Abstract.
Large,
high
severity
wildfires
in
many
regions
across
the
globe
have
increased
concerns
about
their
impacts
on
carbon
cycling
watersheds.
Altered
sources
of
and
changes
catchment
hydrology
after
wildfire
can
lead
to
shifts
dissolved
organic
concentrations
(DOC)
streams,
which
negative
aquatic
ecosystem
health
downstream
drinking
water
treatment.
Despite
its
importance,
post-fire
DOC
responses
remain
relatively
unconstrained
literature,
we
lack
critical
knowledge
how
burn
severity,
landscape
elements,
climate
interact
affect
concentrations.
To
improve
our
understanding
impact
concentrations,
measured
at
~100
sites
a
stream
network
extending
upstream,
within,
large,
Oregon,
USA.
We
collected
samples
study
sub-basin
during
four
distinct
seasonal
wetness
conditions.
used
spatial
resolution
data
develop
(SSN)
models
predict
controls
Spatially,
found
no
obvious
signal—instead
observed
pattern
increasing
from
elevation
headwaters
outlet,
while
mainstem
maintained
consistently
low
This
suggests
that
effects
large
may
be
“averaged”
out
higher
orders
larger
scales.
With
measurements
grouped
by
group,
significant
decrease
variability
moderate
sub-catchments.
However,
SSN
were
able
decreases
with
increases
network.
Decreases
also
highly
variable
conditions,
greatest
(-1.40
-1.64
mg
L-1)
group
wetting
season.
Additionally,
indicated
all
seasons,
baseflow
index
was
more
influential
predicting
than
indicating
groundwater
discharge
obscure
Overall,
results
suggest
characteristics
regulate
response
wildfire.
Moreover,
indicate
timing
sampling
influence
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(16), С. 7032 - 7044
Опубликована: Апрель 11, 2024
High-elevation
mountains
have
experienced
disproportionately
rapid
warming,
yet
the
effect
of
warming
on
lateral
export
terrestrial
carbon
to
rivers
remains
poorly
explored
and
understood
in
these
regions.
Here,
we
present
a
long-term
data
set
dissolved
inorganic
(DIC)
more
detailed,
short-term
DIC,
δ13CDIC,
organic
from
two
major
Qinghai–Tibetan
Plateau,
Jinsha
River
(JSR)
Yalong
(YLR).
In
higher-elevation
JSR
with
∼51%
continuous
permafrost
coverage,
(>3
°C)
increasing
precipitation
coincided
substantially
increased
DIC
concentrations
by
35%
fluxes
110%.
lower-elevation
YLR
∼14%
permafrost,
such
increases
did
not
occur
despite
comparable
extent
warming.
Riverine
particulate
discharge
(mobilization)
both
rivers.
JSR,
transitioned
dilution
(decreasing
concentration
discharge)
earlier,
colder
years
chemostasis
(relatively
constant
concentration)
later,
warmer
years.
This
changing
pattern,
together
lighter
δ13CDIC
under
high
discharge,
suggests
that
thawing
boosts
production
via
enhancing
soil
respiration
weathering.
These
findings
reveal
predominant
role
altering
escalating
modifying
patterns.
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(10), С. 4772 - 4780
Опубликована: Фев. 29, 2024
Investigating
dissolved
organic
carbon
(DOC)
dynamics
and
drivers
in
rivers
enhances
the
understanding
of
carbon–environment
linkages
support
sustainability.
Previous
studies
did
not
fully
consider
dynamic
nature
key
that
influence
long-term
changing
trends
DOC
concentration
over
time
(the
controlling
factors
their
roles
trend
can
undergo
alterations
time).
We
analyzed
42
years
(1979–2018)
hydrometeorology,
sulfate
SO4,
data
from
a
5.42
km2
watershed
central-southern
Ontario,
Canada.
Our
findings
reveal
significant
(p
≤
0.01)
overall
increase
concentrations,
mainly
due
to
coevolution
SO4
streamflow
trends,
especially
extreme
flows.
Over
42-year
period,
(especially
high
or
low
flows)
have
significantly
<
0.05)
intensified
on
increasing
by
an
average
30%.
Conversely,
impact
has
weakened,
experiencing
decrease
32.6%.
The
upward
annual
is
attributed
number
maximum
flow
days
within
year,
while
decreasing
minimum
contrasting
effect.
In
other
words,
changes
counteracting
effect
trends.
These
results
underscore
importance
considering
effects
altered
processes
cycle
under
evolving
environmental
conditions.
Water Resources Research,
Год журнала:
2024,
Номер
60(6)
Опубликована: Июнь 1, 2024
Abstract
Dissolved
organic
and
inorganic
carbon
(DOC
DIC)
influence
water
quality,
ecosystem
health,
cycling.
species
are
produced
by
biogeochemical
reactions
laterally
exported
to
streams
via
distinct
shallow
deep
subsurface
flow
paths.
These
processes
arduous
measure
challenge
the
quantification
of
global
cycles.
Here
we
ask:
when,
where,
how
much
is
dissolved
in
from
streams?
We
used
a
catchment‐scale
reactive
transport
model,
BioRT‐HBV,
with
hydrometeorology
stream
data
illuminate
“invisible”
at
Sleepers
River,
carbonate‐based
catchment
Vermont,
United
States.
Results
depict
conceptual
model
where
DOC
mostly
soils
(3.7
±
0.6
g/m
2
/yr)
summer
peak
root
microbial
respiration.
flushed
(1.0
0.2
especially
during
snowmelt
storms.
A
large
fraction
(2.5
percolates
deeper
subsurface,
fueling
respiration
generate
DIC.
DIC
predominantly
(7.1
0.4
/yr,
compared
1.3
0.3
/yr
soils).
Deep
reduces
increases
concentrations
depth,
leading
commonly
observed
flushing
(increasing
discharge)
dilution
patterns
(decreasing
discharge).
Surprisingly,
more
than
weathering
this
catchment.
findings
underscore
importance
vertical
connectivity
between
highlighting
overlooked
role
processing
export.
Water Resources Research,
Год журнала:
2025,
Номер
61(3)
Опубликована: Март 1, 2025
Abstract
Hydrologic
regimes
are
affecting
terrestrial
carbon
transformation,
chemical
weathering
and
lateral
transport.
However,
its
impacts
on
dissolved
export
patterns
remains
elusive.
In
this
study,
we
collected
a
2‐year
high‐frequency
inorganic
(DIC)
organic
(DOC)
dataset,
namely
wet
year
(Rainfall
=
1,158
mm)
dry
603
mm).
The
results
showed
that
drought
led
to
significant
decrease
in
concentration
discharge
during
the
monitoring
period.
During
non‐storm
periods,
DIC
DOC
shifted
from
dilution
chemostatic
enrichment
years,
respectively.
were
reversed
storm
periods.
dominated
by
chemostatic,
respectively,
while
both
year.
Structural
equation
models
revealed
aridity
index
temperature
may
affect
patterns.
We
further
classified
events
into
three
major
types
conceptualized
catchment‐scale
transport
mechanisms
for
carbon.
Dry‐AMCs
result
behavior,
whereas
Wet‐AMCs
behavior
due
increased
hydrological
connectivity.
third
type
corresponds
extreme
events,
where
larger
overland
flow
often
but
behavior.
These
findings
reveal
predominant
role
of
altering
decreasing
concentrations
fluxes
modifying
Water Resources Research,
Год журнала:
2024,
Номер
60(7)
Опубликована: Июль 1, 2024
Abstract
Terrestrial
production
and
export
of
dissolved
organic
inorganic
carbon
(DOC
DIC)
to
streams
depends
on
water
flow
biogeochemical
processes
in
beneath
soils.
Yet,
understanding
these
a
rapidly
changing
climate
is
limited.
Using
the
watershed‐scale
reactive‐transport
model
BioRT‐HBV
stream
data
from
snow‐dominated
catchment
Rockies,
we
show
deeper
groundwater
averaged
about
20%
annual
discharge,
rising
∼35%
drier
years.
DOC
DIC
peaked
during
snowmelt
wet
years,
driven
more
by
hydrology
than
temperature.
was
primarily
produced
shallow
soils
(1.94
±
1.45
gC/m
2
/year),
stored
via
sorption,
flushed
out
snowmelt.
Some
recharged
further
consumed
subsurface
respiration
(−0.27
0.02
therefore
reducing
concentrations
at
low
discharge.
Consequently,
exported
zone
(1.62
0.96
/year,
compared
0.12
/year
zone).
both
zones
but
higher
rates
(1.34
1.00
/year)
deep
(0.36
/year).
Deep
elevated
In
other
words,
responsible
for
commonly‐observed
increasing
(flushing)
decreasing
(dilution)
with
~66%
can
drop
∼53%
Numerical
experiments
suggest
lower
warmer,
future,
proportion
processes.
These
results
underscore
often‐overlooked
growing
importance
warming
climate.
Water Resources Research,
Год журнала:
2024,
Номер
61(1)
Опубликована: Дек. 26, 2024
Abstract
The
dissolution
of
sulfide
minerals
in
subsurface
porous
media
has
important
environmental
implications.
We
investigate
the
oxidative
pyrite
under
evaporative
conditions
and
advance
a
mechanistic
understanding
interactions
between
multiple
physical
processes
mineral/surface
reactions.
performed
set
experiments
which
initially
water
saturated
anoxic
soil
columns,
containing
top
layer
pyrite,
are
exposed
to
atmosphere
no
evaporation
(single‐phase)
natural
(two‐phase)
conditions.
was
monitored
by
non‐invasive
high‐resolution
measurements
oxygen
pH.
Additionally,
we
developed
applied
multiphase
multicomponent
reactive
transport
model
quantitatively
describe
experimental
outcomes
elucidate
interplay
physico‐chemical
mechanisms
controlling
extent
dissolution.
results
confirm
that
single‐phase
constrained
slow
diffusive
liquid
phase.
In
contrast,
during
evaporation,
evolution
fluid
phases
interphase
mass
transfer
imposed
distinct
constraints
on
dynamics
oxidation.
Initially,
invasion
gaseous
phase
led
fast
delivery
high
concentrations
zone
thus
markedly
increased
oxidation
acidity/sulfate
production.
However,
such
enhanced
release
reaction
products
progressively
limited
over
time
as
drying
prevailed
inhibited
transient
displacement
also
found
control
distribution
aqueous
species
formation
secondary
creating
spatio‐temporally
variable
redox
Biogeosciences,
Год журнала:
2024,
Номер
21(13), С. 3093 - 3120
Опубликована: Июль 2, 2024
Abstract.
Large,
high-severity
wildfires
in
many
regions
across
the
globe
have
increased
concerns
about
their
impacts
on
carbon
cycling
watersheds.
Altered
sources
of
and
changes
catchment
hydrology
after
wildfire
can
lead
to
shifts
dissolved
organic
(DOC)
concentrations
streams,
which
negative
aquatic
ecosystem
health
downstream
drinking-water
treatment.
Despite
its
importance,
post-fire
DOC
responses
remain
relatively
unconstrained
literature,
we
lack
critical
knowledge
how
burn
severity,
landscape
elements,
climate
interact
affect
concentrations.
To
improve
our
understanding
impact
severity
concentrations,
measured
at
129
sites
a
stream
network
extending
upstream,
within,
large,
Oregon,
USA.
We
collected
samples
study
sub-basin
during
four
distinct
seasonal
wetness
conditions.
used
high-spatial-resolution
data
develop
spatial
(SSN)
models
predict
controls
Spatially,
found
no
obvious
signal
–
instead,
observed
pattern
increasing
from
high-elevation
headwaters
outlet,
while
mainstem
maintained
consistently
low
This
suggests
that
effects
large
may
be
“averaged”
out
higher
orders
larger
scales.
When
grouped
by
group,
significant
decrease
variability
moderate
high
sub-catchments.
However,
SSN
were
able
decreases
with
increases
network.
Decreases
also
highly
variable
conditions,
greatest
(−1.40
−1.64
mg
L−1)
occurring
group
wetting
season.
Additionally,
indicated
all
seasons,
baseflow
index
was
more
influential
predicting
than
was,
indicating
groundwater
discharge
obscure
Overall,
results
suggested
characteristics
regulate
response
wildfire.
Moreover,
timing
sampling
influence
