Abstract Detail

Recent Topics Posters

Scherer, Jacquelyn [1], Suarez, Marina [2].

Ground-truthing  Paleoprecipitation Proxies Across Modern Texas Floras.

Using plant fossils to predict climate parameters has been a goal of paleobotanists for decades.  Stable carbon isotopes of C3 leaves have been shown to correlate with precipitation, although a universal model continues to be elusive.  In this study, the model published by Matthew Kohn in 2011 is tested in modern floras across precipitation gradients in Texas ranging from 250 mm to 1500 mm.   Leaf litter, bulk leaf matter, and wood were collected from eight relatively undisturbed sites and analyzed for δ¹³C.  Values averaged across species and sample type ranged from an average of -26.34‰ from the Davis Mountains to -30.06‰ average from near Beaumont, Texas.  Regression of latitude, altitude, and log₁₀ of mean annual precipitation + 300 mm against δ¹³C averages produced an R² of 0.92. Precipitation predicted from the Kohn equation using measured δ¹³C ranged from 272 mm to 2720 mm.  However, compared to actual precipitation, the Kohn model produced error generally increasing from west (3% under-prediction) to east (75% over-prediction).  Additional collections and analysis, especially from more eastern (and therefore wetter) environments need to be added to complete the evaluation of the Kohn model. 

Broader Impacts:

1 - 27026 Granite Path, San Antonio, TX, 78258, USA
2 - University of Texas at San Antonio, Geological Sciences, One UTSA Circle, San Antonio, TX, 78249, USA

Keywords:
Paleobotany
paleoclimatology
stable isotopes
precipitation.

Presentation Type: Recent Topics Poster
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PRT023
Abstract ID:1316
Candidate for Awards:None