Proceedings of the National Academy of Sciences,
Год журнала:
2024,
Номер
121(25)
Опубликована: Июнь 10, 2024
Permafrost
regions
contain
approximately
half
of
the
carbon
stored
in
land
ecosystems
and
have
warmed
at
least
twice
as
much
any
other
biome.
This
warming
has
influenced
vegetation
activity,
leading
to
changes
plant
composition,
physiology,
biomass
storage
aboveground
belowground
components,
ultimately
impacting
ecosystem
balance.
Yet,
little
is
known
about
causes
magnitude
long-term
above-
ratio
plants
(η).
Here,
we
analyzed
η
values
using
3,013
plots
26,337
species-specific
measurements
across
eight
sites
on
Tibetan
Plateau
from
1995
2021.
Our
analysis
revealed
distinct
temporal
trends
for
three
types:
a
17%
increase
alpine
wetlands,
decrease
26%
48%
meadows
steppes,
respectively.
These
were
primarily
driven
by
temperature-induced
growth
preferences
rather
than
shifts
species
composition.
findings
indicate
that
wetter
ecosystems,
climate
promotes
growth,
while
drier
such
allocate
more
belowground.
Furthermore,
observed
threefold
strengthening
effect
over
past
27
y.
Soil
moisture
was
found
modulate
sensitivity
soil
temperature
but
not
wetlands.
results
contribute
better
understanding
processes
driving
response
distribution
warming,
which
crucial
predicting
future
trajectory
permafrost
feedback.
Earth system science data,
Год журнала:
2023,
Номер
15(9), С. 4181 - 4203
Опубликована: Сен. 25, 2023
Abstract.
Global
products
of
remote
sensing
Normalized
Difference
Vegetation
Index
(NDVI)
are
critical
to
assessing
the
vegetation
dynamic
and
its
impacts
feedbacks
on
climate
change
from
local
global
scales.
The
previous
versions
Inventory
Modeling
Mapping
Studies
(GIMMS)
NDVI
product
derived
Advanced
Very
High
Resolution
Radiometer
(AVHRR)
provide
biweekly
data
starting
1980s,
being
a
reliable
long-term
time
series
that
has
been
widely
applied
in
Earth
environmental
sciences.
However,
GIMMS
have
several
limitations
(e.g.,
orbital
drift
sensor
degradation)
cannot
continuous
for
future.
In
this
study,
we
presented
machine
learning
model
employed
massive
high-quality
Landsat
samples
consolidation
method
generate
new
version
product,
i.e.,
PKU
(1982–2022),
based
AVHRR
Moderate-Resolution
Imaging
Spectroradiometer
(MODIS)
data.
A
total
3.6
million
were
well
spread
across
globe
extracted
biomes
all
seasons.
exhibits
higher
accuracy
than
predecessor
(GIMMS
NDVI3g)
terms
R2
(0.97
over
0.94),
root
mean
squared
error
(RMSE:
0.05
0.09),
absolute
(MAE:
0.03
0.07),
percentage
(MAPE:
9
%
20
%).
Notably,
effectively
eliminates
evident
degradation
effects
tropical
areas.
consolidated
high
consistency
with
MODIS
pixel
value
(R2
=
0.956,
RMSE
0.048,
MAE
0.034,
MAPE
6.0
%)
trend
(0.9×10-3
yr−1).
can
potentially
more
solid
basis
studies.
theoretical
framework
employs
facilitate
generation
other
land
surface
parameters.
is
open
access
available
under
Creative
Commons
Attribution
4.0
License
at
https://doi.org/10.5281/zenodo.8253971
(Li
et
al.,
2023).
The
carbon
sequestration
capacity
of
alpine
grasslands,
composed
meadows
and
steppes,
in
the
Tibetan
Plateau
has
an
essential
role
regulating
regional
cycle.
However,
inadequate
understanding
its
spatiotemporal
dynamics
regulatory
mechanisms
restricts
our
ability
to
determine
potential
climate
change
impacts.
We
assessed
spatial
temporal
patterns
net
ecosystem
exchange
(NEE)
dioxide
Plateau.
grasslands
ranged
from
26.39
79.19
Tg
C
year-1
had
increasing
rate
1.14
between
1982
2018.
While
were
relatively
strong
sinks,
semiarid
arid
steppes
nearly
neutral.
Alpine
meadow
areas
experienced
increases
mainly
because
temperatures,
while
steppe
weak
due
precipitation.
Carbon
on
plateau
undergone
persistent
enhancement
under
a
warmer
wetter
climate.
Climate Dynamics,
Год журнала:
2023,
Номер
61(5-6), С. 2139 - 2153
Опубликована: Янв. 16, 2023
Abstract
The
Tibetan
Plateau
(TP),
also
called
the
Third
Pole,
is
considered
to
be
“the
world
water
tower”.
northwestern
TP
(NWTP),
which
has
an
average
elevation
higher
than
4800
m,
arid
region
where
summer
precipitation
largely
overestimated
by
ERA5
global
reanalysis
product.
We
hypothesize
that
this
wet
bias
mainly
caused
unrealistic
lower-level
winds
trigger
strong
convection
over
region;
it
can
reduced
using
a
high-resolution
regional
climate
model
with
large
domain
allows
realistically
representing
interactions
between
Westerlies
and
Asian
monsoons.
Here,
downscaling
Weather
Research
Forecasting
(WRF)
driven
was
conducted
(8°‒50°
N,
65°‒125°
E)
at
9
km
for
period
1979‒2019
(WRF9km).
Precipitation
values
from
WRF9km
were
evaluated
against
satellite
observations;
compared
ERA5,
captured
climatological
NWTP
much-reduced
bias.
overestimation
excessive
convective
precipitation,
likely
linked
vertical
motions
induced
southerly
wind.
Ecological Indicators,
Год журнала:
2023,
Номер
148, С. 110020 - 110020
Опубликована: Фев. 20, 2023
Vegetation
dynamics
in
Qinghai-Tibet
Plateau
(QTP)
have
been
debated
recent
decades.
Most
studies
suggest
that
wetter
and
warmer
climatic
conditions
would
release
low
temperature
constraints
stimulate
alpine
vegetation
growth.
Other
climate
warming
might
inhibit
growth
by
increasing
soil
moisture
depletion
the
southern
QTP.
of
previous
relied
on
indices
derived
from
satellite
observations
to
retrieve
large-scale
changes,
uncertainty
makes
it
difficult
accurately
characterize
trends
Here,
we
developed
a
deep
learning
algorithm
Google
Earth
Engine
(GEE)
platform
map
land
use/cover
change
(LUCC)
QTP,
then
infer
gain
loss
their
drivers
during
period
1988–2018.
The
QTP
experienced
rapid
greening,
which
was
dominated
transitions
bareland
grassland
(27.45
×
104
km2)
meadow
(17.43
Furthermore,
although
human
activities
influence
succession
at
local
scale,
dominant
influencing
factors
affecting
greening
are
precipitation
(q-statistic
=
23.87
%)
11.01
%).
A
30-year
time
series
analysis
clarified
specific
thus
contributing
understanding
response
mechanisms
under
providing
reference
for
formulating
reasonable
ecological
protection
policies
development
strategies.
Nature Communications,
Год журнала:
2023,
Номер
14(1)
Опубликована: Апрель 15, 2023
Abstract
Long-term
observations
have
shown
that
many
plants
and
aboveground
animals
changed
their
phenology
patterns
due
to
warmer
temperatures
over
the
past
decades.
However,
empirical
evidence
for
phenological
shifts
in
alpine
organisms,
particularly
belowground
is
scarce.
Here,
we
investigate
how
activities
of
plants,
soil
microbes,
fauna
will
respond
warming
an
meadow
on
Tibetan
Plateau,
whether
potential
changes
be
synchronized.
We
experimentally
simulate
increase
temperature
by
2–4
°C
according
future
projections
this
region.
find
promotes
plant
growth,
microbial
respiration,
feeding
8%,
57%,
20%,
respectively,
but
causes
dissimilar
during
growing
season.
Specifically,
advances
faunal
activity
spring
delays
it
autumn,
while
peak
does
not
change;
whereas
increases
growth
respiration
with
only
minor
phenology.
Such
asynchrony
organisms
may
alter
ecosystem
functioning
stability.
Ecological Indicators,
Год журнала:
2023,
Номер
154, С. 110533 - 110533
Опубликована: Июнь 24, 2023
Both
net
primary
productivity
(NPP)
and
vegetation
phenology
play
essential
roles
in
influencing
the
carbon
sequestration
of
terrestrial
ecosystems.
However,
relationship
between
NPP
remains
unclear
under
effects
global
warming.
This
study
used
Geodetector
to
analyze
interaction
mechanisms
climate,
phenology,
elevation,
Yunnan,
China.
The
results
are
as
follows.
(1)
is
positively
correlated
with
NDVI,
LOS,
EOS,
TEMP,
PREC
SRAD,
negatively
ELEV,
NDBI
SOS.
main
factors
leading
variation
differ
region.
(2)
spatial
distribution
LOS
Yunnan
Province
mainly
influenced
by
monsoon,
showing
a
pattern
high
southwest
low
northeast,
reason
for
NPP.
(3)
In
high-altitude
region
northwest
altitude
factor
affecting
variation.
(4)
tropical
monsoon
forest
southern
SRAD
cause
changes.
(5)
Despite
having
small
effect
on
NPP,
SOS
was
only
phenological
that
showed
significant
linear
reveals
complex
diverse
interactions
different
regions
provides
new
perspective
understanding
cycle
ecological
processes
ecosystems