Remote Sensing,
Год журнала:
2024,
Номер
16(22), С. 4234 - 4234
Опубликована: Ноя. 14, 2024
The
ecosystem’s
gross
primary
productivity
(GPP)
and
greenness,
as
indicated
by
the
normalized
difference
vegetation
index
(NDVI),
are
both
essential
ecological
indicators
used
to
evaluate
how
ecosystems
responded
climate
variability.
However,
relationships
between
NDVI
GPP
under
influence
of
drying
wetting
its
characteristics
along
aridity
(AI)
gradients
were
not
yet
fully
understood.
In
this
study,
we
investigated
NDVI-GPP
(i.e.,
strength
coupling
sensitivity,
quantified
coefficient
determination
(R2)
slope
linear
regression,
respectively)
during
growing
season
from
1982
2018
in
China.
results
show
that
was
stronger
high
R2)
semi-arid
regions
(0.24)
compared
humid
hyper-humid
(R2
values
0.11).
For
different
plant
functional
types
(PFTs),
decoupling
occurred
ENF
with
a
value
0.04,
whereas
GRA
shows
higher
an
R2
0.20.
trend
experienced
shift
regions,
characterized
ranging
0.20
0.50.
Additionally,
sensitivity
also
decreased
increasing
aridity.
0.19,
0.21,
0.24,
0.20,
0.11,
0.11
hyper-arid,
arid,
semi-arid,
dry
sub-humid,
humid,
hyper-humid,
respectively.
What
is
more,
asynchronous
changes
greenness
can
be
detected
capturing
inter-annual
variability
(IAV)
GPP.
IAV
steadily
gradients,
while
present
fluctuated,
suggesting
more
variable
than
conditions.
Our
study
suggests
there
may
trade-off
ecosystem
photosynthesis
areas.
Remote Sensing,
Год журнала:
2025,
Номер
17(2), С. 316 - 316
Опубликована: Янв. 17, 2025
The
ecosystem
water
use
efficiency
(WUE)
plays
a
critical
role
in
many
aspects
of
the
global
carbon
cycle,
management,
and
ecological
services.
However,
response
mechanisms
driving
processes
WUE
need
to
be
further
studied.
This
research
was
conducted
based
on
Gross
Primary
Productivity
(GPP),
Evapotranspiration
(ET),
meteorological
station
data,
land
use/cover
methods
Ensemble
Empirical
Mode
Decomposition
(EEMD),
trend
variation
analysis,
Mann–Kendall
Significant
Test
(M-K
test),
Partial
Correlation
Analysis
(PCA)
methods.
Our
study
revealed
spatio-temporal
its
influencing
mechanism
Yellow
River
Basin
(YRB)
compared
differences
change
before
after
implementation
Returned
Farmland
Forestry
Grassland
Project
2000.
results
show
that
(1)
YRB
showed
significant
increase
at
rate
0.56
×
10−2
gC·kg−1·H2O·a−1
(p
<
0.05)
from
1982
2018.
area
showing
(47.07%,
Slope
>
0,
p
higher
than
with
decrease
(14.64%,
0.05).
region
2000–2018
(45.35%,
1982–2000
(8.23%,
0.05),
which
37.12%
comparison.
(2)
Forest
(1.267
gC·kg−1·H2O)
Cropland
(0.972
(0.805
under
different
cover
types.
has
highest
(0.79
gC·kg−1·H2O·a−1)
2000
increased
by
0.082
gC·kg−1·H2O
(3)
precipitation
(37.98%,
R
SM
(10.30%,
are
main
climatic
factors
affecting
YRB.
A
total
70.39%
exhibited
an
increasing
trend,
is
mainly
attributed
simultaneous
GPP
ET,
ET.
could
provide
scientific
reference
for
policy
decision-making
terrestrial
cycle
biodiversity
conservation.
Agriculture,
Год журнала:
2025,
Номер
15(6), С. 613 - 613
Опубликована: Март 13, 2025
The
carbon
cycle
in
terrestrial
ecosystems
is
a
crucial
component
of
the
global
cycle,
and
drought
increasingly
recognized
as
significant
stressor
impacting
their
sink
function.
Net
ecosystem
productivity
(NEP),
which
key
indicator
capacity,
closely
related
to
vegetation
Primary
Productivity
(NPP),
derived
using
Carnegie-Ames-Stanford
Approach
(CASA)
model.
However,
there
limited
research
on
desert
grassland
ecosystems,
offer
unique
insights
due
long-term
data
series.
relationship
between
NEP
complex
can
vary
depending
intensity,
duration,
frequency
events.
an
exchange
atmosphere,
it
soil
respiration.
Drought
known
negatively
affect
growth,
reducing
its
ability
sequester
carbon,
thus
decreasing
NEP.
Prolonged
conditions
lead
decrease
NPP,
turn
affects
overall
balance
ecosystems.
This
study
employs
improved
CASA
model,
remote
sensing,
climate,
land
use
estimate
NPP
grasslands
then
calculate
Standardized
Precipitation
Evapotranspiration
Index
(SPEI),
based
precipitation
evapotranspiration
data,
was
used
assess
wetness
dryness
ecosystem,
allowing
for
investigation
drought.
results
show
that
(1)
from
1982
2022,
distribution
pattern
Inner
Mongolia
showed
gradual
increase
southwest
northeast,
with
multi-year
average
value
29.41
gCm⁻2.
area
(NEP
>
0)
accounted
67.99%,
regional
growth
rate
0.2364
gcm−2yr−1,
In
addition,
increasing
35.40%
total
(p
<
0.05);
(2)
SPEI
characterize
changes
region
whole
mainly
affected
by
light
Spatially,
cumulative
effect
primarily
driven
short-term
(1–2
months),
covering
54.5%
area,
relatively
fast
response
rate;
(3)
analyzing
driving
factors
Geographical
detector,
annual
had
greatest
influence
Mongolian
ecosystem.
Interaction
analysis
revealed
combined
most
stronger
than
single
factor,
interaction
two
higher
explanatory
power
demonstrates
has
increased
significantly
drought,
characterized
SPEI,
clear
productivity,
particularly
areas
experiencing
Future
could
focus
extending
this
other
incorporating
additional
environmental
variables
further
refine
understanding
dynamics
under
conditions.
improving
our
cycling
grasslands,
are
sensitive
climate
variability
gained
help
inform
strategies
mitigating
change
enhancing
sequestration
arid
regions.
Geophysical Research Letters,
Год журнала:
2025,
Номер
52(6)
Опубликована: Март 16, 2025
Abstract
Global
climate
change
has
intensified
flash
droughts,
which
differ
from
traditional
and
have
significant
ecological
impacts.
However,
differences
in
ecosystem
responses
to
normal
droughts
China
remain
unclear,
particularly
terms
of
vegetation
vulnerability
resilience.
Using
a
three‐dimensional
clustering
method,
we
identified
disparities
between
these
drought
types
1982
2022
found
that
developed
40%
faster
than
but
caused
more
severe
damage.
With
the
transition
sensitivity
increased.
Shapley's
additive
interpretation
assessed
role
each
environmental
factor
recovery.
The
results
show
characteristics
drive
resilience
vegetation,
whereas
temperature
vapor
pressure
deficit
become
significant.
These
insights
provide
deeper
understanding
tolerance
under
changing
climatic
conditions.
Water,
Год журнала:
2024,
Номер
16(17), С. 2416 - 2416
Опубликована: Авг. 27, 2024
Ecological
protection
in
the
Yellow
River
Basin
(YRB)
is
a
major
strategy
for
China’s
sustainable
development.
Amid
global
warming,
droughts
have
occurred
more
frequently,
severely
affecting
vegetation
growth.
Based
on
Standardized
Precipitation
Evapotranspiration
Index
(SPEI)
and
Normalized
Difference
Vegetation
(NDVI)
at
different
time
scales
from
2003
to
2020,
this
study
employed
linear
trend
method
Spearman
correlation
coefficient
calculate
trends
coefficients
of
NDVI
SPEI
pixel
scale
explored
spatial
distribution
pattern
sensitivity
growth
YRB
drought.
The
results
show
that:
(1)
are
positively
correlated
77%
area,
negatively
9%,
arid
semi-arid
areas,
while
humid
subhumid
areas.
significant
negative
between
drought
high
altitudes
may
be
due
fact
that
Gramineae
sensitive
drought,
with
heat
being
affected
than
water.
(2)
Urbanization
has
relatively
obvious
impact
Extreme
mainly
occurs
middle
upper
reaches
Wei
River;
severe
central
area
Guanzhong
Plain
centered
Xi’an;
Loess
Plateau;
surrounding
areas
Zhengzhou-centered
Central
Plains
City
Group.
(3)
showed
an
upward
indicating
increase
density
or
expansion
coverage.
From
temporal
trend,
decreased
rate
−0.17/decade,
entire
watershed
annual
scale.
(4)
Spring
water
supply
provided
by
SPEI-1,
positive
begins
rise
June
its
peak
July,
then
starts
decline
August.
In
autumn
winter,
3–6-month
accumulated
(5)
dynamic
transmission
laws
levels
correlation,
3-month
most
significant,
influence
SPEI-1
significant.
This
paper
aims
clarify
time-scale
droughts,
provide
basis
alleviating
YRB,
promote
development
ecological
environmental
protection.
research
findings
enable
us
gain
profound
insight
into
responsiveness
context
warming
offer
valuable
theoretical
foundation
devising
pertinent
measures
alleviate
stress
regions
prone
frequent
droughts.
