10.5061/DRYAD.MR5P1
Guerin, Marceau
Columbia University
Martin-Benito, Dario
Columbia University
Swiss Federal Institute of Technology in Zurich
Forest Research
von Arx, Georg
Swiss Federal Institute for Forest, Snow and Landscape Research
Andreu Hayles, Laia
Columbia University
Griffin, Kevin L.
Columbia University
Hamdan, Rayann
École Polytechnique
McDowell, Nate G.
Pacific Northwest National Laboratory
Muscarella, Robert
Aarhus University
Pockman, Will
University of New Mexico
Gentine, Pierre
Columbia University
Pockman, William
University of New Mexico
Andreu-Hayles, Laia
Columbia University
Data from: Interannual variations in needle and sapwood traits of Pinus
edulis branches under an experimental drought
Dryad
dataset
2018
stomatal conductance
functional ratio
2007-2013
Pinus Edulis
stomatal density
Huber value
ring area
leaf area
2018-12-27T00:00:00Z
2018-12-27T00:00:00Z
en
https://doi.org/10.1002/ece3.3743
348670 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1) In the Southwest United States, recent large-scale die-offs of conifers
raise the question of their resilience and mortality under droughts. To
date, little is known about the interannual structural response to
droughts. 2) We hypothesized that piñon pines (Pinus edulis) respond to
drought by reducing the drop of leaf water potential in branches from year
to year through needle morphological adjustments. We tested our hypothesis
using a seven-year experiment in central New Mexico with three watering
treatments (irrigated, normal and rain exclusion). 3) We analyzed how
variation in ‘evaporative structure’ (needle length, stomatal diameter,
stomatal density, stomatal conductance) responded to watering treatment
and interannual climate variability. We further analyzed annual functional
adjustments by comparing yearly addition of needle area (LA) with yearly
addition of sapwood area (SA) and distance to tip (d), defining the yearly
ratios SA:LA and SA:LA/d. 4) Needle length (l) increased with increasing
winter and monsoon water supply, and showed more interannual variability
when the soil was drier. Stomatal density increased with dryness while
stomatal diameter was reduced. As a result anatomical maximal stomatal
conductance was relatively invariant across treatments. SA:LA and SA:LA/d
showed significant differences across treatments and contrary to our
expectation were lower with reduced water input. Within average
precipitation ranges, the response of these ratios to soil moisture was
similar across treatments. However, when extreme soil drought was combined
with high VPD, needle length, SA:LA and SA:LA/d became highly non-linear,
emphasizing the existence of a response threshold of combined high VPD and
dry soil conditions. 5) In new branch tissues, the responses of annual
functional ratios to water stress were immediate (same year) and do not
attempt to reduce the drop of water potential. We suggest that unfavorable
evaporative structural response to drought is compensated by dynamic
stomatal control to maximize photosynthesis rates.
SEV_BRANCH_2013_1.0Sevilleta Long-Term Ecological Research Area LTER
(34°23′11″N,106°31′46″W; 1,911 m asl) in the Los Pinos Mountains of the
Sevilleta National Wildlife Refuge, NEW MEXICO, USA
USA
Sevilleta LTER
New Mexico
34°23’11”N
106°31’46”W