Application of a midge-based inference model for air temperature reveals evidence of late-20th century warming in sub-alpine lakes in the central Great Basin, United States

作者：Porinchu, David F.; Reinemann, Scott; Mark, Bryan G.; Box, Jason E.; Rolland, Nicolas

来源：Quaternary International, 2010, 215(1-2): 15-26.

DOI：10.1016/j.quaint.2009.07.021

• COMMUNITY STRUCTURE
• MOUNTAIN LAKES
• SIERRA-NEVADA
• CLIMATE
• CALIFORNIA
• DIPTERA
• WEST
• CHIRONOMIDS
• PROGRESS
• SHIFTS

Sediment cores were recovered from Stella Lake and Baker Lake, sub-alpine lakes located in Great Basin National Park, NV, in 2005 and 2007, respectively. The cores were analyzed for subfossil chironomid (Insecta: Diptera: Chironomidae) remains. Chronologies for the sediment cores, developed using Pb-210, indicate the cores span the 20th century. The midge communities present in the lakes experience muted compositional change through much of the 20th century; however, the post-AD 1980 interval is notable due to rapid lake-specific faunal turnover. The recently deposited sediment in Baker Lake is characterized by decreases in the relative of abundance of Psectrocladius semicirculatus/sordillelus, Cladotanytarsus mancus group and Procladius, the local extirpation of Chironomus, and an increase the proportion of Sergentia, Tanytarsus type G and Tanytarsus type B. The Stella Like midge community experienced a shift post-AD 1990 from an assemblage dominated by Tanytarsus type G to a P. semicirculatus/sordillelus dominated community. Application of a chironomid-based inference model for mean July air temperature (MJAT), based on a calibration set developed for the Inter-Mountain West of the United States consisting of 79 lakes and 54 midge taxa (r(jack)(2) = 0.55 degrees C, RMSEP = 0.9 degrees C, maximum bias = 1.66 degrees C), provided a means to reconstruct the 20th century temperature regime for the region. Stella Lake and Baker Lake experience large fluctuations in MJAT during the early to mid-20th century and consistently above average temperature during the late-20th century. The chironomid-inferred MJAT reconstructions for Stella Lake and Baker Lake track observed July temperature in the region encompassed by Nevada Climate Division #2 during the late-20th century.

• 出版日期2010-3-15