European Journal of Forest Research,
Год журнала:
2023,
Номер
142(4), С. 797 - 809
Опубликована: Март 29, 2023
Abstract
Catchment-scale
transpiration
is
commonly
determined
by
the
use
of
sap-flow
sensors,
and
its
quantification,
which
critical
for
water
forest
management,
relies
crucially
on
total
catchment’s
sapwood
area
(
A
s
).
Species-specific
allometric
relationships
between
trees
diameter
at
breast
height
(DBH)
are
widely
used
determining
stand
or
catchment
.
However,
substantial
differences
studies
challenge
robustness
these
sites
displaying
various
topographical
environmental
characteristics.
Our
objectives
this
study
to
compare
parameters
species
Quercus
genus
from
different
across
globe
test
role
factors
-DBH
relationship
in
petraea
Using
145
sampled
within
a
0.455
km
2
catchment,
we
found
that
topography
(slope,
flow
accumulation,
aspect,
curvature,
topographic
wetness
index)
does
not
modulate
Q.
,
our
catchment.
We
compared
curve
with
those
16
oak
only
species-specific,
but
depends
site’s
conditions.
The
species-specific
other
may
lead
more
than
100%
difference
calculation
therefore
transpiration.
In
light
results,
recommend
building
site-
transpiration,
using
minimum
nine,
randomly
trees,
methods
azimuthal
directions
depth.
Water Resources Research,
Год журнала:
2025,
Номер
61(2)
Опубликована: Фев. 1, 2025
Abstract
The
spatial
variation
of
soil
water
isotopes
(SWI)—representing
the
baseline
for
investigating
root
uptake
(RWU)
depths
with
stable
isotope
techniques—has
rarely
been
investigated.
Here,
we
use
SWI
depth
profile
sampling
in
combination
unmanned
aerial
vehicle
(UAV)
based
land
surface
temperature
estimates
and
vegetation
indices
(VI)
order
to
improving
process
understanding
relationships
between
variability
content
patterns
canopy
status,
represented
form
VI.
We
carried
out
a
10
profiles
tropical
dry
forest.
UAV
data
were
collected
analyzed
obtain
detailed
characterization
status.
then
performed
statistical
analysis
VI
temperatures
values
at
different
resolutions
(3
cm–5
m).
Best
used
generating
isoscapes
entire
study
area.
Results
suggest
that
are
strongly
mediated
by
parameters
(VI).
Various
correlate
across
all
depths.
depend
on
(
R
2
0.66
δ
18
O
0.64
H).
Strongest
overall
correlations
found
resolution
0.5
m.
speculate
this
might
be
ideal
spatially
characterizing
investigate
RWU
forest
environments.
Supporting
analyses
UAV‐based
approaches
future
avenue
representation
credibility
such
studies.
Abstract
In
most
tree
species,
xylem
consists
of
two
different
functional
parts:
sapwood
and
heartwood.
While
sapwood,
as
the
flowpath
for
sap,
has
received
more
attention
in
isotope
studies
assessing
water
sources
accessed
by
trees
(e.g.
soil
from
depths,
groundwater,
stream
or
a
mixture
these),
much
remains
unknown
about
heartwood
possible
exchange
between
parts.
We
investigated
four
species
(
Fagus
sylvatica
,
Quercus
petraea
Pseudotsuga
menziesii
Picea
abies
)
characterised
anatomy
timing
physiological
activity
to
evaluate
degree
differentiation
isotopic
composition
on
biweekly
time
scale.
found
that
all
displayed
concurrent
variation
their
throughout
growing
season
day‐night
scale
suggesting
are
not
isolated
compartments.
parts
display
consistent
difference
conifers,
they
similar
values
broadleaved
higher
exchange.
Furthermore,
we
have
also
observed
progressive
change
with
sampling
depth
rather
than
xylem.
Our
study
highlights
value
accounting
radial
variation,
which
might
potentially
lead
uncertainties
concerning
origin
extracted
uptake
studies.
Hydrology and earth system sciences,
Год журнала:
2024,
Номер
28(12), С. 2683 - 2703
Опубликована: Июнь 26, 2024
Abstract.
Understanding
the
interrelation
between
topography
and
vegetation
across
different
environments
is
important
to
assess
how
hydrological
climatic
conditions
affect
tree
physiological
activity.
This
becomes
especially
given
expected
reduction
in
water
availability
increase
demand
driven
by
climate
change.
These
extremes
could
enhance
thermal
hydrologic
gradients
along
slopes.
Here,
we
aimed
test
if
response
of
beech
trees
(Fagus
sylvatica
L.)
environmental
variables
two
topographic
sequences.
For
this
purpose,
set
up
a
comparative
study
on
gentle
hillslope
Weierbach
catchment
Luxembourg
(oceanic
climate)
steep
Lecciona
Italy
(Mediterranean
climate).
We
combined
sap
velocity
measurements
with
isotopic
soil,
precipitation,
stream
water,
groundwater,
xylem
over
2019
2020
for
Luxembourgish
site
2021
Italian
site.
found
that,
catchment,
trees'
responses
(i.e.
vapour
pressure
deficit
relative
extractable
soil)
were
similar
among
positions
monitored
years,
resulting
from
homogeneous
growing
sequence.
also
did
not
find
any
statistical
difference
composition
positions,
suggesting
that
relied
sources
landscape.
In
observed
lower
velocities
shorter
season
upper
portions
hillslope,
likely
related
redistribution
soil
moisture
catena.
Xylem
was
significantly
lighter
at
footslope
location
throughout
than
upslope
locations,
location-specific
use.
results
emphasize
differing
hydrometeorological
processes
occurring
scale
can
lead
contrasting
responses.
Journal of Hydrology,
Год журнала:
2024,
Номер
633, С. 131020 - 131020
Опубликована: Март 6, 2024
Urban
trees
are
an
integral
part
of
sustainable
cities.
They
regulate
the
local
microclimate
and
enhance
urban
water
cycle.
Increasing
periods
drought
can
impair
by
affecting
their
uptake,
transpiration
growth
patterns.
In
this
study,
we
used
a
multi-proxy
approach
to
assess
how
non-irrigated
react
changing
supply
throughout
full
vegetative
period
2022
including
major
in
Berlin,
Germany.
Our
work
focused
on
individual
mature
green
space;
examining
daily
mean
in-situ
isotopes
plant
xylem
(δxyl)
while
also
monitoring
vegetation
dynamics
via
sap
flow,
stem
increments,
LAI,
as
well
groundwater,
soil
moisture
at
different
depths.
The
was
characterised
spring
with
average
precipitation
inputs,
followed
extremely
dry
from
July
until
mid-August,
then
gradual
rewetting
end
August
October.
At
beginning
growing
period,
changes
ecohydrological
investigated
maple
birch
were
high
increases
size
but
decreasing
moisture.
spring,
δxyl
signatures
both
trees,
effect
more
marked
hinting
dependence
species
specific-storage
effects
distinct
start
transpiration.
During
summer,
stress
apparent
fluxes
monitored
reduction
growth,
midday
potential
Yet
flow
rates
relatively
stable
tree
maintained.
We
noted
midsummer
enrichment
species.
Most
importantly,
measured
isotopically
range
deep
waters
groundwater
implying
that
deeper
sources
sustaining
trees'
during
drought.
detected
fractionation
δxyl,
which
is
possibly
induced
heterogenous
uptake
strategies
biochemical
processes
xylem,
CH4
transport.
results
suggest
rely
internal
storage
conclude
shrubs
shallow
root
development
would
be
vulnerable
summers
particular
threat
future
accelerated
summer
droughts
combined
insufficient
autumn
causing
layers
out.
Hydrology and earth system sciences,
Год журнала:
2025,
Номер
29(3), С. 701 - 718
Опубликована: Фев. 5, 2025
Abstract.
A
declining
spring
snowpack
is
expected
to
have
widespread
effects
on
montane
and
subalpine
forests
in
western
North
America
across
the
globe.
The
way
that
tree
water
demands
respond
this
change
will
important
impacts
forest
health
downstream
subsidies.
Here,
we
present
data
from
a
network
of
sap
velocity
sensors
xylem
isotope
measurements
three
common
species
(Picea
engelmannii,
Abies
lasiocarpa
Populus
tremuloides)
hillslope
transect
watershed
Upper
Colorado
River
basin.
We
use
these
compare
tree-
stand-level
responses
historically
high
but
low
summer
rainfall
2019
against
amounts
2021
2022.
From
data,
found
only
40
%
trees
showed
an
increase
cumulative
transpiration
response
large
year
(2019),
illustrating
absence
interannual
variability.
increased
during
with
were
all
dense
canopy
stands
–
irrespective
while
open-canopy
more
reliant
rains
and,
thus,
active
years
modest
snow
higher
rain
amounts.
Using
along
supporting
soil
moisture
depth,
propose
mechanisms
lead
stand
density
modulating
tree-level
changing
seasonality
precipitation:
Topographically
mediated
convergence
zones
consistent
access
recharge
snowmelt
which
supports
denser
are
sensitive
snow.
Interception
reduces
throughfall
surface
soils,
limiting
sensitivity
changes
rain.
Shading
allows
persist
deeper
into
growing
season,
providing
local
reliance
fore-summer
(early-summer)
drought
period.
Combining
generated
natural
gradients
density,
like
experiment,
results
controlled
forest-thinning
experiments
can
be
used
develop
better
understanding
forested
ecosystems
futures
reduced
snowpack.
