This study established the preferences of shrubsteppe granivores among seeds of 6 common sagebrushsteppe plants and related the preferences observed to physical and nutritional attributes of the seeds. Seeds of big sagebrush (Artemisia tridentata), cheatgrass (Bromus tectorum), Indian ricegrass (Oryzopsis hymenoides), western wheatgrass (Pascopyrum smithii), bitterbrush (Purshia tridentata) and green needlegrass (Stipa viridula) were placed in groups of petri dishes designed such that seed removal could be ascribed to either diurnal vertebrates, nocturnal vertebrates or ants. Though absolute quantities of seeds removed varied among the 3 granivore classes, calculations of preference based on weights of each seed species removed by each granivore class indicated that all 3 ranked the seeds similarly. Preference hierarchies of the 3 granivore classes were highly positively correlated with both calories per seed and % soluble carbohydrate of the seeds. The first correlation supports a basic prediction of optimal foraging theory -that foragers should maximize energy intake per unit time spent foraging. Both correlations emphasize the role of seed nutritional qualities in granivore seed selectivity in that soluble carbohydrate is a water-efficient energy source and its percentage is a good indicator of the digestible energy available in a food item. A corollary experiment comparing granivore use of an exotic seed (millet [Panicum miliaceum]) and a preferred native seed (Oryzopsis) demonstrated a distinct preference for the exotic. Since millet seeds are particularly high in % soluble carbohydrate, this result reinforced the apparent value of this nutritional attribute as a predictor of granivore seed preference. Among many seed resource characteristics upon which granivore seed selectivity might operate, our results indicate that individual species' nutritional composition may be particularly important. Thus, inferences about seed selectivity and resource partitioning among arid-land granivores should be interpreted with caution, especially those based on experiments using seed introductions, since the influence of seed nutritional attributes has not been widely acknowledged heretofore.

Summary 0[ The individual and joint e}ectiveness of two biorational tactics "crop interference and exploitation of negative cross!resistance to certain herbicides# in the management of triazine!resistant Amaranthus hybridus L[ "smooth pigweed# were estimated[ Bio! rational tactics exploit biological idiosyncracies of resistant "R# genotypes to maximize _tness cost"s# of resistance[ We quanti_ed selection against triazine resistance by relative performance comparisons between lines having comparable nuclear genomes but either resistant or susceptible cytoplasm[ Increasing soybean density by reducing row spacing "from 65 cm to 14 cm# did not signi_cantly increase the _tness cost of resistance[ 1[ Low doses of bentazon "099 and 299 g active ingredient ha Ð0 # did strongly increase the cost of resistance[ Over 1 years\ the mean relative performance of R genotypes in bentazon treatments was 9=39\ compared to 9=59 in the absence of bentazon[ Therefore\ use of bentazon in soybean production has the potential to delay evolution of triazine resistance in maizeÐsoybean rotations using triazines[ 2[ There was no consistent indication that increased soybean density and bentazon herbicide could act synergistically to increase costs of triazine resistance in Amaranthus hybridus[ Nor were di}erences in response to biorational tactics evident between the two populations of origin "Maryland and Virginia\ USA# from which experimental lines were derived[ 3[ E}ects of the biorational tactics di}ered markedly between years\ highlighting that resistance management depending primarily on these tactics would have widely variable results[ Use of such tactics is likely to be most e}ective in the context of diversi_ed weed management[ Key!words] herbicide resistance\ negative cross!resistance\ resistance management\ Amaranthus hybridus\ weed evolution[ Journal of Applied Ecology "0888# 25\ 012Ð021

This paper describes the development and validation of the PULSE Vision & Change Rubrics, version 1.0, a reliable tool for measuring departmental change. It was found that liberal arts institutions are farther along in implementing the recommendations of Vision and Change and that institutions overall earned the highest scores on the Curriculum rubric and the lowest scores on the Assessment rubric.

A study was conducted to identify seed attributes which might influence granivore preferences. Physical and chemical characteristics were estimated for seeds of 7 common sagebrush-steppe species (Artemisia tridentata, Bromus tectorum, Oryzopsis hymenoides, Pascopyrum smithii, Purshia tridentata, Stipa comata and Stipa viriduia) and 1 sacrifice food species (Panicum miliaceum). Seed-weights and caloric contents were determined, as well as % composition contributed by 5 organic, 3 inorganic and 5 synthetically defined fractions (including crude protein, solvent extract, structural and soluble carbohydrates and lignin). Results indicate that 70 soluble carbohydrate may be a good predictor of granivore seed preference. The generality of this or any other predictor is unknown, since sufIiciently detailed seed attribute data are unavailable for most species. For management scenarios involving seeds subject to predation, such data would help effectively translate ecological understanding of granivory into more efficient management practices. In any land management effort involving direct seeding or depending upon the natural input of seeds, the manager must consider those biotic and abiotic factors which may ultimately affect the successful establishment of the desired vegetation. While abiotic influences such as seedbed characteristics, germination requirements, and soil nutrient levels have been routinelyacknowledged and manipulated, biotic interactions affecting the seeds have often been ignored. One biotic factor which may limit plant establishment is granivory, the consumption of seeds by animals. Since the publication of Janzen's (1971) pivotal review of seed predation by animals, awareness of the potential importance of granivory in the structure and functioning of many ecosystems has expanded and matured. Yet despite the considerable research already conducted, relatively little attention has been devoted to the integration of ecological studies of granivory with vegetation management. Rangelands may be particularly appropriate systems for attempting such an integration, since they occur in relatively xeric habitats, where seeds may be an important food resource ".. .coupling primary production to the infrequent, unpredictable precipitation that limits the productivity of most arid ecosystems" (Brown et al. 1979). Insects (especially ants), birds, and small mammals consume large quantities of seeds on native rangelands (Nelson et al. 1970, Pulliam and Brand 1975, Goebel and Berry 1976, Everett et al. 1978, Whitford 1978) and manipulative field studies have demonstrated that granivores, via their seed selection, can affect the species composition of their plant community (Inouye et al. 1980). It follows, then, that understanding patterns of granivory might con-Authors are graduate student and Professor of

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