Evaluating the ability of the Wind Erosion Prediction System (WEPS) to simulate near-surface wind speeds in the Inland Pacific Northwest, USA.

Wind speed is one of the main control factors of wind erosion and dust emissions, which are major problems in arid and semiarid regions of the world. Accurately simulating highly precise hourly wind speeds is critical and cost-efficient for land management decisions with the goal of mitigating wind erosion and land degradation. The Wind Erosion Prediction System (WEPS) is a process-based, daily time-step model that simulates changes in the soil-vegetation-atmosphere.

Competitive interaction in plant populations exposed to supplementary ultraviolet-B radiation.

Changes in plant growth and competitive balance between pairs of competing species were documented as a result of supplementary ultraviolet-B radiation (principally in the 290-315 nm waveband) under field conditions. This component of the terrestrial solar spectrum would be intensified if the atmospheric ozone layer were reduced. A method for calculating and statistically analyzing relative crowding coefficients was developed and used to evaluate the competitive status of the species pairs sown in a modified replacement series.