Nitrogen,
Journal Year:
2022,
Volume and Issue:
3(3), P. 458 - 501
Published: Aug. 12, 2022
Permafrost-affected
tundra
soils
are
large
carbon
(C)
and
nitrogen
(N)
reservoirs.
However,
N
is
largely
bound
in
soil
organic
matter
(SOM),
ecosystems
generally
have
low
availability.
Therefore,
microbial
induced
N-cycling
processes
losses
were
considered
negligible.
Recent
studies
show
that
processing
rates,
inorganic
availability,
lateral
from
thawing
permafrost
increase
when
vegetation
cover
disturbed,
resulting
reduced
uptake
or
increased
input
permafrost.
In
this
review,
we
describe
currently
known
hotspots,
particularly
bare
patches
peatland
affected
by
thermokarst,
their
microbiogeochemical
characteristics,
present
evidence
for
previously
unrecorded
hotspots
the
tundra.
We
summarize
current
understanding
of
cycling
promote
release
potent
greenhouse
gas
(GHG)
nitrous
oxide
(N2O)
translocation
terrestrial
into
aquatic
ecosystems.
suggest
certain
characteristics
traits
can
be
used
as
indicators
availability
losses.
Identifying
key
to
assessing
potential
permafrost-affected
under
global
warming,
well
impact
on
emissions
carbon-containing
GHGs.
Global Change Biology,
Journal Year:
2022,
Volume and Issue:
28(24), P. 7410 - 7427
Published: Sept. 23, 2022
Dissolved
organic
matter
(DOM)
plays
a
vital
role
in
biogeochemical
processes
and
determining
the
responses
of
soil
(SOM)
to
global
change.
Although
quantity
DOM
has
been
inventoried
across
diverse
spatio-temporal
scales,
underlying
mechanisms
accounting
for
variability
dynamics
remain
unclear
especially
upland
ecosystems.
Here,
gradient
SOM
storage
12
croplands
northeast
China
was
used
understand
links
between
dynamics,
microbial
metabolism,
abiotic
conditions.
We
assessed
composition,
biodegradability,
key
biodegradable
components
DOM.
In
addition,
mineral-associated
(MAOM)
enzyme
activities,
oxygen
availability,
texture,
iron
(Fe),
Fe-bound
matter,
nutrient
concentrations
were
quantified
clarify
drivers
quality
(composition
biodegradability).
The
proportion
increased
exponentially
with
decreasing
initial
concentration
due
larger
fractions
depolymerized
that
rich
small-molecular
phenols
proteinaceous
components.
Unexpectedly,
composition
decoupled
from
or
MAOM,
but
significantly
related
enzymatic
properties.
These
results
indicate
metabolism
exhibited
dominant
generation.
As
declined,
availability
regulated
enhanced
its
biodegradability
mainly
through
mediating
Fe
oxidation.
oxygen-induced
oxidation
Fe(II)
Fe(III)
removed
complex
compounds
large
molecular
weight.
Moreover,
stimulated
oxidase-catalyzed
depolymerization
aromatic
substances,
promoted
production
protein-like
lower
C/N
acquisition
ratio.
changes
temperature
moisture
will
have
impacts
on
regulating
highlights
importance
integrating
supply
redox
status
improve
model
predictions
carbon
under
climate
Global Change Biology,
Journal Year:
2021,
Volume and Issue:
27(7), P. 1408 - 1430
Published: Jan. 4, 2021
Abstract
Climate
change
is
creating
widespread
ecosystem
disturbance
across
the
permafrost
zone,
including
a
rapid
increase
in
extent
and
severity
of
tundra
wildfire.
The
expansion
this
previously
rare
has
unknown
consequences
for
lateral
nutrient
flux
from
terrestrial
to
aquatic
environments.
Lateral
loss
nutrients
could
reduce
carbon
uptake
slow
recovery
already
nutrient‐limited
ecosystems.
To
investigate
effects
wildfire
on
export,
we
analyzed
water
chemistry
around
10‐year‐old
Anaktuvuk
River
fire
scar
northern
Alaska.
We
collected
samples
21
burned
unburned
watersheds
during
snowmelt,
at
peak
growing
season,
after
plant
senescence
2017
2018.
After
decade
recovery,
aboveground
biomass
had
recovered
watersheds,
but
overall
nitrogen
remained
~20%
lower,
active
layer
~10%
deeper.
Despite
lower
organic
matter
stocks,
dissolved
were
substantially
elevated
with
higher
flow‐weighted
concentrations
(25%
higher),
(59%
phosphorus
(65%
sulfur
(47%
higher).
Geochemical
proxies
indicated
greater
interaction
mineral
soils
surface
subsidence,
optical
analysis
isotopes
suggested
that
recent
growth,
not
soil,
was
main
source
watersheds.
Burned
similar
δ
15
N‐NO
3
−
,
indicating
exported
preburn
origin
(i.e.,
recently
fixed).
2‐
10‐fold
than
rates
background
fixation
atmospheric
deposition
estimated
area.
These
findings
indicate
Arctic
can
destabilize
nitrogen,
phosphorus,
stored
via
leaching.
This
plant‐mediated
exacerbate
limitation
or
serve
as
an
important
release
mechanism
succession.
Nature Communications,
Journal Year:
2022,
Volume and Issue:
13(1)
Published: Oct. 14, 2022
Abstract
Nitrogen
regulates
multiple
aspects
of
the
permafrost
climate
feedback,
including
plant
growth,
organic
matter
decomposition,
and
production
potent
greenhouse
gas
nitrous
oxide.
Despite
its
importance,
current
estimates
nitrogen
are
highly
uncertain.
Here,
we
compiled
a
dataset
>2000
samples
to
quantify
stocks
in
Yedoma
domain,
region
with
organic-rich
that
contains
~25%
all
carbon.
We
estimate
domain
41.2
gigatons
down
~20
metre
for
deepest
unit,
which
increases
previous
entire
zone
by
~46%.
Approximately
90%
this
(37
gigatons)
is
stored
therefore
currently
immobile
frozen.
show
amount,
¾
>3
depth,
but
if
partially
mobilised
thaw,
large
pool
could
have
continental-scale
consequences
soil
aquatic
biogeochemistry
global-scale
feedback.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(17), P. 7380 - 7392
Published: April 19, 2024
Optical
surrogates,
derived
from
absorbance
and
fluorescence
spectra,
are
widely
used
to
infer
dissolved
organic
matter
(DOM)
composition
(molecular
weight,
aromaticity)
genesis
(autochthonous
vs
allochthonous).
Despite
the
broad
adoption
of
optical
several
limitations
exist,
such
as
context-
sample-specific
factors.
These
create
uncertainty
about
how
compositional
interpretations
based
on
surrogates
generalized
across
contexts,
specifically
if
there
is
duplicative
or
contradictory
information
in
those
interpretations.
To
explore
these
limitations,
we
performed
a
meta-analysis
for
DOM
diverse
sources,
both
natural
systems
after
water
treatment
processes
(
Global Biogeochemical Cycles,
Journal Year:
2020,
Volume and Issue:
35(1)
Published: Nov. 18, 2020
Abstract
Permafrost
degradation
is
delivering
bioavailable
dissolved
organic
matter
(DOM)
and
inorganic
nutrients
to
surface
water
networks.
While
these
permafrost
subsidies
represent
a
small
portion
of
total
fluvial
DOM
nutrient
fluxes,
they
could
influence
food
webs
net
ecosystem
carbon
balance
via
priming
or
effects
that
destabilize
background
DOM.
We
investigated
how
addition
biolabile
(acetate)
(nitrogen
phosphorus)
affected
decomposition
with
28‐day
incubations.
incubated
late‐summer
stream
from
23
locations
nested
in
seven
northern
high‐altitude
regions
Asia,
Europe,
North
America.
loss
ranged
3%
52%,
showing
variety
longitudinal
patterns
within
optical
properties
varied
widely,
but
showed
compositional
similarity
based
on
Fourier
transform
ion
cyclotron
resonance
mass
spectrometry
(FT‐ICR
MS)
analysis.
Addition
acetate
decreased
bulk
mineralization
(i.e.,
negative
priming),
more
biodegradable
neutral
positive
stable
Unexpectedly,
triggered
breakdown
colored
(CDOM),
median
decreases
1.6%
the
control
22%
amended
treatment.
Additionally,
uptake
added
was
strongly
limited
by
availability
across
sites.
These
findings
suggest
released
degrading
may
decrease
alter
stoichiometry
light
conditions
receiving
waterbodies.
conclude
are
coupled
aquatic
ecosystems
quantifying
two‐way
interactions
between
environmental
resolve
conflicting
observations
about
drivers
zone
waterways.
Water Resources Research,
Journal Year:
2023,
Volume and Issue:
59(2)
Published: Jan. 30, 2023
Abstract
In
cold
alpine
areas,
the
hydrological
control
on
dissolved
organic
matter
(DOM)
export
in
relation
to
permafrost
distribution
remains
uncertain
a
catchment
scale.
To
address
this,
seasonal
variations
DOM
chemical
features
of
groundwater
and
stream
water
were
examined
from
2013
2019
representative
northeastern
Qinghai–Tibet
Plateau,
which
is
covered
by
both
(at
elevations
higher
than
3,500
m
a.s.l.)
seasonally
frozen
areas.
The
results
show
that
highest
carbon
(DOC)
concentration
occurred
during
thawing
period
(April–May),
while
DOC
flux
thawed
(June–early
October).
area,
freeze–thaw
process
significantly
influenced
flow
paths
DOM.
During
period,
with
shallow
path
through
soil
layer,
recharged
suprapermafrost
was
characterized
high
aromaticity
concentrations.
deepening
mineral
layer
dilution
overland
flow,
resulted
low
concentrations
lower
water.
When
flowed
area
into
porous
aquifers
also
affected
dynamics.
at
outlet,
received
discharge
aquifer,
showed
peak
concentration,
proportion
protein‐like
DOM,
contribution
season
annual
when
compared
flowing
out
area.
Our
work
highlights
role
thick,
aquifer
regulating
export.
suggest
may
exhibit
stronger
positive
feedback
climate
warming
Arctic
Scientific Reports,
Journal Year:
2023,
Volume and Issue:
13(1)
Published: June 9, 2023
Abstract
Subsea
permafrost
carbon
pools
below
the
Arctic
shelf
seas
are
a
major
unknown
in
global
cycle.
We
combine
numerical
model
of
sedimentation
and
evolution
with
simplified
turnover
to
estimate
accumulation
microbial
decomposition
organic
matter
on
pan-Arctic
over
past
four
glacial
cycles.
find
that
is
globally
important
long-term
sink
storing
2822
(1518–4982)
Pg
OC,
double
amount
stored
lowland
permafrost.
Although
currently
thawing,
prior
aging
limit
rates
less
than
48
Tg
OC/yr
(25–85)
constraining
emissions
due
thaw
suggesting
large
pool
largely
insensitive
thaw.
identify
an
urgent
need
reduce
uncertainty
cold
saline
subaquatic
environments.
Large
methane
more
likely
derive
from
older
deeper
sources
thawing
Frontiers in Earth Science,
Journal Year:
2021,
Volume and Issue:
9
Published: March 24, 2021
Climate
warming
is
accelerating
erosion
along
permafrost-dominated
Arctic
coasts.
This
results
in
the
additional
supply
of
organic
matter
(OM)
and
nutrients
into
coastal
zone.
In
this
study
we
investigate
impact
on
marine
microbial
community
composition
growth
rates
Beaufort
Sea.
Dissolved
(DOM)
derived
from
three
representative
glacial
deposit
types
(fluvial,
lacustrine,
moraine)
Yukon
plain,
Canada,
were
used
as
substrate
to
cultivate
bacteria
using
a
chemostat
setup.
Our
show
that
DOM
(inferred
UV-Visible
spectroscopy)
biodegradability
DOC
concentration,
bacterial
production
respiration)
significantly
differ
between
types.
fluvial
moraine
clear
terrestrial
characteristics
with
low
aromaticity
(
S
r
:
0.63
±
0.02
SUVA
254
1.65
0.06
L
mg
C
−1
m
&
0.68
0.01
1.17
,
respectively)
compared
lacustrine
soil
type
0.71
2.15
0.05
).
The
difference
leads
development
different
communities.
Whereas
Alphaproteobacteria
dominate
(67
87%
relative
abundance,
respectively),
Gammaproteobacteria
most
abundant
class
for
(88%
abundance).
Bacterial
efficiency
(BGE)
66%
type,
while
13
28%
types,
respectively.
communities
therefore
strongly
their
net
effect
utilization
depending
eroded
landscape
type.
high
BGE
value
moraine-derived
probably
caused
by
larger
proportion
labile
colorless
DOM.
These
indicate
controls
activities
waters.
suggests
biogeochemical
changes
zone
will
depend
character
adjacent
which
determine
speed
extent
mineralization
thereby
carbon
channeling
food
web.
We
conclude
microbes
respond
input
released
differently
influence
microbes.