Remote sensing and Geographic Information Systems (GIS) are well known tools for the study of time change analysis in natural systems. However, long-term studies of riparian systems using large-scale aerial photography are less common. The purpose of this project was to combine large scale aerial photography, GIS, Global Positioning Systems...
Weeping alkaligrass (Puccinellia distans) and Nuttall’s alkaligrass (Puccinellia
nuttalliana) infest Kentucky bluegrass seed fields of eastern Oregon. Weeping
alkaligrass is an introduced species from Eurasia, whereas Nuttall’s alkaligrass is
native to semi arid environments of western North America. These species are often
referred to collectively as ‘alkaligrass’; however, for farmers...
In some practical systems, most of the errors are of 1 → 0 type and 0 → 1
errors occur very rarely. In this thesis, first, the capacity of the asymmetric
channel is derived. The capacity of the binary symmetric channel (BSC) and the
Z-channel can be derived from this...
Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that...
Full Text:
-Philippe L�egar�e139,
Susan G. Letcher140, Nick A. Littlewood141, Carlos A. L�opez-Quintero142, Mounir
Published June 2009. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
This study identified new compounds with pest control activities. The two sources of candidates that were followed here were the main heartwood extract of Alaska Yellow Cedar (AYC) constituents and several semi-synthetic counterparts. Five compounds were isolated and identified for the first time in AYC heartwood in this research: two...
Medusahead [Taeniatherum caput-medusae (L.) Nevski], a non-native, winter-annual grass (Poaceae), has
invaded rangelands throughout the western USA. Medusahead is an aggressive competitor that crowds out native plants
and reduces forage for wildlife and livestock. Sulfometuron methyl is a sulfonylurea herbicide used to control medusahead,
but its effect on non-target native...
Slickspots are soil inclusions with unique loamy soils that provide habitats for many endemic plants worldwide, including those within sagebrush steppe. Sagebrush-dominated communities are declining and require restoration, but restoration techniques commonly used may impact negatively some intermixed communities found on soil inclusions including those on slickspot soils. Slickspot soils...
A greater than 10-fold increase in Canada goose (Branta canadensis) populations over the past several years has resulted in concerns over grazing impacts on grass seed production in the mid-Willamette Valley, Oregon. This study was designed to develop methods to quantify and statistically analyze goose-grazing impacts on seed yields of...
Direct seeding techniques often result in unsatisfactory outcomes in rangeland rehabilitation, primarily because of low seedling emergence and poor establishment. Seed processing techniques aimed at improving seedling emergence have gained interest by pasture managers. The purpose of this study was to investigate the combined effects of bracteole removal and seeding...