Chironomids as indicators of recent and long-term climate change in the Sierra Nevada, CA. Title Slide with Image

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and long-term climate change in the Sierra Nevada, CA David F.

1 Funding provided by The National Science Foundation: Geography and Regional Sciences and Paleoclimate Chironomids as indicators of recent and long-term climate change in the Sierra Nevada, CA David F. Porinchu Department of Geography The Ohio State University Title Slide with Image

Roosevelt Lake, Sierra Nevada August, 2002 Collaborators: Glen MacDonald: Departments of Geography and OBEE, UCLA Katrina Moser: Department of Geography, University of Western Ontario Aaron Potito:

2 Roosevelt Lake, Sierra Nevada August, 2002 Collaborators: Glen MacDonald: Departments of Geography and OBEE, UCLA Katrina Moser: Department of Geography, University of Western Ontario Aaron Potito: Department of Geography, National University Ireland Amy Bloom: Department of Geology-Geography, Illinois State University Jeff Munroe: Department of Geology, Middlebury College Amanda Petel, Department of Geography, UCLA

3 The Harlequin Fly Miall and Hammond, 1900 Porinchu and MacDonald, 2003

4 Lake Myvatn, Iceland

5 Reasons chironomids are used in paleolimnological studies: sensitive to key environmental variables relatively short lifecycles the adults are mobile possess chitinous head capsules extremely abundant

6 Levesque et al., 1997

7 Tanytarsina Dicrotendipes Psectrocladius Microtendipes Heterotrissocladius

8 Calibration Set Development

9 Decrease in temperature, salinity, and nutrients with increase in elevation Mid-Elevation High-Elevation Low-Elevation

10 Sierra Nevada Snake Range Uinta Mountains

11 NASA, 1991

12 Sierra Nevada Calibration Set Porinchu et al., 2002

13 Adapted from Munroe and Mickleson (2002)

14 Uinta Mountains, UT Porinchu et al., submitted

15 Porinchu et al., submitted

16 Observed Surface Water Temperature ( o C) r 2 = 0.66 RMSEP = 1.4 o C N = Inferred Surface Water Temperature ( o C) Porinchu et al., submitted

17 Summary distribution of midges in the Sierra Nevada and the Uinta Mountains is strongly correlated to surface water temperature Relationship between chironomid distribution and SWT was quantified using WA-PLS, providing a robust model (r 2 = 0.66; RMSEP = 1.4 o C) Training set and associated SWT inference model may be used to develop paleo-temperature reconstructions for the Great Basin spanning the late Quaternary

18 Porinchu et al., 2007

19 MG-2 Moat Lake Rocky Bottom Lake

20 ea a Tanytarsus type C Tanytarsus type E Tanytarsus type H Zalutschi H Heterotrissocladius marcidus type (14.0) Heterotrissocladius grimshawi type (14.3) Cricotopus/Orthocladius (14.5) Dicrotendipes (15.6) Corynocera nr. ambigua (15.6) Psectrocladius semi/sordi (15.2) Chironomus (14.9) Tanytarsus indeterminable (15.2) Procladius (15.3) Corynocera oliveri type (13.9) Synorthocladius (13.9) Depth (cm) R e l a t i v e A b u n d a n c e Pentaneurini (Other) (15.3) Moat Lake Cool Water Taxa Temperate Taxa Year

21 17.0 Midge-Inferred SWT ( o C) MG2 - mean RBL - mean MTL - mean RBL MG2 MTL Year AD Porinchu et al., 2007

22 RECONSTRUCTED LAKE TEMPERATURES McGee Lake Rocky Bottom Moat Lake Fresno, CA Summer Temperatures year AD Porinchu et al., 2007 Deviation from mean temperature (ºC)

23 Sierra Nevada Snake Range Uinta Mountains

24 Summary Chironomid communities in high elevation lakes in the Sierra Nevada are sensitive to fluctuations in surface water temperature Chironomid analysis may be able to provide high-resolution (decadal to sub-decadal) paleoclimatic reconstructions of regional climate change (LIA and MWP) The inferred-warming that has occurred post-1980 is likely greater in magnitude than any period in the preceding century

25 Starkweather Lake Barrett Lake

26 MacDonald et al., submitted

27 Chironomid head capsule concentration Loss-On-Ignition Corynocera oliveri type Psectrocladius (Semi/Sordi) Dicrotendipes Microtendipes Corynocera nr. ambigua Tanytarsus grp. 1 Mayfly Chironominae Chironomid Percentage Diagram Heterotrissocladius grimshawi type Heterotrissocladius marcidus type Procladius Age (cal yr BP) Cold Water Taxa Temperate Taxa % of total identifiable midges Zone BRL-5 BRL-4 BRL-3 BRL-2 BRL head capsules/ml % LOI Lake Barrett, California

28 MacDonald et al., submitted

29 MacDonald et al., submitted

30 Summary Midge-inferred inferred SWT estimates suggest a 2-42 o C depression coeval with YD stade stable isotopes and diatoms provide evidence of wet conditions during the early YD and a shift to drier conditions during the late YD the combination of changing thermal and hydrologic regimes during the YD stade underscore the challenges that exist in detecting and understanding the YD in the western United States

Chironomids as a paleoclimate proxy

Chironomids as a paleoclimate proxy Tomi P. Luoto, PhD Department of Geosciences and Geography University of Helsinki, Finland Department of Biological and Environmental Science University of Jyväskylä,