http://hdl.handle.net/10150/635573 2026-05-10T18:24:03Z http://hdl.handle.net/10150/650504 Journal of Range Management, Volume 40, Number 3 (May 1987) Complete digitized issue. 1987-05-01T00:00:00Z http://hdl.handle.net/10150/645406 The Use of a Portable Computer for Real-Time Recording of Observations of Grazing Behavior in the Field Demment, M. W.; Greenwood, G. B. A real-time system for recording grazing behavior in the field is described. A NEC 8201a portable computer was programmed to allow the incidence, duration, and sequence of behaviors to be recorded. This system was used in the field to record bites, chews, steps, and swallows of grazing cattle. Data files were analyzed to determine biting, stepping, and swallowing rates as well as bites per feeding station. Durations of all activities can be summarized. This system permits the observer to record accurately feeding behavior and reduce significantly the time and cost of processing data. 1987-05-01T00:00:00Z http://hdl.handle.net/10150/645404 The Influence of Grazing Pressure on Rooting Dynamics of Caucasian Bluestem Svejcar, T.; Christiansen, S. Caucasian bluestem (Bothriochloa caucasica (Trin.) C.E. Hubb.) is a warm-season grass introduced from Eurasia that is currently used for reseeding farmland and depleted range in the Southern Great Plains. Although this species is thought to be grazing tolerant, little specific information is available concerning its response to grazing. Variable (put-and-take) stocking was used to maintain heavy (3 to 8 steers/ha) and light (2.5 to 4.5 steers/ha) grazing treatments during mid May to late September from 1983 to 1985. Seasonal changes in root mass and root length to a depth of 60 cm were measured the first 2 years, and end-of-season root length was measured the third year. Leaf area index (LAI) was measured during the first 2 years. Peak root mass was 27 and 46% less in heavily relative to lightly grazed swards in 1983 and 1984, respectively. Total root length for heavily grazed swards was 33 and 45% less than lengths of lightly grazed swards in 1983 and 1984, respectively. Heavy grazing resulted in a relatively larger reduction in LAI than in either root mass or length, and thus the ratio of absorbing root surface to transpiring leaf surface was greater for heavily grazed than lightly grazed plants. This increased ratio may explain our previous observation that heavy grazing resulted in an improved water status of leaf tissue. End-of-season total root length over the 3-year period (15 to 18 and 24 to 28 km/m2 for heavily and lightly grazed swards, respectively) was remarkably consistent given the variable climatic conditions over the study period. 1987-05-01T00:00:00Z http://hdl.handle.net/10150/645387 Relationships Between Va Mycorrhizal Fungi and Plant Cover Following Surface Mining in Wyoming Waaland, M. E.; Allen, E. B. Spoil spore counts of vesicular arbuscular mycorrhizal (VAM) fungi, VAM root infection, and percent cover of plants were assessed on reclaimed soil and spoil (1-6 years old), orphan spoil (10-31 years old), and undisturbed native sites. There was no relationship of site age with spore densities. Topsoiled sites almost always had significantly higher spore counts than spoil sites (reclaimed or orphan), indicating the importance of substrate on spore colonization and reproduction. Percent root infection of Agropyron smithii and A. dasystachyum showed no increasing trends with time in the mined sites (1-31 years), but the plants in the undisturbed site had greater infection than in any of the mined sites. There was also no correlation between percent cover of Agropyron and root infection or spore counts. These results suggest that time since disturbance is not an adequate explanation for the development of VAM infection and spore counts during the first 31 years, but that other factors such as the kind of substrate may be more important considerations. 1987-05-01T00:00:00Z