The interference of barnyardgrass (Echinochloa crusgalli),
pigweed (Amaranthus retroflexus),downy brome (Bromus
tectorum),and tumble mustard (Sisymbrium altissimum)
with alfalfa was studied. Alfalfa was seeded with each of
the four weeds on August 14 and September 15, 1981, and on
April 13, 1982. Alfalfa also was seeded on August 27, 1981,
with...
Living mulches are vegetative covers that can grow in association with row crops and may prevent soil erosion and suppress weeds. Crop reduction from association with the living mulch is a frequent problem with this cultural practice. The interference between a white clover (Trifolium repens L. "New Zealand") living mulch...
Many indicators and criteria have been proposed to assess the sustainable management of
forests but their scientific validity remains uncertain. Because the effects of forest disturbances
(such as logging) are often specific to particular species, sites, landscapes, regions
and forest types, management ‘‘shortcuts’’ such as indicator species, focal species and...
The recovery of a 1.5 million yr long ice core from Antarctica represents a keystone of our understanding of Quaternary climate, the progression of glaciation over this time period and the role of greenhouse gas cycles in this progression. Here we tackle the question of where such ice may still...
Ecological impacts of climate change in the Pacific Northwest may hinge on acclimation to drier summers, highlighting the importance of plant physiological studies in forests. Evaluating dominant forest plant species under old-growth and managed forest conditions is similarly important as timber harvest might change microclimates and alter drought effects on...
We have reconstructed chronology for the disturbed bottom parts of the GRIP and GISP2 ice cores using the combined paleoatmospheric records of CH₄ concentration and δ¹⁸O[subscript atm] in the trapped gases. Our reconstructed ages for basal ice samples are based on comparison of published measurements of CH₄ and δ¹⁸O[subscript atm]...
Automated sound broadcast systems have been used to address a variety of ecological questions, and show great potential as a management tool. Such systems need to be reliable because treatments are often applied in the absence of a human observer and system failure can cause methodological ambiguity. During the breeding...
Full Text:
Broadcast Systems Used
in Ecological Research and Management
Valente, J. J., Legrande, C. L., Johnson, V
Automated sound broadcast systems have been used to address a variety of ecological questions, and show great potential as a management tool. Such systems need to be reliable because treatments are often applied in the absence of a human observer and system failure can cause methodological ambiguity. During the breeding...
Full Text:
Systems Used in
Ecology Research and Management – Supporting Information
JONATHON J. VALENTE,
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