Abstract.
Plant
water
source
tracing
studies
often
rely
on
differences
in
stable
isotope
composition
of
different
sources.
However,
an
increasing
number
has
indicated
a
discrepancy
between
the
isotopic
signature
plant
xylem
and
sources
assumed
to
be
used
by
plants.
Based
meta-analysis
we
have
reconfirmed
this
groundwater
suggest
back-flow
leaf
(BFLW),
defined
as
combination
(i)
Péclet
effect,
(ii)
foliar
uptake
(FWU)
(iii)
hydraulic
redistribution
water,
possible
explanation
for
these
observations.
Using
average
2.21
‰
18O
enrichment
compared
our
meta-analysis,
modelled
potential
BFLW
result
observed
discrepancy.
With
low
flow
velocity
0.052
m.h−1
effective
path
length
2
m,
effect
alone
was
able
account
offset
groundwater.
When
including
realistic
fraction
5–10
%
originating
from
FWU
tissue
dehydration,
60–100
can
explained.
By
combining
with
some
more
extreme
offsets
elucidated.
These
large
effects
are
probable
during
dry
conditions
when
drought
stress
lowers
transpiration
rates,
leading
larger
greater
contribution
FWU.
Hydrological Processes,
Journal Year:
2023,
Volume and Issue:
37(1)
Published: Jan. 1, 2023
Abstract
Understanding
the
relative
importance
of
different
water
sources
that
replenish
soil
storage
is
necessary
to
assess
vulnerability
sub‐arctic
areas
changes
in
climate
and
altered
rain
snow
conditions,
reflected
timing
magnitude
infiltration.
We
examine
spatiotemporal
variability
seasonal
origin
at
soil‐vegetation
interface
Pallas
catchment,
located
northern
Finland.
The
field
study
was
conducted
from
May
2019
June
2020
over
two
snowmelt
seasons
one
summer
growing
season.
sampled
cores
up
a
1‐m
depth
stem
dominant
tree
species
four
sites
forests
forested
peatlands
for
stable
isotopes.
Seasonal
rainfall
variation
late
events
were
well
identifiable
well‐drained
soils
areas,
while
this
input
signal
heavily
attenuated
wetter,
peatland
areas.
Spatiotemporal
forest
similar,
whereas
controlled
by
extent
hydrologic
connectivity
adjoining
pools.
A
mixture
both
winter
precipitation
present
during
entire
period,
mineral
showed
an
ephemeral
response
got
nearly
fully
flushed
twice
hydrological
year.
Meltwater
after
early
spring
but
became
displaced
isotopically
enriched
summer.
evolution
pools
not
dynamics
offset
between
isotopic
signals
less
pronounced
peatlands.
This
data
set
uncovered
high
depth‐resolution,
quantifying
replenishing
sustaining
conditions.
Hydrology and earth system sciences,
Journal Year:
2023,
Volume and Issue:
27(1), P. 123 - 137
Published: Jan. 4, 2023
Abstract.
Stable
water
isotopes
have
been
used
extensively
to
study
the
use
strategy
of
plants
in
various
ecosystems.
In
deep
vadose
zone
(DVZ)
regions,
rooting
depth
trees
can
reach
several
meters
tens
meters.
However,
existence
roots
soils
does
not
necessarily
mean
occurrence
root
uptake,
which
usually
occurs
at
a
particular
time
during
growing
season.
Therefore,
quantifying
contribution
deep-layer
soil
(DLSW)
DVZ
regions
using
natural
abundance
stable
may
be
accurate
because
this
method
assumes
that
always
extract
shallow-
and
water.
We
propose
multi-step
for
addressing
issue.
First,
isotopic
labeling
layers
identifies
whether
absorb
DLSW
determines
layer
depths
from
derive
their
source.
Next,
we
calculate
sources
based
on
determined
above
quantify
trees.
also
compared
results
with
method.
The
11-
17-year-old
apple
were
taken
as
examples
analyses
China's
Loess
Plateau.
Isotopic
showed
uptake
11-year-old
reached
300
cm
blossom
young
fruit
(BYF)
stage
only
100
swelling
(FSW)
stage,
whereas
consumed
0–320
layer.
Overall,
absorbed
most
(>140
cm)
BYF
more
these
than
throughout
addition,
overestimated
DLSW,
especially
320–500
Our
findings
highlight
determining
helps
regions.
Ecohydrology,
Journal Year:
2024,
Volume and Issue:
17(2)
Published: Jan. 17, 2024
Abstract
In
ecohydrology,
water
isotopologues
are
used
to
assess
potential
sources
of
root
uptake
by
comparing
xylem
signatures
with
source
signatures.
Such
comparisons
affected
the
variability
and
uncertainty
isotope
plant
sources.
The
tree‐scale
stand‐scale
variabilities
in
stem
often
unknown
but
important
for
sampling
design
estimation
assessing
tree
uptake.
Here,
we
quantified
beech,
oak
spruce
trees
a
mature
forest
on
Swiss
plateau.
For
water,
sub‐daily
replicates
different
cardinal
directions
showed
no
systematic
differences,
found
differences
height.
observed
at
heights
along
suggests
that
residence
times
within
need
be
considered,
their
effects
compartments
(stem,
branches,
leaves).
Further,
concerning
hydrogen
signatures,
height‐
species‐specific
offsets
(SW‐excess
δ
2
H).
Stem
water's
was
similar
magnitude
its
smaller
than
branch
bulk
soil
around
each
tree.
Xylem
from
cores
close
ground,
therefore,
can
give
more
precise
estimate
isotopic
signal
most
recent
facilitate
accurate
attribution.
Hydrological Processes,
Journal Year:
2024,
Volume and Issue:
38(2)
Published: Feb. 1, 2024
Abstract
Measurements
of
oxygen
and
hydrogen
isotopes
in
plant
xylem
water
(
2
H,
18
O)
have
helped
to
redefine
conceptual
numerical
models
the
hydrological
cycle
understand
how
plants
compete
for
subsurface
water.
Recent
experiments
shown
that
Cryogenic
Vacuum
Extraction
(CVE)
can
result
a
δ
H
bias.
We
tested
if
CVE
H‐biases
varied
significantly
across
seven
foundational
northeastern
US
forest
trees
with
series
tree
core
rehydration
experiments.
Our
analysis
demonstrated
were
well
predicted
by
sample
gravimetric
content
species
identity.
show
species‐level
H‐bias
corrections
substantially
different
understandings
uptake
transpiration
versus
uncorrected
data
or
generic
bias
corrections.
This
research
demonstrates
an
urgent
need
critical
evaluation
extraction.
In
absence
stronger
understanding
H‐biases,
we
recommend
observations
should
not
be
used
studies.
Hydrological Processes,
Journal Year:
2025,
Volume and Issue:
39(3)
Published: Feb. 26, 2025
ABSTRACT
Studies
have
shown
that
water
can
reside
inside
trees
for
up
to
several
months,
but
how
the
duration
of
long‐term
stored
relates
species‐specific
management
strategies
is
not
known.
We
studied
residence
time,
tracer
velocity,
and
internal
mixing
in
two
tree
species
with
differing
by
injecting
deuterated
into
Douglas
fir
(
Pseudotsuga
menziesii
)
trembling
aspen
Populus
tremuloides
then
monitoring
concentration
daily
leaves
weeks
postinjection.
In
a
companion
study,
we
injected
collected
at
subdaily
timescales
explore
patterns
arrival
canopy
leaves.
For
first
experiment,
hypothesised
would
remain
both
days
longer
time
more
isohydric
trees.
explored
if
arrive
sharp
peak,
or
be
spread
out
over
time.
The
resided
7–11
species.
Interestingly,
reached
sooner
yet
remained
compared
fir,
which
exhibited
pulses
breakthrough
canopies.
Surprisingly,
aspens
occurred
distinct
pulses,
separated
1–2
days.
Combined,
results
from
experiments
suggest
may
flow
simple
‘in‐up‐and‐out’
(i.e.,
piston
flow)
ways
complex
reservoirs
paths
occur
some
Hydrological Processes,
Journal Year:
2025,
Volume and Issue:
39(4)
Published: April 1, 2025
ABSTRACT
Sampling
of
stable
isotopes
in
plant
xylem
water
(δ
2
H,
δ
18
O)
has
become
a
ubiquitous
technique
to
study
spatiotemporal
variations
the
taken
up
by
roots;
however,
open
questions
remain
concerning
most
appropriate
time
day
sample
trees
obtain
representative
isotopic
values
XYLEM
).
We
sampled
oak
and
maple
prior
solar
midday
(i.e.,
recommended
sampling
window)
then
again
after
outside
across
4
months.
The
paired
root
mean
squared
difference
between
AM
PM
O
ranged
from
1.00‰
1.16‰
for
maples
0.23‰
2.55‰
oaks
all
dates.
Xylem
seasonal
origin
index
(SOI)
derived
samples
were
significantly
different,
though
both
SOI
estimates
supported
conclusion
that
reflected
summer
precipitation
on
conclude
is
significant
consideration
design
campaigns;
our
findings
also
support
flexibility
collection
field
sites
where
during
optimal
challenging.
