The study of colonizing and of dominant grass species is essential for prairie conservation efforts. We sought to answer how naturalized Kentucky bluegrass in the northern Great Plains has become successful in the last 20 yr despite its long history in the northern Great Plains. We tested for evidence of geographical differentiation using flow cytometry and microsatellite markers to ascertain the population genetics of Kentucky bluegrass. Across all tested wild populations, high levels of genetic diversity were detected along with moderate levels of structure. Mantel tests of geographical patterns were not significant. Using clonal assignment, we found two major clones that made up the majority of the tested wild populations. When we compared the wild individuals to pedigree cultivars, we found virtually no genetic overlap across all tests, which did not support our hypothesis of developed cultivars contributing to high genetic diversity in natural populations. Furthermore, DNA content tests indicated a narrow range in ploidy in wild populations compared with lawn cultivars, further supporting a hypothesis of divergence between wild and pedigree cultivars. These results indicate the recent invasion of Kentucky bluegrass in the northern Great Plains is not because of adaptation or propagule pressure, but rather likely an environmental or land use shift.

Two stalagmites from Devil's Icebox Cave, central Missouri, display similar δ13C and δ18O values and trends during the late Holocene. Positive δ13C excursions at 3.5–2.6 ka and 1.2–0.9 ka are interpreted to reflect drier conditions. These elevated stalagmite δ13C values could have plausibly been driven by increasing C4 plant abundances over the cave or an increased contribution of bedrock carbon, both of which could reflect decreased effective moisture. A lack of corresponding oxygen isotopic anomalies during these intervals suggests that neither mean annual temperature nor the seasonality of precipitation changed concomitantly with dryness. Both of the δ13C excursions identified in our stalagmite record are roughly coincident with dry intervals from a number of sites located across the Great Plains.

Migratory pathways in North American prairies are critical for sustaining endemic biodiversity. Fragmentation and loss of habitat by an encroaching human footprint has extirpated and severely truncated formerly large movements by prairie wildlife populations. Greater sage-grouse Centrocercus urophasianus, a Near Threatened landscape species requiring vast tracts of intact sagebrush Artemisia spp., exhibit varied migratory strategies across their range in response to the spatial composition of available habitats. We unexpectedly documented the longest migratory event ever observed in sage-grouse (> 120 km one way) in 2007–2009 while studying demography of a population at the north-east edge of their range. Movements that encompassed 6,687 km2 included individuals using distinct spring and summer ranges and then freely intermixing on the winter range in what is probably an obligate, annual event. The fate of greater sage-grouse in Canada is in part dependent on habitat conservation in the USA because this population spans an international border. Expanding agricultural tillage and development of oil and gas fields threaten to sever connectivity for this imperilled population. Science can help delineate high priority conservation areas but the fate of landscapes ultimately depends on international partnerships implementing conservation at scales relevant to prairie wildlife.

Des investigations malacologiques ont été réalisées en 1974 et en 1994-1995 dans trois prairies de la Haute-Vienne afin depréciser les caractéristiques des gîtes à limnées lorsque les parcelles sont abandonnées ou modifiées par l'application de mesures agronomiques. L'abandon d'une prairie et l'invasion de ragondins se sont traduits par des modifications dans la distribution des limnées. Lymnaea cf. fuscus a déserté le fossé principal de drainage pour coloniser les rigoles et les couloirs créés par ces rongeurs,ce qui s'est traduit par un accroissement important de la superficie du nouveau gîte. Les effectifs moyens de L. cf. fuscus et de L. truncatula ont augmenté aux dépens de ceux de L. glabra. Un autre mollusque aquatique, Physa acuta, a envahi le fossé laissé libre. Le curage des rigoles dans les deux autres prairies et leur invasion par une ou deux espèces aquatiques (L. ovata, Potamopyrgus antipodarum ou Physa acuta) se sont traduits par une extension dans la superficie du gîte aussi bien pour les mollusques colonisateurs que pour L. glabra et L. truncatula. Les effectifs des trois premières espèces sont assez importants dans ces deux rigoles ; par contre, on note une réduction du nombre des deux limnées.