Schmer, M. R., Xue, Q. and Hendrickson, J. R. 2012. Salinity effects on perennial, warm-season (C 4 ) grass germination adapted to the northern Great Plains. Can. J. Plant Sci. 92: 873Á881. Limited information is available on the germination of perennial C 4 grasses adapted to the northern Great Plains under saline conditions. Big bluestem (Andropogen gerardii Vitman), indiangrass [Sorghastrum nutans (L.) Nash], prairie cordgrass (Spartina pectinata Link), and switchgrass (Panicum virgatum L.) seeds were evaluated under non-saline and saline conditions corresponding to electric conductivity (EC) values of 0, 4, 8, 12, 16, and 20 dS m (1 , respectively. Ten cultivars were evaluated to determine salinity tolerance differences among and within species. Seeds were monitored for 21 d and analyzed for final germination percentage (GP), germination rate index (GRI), corrected germination rate index (CGRI), and germination velocity (GV). Differences among species were observed for all indices tested (PB0.01). Indices showed within species variation for big bluestem, indiangrass, and switchgrass. Big bluestem had the highest germination rates under increased salinity levels while prairie cordgrass had the lowest germination rates under non-saline and saline conditions. Indiangrass showed higher seed germination than switchgrass under low EC levels (0 to 4 dS m (1 ) but declined at a higher rate when EC levels exceeded 16 dS m (1 . Results from this study suggest grassland reestablishment from seed on variable saline soils will be dependent on both the species chosen and the specific cultivar used. ix cultivars pour de´terminer dans quelle mesure la tole´rance au sel varie au sein d'une espe`ce et d'une espe`ce a`l'autre. Les semences ont e´te´surveille´es pendant 21 jours, puis on a e´tabli le pourcentage final de germination, l'indice du taux de germination, l'indice corrige´du taux de germination et la rapidite´de la germination. Tous les indices teste´s varient d'une espe`ce a`l'autre (P B 0,01). Ces indices pre´sentent aussi des variations intra-spe´cifiques pour le barbon de Ge´rard, le fauxsorgho penche´et le panic raide. Le barbon de Ge´rard se caracte´rise par le meilleur taux de germination avec la saliniteć roissante, la spartine pectine´e ayant le taux de germination le plus faible dans les conditions salines ou pas. Les graines du faux-sorgho penche´germent mieux que celles du panic raide a`faible CE (0 a`4 ds par me`tre), mais cette proprie´te´diminue quand la CE de´passe 16 ds par me`tre. Les re´sultats de cette e´tude laissent croire que la restauration des prairies par ensemencement des sols salins de´pendra a`la fois de l'espe`ce et du cultivar choisis.

Sanderson, M. A., Liebig, M. A., Hendrickson, J. R., Kronberg, S. L., Toledo, D., Derner, J. D. and Reeves, J. L. 2015. Long-term agroecosystem research on northern Great Plains mixed-grass prairie near Mandan, North Dakota. Can. J. Plant Sci. 95: 1101–1116. In 1915, a stocking rate experiment was started on 101 ha of native mixed-grass prairie at the Northern Great Plains Research Laboratory (NGPRL) near Mandan, ND (100.9132N, 46.7710W). Here, we document the origin, evolution, and scientific outcomes from this long-term experiment. Four pastures of 12.1, 20.2, 28.3, and 40.5 ha were laid out and stocked continuously from May until October with 2-yr-old or yearling beef steers at four rates [initially 0.98, 1.39, 1.83, and 2.4 animal unit months ha−1]. The experiment generated some of the first information on the resilience of mixed-grass prairie to grazing and drought and relationships of livestock productivity to soil moisture for predictive purposes. After 1945, the experiment was reduced to the light and heavy stocking rate pastures only, which have been managed and grazed in approximately the same manner to the present day. The pastures were used to assess responses of vegetation to fertilizer in the 1950s and 1960s, develop grazing readiness tools in the 1990s, and assess remote sensing technologies in the 2000s. The long-term pastures currently serve as a unique resource to address contemporary questions dealing with drought, soil quality, carbon dynamics, greenhouse gas emissions, invasive species, and climate change.