Browsing Journal of Range Management, Volume 54, Number 4 (July 2001) by Authors
A proposed method for determining shrub utilization using (LA/LS) imageryQuilter, M. C.; Anderson, V. J. (Society for Range Management, 2001-07-01)Utilization of plant above ground biomass has continued to be a critical yet difficult assessment in rangeland monitoring. Shrub size and woody structure further compound the measurement of shrub biomass utilization. This study was designed to determine the potential utility of low altitude/large scale (LA/LS) imagery in assessing shrub utilization. A near monoculture of Ceriotoides lanata (Pursh) J.T. Howell (winterfat) located in the western desert shrubland of Utah was used to evaluate this technique. Four, 3.1 by 3.1 m plots were identified and the shrubs within the plots were defoliated by hand-picking at about 10% intervals with imagery of the plots obtained between pickings. Imagery was obtained using a radio controlled airplane (drone) fitted with a 35 mm camera. Images were evaluated using image processing software and the resulting reflectance data correlated with defoliation percentages (weight basis) for each plot. Reflectance data from images correlated highly with defoliation percentages (r2 > 0.9). This technique of using LA/LS imagery shows promise for a quick and accurate tool in assessing utilization of shrubs.
'Immigrant' forage kochia seed viability as impacted by storage methodsStewart, A.; Anderson, V. J.; Kitchen, S. G. (Society for Range Management, 2001-07-01)'Immigrant' forage kochia (Kochia prostrata (L.) Schrad.) is a valuable introduced subshrub, often used in reclamation plantings and seedings on western rangelands. Seedling establishment is best from fresh seed; however, many users plant stored seed and experience poor seeding success. One cause for failure is loss of seed viability in storage. Forage kochia seed was harvested on 4 dates in fall 1996 from 2 sites (wildland and irrigated) and tested for viability when fresh and after storage treatments. Storage treatments included low and high seed water contents (2-6% and 12-16%), cold and warm storage temperatures (2 degrees and 25 degrees C), and duration of storage (4, 8, and 12 months). Mature, highly viable forage kochia seed remains viable in storage longer than seed harvested prematurely. Low seed water content (2-6%) is essential to preserving maximum seed viability. Storing seed at a cold temperature (2 degrees C) is also helpful in maintaining viability.