Scientific Reports,
Journal Year:
2023,
Volume and Issue:
13(1)
Published: March 22, 2023
Abstract
Solar
spectral
reflectance
and
transmittance
of
natural
leaves
exhibit
dramatic
similarity.
To
elucidate
the
formation
mechanism
physiological
significance,
a
radiative
transfer
model
was
constructed,
effects
stacked
mesophyll
cells,
chlorophyll
content
leaf
thickness
on
visible
light
absorptance
were
analyzed.
Results
indicated
that
scattering
caused
by
cells
is
responsible
for
The
optical
path
in
increased
with
process,
resulting
significantly
reduced
meanwhile
at
low
level,
thus
tends
to
maximum
absorption
photosynthetically
active
radiation
(PAR)
enhanced.
Interestingly,
as
two
key
functional
traits
affecting
process
PAR,
certain
environment
show
convergent
behavior,
high
leaves,
which
demonstrates
PAR
utilizing
strategies
leaves.
This
work
provides
new
perspective
revealing
evolutionary
processes
ecological
can
be
adopted
guide
improvement
directions
crop
photosynthesis.
Ecological Indicators,
Journal Year:
2023,
Volume and Issue:
147, P. 109978 - 109978
Published: Feb. 8, 2023
Ecosystem
services
(ES)
contribute
to
human
well-being
and
provide
an
important
contribution
economies
at
all
scales.
However,
ES
are
often
difficult
measure
quantify,
thus,
it
is
adequately
account
for
the
true
value
of
their
contributions.
The
use
indicators,
understood
as
proxies
estimating
provision
ES,
has
been
proposed
a
solution
this
obstacle.
In
context,
indicators
physical
elements
ecosystems
that
can
be
relatively
easily
quantified
with
available
tools
knowledge,
usually
communicated
decision-makers
practitioners.
study,
we
conducted
literature
review
peer
reviewed
publications,
aiming
complete
up-to-date
list
ES.
total,
generated
85
individual
have
previously
used
in
practice
linked
them
each
one
described
by
CICES
(v5.1)
classification
system.
Moreover,
identified
which
those
could
derived
from
remotely
sensed
(RS)
data
following
three
categories:
i)
RS
direct
relation
indicator,
ii)
indirect
indicator
requires
additional
information
or
modelling,
iii)
Indicators
not
derivable
currently
without
enough
available.
Only
minority
these
(6)
directly
data,
while
most
(46)
indirectly,
some
(33)
data.
Remote Sensing of Environment,
Journal Year:
2023,
Volume and Issue:
290, P. 113530 - 113530
Published: March 10, 2023
Functional
diversity
is
a
critical
component
driving
ecosystem
functioning.
Spatially
explicit
data
of
plant
functional
traits
and
are
essential
for
understanding
biodiversity
effects
on
Here
we
retrieved
three
morphological
(95th
quantile
height,
leaf
area
index,
foliage
height
diversity)
physiological
(chlorophyll
+
b
content,
specific
area,
equivalent
water
thickness)
from
airborne
laser
scanning
multispectral
Sentinel-2
data,
respectively.
We
found
LiDAR-derived
parameters
correlated
well
with
in-situ
plot-level
(R2
≥
0.67).
For
satellite-derived
traits,
partial
least
squares
regression
(PLSR)
obtained
higher
prediction
accuracy
=
0.26–0.43,
cross-validation
community-weighted
mean
(CWM)
trait
data)
than
vegetation
index
(VI)
approach.
The
remotely-sensed
were
used
as
input
to
estimate
multi-trait
(FD)
indices
in
species-rich
subtropical
mountainous
forest.
Finally,
investigated
the
influence
single-trait
CWMs,
FD
environmental
variables
remotely-derived
aboveground
carbon
stocks
(aboveground
biomass,
AGB)
primary
productivity
(kernel
normalized
difference
kNDVI).
CWMs
all
significant
predictors
AGB
kNDVI,
suggested
by
mass-ratio
hypothesis.
Morphological
also
important
indicating
complementarity
crown
architectures.
In
best-fit
multivariate
models,
first
principal
CWM
that
most
richness
was
additionally
selected
models
kNDVI
at
landscape
scales.
Our
work
highlights
potential
using
assess
relationship
between
functioning
across
large,
contiguous
areas.
International Journal of Applied Earth Observation and Geoinformation,
Journal Year:
2020,
Volume and Issue:
95, P. 102242 - 102242
Published: Oct. 17, 2020
Machine
learning
algorithms,
in
particular,
kernel-based
machine
methods
such
as
Gaussian
processes
regression
(GPR)
have
shown
to
be
promising
alternatives
traditional
empirical
for
retrieving
vegetation
parameters
from
remotely
sensed
data.
However,
the
performance
of
GPR
predicting
forest
biophysical
has
hardly
been
examined
using
full-spectrum
airborne
hyperspectral
The
main
objective
this
study
was
evaluate
potential
estimate
leaf
area
index
(LAI)
To
achieve
this,
field
measurements
LAI
were
collected
Bavarian
Forest
National
Park
(BFNP),
Germany,
concurrent
with
acquisition
Fenix
images
(400−2500
nm)
July
2017.
further
compared
three
commonly
used
(i.e.,
narrowband
indices
(VIs),
partial
least
square
(PLSR),
and
artificial
neural
network
(ANN)).
cross-validated
coefficient
determination
(Rcv2)
root
mean
error
(RMSEcv)
between
retrieved
field-measured
examine
accuracy
respective
methods.
Our
results
showed
that
entire
spectral
data
nm),
yielded
most
accurate
estimation
(Rcv2
=
0.67,
RMSEcv
0.53
m2
m−2)
best
performing
VIs
SAVI2
0.54,
0.63
m−2),
PLSR
0.74,
0.73
ANN
0.68,
0.54
m−2).
Consequently,
when
a
subset
obtained
analysis
model
input,
predictive
accuracies
generally
improved
(GPR
0.52
m−2;
0.55
0.69
indicating
extracting
useful
information
vast
bands
is
crucial
improving
performance.
In
general,
there
an
agreement
measured
estimated
different
approaches
(p
>
0.05).
generated
map
BFNP
endorsed
spatial
distribution
across
dominant
classes
(e.g.,
deciduous
stands
associated
higher
values).
accompanying
uncertainty
by
shows
uncertainties
observed
mainly
regions
low
values
(low
cover)
areas
which
not
well
represented
sample
plots.
This
demonstrated
estimating
Owing
its
capability
generate
predictions
estimates,
evaluated
candidate
operational
retrieval
applications
traits.
Remote Sensing of Environment,
Journal Year:
2021,
Volume and Issue:
266, P. 112676 - 112676
Published: Sept. 21, 2021
Vitality
loss
of
trees
caused
by
extreme
weather
conditions,
drought
stress
or
insect
infestations,
are
expected
to
increase
with
ongoing
climate
change.
The
detection
vitality
at
an
early
stage
is
thus
vital
importance
for
forestry
and
forest
management
minimize
ecological
economical
damage.
Remote
sensing
instruments
able
detect
changes
over
large
areas
down
the
level
individual
trees.
scope
our
study
investigate
whether
it
possible
stress-related
spectral
using
hyperspectral
sensors.
For
this
purpose,
two
Norway
spruce
(Picea
abies)
stands,
both
different
in
age
maintenance,
were
monitored
field
vegetation
periods.
In
parallel,
time
series
airborne
remote
data
acquired.
each
stand
70
artificially
stressed
(ring-barked)
used
as
control
collected
south-eastern
Germany
consists
measurements
multiple
times
scales:
(1)
crown
conditions
visually
assessed
(2)
needle
reflectance
spectra
acquired
laboratory
a
FieldSpec
spectrometer,
(3)
(HySpex)
flown
0.5
m
spatial
resolution.
We
aimed
simultaneous
acquisition
three
levels.
This
unique
set
was
investigated
any
feature
can
be
discriminated
stage.
Several
transformations
applied
tree
spectra,
such
derivatives,
indices
angle
indices.
All
features
examined
their
separability
(ring-barked
vs.
trees)
Random
Forest
(RF)
classification
algorithm.
As
result,
younger,
well
maintained
only
showed
minor
2-year
period,
whereas
older
observable
respectively.
These
could
even
detected
before
visible
observations.
reactions
ring-barking
first
noticeable
11
months
after
6
weeks
they
inspection.
most
discriminative
separating
groups
VIs
separated
RF
classifier
79%
overall
accuracy
beginning
second
period
1
month
later
92%
high
kappa
index.
results
clearly
demonstrate
great
potential
detecting
The Crop Journal,
Journal Year:
2022,
Volume and Issue:
10(5), P. 1251 - 1263
Published: May 16, 2022
Leaf
pigments
are
critical
indicators
of
plant
photosynthesis,
stress,
and
physiological
conditions.
Inversion
radiative
transfer
models
(RTMs)
is
a
promising
method
for
robustly
retrieving
leaf
biochemical
traits
from
canopy
observations,
adding
prior
information
has
been
effective
in
alleviating
the
"ill-posed"
problem,
major
challenge
model
inversion.
Canopy
structure
parameters,
such
as
area
index
(LAI)
average
inclination
angle
(ALA),
can
serve
pigment
retrieval.
Using
spectra
simulated
PROSAIL
model,
we
estimated
effects
uncertainty
LAI
ALA
used
lookup
table-based
inversions
chlorophyll
(Cab)
carotenoid
(Car).
The
retrieval
accuracies
two
were
increased
by
use
priors
(RMSE
Cab
7.67
to
6.32
μg
cm−2,
Car
2.41
2.28
cm−2)
5.72
2.23
cm−2).
However,
this
improvement
deteriorated
with
an
increase
additive
multiplicative
uncertainties,
when
40%
20%
noise
was
added
respectively,
these
ceased
accuracy.
Validation
using
experimental
winter
wheat
dataset
also
showed
that
compared
Car,
estimation
accuracy
more
or
less
structure.
This
study
demonstrates
possible
limitations
RTM
biochemistry,
large
uncertainties
present.
Remote Sensing,
Journal Year:
2023,
Volume and Issue:
15(10), P. 2627 - 2627
Published: May 18, 2023
Protecting
and
enhancing
forest
carbon
sinks
is
considered
a
natural
solution
for
mitigating
climate
change.
However,
the
increasing
frequency,
intensity,
duration
of
droughts
due
to
change
can
threaten
stability
growth
existing
sinks.
Extreme
weaken
plant
hydraulic
systems,
lead
tree
mortality
events,
may
reduce
diversity,
making
forests
more
vulnerable
subsequent
disturbances,
such
as
fires
or
pest
infestations.
Although
early
warning
metrics
(EWMs)
derived
using
satellite
remote
sensing
data
are
now
being
tested
predicting
post-drought
physiological
stress
mortality,
applications
unmanned
aerial
vehicles
(UAVs)
yet
be
explored
extensively.
Herein,
we
provide
twenty-four
prospective
approaches
classified
into
five
categories:
(i)
complexities,
(ii)
site-specific
confounding
(abiotic)
factors,
(iii)
interactions
with
biotic
agents,
(iv)
monitoring
optimization,
(v)
technological
infrastructural
developments,
adoption,
future
operationalization,
upscaling
UAV-based
frameworks
EWM
applications.
These
UAV
considerations
paramount
they
hold
potential
bridge
gap
between
field
inventory
assessing
characteristics
their
responses
drought
conditions,
identifying
prioritizing
conservation
needs
and/or
high-carbon-efficient
species
efficient
allocation
resources,
optimizing
management
adaptation
mitigation
practices
in
timely
cost-effective
manner.
Artificial
intelligence
methods
and
application
have
recently
shown
great
contribution
in
modeling
prediction
of
the
hydrological
processes,
climate
change,
earth
systems.
Among
them,
deep
learning
machine
mainly
reported
being
essential
for
achieving
higher
accuracy,
robustness,
efficiency,
computation
cost,
overall
model
performance.
This
paper
presents
state
art
applications
this
realm
current
state,
future
trends
are
discussed.
The
survey
advances
presented
through
a
novel
classification
methods.
concludes
that
is
still
first
stages
development,
research
progressing.
On
other
hand,
already
established
fields,
with
performance
emerging
ensemble
techniques
hybridization.
Remote Sensing,
Journal Year:
2019,
Volume and Issue:
12(1), P. 28 - 28
Published: Dec. 19, 2019
Leaf
pigment
contents,
such
as
chlorophylls
a
and
b
content
(C
)
or
carotenoid
(Car),
the
leaf
area
index
(LAI)
are
recognized
indicators
of
plants’
forests’
health
status
that
can
be
estimated
through
hyperspectral
imagery.
Their
measurement
on
seasonal
yearly
basis
is
critical
to
monitor
plant
response
adaptation
stress,
droughts.
While
extensively
done
over
dense
canopies,
estimation
these
variables
tree-grass
ecosystems
with
very
low
overstory
LAI
(mean
site
<
1
m
2
/m
),
woodland
savannas,
lacking.
We
investigated
use
look-up
table
(LUT)-based
inversion
radiative
transfer
model
retrieve
C
Car
from
AVIRIS
images
at
an
18
spatial
resolution
multiple
dates
broadleaved
savanna
during
California
drought.
compared
performances
different
cost
functions
in
step.
demonstrated
consistency
our
LAI,
,
estimations
using
validation
data
high
canopy
cover
parts
site,
their
temporal
by
qualitatively
confronting
variations
two
years
those
would
expected.
concluded
LUT-based
inversions
medium-resolution
images,
achieved
simple
geometric
representation
within
3D
(RTM),
valid
means
monitoring
savannas
more
generally
sparse
forests,
although
for
maximum
applicability,
should
selected
dates.
Validation
revealed
use:
The
normalized
difference
vegetation
(NDVI)
outperformed
other
indices
(root
mean
square
error
(RMSE)
=
0.22
R
0.81);
band
ratio
ρ
0.750
μ
0.550
retrieved
accurately
than
(RMSE
5.21
g/cm
0.73);
RMSE
0.5–0.55
interval
showed
encouraging
results
estimations.