Skip to main content
U.S. flag

An official website of the United States government

Publications

These publications showcase the significant science conducted in our Science Centers.

Filter Total Items: 16727

Effects of two long-term mowing regimes on vegetation Effects of two long-term mowing regimes on vegetation

Wildlife managers have for many years been interested in the role of mowing as a management technique to benefit wildlife. Two long-term mowing regimes (60 years of similar management) were evaluated at Patuxent Research Refuge during the summer of 1997 to better understand the influence of mowing on vegetation communities. Mowing ceased in 1997 due to reduction in maintenance funds...
Authors
Matthew C. Perry, A.S. Deller

Introduction Introduction

No abstract available.
Authors
J.A. Kushlan, H. Hafner

Temporal and geographic patterns in population trends of brown-headed cowbirds Temporal and geographic patterns in population trends of brown-headed cowbirds

The temporal and geographic patterns in the population trends of Brown-headed Cowbirds are summarized from the North American Breeding Bird Survey. During 1966-1992, the survey-wide population declined significantly, a result of declining populations in the Eastern BBS Region, southern Great Plains, and the Pacific coast states. Increasing populations were most evident in the northern...
Authors
B.G. Peterjohn, J.R. Sauer, S. Schwarz

Airborne electromagnetics (EM) as a three-dimensional aquifer-mapping tool Airborne electromagnetics (EM) as a three-dimensional aquifer-mapping tool

The San Pedro River in southeastern Arizona hosts a major migratory bird flyway, and was declared a Riparian Conservation Area by Congress in 1988. Recharge of the adjacent Upper San Pedro Valley aquifer was thought to come primarily from the Huachuca Mountains, but the U. S. Army Garrison of Fort Huachuca and neighboring city of Sierra Vista have been tapping this aquifer for many...
Authors
Jeff Wynn, Don Pool, Mark Bultman, Mark E. Gettings, Jean Lemieux

Hydraulic characteristics of a rectangular mixed-cell rearing unit Hydraulic characteristics of a rectangular mixed-cell rearing unit

We describe a fish rearing unit modification that establishes mixed flow reactor (MFR) behavior in a rectangular vessel so as to eliminate metabolite concentration gradients, increase current velocities and improve solids scour at low water exchange rates. A standard raceway section 14.5 m long was modified to create six counter-rotating mixed cells, each 2.4 m wide by 2.4 m long. Cells...
Authors
B.J. Watten, D. C. Honeyfield, M.F. Schwartz

Microbound feeds Microbound feeds

No abstract available at this time
Authors
F.T. Barrows, W.A. Lellis

Formation of natural gas hydrates in marine sediments. Gas hydrate growth and stability conditioned by host sediment properties Formation of natural gas hydrates in marine sediments. Gas hydrate growth and stability conditioned by host sediment properties

The stability conditions of submarine gas hydrates (methane clathrates) are largely dictated by pressure, temperature, gas composition, and pore water salinity. However, the physical properties and surface chemistry of the host sediments also affect the thermodynamic state, growth kinetics, spatial distributions, and growth forms of clathrates. Our model presumes that gas hydrate behaves...
Authors
M. B. Clennell, P. Henry, M. Hovland, J.S. Booth, W.J. Winters, M. Thomas

Circulation and sediment transport in the vicinity of the Hudson Shelf Valley Circulation and sediment transport in the vicinity of the Hudson Shelf Valley

Sediment transport in the Hudson Shelf Valley and on the adjacent Long Island Shelf are evaluated using available data along with a three-dimensional wind-driven circulation model and a one-dimensional sediment transport model. Winds from the northwest drive currents up the Hudson Shelf Valley, while winds from the east produce weaker currents directed down the valley. Consistent with...
Authors
Courtney K. Harris, Richard P. Signell
Was this page helpful?