Biogeosciences,
Journal Year:
2025,
Volume and Issue:
22(8), P. 2049 - 2067
Published: April 25, 2025
Abstract.
Dryland
ecosystems
are
the
habitat
supporting
2
billion
people
on
Earth,
and
they
strongly
impact
global
terrestrial
carbon
sink.
Vegetation
growth
in
drylands
is
mainly
controlled
by
water
availability
with
strong
intra-seasonal
variability.
Timely
of
information
at
such
scales
(e.g.,
from
days
to
weeks)
essential
for
early
warning
potential
catastrophic
impacts
emerging
climate
extremes
crops
natural
vegetation.
However,
large-scale
monitoring
vegetation
dynamics
has
been
very
challenging
drylands.
Satellite
solar-induced
chlorophyll
fluorescence
(SIF)
emerged
as
a
promising
tool
characterize
spatiotemporal
photosynthetic
uptake
detect
dynamics.
few
studies
have
evaluated
its
capability
detecting
fast-changing
advantages
over
traditional
approaches
based
indices
(VIs).
To
fill
this
knowledge
gap,
study
utilized
vast
dryland
Horn
Africa
(HoA)
testbed
their
inferred
satellite
SIF.
The
HoA
an
ideal
because
highly
dynamic
responses
short-term
environmental
changes.
satellite-data-based
analysis
was
corroborated
unique
situ
SIF
dataset
collected
Kenya
–
so
far,
only
ground
time
series
continent
Africa.
We
found
that
TROPOspheric
Monitoring
Instrument
(TROPOMI)
daily
revisit
frequency
identified
week-to-week
variations
both
shrublands
grasslands;
rapidly
changing
corresponded
up-
downregulation
fluctuations
variables
air
temperature,
vapor
pressure
deficit,
soil
moisture).
neither
reconstructed
products
nor
near-infrared
reflectance
(NIRv)
Moderate
Resolution
Imaging
Spectroradiometer
(MODIS),
which
widely
used
literature,
able
capture
variations.
same
findings
hold
site
scale,
where
we
TROPOMI
revealed
two
separate
within-season
cycles
response
extreme
moisture
rainfall
amount
duration,
consistent
measurements.
This
generates
novel
insights
evaluation
sensitivities,
enabling
development
predictive
scalable
understanding
how
may
respond
future
change
informing
design
effective
systems
Land,
Journal Year:
2025,
Volume and Issue:
14(5), P. 925 - 925
Published: April 24, 2025
The
Jinsha
River
Basin
in
Yunnan
serves
as
a
crucial
ecological
barrier
southwestern
China.
Objective
assessment
and
identification
of
key
driving
factors
are
essential
for
the
region’s
sustainable
development.
Remote
Sensing
Ecological
Index
(RSEI)
has
been
widely
applied
assessments.
In
recent
years,
interpretable
machine
learning
(IML)
introduced
novel
approaches
understanding
complex
mechanisms.
This
study
employed
Google
Earth
Engine
(GEE)
to
calculate
three
vegetation
indices—NDVI,
SAVI,
kNDVI—for
area
from
2000
2022,
along
with
their
corresponding
RSEI
models
(NDVI-RSEI,
SAVI-RSEI,
kNDVI-RSEI).
Additionally,
it
analyzed
spatiotemporal
variations
these
relationship
indices.
Furthermore,
an
IML
model
(XGBoost-SHAP)
was
interpret
RSEI.
results
indicate
that
(1)
levels
2022
were
primarily
moderate;
(2)
compared
NDVI-RSEI,
SAVI-RSEI
is
more
susceptible
soil
factors,
while
kNDVI-RSEI
exhibits
lower
saturation
tendency;
(3)
potential
evapotranspiration,
land
cover,
elevation
drivers
variations,
affecting
environment
western,
southeastern,
northeastern
parts
area.
XGBoost-SHAP
approach
provides
valuable
insights
promoting
regional
Biogeosciences,
Journal Year:
2025,
Volume and Issue:
22(8), P. 2049 - 2067
Published: April 25, 2025
Abstract.
Dryland
ecosystems
are
the
habitat
supporting
2
billion
people
on
Earth,
and
they
strongly
impact
global
terrestrial
carbon
sink.
Vegetation
growth
in
drylands
is
mainly
controlled
by
water
availability
with
strong
intra-seasonal
variability.
Timely
of
information
at
such
scales
(e.g.,
from
days
to
weeks)
essential
for
early
warning
potential
catastrophic
impacts
emerging
climate
extremes
crops
natural
vegetation.
However,
large-scale
monitoring
vegetation
dynamics
has
been
very
challenging
drylands.
Satellite
solar-induced
chlorophyll
fluorescence
(SIF)
emerged
as
a
promising
tool
characterize
spatiotemporal
photosynthetic
uptake
detect
dynamics.
few
studies
have
evaluated
its
capability
detecting
fast-changing
advantages
over
traditional
approaches
based
indices
(VIs).
To
fill
this
knowledge
gap,
study
utilized
vast
dryland
Horn
Africa
(HoA)
testbed
their
inferred
satellite
SIF.
The
HoA
an
ideal
because
highly
dynamic
responses
short-term
environmental
changes.
satellite-data-based
analysis
was
corroborated
unique
situ
SIF
dataset
collected
Kenya
–
so
far,
only
ground
time
series
continent
Africa.
We
found
that
TROPOspheric
Monitoring
Instrument
(TROPOMI)
daily
revisit
frequency
identified
week-to-week
variations
both
shrublands
grasslands;
rapidly
changing
corresponded
up-
downregulation
fluctuations
variables
air
temperature,
vapor
pressure
deficit,
soil
moisture).
neither
reconstructed
products
nor
near-infrared
reflectance
(NIRv)
Moderate
Resolution
Imaging
Spectroradiometer
(MODIS),
which
widely
used
literature,
able
capture
variations.
same
findings
hold
site
scale,
where
we
TROPOMI
revealed
two
separate
within-season
cycles
response
extreme
moisture
rainfall
amount
duration,
consistent
measurements.
This
generates
novel
insights
evaluation
sensitivities,
enabling
development
predictive
scalable
understanding
how
may
respond
future
change
informing
design
effective
systems