DOI: 10.5061/dryad.qb70g
title: Data from: Phenological responsiveness to climate differs among four species of Quercus in North America

description: 1.The timing of the seasonal activity of organisms is a tractable
 indicator of climate change. Many studies in North America have
 investigated the role of temperature on the onset date of phenological
 transitions in temperate deciduous trees and found that the onset of
 leafing and flowering in numerous species has occurred earlier in recent
 years, apparently in response to higher temperatures in winter and spring.
 2.Few studies have examined the climatic and biogeographic drivers of
 phenological responses in water-limited ecosystems or explored
 inter-specific variation in responses of phenological metrics other than
 the timing of onset, such as the periodicity or duration of phenological
 activity. 3.This study used phenological observations of four species of
 Quercus contributed to the USA National Phenology Network database from
 2009-2014 to investigate how responses to climate (temperature and
 precipitation) and geographic location (latitude, longitude and elevation)
 varied among two western North American species (Q. agrifolia and Q.
 lobata) and two eastern and central North American species (Q. alba and Q.
 rubra). 4.Within years, in species in the western, water-limited
 ecosystems, the phenological phases observed here (bud break, flowers or
 flower buds) tend to occur intermittently throughout the growing season,
 and each event is of longer duration than the same phenophases of the
 temperate-zone species, rendering a single onset date an incomplete metric
 with which to track responsiveness or to compare species. By contrast, the
 eastern/central U.S. species were phenologically more responsive than the
 western species to spatial and temporal variation in winter, spring, and
 fall precipitation and maximum temperature. 5.Synthesis: Within and
 between regions these congeners exhibited a diversity of responses to
 seasonal temperature and precipitation. This indicates that for predictive
 model development it is critical to understand how each underlying driver
 influences species that are adapted to different climatic regimes. These
 results underscore the value of studying a range of phenological metrics
 and species from a variety of ecosystems to better predict phenological
 responses to short-term variation and to long-term change in climate.
description: Quercus phenology
 dataThese data were obtained
 from the USA National Phenology Network (USA-NPN) database, accessible at
 www.usanpn.org/results/data. Data were collected by citizen and
 professional scientists through the Nature's Notebook monitoring
 program (www.naturesnotebook.org). This dataset was selected from the
 "Individual Phenometrics" data type available from the USA-NPN
 Phenology Observation Portal which delivers derived estimates of
 phenophase onset and end for individual plants. This dataset was
 customized by selecting all available data for four species of Quercus: Q.
 alba, Q. agrifolia, Q. lobata, and Q. rubra from 2009-2014 on two
 phenophases, "breaking leaf buds" and "flowers and flower
 buds". The dataset was filtered to only include onset dates that were
 detected within 7 days of a negative observation record. This data files
 includes one tab with estimated onset and end dates for phenophase
 activity and one tab with data field descriptions. For additional
 information on USA-NPN protocols and phenophase definitions visit
 www.usanpn.org/data.QuercusDataset.xlsx