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Context. Soil organic matter (SOM) plays a vital role in carbon (C) storage and agricultural sustainability. Additions of bovine urine to soils can cause positive priming of soil C decomposition and represents a pathway for SOM loss. However, data is limited to a few soils. Aims. We investigated the priming response to bovine urine of 27 dairy grazed pasture soils from the North Island of New Zealand. Methods. Soils from Allophanic, Gley, Recent and Brown soil orders were collected. [sup.14]C-labelled dairy cow urine was applied (1000 kg N [ha.sup.-1]) to undisturbed soil cores and carbon dioxide (C[O.sub.2]) fluxes measured (25[degrees]C) for 21 days. Urine applications were repeated, and C[O.sub.2] measured for a further 21 days (25[degrees]C). Water was the control treatment. Key results. C[O.sub.2] fluxes rapidly increased after both urine additions by 86 [+ or -] 1% 24 h after the first urine addition, and 68 [+ or -] 4% after the second. Positive, negative and no priming were observed, and the mean absolute deviation of priming ranged between 200 and 1000 [micro]gC [g.sup.-1], and variability was greater after the second urine addition. Urine induced changes in pH and electrical conductivity (EC) had no effect on priming, and soil C contents were correlated to cumulative C[O.sub.2], but not priming, and varied over time. Conclusions. Factors affecting soil priming remain elusive and priming was highly variable within and between soil types. Implications. The impacts of bovine urine on C pools requires further investigation to determine if, or when, urine patches are potential pathways for soil C loss. Keywords: buffering capacity, carbon, cumulative urine effect on soil electrical conductivity, cumulative urine effect on soil pH, negative priming, pasture, positive priming, soil organic matter., Introduction Loss of soil organic matter (SOM) reduces the potential of soil to deliver ecosystem services, such as carbon (C) sequestration and nutrient retention (Lal 2014; Orwin et al. 2015). [...]

:: The effects of cattle (Bos taurus L.) grazing on upland plant communities in forested rangelands are poorly understood. Cattle interactions with plant communities were studied in intensively managed (precommercially thinned (PCT) and repeatedly fertilized) silvopasture systems in young lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forests. We investigated the response of plant community abundance and diversity to cattle grazing and how these responses were affected by PCT and repeated fertilization. The study was conducted inside and outside cattle exclosures over 10 years in two regional replicates in south-central British Columbia, Canada. PCT and repeated fertilization increased both the amount and quality of forage. Effects of cattle grazing on plant community abundance and diversity were variable and significantly influenced by the nutrient status of the site. In fertilized stands, cattle grazing increased species richness and diversity, particularly for the herb layer, although these treatment effects often took several years to be expressed. In unfertilized stands, cattle grazing did not significantly reduce herb or shrub volumes; however, species richness and, to a lesser extent, diversity of the shrub layer declined. In a landscape context, management strategies for silvopasture should promote heterogeneity for conservation of plant diversity through a variety of grazing pressures, as well as forest enhancement treatments such as PCT and repeated fertilization. Resume: Les effets du paturage des bovins (Bos taurus L.) sur les communautes vegetales des milieux secs dans les grands paturages boises sont peu connus. Les interactions des bovins avec les communautes vegetales ont ete etudiees dans les systemes sylvopastoraux sous amenagement intensif (eclaircie precommerciale (EPC) et fertilisation repetee) dans les jeunes forets de pin tordu latifolie (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.). Nous avons etudie la reaction de la diversite et de l'abondance des communautes vegetales au paturage des bovins et la facon dont ces reactions etaient influencees par l'EPC et la fertilisation repetee. L'etude a ete realisee a l'interieur et a l'exterieur d'exclos pendant 10 ans et repetee dans deux regions differentes du centre-sud de la Colombie-Britannique, au Canada. L'EPC et la fertilisation repetee ont augmente la quantite et la qualite du fourrage. Les effets du paturage des bovins sur l'abondance et la diversite des communautes vegetales etaient variables et significativement influences par le statut nutritionnel de la station. Dans les peuplements fertilises, le paturage des bovins a augmente la richesse et la diversite des especes, particulierement dans la strate herbacee, bien qu'il se soit souvent ecoule plusieurs annees avant que les effets de ces traitements se manifestent. Dans les peuplements non fertilises, le paturage des bovins n'a pas significativement reduit le volume des plantes herbacees ni des arbustes. Cependant, la richesse en especes de la strate arbustive, et dans une moindre mesure la diversite, ont diminue. Dans un contexte paysager, les strategies d'amenagement sylvopastoral devraient favoriser l'heterogeneite pour conserver la diversite vegetale grace a differentes pressions de paturage et des traitements d'amelioration de la foret tels que l'EPC et la fertilisation repetee. [Traduit par la Redaction], Introduction Livestock grazing is the most widespread land management practice in western North America (NA) and is frequently conducted in silvopasture systems (Wikeem et al. 1993; Fleischner 1994). Silvopasture is [...]