A series of 6 daylight observations was made each summer and again each winter over 2 years to map cattle distribution on a California foothill pasture. Sixty animals were used in the study with no animals appearing in. 1 observation series. During daylight hours, small herds of cows containing between 14 and 16 animals were scan-sampled and videotaped every 15 minutes. A global positioning system was used to record the position of the camera to aid in accurately locating individual animals. Animal locations and individual identifications were then entered into a geographic information system (GIS) by on-screen digitizing using color orthophotographs. Animal positions were determined to be within 5 m of their true location. Association software, ASSOC1, was used to analyze animal positions to determine cattle subgroups and herd units. This position-based grouping was compared with observation-based grouping by researchers. Direct observation also identified dominant herd members. Older animals, up to 16 years of age, were generally dominant over younger animals, and subgroups tended to be composed of animals of similar age. The size of naturally occurring subgroups was between 3 and 6 animals. Some animals exhibited independence in their actions and behaviors compared with subgroup members. ASSOC1 produced grouping results consistent with direct observations. However, accurate interpretation of the ASSOC1 results depended on direct observational data. ASSOC1 identified close association patterns in 3 of the observations that defined the dominant animals in the herd. Forage availability and thermoregulatory needs influenced the distance between associated subgroup members. Distance between animals decreased when animals sought shade in summer or shelter in winter. Computer analysis of spatial data from GPS collars may be able to determine the social structure and identify dominant animals in herd situations. Incorporating knowledge of cattle social behavior should improve management of cattle on the range.

Festuca idahoensis (Idaho fescue) is a perennial caespitose grass, common in semi-arid rangelands of the Intermountain West. To determine how individuals are recruited into a population, we studied two long-term monitoring plots that were established in 1937 at the Northern Great Basin Experimental Range in southeastern Oregon. The plots measured 3.05x3.05 m, and were located approximately 30 m apart. One plot was ungrazed, the other was subject to moderate levels of cattle grazing. The number of F. idahoensis plants in both plots increased ten-fold between 1937 and 1996, but whether this was due primarily to reproduction by seed or clonal fragmentation was unknown. In 1996, we mapped and sampled 160 plants of F. idahoensis. We used dominant inter-simple sequence repeat (ISSR) markers and codominant allozyme markers in order to identify genetic individuals and measure genetic diversity. Both plots were characterized by high levels of genetic and clonal diversity. When information from ISSRs, allozymes and sample location were combined, 126 genets were recognized, each consisting of one to four samples (ramets). By measuring the diameter of clones surrounding plants that were present in 1937, we estimated that clonal spread occurred at a rate of approximately 3.7 cm per decade, and thus was of secondary importance in the maintenance and increase of F. idahoensis stands. Sexual reproduction, rather than clonal fragmentation, accounted for most of the recruitment of new plants into these plots. The grazed plot had fewer ramets, genotypes, and clones than the ungrazed plot, but the ramets were significantly larger. Levels of genetic diversity did not differ in the grazed and ungrazed plots, but there was some evidence for a small, but significant level of genetic differentiation between the two. The results also indicate that F. idahoensis has the potential to be a long-lived species with some individuals persisting in excess of 60 years. This study demonstrates how long-term monitoring can be supplemented by genetic analysis to obtain detailed information on the population dynamics of plants. In the case of this community dominant species, this provides essential information for understanding succession and developing management and restoration strategies.

Assessments of conservation effects are being conducted to determine the effectiveness of agricultural conservation practices. The practice of nutrient supplement placement to improve livestock distribution has not been designated a "best management practice" by the USDA Natural Resources Conservation Service (NRCS). Three studies in California visually and statistically document the effectiveness of nutrient supplement placement for changing livestock distribution. The initial study conducted in the Sierra Nevada foothills demonstrated that use of riparian patches could be reduced with strategic placement of dehydrated molasses supplement. A study on an adjacent ranch found that during the dry season, supplement placement effectively redistributed livestock by attracting them into a zone that extended out to about 600 m (1,980 ft) from the supplement. In a study on a coastal ranch in San Luis Obispo County, nutrient supplements were used to attract cows into an ungrazed forest adjacent to grazed grassland. The results of the studies reported here support the effectiveness of supplement placement for changing livestock distribution. Integration of supplement placement practices into best management practices and into NRCS's prescribed grazing standard is supported by this research.

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