Application of a New Tree-Ring Based Drought Reconstruction Method at Multiple Forest Sites Across Indiana, U.S.A.

<p>This thesis research used techniques of dendrochronology to investigate the efficacy of using multiple co-occurring species (MCOS) in a climate reconstruction model compared to a single species (SS) in four old-growth forests in Indiana: Pioneer Mothers Memorial Forest (PM), Donaldson Woods (DW), Hoot Woods (HW), and Lilly Dickey Woods (LD). The objectives of this study were to [1] evaluate the climate response of all chronologies (<em>n</em> = 19; 7 species) to determine the most appropriate climate variable for reconstruction and [2] determine if the MCOS model outperforms the SS model at each individual study site. Model comparison was conducted with <em>r²</em>, adj. <em>r²</em>, standardized residuals, root-mean-square error (RMSE), F statistic, and Akaike Information Criterion (AIC). Summer (June–August; JJA) Palmer Drought Severity Index (PDSI) was the best predicated climate variable, thus two separate models (SS and MCOS) were created at each site for reconstruction. The MCOS outperformed the SS at each site. During the instrumental period (1895–2000), the MCOS at PM, DW, HW and LD explained 50%, 49%, 36%, and 50% of the variance in JJA PDSI, respectively; whereas explained variance of the SS was 40%, 45%, 33%, and 47%. Further, adj. <em>r²</em>, standardized residuals, RMSE, and AIC all suggest that using the MCOS method to reconstruct drought outperforms the SS method. Future tree-ring based climate reconstructions should consider using the MCOS model because it allows reconstructions to go further back in time and produces more accurate estimates of climate conditions.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Discipline thesis:degree_discipline

Geography and Geology

Year dc:date.available

2015

Author dc:creator

• Pendergrass, Kayla Mechelle

Contributors dc:contributor

• Grant L. Harley
• Carl A. Reese
• Bandana Kar

• Dendrochronology
• Climate
• Multiple Species
• Dendroclimatology
• Indiana
• Earth Sciences
• Environmental Sciences

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/127

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1136