Evans, C. R. W., Krzic, M., Broersma, K. and Thompson, D. J. 2012. Long-term grazing effects on grassland soil properties in southern British Columbia. Can. J. Soil Sci. 92: 685–693. Although grazing effects on soil properties have been evaluated on various temperate grasslands, no study has dealt with these effects in the southern interior of British Columbia. The objective of this study was to determine the effects of spring versus fall season grazing as well as grazing [at a moderate rate of 0.6 animal unit months (AUM) ha−1] versus non-grazing by beef cattle on selected soil properties. Effects were determined 20 and 30 yr after the establishment of the field experiment. Soil properties were determined for the 0- to 7.5-cm, 7.5- to 15-cm, and 15- to 30-cm depths. In comparison with fall grazing, spring grazing had greater soil bulk density, greater mechanical resistance within the top 15 cm of the soil profile, higher pH, and lower polysaccharides. This was true for both 20 and 30 yr of treatment. Grazing effects on aggregate stability were observed only after 30 yr with spring grazing leading to a more stable structure with a mean weight diameter (MWD) of 1.5 mm and 32% and 10% of aggregates in the 2- to 6-mm and 1- to 2-mm size fractions, respectively, compared with a MWD of 1.0 mm and 20% and 6% under fall grazing. Greater soil bulk density, mechanical resistance, and pH were observed under the grazed treatment relative to the control without grazing, but as we used a moderate stocking rate the impacts were not as great as in previous studies, which used heavy stocking rates. Our findings show that long-term grazing at a moderate stocking rate of 0.6 AUM ha−1did not have critical detrimental effects on soil properties as some land managers and ranchers have suggested.

Thompson, D. J. and Willms, W. D. 2014. Effects of long-term protection from grazing on phenotypic expression in geographically separated mountain rough fescue populations. Can. J. Plant Sci. 94: 33–39. Whether or not long-term grazing or protection from grazing alters the genetic makeup of grass populations has been debated. Mountain rough fescue [(Festuca campestris (Rydb.)], which is highly sensitive to summer grazing, and becomes dominant in plant communities with long-term protection, was chosen to address this question. Plants from three geographic sites (Stavely in AB, Milroy in the Kootenay trench, BC and Goose Lake on the BC interior plateau) with divergent grazing histories were vegetatively propagated from tillers. Daughter plants were planted into two field nurseries (at Kamloops, BC, and Stavely, AB) and morphological measurements were taken in two field seasons post-establishment. Plants from all three populations were taller, flowered earlier, and were more productive at the Kamloops nursery site. Of the three geographic sources, plants from the Goose Lake site were most distinct with narrower leaves, later flowering, and greater yield. Plants with a long history of grazing had slightly shorter fertile tillers and leaves than plants with a history of long-term protection.

, J. 2015. Comparing grazing and resting electivity of beef cattle for BC bunchgrass communities using GPS collars. Can. J. Anim. Sci. 95: 499Á507. Grasslands in the interior of British Columbia often contain a mosaic of plant communities that provide variable habitat for free-ranging cattle. Global positioning system (GPS) collars have been used to study natural habitat use by cattle on a coarse scale (such as riparian, grassland and forested habitats), but not on a fine scale (such as choice among grassland plant communities). Cows equipped with GPS collars were tracked during the spring grazing period for 4 yr. Six grassland pastures were used as replicates. The activity (grazing or resting) of cattle at GPS locations was classified using a distance travelled algorithm. A detailed plant community map of five plant community types was constructed, and cow relative use within the plant communities was determined. Electivity, which scales for differences in community area, was used to compare the use of plant communities. While grazing, electivity for the Kentucky bluegrass community (mean '0.3) was greater than for the bluebunch wheatgrass community (mean (0.2). While resting, these differences were more pronounced. GPS collars can be used to estimate fine-scale choices among grassland communities.Key words: Free-ranging cows, plant community electivity, grazing, resting Thompson, D., Wheatley, B. J., Church, J. S., Newman, R. et Walker, J. 2015. Comparer le choix de paˆturage et de repos chez les bovins de boucherie dans les communaute´s de gramine´es cespiteuses de la Colombie-Britannique au moyen de colliers GPS. Can. J. Anim. Sci. 95: 499Á507. Les prairies de l'inte´rieur de la Colombie-Britannique contiennent souvent une mosaı¨que de communaute´s ve´ge´tales qui offrent des habitats variables pour les bovins qui broutent en liberte´. Des colliers GPS (« global positioning system » ou syste`me de localisation mondiale) ont e´te´utilise´s pour e´tudier les habitats naturels utilise´s les bovins a`grande e´chelle (tels que les habitats riverains, prairies et forestiers), mais pas a`l'e´chelle plus fine (tel qu'un choix entre plusieurs communaute´s ve´ge´tales des prairies). Les vaches munies de colliers GPS ont e´te´suivies pendant la pe´riode de paˆturage printanie`re pendant 4 ans. Six pre´s de prairies ont e´te´utilise´s comme re´plicats. L'activite´(broutage ou repos) des bovins aux endroits de´signe´s par GPS a e´te´classe´e au moyen d'un algorithme de distance voyage´e. Une carte de´taille´e des communaute´s ve´ge´tales de cinq types de plantes a e´te´construite et l'utilisation relative par les bovins dans chaque communaute´a e´te´de´termine´e. Le choix, qui change d'e´chelle selon les diffe´rences de superficie des communaute´s, a e´te´utiliseṕ our comparer l'utilisation des communaute´s ve´ge´tales. Lors du broutage, le choix de la communaute´de paˆturin des pre´s (moyenne '0,3) e´tait plus e´leve´que pour la communaute´d'agropyre a`e´pi (moyenne (0,2). Au repos, ces diffe´rences e´taient encore plus...