Main Experiment: Stomatal conductance of 39 tree species in the main experiment

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Dataset Abstract

Measurement design: We randomly selected 12 high-diversity plots, each containing 16 or 24 species, which allowed us to compare as many species as possible across relatively short distances. The aim of our study was to establish links between stomatal control and functional leaf traits.

Dataset Design

We recorded daily courses of stomatal conductance for all species in a particular plot by taking repeated measurements on the same leaf from the same individual. Each sampled leaf was fully developed, undamaged, and fully exposed to the sun each day, and leaves were marked with colored plastic ties to ensure the same leaf was measured each day. To provide comparable environmental conditions, all measurements were taken in summer dur- ing dry spells and only on sunny days. Stomatal con- ductance was measured using an SC1 porometer (Decagon), which is based on steady-state technology. It measures the gradient of relative humidity at two dis- tances from the leaf and then calculates vapor flux from the stomata and stomatal conductance per area and time. Only stomatal conductance of the abaxial leaf side was measured as none of the species displayed adaxial sto- mata. For each measurement of stomatal conductance, we also recorded air temperature and relative humidity using a T2 thermo-hygrometer (Trotec) as well as photosyn- thetically active photon flux density (PPFD) using a HD2102.2 PAR Logger (DELTA OHM). The field studies took place in August to October 2010, May/June 2011 and August to October 2011 and only included continuous periods of sunny days to ensure radiation was not limiting photosynthesis and stomatal conductance.

Spatial Extent

Main Experiment, Site A and B, high diversity plots

Published

Kröber, W., & Bruelheide, H. (2014). Transpiration and stomatal control: A cross-species study of leaf traits in 39 evergreen and deciduous broadleaved subtropical tree species. Trees, 28(3), 901–914. Kröber, W., Heklau, H., & Bruelheide, H. (2014). Leaf morphology of 40 evergreen and deciduous broadleaved subtropical tree species and relationships to functional ecophysiological traits. Plant Biology. Kröber, W., Zhang, S., Ehmig, M., & Bruelheide, H. (2014). Xylem hydraulic structure and the Leaf Economics Spectrum - A cross-species study of 39 evergreen and deciduous broadleaved subtropical tree species. Plos One.

Temporal Extent

08/2010 - 09/2011

Taxonomic Extent

39 tree species of the experimental sites

Measurement Circumstances

hot sunny humid to dry

Data Analysis

stomatal conductance and vapour pressure deficit

Paper proposal submissions

Published

2014

Data columns available in the raw data part of this dataset

PTAG
research plot name. Research plots on the main experiment have a "p" in front of their IDs and then a 6 digit code: Plots in the main sites A and B are named according to their position in the original spreadsheet, in which they were designed. They consist of 6 digits: _1st digit_: Site (1:A, 2:B), _digit 2and3_: southwards row: as in spreadsheets the rows are named from the top to the bottom; _digit 4 and 5_: westward column: as in the original spreadsheet, but the letters are converted to numbers (A=01, B=02); _6th digit_: indicator, if the plot has been shifted a quarter mu. Example: "p205260": "p" means that this is a plot that is specified. "2" means, that we are at site B. Now the coordinates of the south - west corner: "0526". Since "e" is the fifth letter of the alphabet, this is Plot E26. The last digit "0" means that this plot was not moved by a quarter of a Mu, as some sites in Site A. The 6th digit can also indicate the subplot within the plot. "5", "6", "7", "8" indicate the northwest, northeast, southeast, and southwest quarter plot respectively.
Data group: BEF research plot name
Keywords: plot
Values
p112210
p113210
p114090
p116200
p115190
species_name
species_name
Data group: Scientific plant species name
Keywords: Scientific plant species name
Values
Acer davidii
Castanea henryi
Betula luminifera
Alniphyllum fortunei
Ailanthus altissima
rh
relative humidity
Unit: %
Data group: Relative humidity
Keywords: humidity
Values
33.4
34
33
32
31
par
photosynthetically active radiation
Unit: µmol m2 s
Data group: Photosynthetically active radiation (PAR)
Keywords: PAR (photosynthetically active radiation)
Values
1000
1006.1
1001.2
1005.5
1002.6
leaftemp
leaf surface temperature
Unit: °C
Data group: Temperature
Keywords: temperature
Values
20.7
21.4
19.7
20.6
20.3
date
date of measurement
Data group: Date time information
Keywords: date
Values
06.09.2011
07.08.2011
02.08.2011
01.08.2011
01.09.2010
time
time of measurement
Data group: Date time information
Values
1899-12-30T06:41:00+00:00
1899-12-30T06:46:00+00:00
1899-12-30T06:52:00+00:00
1899-12-30T06:50:00+00:00
1899-12-30T06:54:00+00:00
con
stomatal conductance
Unit: mmol m2 s
Data group: Stomatal conductance
Keywords: Stomatal conductance
Values
1002.7
1000.3
1001.4
1001.8
1003.1
temp
ambient air temperature
Unit: °C
Data group: Air temperature
Keywords: air temperature
Values
24
24.4
24.9
24.6
24.7
vpd
vapour pressure deficit derived from relative humidity and air temperature
Unit: hPa
Data group: Vapour pressure deficit
Keywords: vapour pressure deficit
Values
0.32349819
0.319684386
0.32158636
0.308851347
0.257698624