DOI: 10.5061/dryad.b327c
title: Data from: Tree circumference dynamics in four forests characterized using automated dendrometer bands

description: Stem diameter is one of the most commonly measured attributes of trees,
 forming the foundation of forest censuses and monitoring. Changes in tree
 stem circumference include both irreversible woody stem growth and
 reversible circumference changes related to water status, yet these
 fine-scale dynamics are rarely leveraged to understand forest
 ecophysiology and typically ignored in plot- or stand-scale estimates of
 tree growth and forest productivity. Here, we deployed automated
 dendrometer bands on 12–40 trees at four different forested sites—two
 temperate broadleaf deciduous, one temperate conifer, and one tropical
 broadleaf semi-deciduous—to understand how tree circumference varies on
 time scales of hours to months, how these dynamics relate to environmental
 conditions, and whether the structure of these variations might introduce
 substantive error into estimates of woody growth. Diurnal stem
 circumference dynamics measured over the bark commonly—but not
 consistently—exhibited daytime shrinkage attributable to
 transpiration-driven changes in stem water storage. The amplitude of this
 shrinkage was significantly correlated with climatic variables (daily
 temperature range, vapor pressure deficit, and radiation), sap flow and
 evapotranspiration. Diurnal variations were typically &lt;0.5 mm
 circumference in amplitude and unlikely to be of concern to most studies
 of tree growth. Over time scales of multiple days, the bands captured
 circumference increases in response to rain events, likely driven by
 combinations of increased stem water storage and bark hydration.
 Particularly at the tropical site, these rain responses could be quite
 substantial, ranging up to 1.5 mm circumference expansion within 48 hours
 following a rain event. We conclude that over-bark measurements of stem
 circumference change sometimes correlate with but have limited potential
 for directly estimating daily transpiration, but that they can be valuable
 on time scales of days to weeks for characterizing changes in stem growth
 and hydration.
description: Automated dendrometer
 band measurementsThis file contains data
 collected by automated dendrometer bands on 119 trees in 4 different
 sites. The data focuses only on the 2-month study periods of each site.
 Included are data from 119 of 121 instrumented trees, as 2 loggers failed
 to record data just before the start of study period at site WFDP (see
 appendix 1 and 2 of paper).ADB_Data.csvManual measurement dataThese are manual measurements made with a caliper on visual marks of the automated dendrometer bands. They were used to check the validity of automatic records. They were performed in 3 out of 4 sites (SCBI, SERC, and WFDP) on a total of 87 trees.Manual_Measurement_Data.csvMeteorological variablesThis file contains weather data measured on each of the four study sites as well as evapotranspiration for WFDP and BCI.Weather_Data.csvSap Flow Data for SCBIThis file contains sap flux density measured at SCBI by 28 Granier-style probes on 23 tree stems (see list of trees equipped with sap flow probes).SF_Data_SCBI.csvSap Flow Data for SERCThis file contains sap flux density measured at SERC by 30 Granier-style probes on 30 tree stems (see list of trees equipped with sap flow probes).SF_Data_SERC.csvList of trees equipped with sap flow probesThis is the list of trees that were equipped with Granier-style probes to measure sap flux density.SF_Trees.csvList of trees equipped with automated dendrometer bandsThis is the list of 121 trees that were equipped with automated dendrometer bands in 4 different sites.ADB_Trees.csv