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Estimating species richness: The importance of heterogeneity in species detectability Estimating species richness: The importance of heterogeneity in species detectability

Estimating species richness (i.e., the actual number of species present in a given area) is a basic objective of many field studies carried out in community ecology and is also of crucial concern when dealing with the conservation and management of biodiversity. In most studies, the total number of species recorded in an area at a given time is taken as a measure of species richness...
Authors
T. Boulinier, James D. Nichols, John R. Sauer, James E. Hines, K. H. Pollock

Natural processes for managing nitrate in ground water discharged to Chesapeake Bay and other surface waters: More than forest buffers Natural processes for managing nitrate in ground water discharged to Chesapeake Bay and other surface waters: More than forest buffers

Ground-water discharge is a significant source of nitrate load to tidal creeks, coastal estuaries, and Chesapeake Bay. Different studies have found that forest buffers greater than 200 feet wide remove most of the nitrate from passing ground water. These buffers are commonly included in regional nutrient-management strategies. Results of a U.S. Geological Survey study on the Eastern...
Authors
Gary K. Speiran, Pixie A. Hamilton, Michael D. Woodside

Changes in sediment and nutrient storage in three reservoirs in the lower Susquehanna River Basin and implications for the Chesapeake Bay Changes in sediment and nutrient storage in three reservoirs in the lower Susquehanna River Basin and implications for the Chesapeake Bay

The Susquehanna River contributes nearly 50 percent of the freshwater discharge to the Chesapeake Bay in a year of normal or average streamflow. The river also transports the greatest amount of nutrients (estimates of nearly 66 percent of the nitrogen and 40 percent of the phosphorus load) from all nontidal areas in the Chesapeake Bay Basin. Excessive nutrients in the Bay result in algal...
Authors
Michael J. Langland

Limits of retrospective power analysis Limits of retrospective power analysis

Power analysis after study completion has been suggested to interpret study results. We present 3 methods of estimating power and discuss their limitations. We use simulation studies to show that estimated power can be biased, extremely variable, and severely bounded. We endorse the practice of computing power to detect a biologically meaningful difference as a tool for study planning...
Authors
Patrick D. Gerard, David R. Smith, Govinda Weerakkody

Dasypodidae Borner, 1919 (Insecta, Hymenoptera): Proposed emendation of spelling to Dasypodaidae, so removing the homonymy with Dasypodidae Gray, 1821 (Mammalia, Xenarthra) Dasypodidae Borner, 1919 (Insecta, Hymenoptera): Proposed emendation of spelling to Dasypodaidae, so removing the homonymy with Dasypodidae Gray, 1821 (Mammalia, Xenarthra)

The family-group name DASYPODIDAE Borner, 1919 (Insecta, Hymenoptera) is a junior homonym Of DASYPODIDAE Gray, 1821 (Mammalia, Xenarthra). It is proposed that the homonymy between the two names, which relate to short-tongued bees and armadillos respectively, should be removed by emending the stem of the generic name Dasypoda Latreille, 1802, on which the insect familygroup name is based...
Authors
B.A. Alexander, C.D. Michener, A. L. Gardner

The seventy-second Christmas bird count. 302. Southern Dorchester County, Md The seventy-second Christmas bird count. 302. Southern Dorchester County, Md

We located 511 Acadian Flycatcher (Empidonax virescens) nests in bottomland hardwood forest of eastern Arkansas. Microhabitat characteristics were measured and their relationship with nest success evaluated. Fifty-two percent of all nesting attempts resulted in predation. Attributes of nest placement were similar between successful and unsuccessful nests, although successful nests were...
Authors
C.S. Robbins

Atlantic Flyway review: Piedmont-Coastal Plain Region IV - Fall 1997: Robbins Nest, Laurel, MD (390-0765) Atlantic Flyway review: Piedmont-Coastal Plain Region IV - Fall 1997: Robbins Nest, Laurel, MD (390-0765)

The 25th year of fall banding at this back yard station atop the Patuxent River gorge between Laurel and the 1-95 bridge netted more birds of summer and winter resident species than migrants. Myrtle Warbler was the only one of the six commonest species captured that is primarily a transient here. My 5214 net-hours, my fourth highest, were 48% above the 24-year mean of 3512, but the only...
Authors
Chandler S. Robbins

Increasing point-count duration increases standard error Increasing point-count duration increases standard error

We examined data from point counts of varying duration in bottomland forests of west Tennessee and the Mississippi Alluvial Valley to determine if counting interval influenced sampling efficiency. Estimates of standard error increased as point count duration increased both for cumulative number of individuals and species in both locations. Although point counts appear to yield data with...
Authors
W.P. Smith, D.J. Twedt, P.B. Hamel, R.P. Ford, D.A. Wiedenfeld, R.J. Cooper
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