DOI: 10.5061/dryad.b5mkkwhcz
title: Data From: Respiratory temperature responses of tropical conifers differ with leaf morphology

description: Photosynthetic traits suggest that shade tolerance may explain the
 contrasting success of two conifer taxa, Podocarpaceae and Pinaceae, in
 tropical forests. Needle-leaved species from Pinus (Pinaceae) are
 generally absent from tropical forests, while Pinus krempfii, a
 flat-leaved pine, and numerous flat-leaved Podocarpaceae are abundant.
 Respiration (R) traits may provide additional insight into the drivers of
 the contrasting success of needle- and flat-leaved conifers in tropical
 forests.  We measured the short-term respiratory temperature (RT)
 response between 10 – 50°C and foliar morphological traits of 3 needle-
 and 7 flat-leaved conifer species coexisting in a tropical montane forest
 in the Central Highlands of Vietnam containing notable conifer diversity.
 We fit a lognormal polynomial model to each RT curve and extracted the
 following three parameters: a (basal R), and b and c (together describing
 the shape of the response).  Needle-leaved species (Pinus kesiya,
 Pinus dalatensis and Dacrydium elatum) had higher rates of area-based R at
 25°C (R25-area) as well as higher area-based modeled basal respiration (a)
 than flat-leaved species (P. krempfii, Podocarpus neriifolius, Dacrycarpus
 imbricatus, Nageia nana, Taxus wallichiana, Keteeleria evelyniana and
 Fokienia hodginsii).  No significant differences were found
 between needle- and flat-leaved species in mass-based R25 (R25-mass) or in
 the shape of the RT response (b and c); however, interspecific differences
 in R25-mass, R at nighttime temperature extremes (R4.1 & R20.6)
 and leaf traits were apparent.  Differences in R25-area and a
 suggest that needle-leaved foliage may be more energetically costly to
 maintain than flat-leaved foliage, providing new insight and additional
 support for the hypothesis that shade tolerance is an important driver of
 Podocarpaceae success and Pinaceae absence in the majority of tropical
 forests.  Interspecific differences in R25-mass and leaf traits
 highlight that varying ecological strategies are employed by conifers to
 coexist and survive in the Central Highlands of Vietnam. Ultimately, these
 data further our understanding of current conifer biogeographic
 distributions and underscore the need for additional studies to elucidate
 the effects of extreme temperature events on the continued survival of
 conifers in this unique forest.
description: Respiration temperature response curves were collected using an
 LI-6400XT modified to include a custom-built leaf chamber attached to a
 temperature controller. Leaf samples were collected from branches of upper
 canopies of adult trees of 10 conifer species growing in the Central
 Highlands of Vietnam in January 2018. Respiration temperature responses
 were measured from ~ 10 - 50 degrees celcius.  Full methods are available
 in the accompanying publication in Functional Ecology.
description: ReadMe File includes column names, descriptions and units for
 each dataset.  Missing data, or data removed due to measurement error are
 denoted by "NA".
 <strong>SSchmiege_master_results_Vietnam_RT.csv</strong><br> All foliar traits included in the analysis. <strong>SSchmiege_Vietnam_RTcurves_raw.csv</strong><br> Output of the raw LI-6400XT respiration temperature response curves.