uid=HFR,o=lter,dc=ecoinformatics,dc=org
all
public
read
doi:10.6073/pasta/eb5cc21e8a00d29ce30884da36044f2b
Photosynthetic Light Response Curves in CRUI Land Use Project at Harvard Forest 1998
Timothy
Sipe
Richard
Bowden
Charles
McClaugherty
https://orcid.org/0000-0001-5884-0756
Chelsea
Halback
Researcher
Brie
Kessler
Researcher
Melissa
Kibler
Researcher
Kyle
Schwabenbauer
Researcher
Matthew
Wodkowski
Researcher
2023
English
Ambient CO2 concentrations in terrestrial ecosystems vary substantially on several spatial and temporal scales as numerous soil, plant, and atmospheric processes respond to irradiance, temperature, moisture and wind. There is one widespread microhabitat in terrestrial ecosystems, the nearground zone, in which CO2 is naturally enhanced above average background levels. CO2 produced by soil respiration diffuses through the litter and boundary layers and dissipates fairly rapidly into the overlying bulk air. However, a marked vertical profile of nearground enriched CO2 (hereafter NEC) is usually present in the first 0-50 cm above ground. The degree of enrichment varies primarily with soil respiration rate and turbulent mixing, secondarily with photosynthesis by plants in the herbaceous stratum, and usually shows marked diel and seasonal variation. References to this CO2 "subsidy" and its effects on plants have occurred occasionally in the literature since 1939, but there have been few detailed studies of either the nearground profile or plant responses in the field, particularly for species that consistently occupy the nearground stratum.
Considerable research over the last twenty years in both controlled and field environments has shown that co-occurring plant species may respond differently to artificially elevated CO2. But in contrast to light, temperature, water, and nutrients, plant community ecologists have generally not considered CO2 among the factors that regulate species’ distribution and abundance, except indirectly as it may affect water balance.
We have documented differences in forest composition (woody and herbaceous), soil characteristics, microclimates, and nearground CO2 levels among six sites that were formerly plowed, pastured, or continuously forested woodlots in Prospect Hill. We selected three perennial herbaceous species (Aralia nudicaulis, wild sarsaparilla; Clintonia borealis, blue-bead lily; Medeola virginiana, Indian cucumber root) and two dominant tree species in the Harvard Forest system (Acer rubrum, red maple; Quercus rubra (northern red oak) and measured their photosynthetic light responses to ambient CO2 variation within the range commonly encountered in the field (350-450 ppm) to address five questions: (1) What is the overall effect of NEC on net carbon assimilation? (2) Do species differ overall (land use sites combined) in their responses to NEC? (3) Do the land use sites differ overall (species combined) in plant responses to NEC? (4) Are there site x CO2 or species x CO2 interactions in response to NEC?
Light response curves were measured at three CO2 levels (350, 400, and 450 ppm inside the cuvette) on 3 randomly-selected, healthy replicates of each species in each of the three sites, generating a total of 135 curves. Gas-exchange measurements were made with a LI-6400 infrared gas analyzer (Li-Cor Inc., Lincoln, NE, USA) during ~7:30-12:30 a.m. solar time in late July and early August 1998. The analyzer was calibrated daily just prior to measurements. Air temperature in the cuvette was maintained at 23 deg C (mean morning air temperature in the sites), and relative humidity was maintained at either constant or slowly rising levels (typically less than 5% increase overall) during the 20-25 minutes required for each curve.
Rectangular hyperbolic curves were fitted to the scatterplots and curve parameters (daytime respiration rate, Rday; apparent quantum efficiency, AQE; maximum assimilation rate, Amax; curve convexity; light compensation point, LCP; and light saturation point, Lsat) were estimated using Photosyn Assistant software v. 1.1 (Dundee Scientific, Dundee, Scotland, UK). Six of the curves produced questionable parameters in the quantum yield region and were excluded from further analyses, leaving a total sample size of 129.
carbon dioxide
herbs
land use
light
photosynthesis
seedlings
LTER controlled vocabulary
primary production
disturbance
LTER core area
Harvard Forest
HFR
LTER
USA
HFR default
This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.
Creative Commons Zero v1.0 Universal
https://spdx.org/licenses/CC0-1.0.html
CC0-1.0
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf139
Prospect Hill Tract (Harvard Forest). Coordinates based on WGS84 datum.
-72.20
-72.17
+42.55
+42.53
335
357
meter
1998
1998
genus
Acer
species
rubrum
red maple
genus
Aralia
species
nudicaulis
wild sarsaparilla
genus
Clintonia
species
borealis
blue-bead lily
genus
Medeola
species
virginiana
indian cucumber-root
genus
Quercus
species
rubra
red oak
complete
Information Manager
Harvard Forest
324 North Main Street
Petersham
MA
01366
USA
(978) 724-3302
hf-im@lists.fas.harvard.edu
Harvard Forest
324 North Main Street
Petersham
MA
01366
USA
(978) 724-3302
(978) 724-3595
https://harvardforest.fas.harvard.edu
Plot locations: Plow #2 Site: Prospect Hill Tract, Compartment # III, southern end. Pasture #1 Site: Prospect Hill Tract, Compartment # I, southeastern edge. Woodlot #2 Site: Prospect Hill Tract, Compartment # VII, central.
Harvard Forest Long-Term Ecological Research
Harvard Forest
324 North Main Street
Petersham
MA
01366
USA
(978) 724-3302
(978) 724-3595
https://harvardforest.fas.harvard.edu
https://ror.org/059cpzx98
pointOfContact
The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts.
National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210.
hf139-01-light-curve.csv
light response curves
hf139-01-light-curve.csv
8997
dbf8928873acf88a85818b6fab0ee58b
1
\r\n
column
,
https://harvardforest.fas.harvard.edu/data/p13/hf139/hf139-01-light-curve.csv
species
six-letter genus-species abbreviations for the 5 taxa used in this study
six-letter genus-species abbreviations for the 5 taxa used in this study
site
site
P2
Plow 2
S1
Pasture 1
W2
Woodlot 2
co2
controlled ambient CO2 levels at which light response curves were measured
dimensionless
1
whole
NA
missing value
n
sample size
number
1
whole
NA
missing value
statistic
statistic
Mean
mean
std dev
standard deviation
std err
standard error
rday.meas
daytime respiration rate at PPF = 0 actually measured during gas-exchange, in µmol C m-2 s-1. Included here since Rday values extrapolated from the curve fitting are sometimes questionable.
micromolePerMeterSquaredPerSecond
0.001
real
NA
missing value
rday.curvefit
daytime respiration rate at PPF = 0 estimated from the curve fit
micromolePerMeterSquaredPerSecond
0.001
real
NA
missing value
aqe
apparent quantum efficiency, slope of the initial linear portion of the light response curve
dimensionless
0.001
real
NA
missing value
amax
maximum net assimilation rate estimated asymptotically from the fitted curve
micromolePerMeterSquaredPerSecond
0.001
real
NA
missing value
convexity
convexity parameter for the fitted curve
dimensionless
0.001
real
NA
missing value
lcp
light compensation point, estimated as the X-intercept by the fitted curve
micromolePerMeterSquaredPerSecond
0.001
real
NA
missing value
lsat
light saturation point, calculated as the PPF value that corresponds to the intersection between
the quantum yield slope and estimated Amax
micromolePerMeterSquaredPerSecond
0.001
real
NA
missing value
135
historical
plot
community
short-term measurement
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf133
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf134
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf135
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf136
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf137
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf138
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf140
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf141
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf142
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf143
https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf144