10.5061/DRYAD.547D7WM7H
Bialic-Murphy, Lalasia
0000-0001-6046-8316
University of Tennessee at Knoxville
Smith, Nick
Texas Tech University
Voothuluru, Priya
University of Tennessee at Knoxville
McElderry, Robert
University of Tennessee at Knoxville
Roche, Morgan
University of Tennessee at Knoxville
Cassidy, Steven
University of Florida, Gainesville
Kivlin, Stephanie
University of Tennessee at Knoxville
Kaliz, Susan
University of Tennessee at Knoxville
Data from: Invasion-induced root-fungal disruptions alter plant water and
nitrogen economies
Dryad
dataset
2021
National Science Foundation Grants, Long-term Research in Environmental
Biology (LTREB) *
DEB-0108208 and DEB-1457531
2022-04-09T00:00:00Z
2022-04-09T00:00:00Z
en
180728 bytes
4
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Despite widespread evidence that biological invasion influences both the
biotic and abiotic soil environments, the extent to which these two
pathways underpin the effects of invasion on plant traits and performance
is unknown. Leveraging a long-term (14-yr) field experiment, we show that
an allelochemical-producing invader affects plants through biotic
mechanisms, altering the soil fungal community composition, with no
apparent shifts in soil nutrient availability. Changes in belowground
fungal communities resulted in high costs of nutrient uptake for native
perennials and a shift in plant traits linked to their water and nutrient
use efficiencies. Some plants in the invaded community compensate for the
disruption of nutritional symbionts and reduced nutrient provisioning
by sanctioning more nitrogen to photosynthesis and expending more water,
which demonstrates a trade-off in trait investment. For the first time, we
show that the disruption of belowground nutritional symbionts can drive
plants toward alternative regions of their trait space in order to
maintain water and nutrient economics.
Our study site is in Fox Chapel, PA (40.520237, -79.900932) in the
Trillium Trail Nature Reserve, on steep slopes (25- 75%) with
Gilpin-Upshur-Atkins soils of shale, sandstone, and red clay shale bedrock
(USDA 2015). The mean annual precipitation is 36-46 inches and the mean
annual air temperature of 41° to 62° F (USDA 2015). The experimental
design includes five 14 x 14 m plots that were surrounded by 2.5 m tall
wire fencing (erected in 2002) to exclude deer. Beginning in 2006, we
weeded Alliaria by hand from the left side of each plot and carried the
weeded material offsite. The right side of each plot was left at ambient
Alliaria field densities, which averaged 15.2% cover (Roche et al. 2020).
This experiment is a split plot design with two treatments per plot,
referred to here after as the weeded and ambient treatments. To minimize
allelochemical leaching from the ambient treatment to the weeded treatment
within each plot, the Alliaria treatments were positioned parallel to the
slope. We also installed a 0.5 m buffer between the ambient and weeded
treatments within each plot to prevent native plant roots in the weeded
treatment from being exposed to Alliaria roots and allelochemicals. In the
spring of subsequent years, seedlings that emerged from the seed bank were
hand pulled from the weeded treatment. To prevent seed dispersal and
re-infestation of Alliaria, we installed temporary aboveground mesh
barriers between the weeded and ambient sides of the plots prior to
Alliaria seed maturation that were removed post seed dispersal each year.
Hand pulling and annual seedling removal was an effective method of
invasion suppression, with a 0.08% mean abundance of Alliaria in the
weeded plots (Roche et al. 2020). ##### Leaf-level morphological and
physiological traits #####
To characterize the effect of the Alliaria treatments on morphological
and physiological traits associated with water and nutrient use efficiency
for the focal native understory species, we quantified the instantaneous
physiology of additional reproductive and non-reproductive plants in 2018
whose roots were not sampled. We measured the net photosynthetic rate
(Asat), and stomatal conductance (gs) using a Li-COR LI-6400XTR portable
photosynthesis system, equipped with a CO2 control module, 2 x 3 cm leaf
cuvette and a red-blue light-emitting diode (LED) light source (Li-Cor,
Lincoln, NE, USA). Measurements were taken at a saturating light level of
800 μmol m-2s-1, ambient temperature and humidity, and a reference chamber
CO2 concentration of 400 μmol mol-1, following Heberling et al. (2017). A
saturating light level of 800 μmol m-2s-1 was based on detailed light
response curves for these understory species at our field site (Heberling
et al. 2017; Heberling et al. 2019a). To minimize within-plant variability
for Maianthemum, we restricted our sampling to either the 2nd or 3rd leaf
from the terminal end of the stem following Cornelissen et al. (2003) and
only used leaves without signs of senescence or damage (e.g. insect
herbivory). Specific leaf area (SLA) and leaf carbon and nitrogen
concentration were measured on a subset of individuals (11-18 individuals
x 2 Alliaria treatments x 3 species x 2 life stages). To measure SLA, we
collected two to three 5.32 cm2 leaf tissue samples from each individual
and calculated the mean leaf surface area per g dry mass (cm2 g-1). Leaf
carbon and nitrogen concentration were measured on dry leaf samples using
an elemental analyzer (Costech Inc., Valencia, CA). We used these
physiological measurements to calculate water use efficiency (WUE = Asat
/gs; µmol CO2 mmol H2O-1) and photosynthetic nitrogen use efficiency (PNUE
= Asat / Narea; μmol CO2 gN-1 s-1) (Field et al. 1983; Wright et al.
2003). A mean chlorophyll index of three leaflets per plant was measured
using a SPAD 502 Chlorophyll Meter (spectrum Technologies, Inc, Aurora,
IL, USA). To standardize our sampling, we chose to take SPAD readings from
the darkest green section of each leaflet. The Chl-sampled individuals are
a subset of plants for which the other functional traits were measured and
the same plants for which whole-plant performance were measured. The
associated CSV file for the plant physology and performance results is
named plant_traits_performance_EcoLetters. Before doing the physiology
analyses, we subset the raw data to exclude Ci values <60. The
treatment column in the CSV file refers to the two garlic mustard
treatmetns (i.e., 'Ambient' and 'Weeded') The Sp
column in the 'plant_traits_performance_EcoLetters' CSV refers
to the three focal native species, Mai = Maianthmum, Tri = Trillium, and
Ari = Arisaema. The units for each measurement is reported in the main
manuscript. Leaf area in the CSV is cm^2. To convert leaf area from cm^2
to m^2 (as it is reported in the manuscript), multiply leaf area x 10000.
##### fungal community composition #####
The associated CSV file
for the fungal community composition results is named
Soil_AM_Fungal_communites_EcoLetters. Refer to the methods section of the
published paper for details on how the soil samples were taken. The
associated soil fungal DNA sequences have been deposited with links to
BioProject accession number PRJNA691885 in the DDBJ BioProject database.
##### root conolozation rates #####
The associated CSV
file for the root colonization results is named
AM_fungal_root_colonization_EcoLetters. Refer to the methods section of
the published paper for details on how the root sampls were processed.
The treatment column in associated files refers to the two garlic mustard
treatmetns (i.e., 'Ambient' and 'Weeded') The sp
column in the CSV refers to the three focal native species, Mai=
Maianthmum, Tri =Trillium, and Ari = Arisaema. FoV column is short for
field of view. For beta regressions, percent colonization rates were
calcuated as Arbuscules / FoV and Aseptate/FoV. Percent values = 0 were
changed to 0.00001 for analysis purposes. ##### aboitic soil proporties
#####
The associated CSV file for the abiotic soil
proporties results is named soil_properties_EcoLetters.