Global Change Biology,
Journal Year:
2021,
Volume and Issue:
27(8), P. 1627 - 1644
Published: Jan. 15, 2021
Abstract
Coastal
wetlands
are
among
the
most
productive
ecosystems
and
store
large
amounts
of
organic
carbon
(C)—the
so
termed
“blue
carbon.”
However,
in
tropics
subtropics
have
been
invaded
by
smooth
cordgrass
(
Spartina
alterniflora
)
affecting
storage
blue
C.
To
understand
how
S.
affects
soil
(SOC)
stocks,
sources,
stability,
their
spatial
distribution,
we
sampled
soils
along
a
2500
km
coastal
transect
encompassing
tropical
to
subtropical
climate
zones.
This
included
216
samplings
within
three
wetland
types:
marsh
Phragmites
australis
two
mangroves
Kandelia
candel
Avicennia
marina
).
Using
δ
13
C,
C:nitrogen
(N)
ratios,
lignin
biomarker
composition,
traced
changes
SOC
response
invasion.
The
contribution
‐derived
C
up
40
cm
accounts
for
5.6%,
23%,
12%
P.
,
K.
A.
communities,
respectively,
with
corresponding
change
+3.5,
−14,
−3.9
t
ha
−1
.
did
not
follow
trend
aboveground
biomass
from
native
invasive
species,
or
vegetation
types
invasion
duration
(7–15
years).
decreased
increasing
mean
annual
precipitation
(1000–1900
mm)
temperature
(15.3–23.4℃).
Edaphic
variables
marshes
remained
stable
after
invasion,
hence,
effects
on
content
were
absent.
In
mangrove
wetlands,
however,
electrical
conductivity,
total
N
phosphorus,
pH,
active
silicon
main
factors
controlling
stocks.
Mangrove
strongly
impacted
efforts
needed
focus
restoring
vegetation.
By
understanding
mechanisms
consequences
sequestration
can
be
predicted
optimize
developed.
Global Change Biology,
Journal Year:
2021,
Volume and Issue:
27(19), P. 4657 - 4670
Published: July 9, 2021
Smart
cropland
management
practices
can
mitigate
greenhouse
gas
(GHG)
emissions
while
safeguarding
food
security.
However,
the
integrated
effects
on
net
budget
(NGHGB)
and
grain
yield
from
different
remain
poorly
defined
vary
with
environmental
application
conditions.
Here,
we
conducted
a
global
meta-analysis
347
observation
sets
of
non-CO2
GHG
(CH4
N2
O)
yield,
412
observations
soil
organic
carbon
sequestration
rate
(SOCSR).
Our
results
show
that
for
paddy
rice,
replacing
synthetic
nitrogen
at
30%-59%
fertilizer
significantly
decreased
(NGHGB:
-15.3
±
3.4
[standard
error],
SOCSR:
-15.8
3.8,
GHGs:
0.6
0.1
in
Mg
CO2
eq
ha-1
year-1
)
improved
rice
(0.4
).
In
contrast,
intermittent
irrigation
increased
by
11.2
3.1
0.4
0.1.
The
reduction
SOC
(15.5
3.3),
which
was
most
severe
(>20)
alkaline
soils
(pH
>
7.5),
completely
offset
mitigation
CH4
emissions.
Straw
return
also
led
to
increase
4.8
1.4)
silt-loam
soils,
where
(6.3
1.3)
were
greatly
stimulated.
For
upland
cropping
systems,
mostly
enhancing
sequestration,
straw
-3.4
0.8,
yield:
-0.5
0.6)
no-tillage
-2.9
0.7,
-0.1
0.3)
more
effective
warm
climates.
This
study
highlights
importance
carefully
managing
croplands
sequester
without
sacrifice
limiting
paddies.
Global Change Biology,
Journal Year:
2021,
Volume and Issue:
27(8), P. 1627 - 1644
Published: Jan. 15, 2021
Abstract
Coastal
wetlands
are
among
the
most
productive
ecosystems
and
store
large
amounts
of
organic
carbon
(C)—the
so
termed
“blue
carbon.”
However,
in
tropics
subtropics
have
been
invaded
by
smooth
cordgrass
(
Spartina
alterniflora
)
affecting
storage
blue
C.
To
understand
how
S.
affects
soil
(SOC)
stocks,
sources,
stability,
their
spatial
distribution,
we
sampled
soils
along
a
2500
km
coastal
transect
encompassing
tropical
to
subtropical
climate
zones.
This
included
216
samplings
within
three
wetland
types:
marsh
Phragmites
australis
two
mangroves
Kandelia
candel
Avicennia
marina
).
Using
δ
13
C,
C:nitrogen
(N)
ratios,
lignin
biomarker
composition,
traced
changes
SOC
response
invasion.
The
contribution
‐derived
C
up
40
cm
accounts
for
5.6%,
23%,
12%
P.
,
K.
A.
communities,
respectively,
with
corresponding
change
+3.5,
−14,
−3.9
t
ha
−1
.
did
not
follow
trend
aboveground
biomass
from
native
invasive
species,
or
vegetation
types
invasion
duration
(7–15
years).
decreased
increasing
mean
annual
precipitation
(1000–1900
mm)
temperature
(15.3–23.4℃).
Edaphic
variables
marshes
remained
stable
after
invasion,
hence,
effects
on
content
were
absent.
In
mangrove
wetlands,
however,
electrical
conductivity,
total
N
phosphorus,
pH,
active
silicon
main
factors
controlling
stocks.
Mangrove
strongly
impacted
efforts
needed
focus
restoring
vegetation.
By
understanding
mechanisms
consequences
sequestration
can
be
predicted
optimize
developed.