Offered Papers Theme A: Efficient Production from Grassland
Description
Bromus tectorum is a highly invasive exotic weed that has spread over millions of hectares of grazing land in the semi-arid regions of far western North America. The annual grass is an important grazing resource, but herbage production is highly variable among years, depending on the amount and periodicity of precipitation. When production is abundant, the accumulations of fine-textured, early-maturing herbage increase the chance of ignition and the rate of spread of wildfires. On certain years the area burned in such fires may be several million hectares. Such fires destroy forage resources and degrade watershed quality on extensive areas as well as threaten human property and lives. Bromus tectorum plants can produce a very large number of caryopses. Caryopses that fail to find a safe site for germination acquire a dormancy in the field that leads to the building of large seedbanks (Young et al., 1968). It is critical for managers to have estimates of the size and extent of Bromus tectorum seedbanks during the planning and implementation of pasture restoration treatments. Our objective was to obtain an estimate of Bromus tectorum seedbank size and germinability through bioassay of samples obtained from a variety of plant communities and to relate this information to site characteristics easily ascertained by pasture managers.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Density and Germination Characteristics of Seeds of Bromus tectorum in Field Seedbanks
Bromus tectorum is a highly invasive exotic weed that has spread over millions of hectares of grazing land in the semi-arid regions of far western North America. The annual grass is an important grazing resource, but herbage production is highly variable among years, depending on the amount and periodicity of precipitation. When production is abundant, the accumulations of fine-textured, early-maturing herbage increase the chance of ignition and the rate of spread of wildfires. On certain years the area burned in such fires may be several million hectares. Such fires destroy forage resources and degrade watershed quality on extensive areas as well as threaten human property and lives. Bromus tectorum plants can produce a very large number of caryopses. Caryopses that fail to find a safe site for germination acquire a dormancy in the field that leads to the building of large seedbanks (Young et al., 1968). It is critical for managers to have estimates of the size and extent of Bromus tectorum seedbanks during the planning and implementation of pasture restoration treatments. Our objective was to obtain an estimate of Bromus tectorum seedbank size and germinability through bioassay of samples obtained from a variety of plant communities and to relate this information to site characteristics easily ascertained by pasture managers.
