: Trask, Sediment
Post-breeding habitat selection by songbirds in the headwaters of the Trask River, northwestern Oregon
Jenkins, Stephanie R.

Little is known on the importance of riparian areas to birds near small headwater streams in mesic forests. Progress towards understanding limiting factors that affect bird populations has been difficult because of lack of information beyond the breeding period. I compared bird assemblages between headwater riparian and upland areas throughout the post-breeding period by capturing birds using mist-nets in six paired riparian and upland locations along six headwater streams of the Trask River in northwestern Oregon. In order to assess whether birds prefer headwater riparian areas, I also examined factors affecting habitat selection by juvenile Swainson's thrushes (n=37) using radio telemetry. While riparian and upland locations had similar coarse wood volume and fruiting and tall (> 1.3 m tall) shrub cover, riparian locations had less shrub cover (< 1.3 m tall) and different shrub composition than upland locations. Total capture rate was double that of upland in riparian locations, while bird species richness was similar. Similar numbers of birds were captured in mist-nets oriented perpendicular and parallel to the stream suggesting that birds were not using riparian areas as movement corridors. Adult capture rate was greater in riparian locations than adjacent uplands while results of juvenile capture rates were ambiguous. Riparian locations supported higher capture rates of Swainson's thrushes and winter wrens than adjacent uplands.

DISCIPLINE: Wildlife    STUDY: Trask    TYPE: Theses    TAGS: Songbirds, habitat, Breeding, Wildlife, Oregon, Trask, Riparian, Bird, Pacific Northwest, Landscape Ecology, Radio Telemetry, Bird Assemblages, Forest management, Mist Net
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