Streamflow Variability Indicated by False Rings in Bald Cypress (Taxodium distichum (L.) Rich.)

Forests

GlennA. Tootle¹  GrantL. Harley²  JoshuaC. Bregy³  JustinT. Maxwell³  MatthewD. Therrell⁴  EmilyA. Elliott⁴  ClayS. Tucker⁴  MatthewD. Meko⁵ 

[1] Department of Civil, Construction and Environmental Engineering, University of Alabama, Tuscaloosa, AL 35487, USA;Department of Geography and Geological Sciences, University of Idaho, Moscow, ID 83844, USA;Department of Geography, Indiana University, Bloomington, IN 47405, USA;Department of Geography, University of Alabama, Tuscaloosa, AL 35487, USA;Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA;

关键词: Taxodium distichum;    bald cypress;    dendrochronology;    tree rings;    intra-annual density fluctuation;   

DOI  :  10.3390/f11101100

来源: DOAJ

【 摘 要 】

Despite growing in wet lowland and riparian settings, Taxodium distichum (L.) Rich. (bald cypress) has a strong response to hydroclimate variability, and tree ring chronologies derived from bald cypress have been used extensively to reconstruct drought, precipitation and streamflow. Previous studies have also demonstrated that false rings in bald cypress appear to be the result of variations in water availability during the growing season. In this study 28 trees from two sites located adjacent to the Choctawhatchee River in Northwestern Florida, USA were used to develop a false ring record extending from 1881 to 2014. Twenty false ring events were recorded during the available instrumental era (1931–2014). This record was compared with daily and monthly streamflow data from a nearby gage. All 20 of the false-ring events recorded during the instrumental period occurred during years in which greatly increased streamflow occurred late in the growing season. Many of these wet events appear to be the result of rainfall resulting from landfalling tropical cyclones. We also found that the intra-annual position of false rings within growth rings reflects streamflow variability and combining the false-ring record with tree ring width chronologies improves the estimation of overall summer streamflow by 14%. Future work using these and other quantitative approaches for the identification and measurement of false ring variables in tree rings may improve tree-ring reconstructions of streamflow and potentially the record of tropical cyclone rainfall events.

【 授权许可】

Unknown