Stevia (Stevia rebaudiana) is a perennial herbaceous plant native to Paraguay and used traditionally by the native Guarani peoples for centuries to sweeten medicinal teas. Stevia has only been commercially cultivated over the past 50 years and cultural practice information suitable for implementation by growers is limited. Currently stevia’s commercial...
The use of cover crops in young vineyards is not widely accepted in the Pacific Northwest due to concerns of water and nutrient competition between the cover crop and vines. The last 2 years of a 4-year study started in 2009 are reported here. The study evaluated the use of...
Vegetation patterns and species distributions are strongly linked to soil moisture regimes, and populations within a species from contrasting climatic regimes could exhibit differences in the degree to which certain functional traits related to establishment are expressed. Tree seedling survival is crucial for forest regeneration, and thus may be a...
Measurement of plant moisture stress of 1-2 m understory conifers
was made in "reference stands" on the H. J. Andrews Experimental
Forest in 1970-1972. Maximum stress each year (measured between midnight
and dawn) is closely correlated with the position of each community
along one axis of an ordination of the...
A Study conducted at The Island, Lake Billy Chinook, in Central Oregon, examined
differences in the pattern of soil properties between a sagebrush-grass and a juniper-sagebrush-grass community. Juniper invasion is linked with the desertification
process in which the sagebrush shrubs and perennial grasses decline. Patterns in soil
nutrients and other...
B and C horizon samples from twenty four selected profiles along
a north-south transect in the Willamette Valley were examined for
possible correlation between shrinkage properties and kind of clay
minerals present.
Observations of linear shrinkage, weight loss from a condition
of maximum plasticity, and changing character of X-ray diffraction...
The links between forests, streamflow, and climate are poorly understood. Despite hundreds of studies over the past 60 years, fundamental questions of forests' effects on the hydrologic cycle remain unanswered. The hydrological cycle involves mutually-dependent biological and physical processes that operate at multiple scales of time and space, and this...
Forest management is rapidly undergoing a transformation from a discipline based on efficient commodity production to one for multiple uses, especially on federally managed land in the United States. This new management paradigm has challenged silviculturists to develop and adapt forest management techniques that can deal with increased demands. Using...