Sap Flow of Northern Red Oak Trees Under Ecosystem Warming at Harvard Forest 2011

doi:10.6073/pasta/c9761fcf3fcda34f9a9513a4c5acf527 Sap Flow of Northern Red Oak Trees Under Ecosystem Warming at Harvard Forest 2011 Pamela Templer https://orcid.org/0000-0002-6570-3837 Nathan Phillips Stephanie Juice https://orcid.org/0000-0002-0891-2202 Aaron Ellison https://orcid.org/0000-0003-4151-6081 Shannon Pelini Researcher 2023 English

Over the next century, air temperature increases up to 5 °C are projected for the northeastern USA. Because evapotranspiration dominates water loss from terrestrial ecosystems, tree ecophysiological response to warming will have important consequences for forest water budgets. We measured growing season sap flow rates in mature northern red oak (Quercus rubra L.) trees in a combined air (up to 5.5 °C above ambient) and soil (up to 1.85 °C above ambient at 6-cm depth) warming experiment at Harvard Forest, MA, USA. Principal components analysis found air and soil temperatures had the largest effects on sap flow. On average, each 1 °C increase in temperature increased sap flow rates by approximately 1100 kg H2O m-2 sapwood area day-1 throughout the growing season and by 1200 kg H2O m-2 sapwood area day-1 during the early growing season. Reductions in the number of cold winter days correlated positively with increased sap flow at night during the early growing season (a decrease of 100 heating-degree-days was associated with a sapflow increase of approximately 5 kg H2O m-2 sapwood area day-1). Soil moisture declined with increased treatment temperatures, and each soil moisture percentage increase resulted in an increase in sap flow of approximately 360 kg H2O m-2 sapwood area day-1. At night, soil moisture correlated positively with sap flow rate. These results demonstrate that warmer air and soil temperatures in winter and throughout the growing season lead to increased sap flow rates, which could affect forest water budgets throughout the year.

air temperature climate change relative humidity tree physiology water balance LTER controlled vocabulary disturbance LTER core area Harvard Forest HFR LTER USA HFR default

This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.

Creative Commons Zero v1.0 Universal https://spdx.org/licenses/CC0-1.0.html CC0-1.0 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf247 Prospect Hill Tract (Harvard Forest). Coordinates based on WGS84 datum. -72.19 -72.19 +42.53 +42.53 340 340 meter 2011 2011 genus Quercus species rubra northern red oak complete Information Manager Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 hf-im@lists.fas.harvard.edu Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu

This research was conducted in the Prospect Hill Tract of Harvard Forest. Our study was conducted within an ongoing warming experiment. The design of the experiment is described thoroughly by Pelini and others (2011); only salient details are presented here. Twelve open-top octagonal chambers (5-m diameter, 1.2-m tall; internal volume = 21.7 m3) were installed in 2009 in a forest tract dominated by ca.70-year-old northern red oak and red maple trees. Each chamber is centered around an overstory northern red oak tree; the diameters (measured at 1.3 m aboveground) of the twelve trees used in this study ranged from 20−50 cm. Sap flux density measurements were made using thermal dissipation probes consisting of a pair of 1-mm diameter, 11-mm-long stainless-steel hollow needles with copper constantan (type T) thermocouples inserted at the midpoint (Granier 1987). Probes were installed in April 2011 in freshly drilled holes at 1.3-m height on both the north and south side of the trunk of each of the 12 trees. All statistical analyses were done using various functions within the R statistical software system, version 3.0.3 (R Core Team 2013).

Harvard Forest Long-Term Ecological Research Harvard Forest

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(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu https://ror.org/059cpzx98 pointOfContact The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210. hf247-01-sap-flow.csv sap flow hf247-01-sap-flow.csv 1214137 6363fe1860d5c83c9fd559a0a501fd87 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p24/hf247/hf247-01-sap-flow.csv datetime date and time YYYY-MM-DDThh:mm 1 minute NA missing value year year YYYY 1 year NA missing value doy day of year nominalDay 1 natural NA missing value time time of day hh:mm 1 minute NA missing value hour hour of day nominalHour 1 whole NA missing value air.temp air temperature celsius 0.01 real NA missing value rh relative humidity (%) dimensionless 0.1 real NA missing value vpd vapor pressure deficit kilopascal 0.01 real NA missing value tree tree identification number tree identification number NA missing value sensor sensor identification code sensor identification code NA missing value dbh diameter at breast height centimeter 0.01 real NA missing value deltat temperature above ambient celsius 0.1 real NA missing value sap.flux.den rate of sap flow gramsPerCentimeterSquaredPerHour 0.0001 real NA missing value 16992 hf247-02-R-code.txt R code hf247-02-R-code.txt 25613 f3efe26f0639c3ef3e852a431fe4ad03 none R Markdown https://harvardforest.fas.harvard.edu/data/p24/hf247/hf247-02-R-code.txt script