Abstract.
Seasonal
freeze‒thaw
(FT)
processes
alter
soil
formation
and
causes
changes
in
structure
alpine
ecosystems.
Soil
aggregates
are
basic
structural
units
play
a
crucial
role
organic
carbon
(SOC)
protection
microbial
habitation.
However,
the
impact
of
seasonal
FT
on
pore
its
SOC
fractions
have
been
overlooked.
This
study
characterized
during
unstable
freezing
period
(UFP),
stable
frozen
(SFP),
thawing
(UTP)
thawed
(STP)
typical
ecosystems
via
dry
sieving
procedure,
X-ray
computed
tomography
(CT)
scanning
elemental
analysis.
The
results
showed
that
characteristics
0.25–2
mm
were
more
vulnerable
to
than
>
2
aggregates.
process
promoted
80
μm
pores
total
(TOC),
particulate
(POC)
mineral-associated
(MAOC)
contents
macroaggregates
high
low
period,
demonstrating
enhanced
accumulation
while
early
stage
led
loss.
vertical
distribution
was
uniform
other
periods.
Pore
equivalent
diameter
most
important
characteristic
influencing
In
importance
regulating
obvious
inhibited
loss
by
>80
pores.
15–30
protection.
Our
valuable
for
evaluating
potential
sinks
under
global
warming.
Global Change Biology,
Journal Year:
2025,
Volume and Issue:
31(1)
Published: Jan. 1, 2025
Soil
microorganisms
transform
plant-derived
C
(carbon)
into
particulate
organic
(POC)
and
mineral-associated
(MAOC)
pools.
While
microbial
carbon
use
efficiency
(CUE)
is
widely
recognized
in
current
biogeochemical
models
as
a
key
predictor
of
soil
(SOC)
storage,
large-scale
empirical
evidence
limited.
In
this
study,
we
proposed
experimentally
tested
two
predictors
POC
MAOC
pool
formation:
necromass
(using
amino
sugars
proxy)
CUE
(by
18O-H2O
approach).
sampling
(0-10
10-20
cm
depth)
was
conducted
along
climatic
transect
900
km
on
the
Loess
Plateau,
including
cropland,
grassland,
shrubland,
forest
ecosystems,
to
ensure
homogeneous
parent
material.
We
found
highest
accumulation
occurred
zones
MAT
between
5°C
10°C
or
MAP
300
500
mm.
Microbial
more
positively
related
than
(p
<
0.05),
suggesting
that
residues
may
improve
strongly
compared
pool.
Random
linear
regression
analyses
showed
increased
with
fungal
C,
whereas
bacterial
drove
MAOC.
coupled
0.05)
but
decoupled
SOC
>
0.05).
The
have
faster
turnover
rate
due
lack
clay
protection,
which
lead
rapid
thus
their
decoupling
from
CUE.
sense,
driven
by
necromass,
explains
dynamics.
Our
findings
highlight
insufficiency
relying
solely
predict
bulk
storage.
Instead,
propose
should
be
used
together
explain
dynamics,
each
influencing
distinct
Global Change Biology,
Journal Year:
2025,
Volume and Issue:
31(1)
Published: Jan. 1, 2025
ABSTRACT
Coastal
wetlands
contain
very
large
carbon
(C)
stocks—termed
as
blue
C—and
their
management
has
emerged
a
promising
nature‐based
solution
for
climate
adaptation
and
mitigation.
The
interactions
among
sources,
pools,
molecular
compositions
of
soil
organic
C
(SOC)
within
ecosystems
(BCEs)
remain
elusive.
Here,
we
explore
these
along
an
18,000
km
long
coastal
line
salt
marshes,
mangroves,
seagrasses
in
China.
We
found
that
mineral‐associated
(MAOC)
is
enriched
BCEs
dominated
by
allochthonous
inputs
abundant
active
minerals,
leading
to
increased
proportion
persistent
molecules.
Specifically,
soils
with
(>
50%)
are
characterized
substantial
contribution
MAOC
70%)
total
SOC
notable
preservation
lipids
(36%)
across
seagrasses.
burial
particles,
derived
from
external
sources
such
rivers
or
tidal
influxes,
facilitates
the
formation
stable
through
binding
mineral
surfaces
occlusion
microaggregates.
proportions
particulate
(POC)
important
predictors
matter.
Lipid
composition
decrease
POC
autochthonous
increase.
These
findings
provide
new
insights
into
coupled
control
over
sequestration
BCEs,
emphasizing
role
inputs,
components.
Global Change Biology,
Journal Year:
2024,
Volume and Issue:
30(8)
Published: Aug. 1, 2024
Abstract
Soil
organic
carbon
(SOC)
accrual,
and
particularly
the
formation
of
fine
fraction
(OC
),
has
a
large
potential
to
act
as
sink
for
atmospheric
CO
2
.
For
reliable
estimates
this
efficient
policy
advice,
major
limiting
factors
OC
accrual
need
be
understood.
The
upper
boundary
correlation
between
mineral
particles
(silt
+
clay)
is
widely
used
estimate
maximum
mineralogical
capacity
soils
store
,
suggesting
that
surfaces
get
C
saturated.
Using
dataset
covering
temperate
zone
partly
other
climates
on
contents
SOC
turnover
model,
we
provide
two
independent
lines
evidence,
empirical
does
not
indicate
saturation.
Firstly,
loading
silt
clay
was
found
strongly
exceed
previous
saturation
in
coarse‐textured
soils,
which
raises
question
why
observed
fine‐textured
soils.
Secondly,
subsequent
modelling
exercise
revealed,
74%
all
investigated
local
net
primary
production
(NPP)
would
sufficient
reach
80
g
kg
−1
clay,
previously
assumed
general
point.
proportion
with
potentially
enough
NPP
point
decreased
increasing
content.
High
loadings
can
thus
hardly
reached
more
even
if
available
input.
As
pragmatic
approach,
introduced
texture‐dependent,
fraction,
from
160
coarse
75
most
We
conclude
mainly
limited
by
inputs
modulated
texture,
mineralogy,
climate
site
properties,
could
formulated
an
ecosystem
stabilise
SOC.
Soil Use and Management,
Journal Year:
2025,
Volume and Issue:
41(2)
Published: April 1, 2025
ABSTRACT
Nitrogen
(N)
immobilisation
in
post‐harvest
soils
is
important
for
maintaining
soil
fertility
while
mitigating
N
losses,
but
how
to
achieve
this
crop
rotations
that
do
not
allow
catch
crops
remains
unknown.
High‐carbon
amendments
(HCAs)
incorporated
into
the
after
harvest
can
stimulate
microbial
uptake
and
thus
might
provide
a
viable
option
improve
retention
with
winter
crops.
Here,
we
investigated
efficacy
of
seven
types
HCA
on
mineral
reclaimed
an
incubation
experiment
198
days
under
conditions,
using
15
pulse
labelling
(NH
4
)
2
SO
estimate
conversion
(N
min
non‐extractable
forms.
We
found
induced
by
addition
varied
type,
cellulose
content
HCAs
was
particular
importance
magnitude
duration
could
also
demonstrate
accessible
better
predictor
potential
different
than
C/N
ratio.
Furthermore,
it
observed
95%
cellulose‐amended
converted
within
84
days,
much
more
other
HCAs,
demonstrating
all
tested,
transformation
from
forms
most
effectively,
likely
via
pathways.
Overall,
our
results
basis
management
strategy
mitigate
losses
arable
during
season.
However,
research
needed
effects
microbial‐mediated
transformations
soils.
