Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 2067

Rainforest birds: A land manager's guide to breeding bird habitat in young conifer forests in the Pacific Northwest Rainforest birds: A land manager's guide to breeding bird habitat in young conifer forests in the Pacific Northwest

This document (hereafter Guide) has been prepared to assist land managers interested in conducting conservation and management activities to benefit breeding birds associated with young conifer forests in the Pacific Northwest. Audiences targeted for use of the Guide include land trusts, watershed councils, non-commercial private land owners, forest products companies, land-managing...
Authors
Bob Altman, Joan Hagar

Long-term limnological research and monitoring at Crater Lake, Oregon Long-term limnological research and monitoring at Crater Lake, Oregon

Crater Lake is located in the caldera of Mount Mazama in Crater Lake National Park, Oregon. The lake has a surface area of about 53 km2at an elevation of 1882 m and a maximum depth of 594 m. Limited studies of this ultraoligotrophic lake conducted between 1896 and 1981, lead to a 10-year limnological study to evaluate any potential degradation of water quality. No long-term variations in...
Authors
G.L. Larson, R. Collier, M. Buktenica

Imprint of oaks on nitrogen availability and δ15N in California grassland-savanna: A case of enhanced N inputs? Imprint of oaks on nitrogen availability and δ15N in California grassland-savanna: A case of enhanced N inputs?

Woody vegetation is distributed patchily in many arid and semi-arid ecosystems, where it is often associated with elevated nitrogen (N) pools and availability in islands of fertility. We measured N availability and δ15N in paired blue-oak versus annual grass dominated patches to characterize the causes and consequences of spatial variation in N dynamics of grassland-savanna in Sequoia...
Authors
S.S. Perakis, C.H. Kellogg

Impacts of a gape limited Brook Trout, Salvelinus fontinalis, on larval Northwestern salamander, Ambystoma gracile, growth: A field enclosure experiment Impacts of a gape limited Brook Trout, Salvelinus fontinalis, on larval Northwestern salamander, Ambystoma gracile, growth: A field enclosure experiment

The formation of amphibian population structure is directly affected by predation. Although aquatic predators have been shown to have direct negative effects on larval salamanders in laboratory and field experiments, the potential impacts of gape-limited fish on larval salamander growth has been largely underexplored. We designed an enclosure experiment conducted in situ to quantify the...
Authors
C.R. Currens, W.J. Liss, R.L. Hoffman

Marking techniques Marking techniques

No abstract available.
Authors
Daniel E. Varland, J.A. Smallwood, Leonard S. Young, Michael N. Kochert

Seasonal and interannual variability in the taxonomic composition and production dynamics of phytoplankton assemblages in Crater Lake, Oregon Seasonal and interannual variability in the taxonomic composition and production dynamics of phytoplankton assemblages in Crater Lake, Oregon

Taxonomic composition and production dynamics of phytoplankton assemblages in Crater Lake, Oregon, were examined during time periods between 1984 and 2000. The objectives of the study were (1) to investigate spatial and temporal patterns in species composition, chlorophyll concentration, and primary productivity relative to seasonal patterns of water circulation; (2) to explore...
Authors
McIntire C. David, Gary L. Larson, Robert E. Truitt

Distribution of breeding shorebirds on the Arctic Coastal Plain of Alaska Distribution of breeding shorebirds on the Arctic Coastal Plain of Alaska

Available information on the distribution of breeding shorebirds across the Arctic Coastal Plain of Alaska is dated, fragmented, and limited in scope. Herein, we describe the distribution of 19 shorebird species from data gathered at 407 study plots between 1998 and 2004. This information was collected using a single-visit rapid area search technique during territory establishment and...
Authors
James A. Johnson, Richard B. Lanctot, Brad A. Andres, Jonathan Bart, Stephen C. Brown, Steven J. Kendall, David C. Payer

Nutrient vectors and riparian processing: A review with special reference to African semiarid savanna ecosystems Nutrient vectors and riparian processing: A review with special reference to African semiarid savanna ecosystems

This review article describes vectors for nitrogen and phosphorus delivery to riparian zones in semiarid African savannas, the processing of nutrients in the riparian zone and the effect of disturbance on these processes. Semiarid savannas exhibit sharp seasonality, complex hillslope hydrology and high spatial heterogeneity, all of which ultimately impact nutrient fluxes between riparian...
Authors
Shayne M. Jacobs, J.S. Bechtold, Harry C. Biggs, N. B. Grimm, S. Lorentz, M.E. McClain, R.J. Naiman, Steven S. Perakis, G. Pinay, M.C. Scholes

Invasion by nonnative brook trout in Panther Creek, Idaho: Roles of local habitat quality, biotic resistance, and connectivity to source habitats Invasion by nonnative brook trout in Panther Creek, Idaho: Roles of local habitat quality, biotic resistance, and connectivity to source habitats

Theoretical models and empirical evidence suggest that the invasion of nonnative species in freshwaters is facilitated through the interaction of three factors: habitat quality, biotic resistance, and connectivity. We measured variables that represented each factor to determine which were associated with the occurrence of nonnative brook trout Salvelinus fontinalis in Panther Creek, a...
Authors
Joseph R. Benjamin, Jason B. Dunham, M.R. Dare

Ultraviolet radiation and bio-optics in Crater Lake, Oregon Ultraviolet radiation and bio-optics in Crater Lake, Oregon

Crater Lake, Oregon, is a mid-latitude caldera lake famous for its depth (594 m) and blue color. Recent underwater spectral measurements of solar radiation (300-800 nm) support earlier observations of unusual transparency and extend these to UV-B wavelengths. New data suggest that penetration of solar UVR into Crater Lake has a significant ecological impact. Evidence includes a...
Authors
B.R. Hargreaves, S.F. Girdner, M.W. Buktenica, R.W. Collier, E. Urbach, G.L. Larson
Was this page helpful?