October 1, 2015
Early-Holocene warming in Beringia and its mediation by sea-level and vegetation changes
By P.J. Bartlein, M.E. Edwards, S.W. Hostetler, Sarah Shafer (GECSC), P.M. Anderson, L.B. Brubaker, and A.V. Lozhkin. Published in Climate of the Past.
Recent climate changes are affecting arctic ecosystems and generating land cover changes, such as expansion of woody vegetation into tundra, that may produce feedbacks to the climate system. To better understand the mechanisms controlling these feedbacks, this study used a regional climate model to simulate the effects of arctic land cover changes in Beringia (northeastern Siberia, Alaska, and northwestern Canada) ~11,000 years ago, focusing on the climate feedbacks produced by sea-level rise (e.g., flooding of the Bering-Chukchi land bridge), changes from tundra to deciduous broadleaf woody vegetation, and the formation of thaw lakes. Sea-level rise produced the largest climate effect (cooler summers, warmer winters), while vegetation changes produced warming in spring and early summer, and thaw lakes produced localized cooling in summer and warming in winter.
September 30, 2015
Effects of Fragmentation on the Spatial Ecology of the California Kingsnake (Lampropeltis californiae)
By Michael Anguiano and Jay Diffendorfer (GECSC). Published in the Journal of Herpetology.
The spatial ecology of 34 California Kingsnakes was studied by radiotracking the animals for up to 3 years across unfragmented and fragmented habitat with varying patch sizes and degrees of exposure to urban edges. It was found that there was no relationship between movement of the snakes and the degree of exposure to urban edges and fragmentation. The persistence of California Kingsnakes in fragmented landscapes may be related directly to their small spatial movement patterns, home-range overlap, and ability to use urban edge habitat.
September 29, 2015
Uranium-series ages of fossil corals from Mallorca, Spain: The "Neotyrrhenian" high stand of the Mediterranean Sea revisited
By Dan Muhs (GECSC), Kathleen Simmons (GECSC), Joaquín Meco, and Naomi Porat. Published in Palaeogeography, Palaeoclimatology, Palaeoecology.
On the island of Mallorca two separate high stands of sea—the "Eutyrrhenian" (thought to be approximately 120,000 yeas old) and the "Neotyrrhenian"—lie close to present sea level, implying paleo-sea levels that conflict, at least in part, with sea level records from far-field localities. This study obtained ages from the Neotyrrhenian bed corals, which when compared with previously published studies that employed other dating dating techniques show that the Neotyrrhenian and Eutyrrhenian deposits are not significantly different in age. The conclusion is that the Neotyrrhenian deposits are a beachrock facies of the same age as the Eutyrrhenian deposits.