Abstract.
Forest
stand
mean
height
is
a
critical
indicator
in
forestry,
playing
pivotal
role
various
aspects
such
as
forest
inventory
estimation,
sustainable
management
practices,
climate
change
mitigation
strategies,
monitoring
of
structure
changes,
and
wildlife
habitat
assessment.
However,
there
currently
lack
large-scale,
spatially
continuous
maps.
This
primarily
due
to
the
requirement
accurate
measurement
individual
tree
each
plot,
task
that
cannot
be
effectively
achieved
by
existing
globally
covered,
discrete
footprint-based
satellite
platforms.
To
address
this
gap,
study
was
conducted
using
over
1117
km2
close-range
Light
Detection
Ranging
(LiDAR)
data,
which
enables
plots
with
high
precision.
Besides,
incorporated
climatic,
edaphic,
topographic,
vegetative,
Synthetic
Aperture
Radar
data
explanatory
variables
map
tree-based
arithmetic
(ha)
weighted
(hw)
at
30
m
resolution
across
China.
Due
limitations
obtaining
basal
area
within
UAV
LiDAR
calculated
through
weighting
an
square
its
height.
In
addition,
overcome
potential
influence
different
vegetation
divisions
large
spatial
scale,
we
also
developed
machine
learning-based
mixed-effects
model
The
results
showed
average
ha
hw
China
were
11.3
13.3
standard
deviations
2.9
3.3
m,
respectively.
accuracy
mapped
products
validated
utilizing
field
data.
correlation
coefficient
(𝑟)
for
ranged
from
0.603
0.906
0.634
0.889,
while
RMSE
2.6
4.1
4.3
Comparing
canopy
maps
derived
area-based
approach,
it
found
our
performed
better
aligned
more
closely
natural
definition
methods
presented
provide
solid
foundation
estimating
carbon
storage,
changes
structure,
managing
inventory,
assessing
availability.
dataset
constructed
publicly
available
https://doi.org/10.5281/zenodo.12697784
(Chen
et
al.,
2024).
Remote Sensing of Environment,
Год журнала:
2024,
Номер
305, С. 114099 - 114099
Опубликована: Март 18, 2024
Tree
canopy
height
is
one
of
the
most
important
indicators
forest
biomass,
productivity,
and
ecosystem
structure,
but
it
challenging
to
measure
accurately
from
ground
space.
Here,
we
used
a
U-Net
model
adapted
for
regression
map
all
trees
in
state
California
with
very
high-resolution
aerial
imagery
0.6
m
USDA-NAIP
program.
The
was
trained
using
models
computed
LiDAR
data
as
reference,
along
corresponding
RGB-NIR
NAIP
images
collected
2020.
We
evaluated
performance
deep-learning
42
independent
1
km2
areas
across
various
types
landscape
variations
California.
Our
predictions
tree
heights
exhibited
mean
error
2.9
showed
relatively
low
systematic
bias
entire
range
present
In
2020,
taller
than
5
covered
∼
19.3%
successfully
estimated
up
50
without
saturation,
outperforming
existing
products
global
models.
approach
allowed
reconstruction
three-dimensional
structure
individual
observed
nadir-looking
optical
airborne
imagery,
suggesting
robust
estimation
mapping
capability,
even
presence
image
distortion.
These
findings
demonstrate
potential
large-scale
monitoring
height,
well
biomass
estimation,
imagery.
Earth system science data,
Год журнала:
2023,
Номер
15(11), С. 4927 - 4945
Опубликована: Ноя. 2, 2023
Abstract.
The
contribution
of
forests
to
carbon
storage
and
biodiversity
conservation
highlights
the
need
for
accurate
forest
height
biomass
mapping
monitoring.
In
France,
are
managed
mainly
by
private
owners
divided
into
small
stands,
requiring
10
50
m
spatial
resolution
data
be
correctly
separated.
Further,
35
%
French
territory
is
covered
mountains
Mediterranean
which
very
extensively.
this
work,
we
used
a
deep-learning
model
based
on
multi-stream
remote-sensing
measurements
(NASA's
Global
Ecosystem
Dynamics
Investigation
(GEDI)
lidar
mission
ESA's
Copernicus
Sentinel-1
Sentinel-2
satellites)
create
canopy
map
France
2020
(FORMS-H).
second
step,
with
allometric
equations
fitted
National
Forest
Inventory
(NFI)
plot
data,
created
30
above-ground
density
(AGBD)
(Mg
ha−1)
(FORMS-B).
Extensive
validation
was
conducted.
First,
independent
datasets
from
airborne
laser
scanning
(ALS)
NFI
thousands
plots
reveal
mean
absolute
error
(MAE)
2.94
FORMS-H,
outperforms
existing
models.
Second,
FORMS-B
validated
using
two
inventory
Renecofor
permanent
network
GLORIE
MAE
59.6
19.6
Mg
ha−1,
respectively,
providing
greater
performance
than
other
AGBD
products
sampled
over
France.
Finally,
compared
FORMS-V
(for
volume)
wood
volume
estimations
at
ecological
region
scale
obtained
an
R2
0.63
m3
ha−1.
These
results
highlight
importance
coupling
technologies
recent
advances
in
computer
science
bring
material
insights
climate-efficient
management
policies.
Additionally,
our
approach
open-access
having
global
coverage
high
temporal
resolution,
making
maps
reproducible
easily
scalable.
FORMS
can
accessed
https://doi.org/10.5281/zenodo.7840108
(Schwartz
et
al.,
2023).
The
21st
century
has
seen
the
launch
of
new
space-borne
sensors
based
on
LiDAR
(light
detection
and
ranging)
technology
developed
in
second
half
20th
century.
was
initially
to
integrate
laser-focused
imaging
with
capability
determine
distances
through
measurement
signal
return
times,
utilizing
suitable
data
acquisition
electronics.
Nowadays,
these
have
transformed
into
robust
instruments,
offering
novel
opportunities
for
mapping
terrain,
canopy
heights,
estimating
above-ground
biomass
(AGB)
across
local
regional
scales.
This
work
aims
analyze
scientific
impact
large-scale
for-est
retrieve
3D
information,
monitor
forest
degradation,
estimate
AGB,
model
key
ecosystem
variables
such
as
primary
productivity
biodiversity.
In
this
way,
a
worldwide
bibliometric
analysis
topic
carried
out
up
412
publications
in-dexed
Scopus
database
during
period
2004-2022.
results
showed
that
number
published
documents
increased
exponentially
last
five
years,
coinciding
commis-sioning
two
space
missions:
Ice,
Cloud
Land
Elevation
Satellite
(ICESat-2)
Global
Ecosystem
Dynamics
Investigation
(GEDI).
These
missions
are
providing
since
2018
2019,
respectively.
journal
demonstrated
highest
field
"Remote
Sensing,"
among
leading
contributors,
top
countries
terms
publica-tions
were
USA,
China,
UK,
France,
Germany.
realm
prominent
research
in-stitutions,
France
boasted
six,
USA
had
four,
China
three,
while
UK
Canada
each
one.
upward
trajectory
recorded
from
2004
2022
catego-rizes
subject
under
investigation
highly
trending
topic,
particularly
within
context
enhancing
administration
resources
engaging
global
climate
treaty
frameworks
mandating
surveillance
reporting
carbon
stocks
forests.
recent
August
Terrestrial
Carbon
Monitoring
(TECMS;
State
Administration
Forestry
Grassland),
along
planned
coming
years
three
sensors,
Multi-footprint
Observation
Im-ager
(Japan
Aerospace
Exploration
Agency),
BIOMASS
P-band
Synthetic
Aperture
Radar
(SAR)
(European
Space
Surface
Topography
(LIST;
NASA),
will
greatly
contribute
expanding
ability
map
systems
at
very
large
context,
integration
data,
including
imagery,
SAR,
LiDAR,
is
anticipated
steer
upcoming
years.
International Journal of Applied Earth Observation and Geoinformation,
Год журнала:
2024,
Номер
127, С. 103666 - 103666
Опубликована: Янв. 29, 2024
In
Europe,
the
heterogeneous
features
of
crop
systems
with
majority
small
to
medium
sized
agricultural
holdings,
and
diversity
rotations,
require
high-resolution
information
estimate
cropland
Net
Ecosystem
Exchange
(NEE)
its
two
main
components
Gross
(GEE)
Respiration
(RECO).
this
context,
paper
presents
an
assimilation
Sentinel-2
indices
eddy
covariance
measurements
at
selected
European
flux
sites
in
a
new
modified
version
Vegetation
Photosynthesis
Model
(VPRM).
VRPM
is
data-driven
model
simulating
CO2
fluxes
previously
applied
using
satellite-derived
vegetation
from
Moderate
Resolution
Imaging
Spectroradiometer
(MODIS).
This
study
proposes
modification
VPRM
by
including
explicit
soil
moisture
stress
function
GEE
changing
equation
RECO.
It
also
compares
results
driven
S2
instead
MODIS.
The
parameters
are
calibrated
eddy-covariance
data.
All
possible
optimization
scenarios
include
use
initial
vs.
proposed
VPRM,
S2,
or
MODIS
indices,
finally
choice
calibrating
single
set
against
observations
all
types,
per
type,
one
site.
Then,
we
focus
analysis
on
improvement
distinct
for
different
types
optimized
without
distinction
types.
Our
findings
are:
(1)
superiority
over
simulations,
leading
root
mean
squared
error
(RMSE)
NEE
less
than
3.5
μmolm-2s-1
compared
5
(2)
better
performances
significant
RECO,
(3)
when
crop-type
lumped
together,
lower
RMSE
Akaike
criterion
(AIC),
despite
larger
number
parameters.
Associated
availability
land
cover
maps,
data
parameterization
presented
study,
provide
step
forward
upscaling
carbon
scale.
International Journal of Applied Earth Observation and Geoinformation,
Год журнала:
2024,
Номер
130, С. 103925 - 103925
Опубликована: Май 21, 2024
The
aboveground
biomass
(AGB)
is
closely
linked
to
the
carbon
cycle
in
grassland
ecosystems
worldwide.
Accurately
quantifying
AGB
variations
thus
essential
for
assessing
sequestration
and
its
feedback
on
climate
change.
Although
many
studies
have
investigated
AGB,
they
are
limited
local
areas
few
research
efforts
been
attempted
estimate
at
large
scales
with
constraint
of
situ
quadrat
harvested
AGB.
In
this
study,
we
used
multi-source
satellite
remote
sensing
data
from
2000
2021
abundant
harvest
quadrats
explore
estimation
methods
then
analyze
spatiotemporal
patterns
various
types
across
China's
three
ecoregions.
results
indicate
that:
(1)
temporal
resolution
improvement
a
higher
correlation
between
remotely
sensed
NDVI
Therefore,
MODIS
MCD43A4
dataset
has
better
fit
harvesting
data.
(2)
Compared
statistical
methods,
machine
learning
algorithms
exhibit
high
accuracy
estimating
Among
them,
random
forest
(RF)
model
performs
most
robustly,
highest
R2
0.83
(explaining
83
%
variation
AGB),
lowest
RMSE
43.84
gm−2.
(3)
multi-year
average
annual
maximum
decreases
southeast
northwest,
temperate
steppe
region
having
highest,
followed
by
alpine
vegetation
desert
region.
(4)
While
approximately
61.94
pixels
show
an
increasing
trend
2021,
significant
(P
<
0.05)
changes
mainly
concentrated
eastern
each
ecoregion.
Our
study
presents
valuable
framework
using
datasets.
Additionally,
it
provides
robust
product
grasslands
contributing
our
understanding
long-term
ecosystems.
International Journal of Digital Earth,
Год журнала:
2024,
Номер
17(1)
Опубликована: Авг. 19, 2024
Mangroves
are
vital
coastal
ecosystems
that
provide
crucial
links
between
land
and
sea.
Tree
height
is
a
key
indicator
for
assessing
mangroves'
health
status.
Currently,
there
still
numerous
challenges
in
estimating
mangrove
tree
height.
In
this
study,
multiple
deep
learning
shallow
machine
regression
models
were
developed
to
accurately
estimate
using
multi-dimensional
Light
Detection
Ranging
(LiDAR)
point
clouds
their
derivatives.
We
constructed
novel
CNN_RepMLP
model
mapping.
also
further
verified
the
applicability
of
different
types
heights,
explored
influence
LiDAR-derived
features
on
inversion
accuracy
heights.
The
results
indicated
following:
(1)
displayed
satisfactory
performance
exhibited
better
robustness
generalization
ability
than
convolutional
neural
network
(CNN)
model.
(2)
Among
feature
combinations,
combining
variables
with
intensity
can
not
only
mitigate
negative
impact
models,
but
enhance
accuracy.
(3)
ensemble
framework
ExtraTrees
as
meta-model
make
use
differences
complementarities
single
base
trees
compared
other
models.
(4)
Multiple
based
UAV-LiDAR
point-cloud-derived
suitable
outperformed
CNN
stacking
had
more
detailed
differentiation
terms
Its
prediction
realistically
reflect
spatial
characteristics
Earth system science data,
Год журнала:
2024,
Номер
16(11), С. 5267 - 5285
Опубликована: Ноя. 14, 2024
Abstract.
Forest
stand
mean
height
is
a
critical
indicator
in
forestry,
playing
pivotal
role
various
aspects
such
as
forest
inventory,
sustainable
management
practices,
climate
change
mitigation
strategies,
monitoring
of
structure
changes,
and
wildlife
habitat
assessment.
However,
there
currently
lack
large-scale,
spatially
continuous
maps.
This
primarily
due
to
the
requirement
accurate
measurement
individual
tree
each
plot,
task
that
cannot
effectively
be
achieved
by
existing
globally
covered,
discrete
footprint-based
satellite
platforms.
To
address
this
gap,
study
was
conducted
using
over
1117
km2
close-range
light
detection
ranging
(lidar)
data,
which
enables
heights
plots
with
high
precision.
Apart
from
lidar
incorporated
climatic,
edaphic,
topographic,
vegetative,
synthetic
aperture
radar
data
explanatory
variables
map
tree-based
arithmetic
(ha)
weighted
(hw)
at
30
m
resolution
across
China.
Due
limitations
obtaining
basal
area
within
uncrewed
aerial
vehicle
(UAV)
calculated
through
weighting
an
square
its
height.
In
addition,
overcome
potential
influence
different
vegetation
divisions
large
spatial
scale,
we
also
developed
machine-learning-based
mixed-effects
(MLME)
model
The
results
showed
average
ha
hw
China
were
11.3
13.3
standard
deviations
2.9
3.3
m,
respectively.
accuracy
mapped
products
validated
utilizing
field
data.
correlation
coefficient
(r)
for
ranged
0.603
0.906
0.634
0.889,
while
root
error
(RMSE)
2.6
4.1
4.3
Comparing
canopy
maps
derived
area-based
approach,
it
found
our
performed
better
aligned
more
closely
natural
definition
methods
presented
provide
solid
foundation
estimating
carbon
storage,
changes
structure,
managing
assessing
availability.
dataset
constructed
publicly
available
https://doi.org/10.5281/zenodo.12697784
(Chen
et
al.,
2024).