Frontiers in Forests and Global Change,
Journal Year:
2024,
Volume and Issue:
7
Published: June 11, 2024
Introduction
European
forests
face
increasing
threats
due
to
climate
change-induced
stressors,
which
create
the
perfect
conditions
for
bark
beetle
outbreaks.
The
most
important
spruce
forest
pest
in
Europe
is
Spruce
Bark
Beetle
(
Ips
typographus
L.).
Effective
management
of
I.
outbreaks
necessitates
timely
detection
recently
attacked
trees,
challenging
given
difficulty
spotting
symptoms
on
infested
tree
crowns.
population
density
one
many
factors
that
can
affect
infestation
rate
and
development.
This
study
compares
appearance
early
endemic
epidemic
populations
using
highresolution
Unmanned
Aerial
Vehicles
(UAV)
multispectral
imagery.
Methods
In
spring
2022,
host
colonization
by
beetles
was
induced
groups
trees
growing
10
sites
Southern
Alps,
characterized
different
(5
5
endemic).
A
sensor
mounted
a
drone
captured
images
once
every
2
weeks,
from
May
August
2022.
analyses
set
vegetational
indices
allowed
actual
trees’
reflectance
features
be
observed
at
each
site,
comparing
them
with
those
unattacked
trees.
Results
show
high
triggers
more
rapid
intense
response
regarding
emergence
symptoms.
Infested
were
detected
least
1
month
before
became
evident
human
eye
(red
phase)
sites,
while
this
not
possible
sites.
Key
performing
vegetation
included
NDVI
(Normalized
Difference
Vegetation
Index),
SAVI
(Soil
Adjust
Index,
correction
factor
0.44),
NDRE
Red
Edge
index).
Discussion
early-detection
approach
could
allow
automatic
diagnosis
beetles’
infestations
provide
useful
guidance
areas
suffering
Remote Sensing of Environment,
Journal Year:
2022,
Volume and Issue:
280, P. 113198 - 113198
Published: Aug. 4, 2022
Remote
detection
and
monitoring
of
the
vegetation
responses
to
stress
became
relevant
for
sustainable
agriculture.
Ongoing
developments
in
optical
remote
sensing
technologies
have
provided
tools
increase
our
understanding
stress-related
physiological
processes.
Therefore,
this
study
aimed
provide
an
overview
main
spectral
retrieval
approaches
detecting
crop
Firstly,
we
present
integrated
views
on:
i)
biotic
abiotic
factors,
phases
stress,
respective
plant
responses,
ii)
affected
traits,
appropriate
domains
corresponding
methods
measuring
traits
remotely.
Secondly,
representative
results
a
systematic
literature
analysis
are
highlighted,
identifying
current
status
possible
future
trends
monitoring.
Distinct
occurring
under
short-term,
medium-term
or
severe
chronic
exposure
can
be
captured
with
due
specific
light
interaction
processes,
such
as
absorption
scattering
manifested
reflected
radiance,
i.e.
visible
(VIS),
near
infrared
(NIR),
shortwave
infrared,
emitted
solar-induced
fluorescence
thermal
(TIR).
From
96
research
papers,
following
observed:
increasing
usage
satellite
unmanned
aerial
vehicle
data
parallel
shift
from
simpler
parametric
towards
more
advanced
physically-based
hybrid
models.
Most
designs
were
largely
driven
by
sensor
availability
practical
economic
reasons,
leading
common
VIS-NIR-TIR
combinations.
The
majority
reviewed
studies
compared
proxies
calculated
single-source
rather
than
using
synergistic
way.
We
identified
new
ways
forward
guidance
improved
detection:
(1)
combined
acquisition
multiple
sensors
analysing
simultaneously
(holistic
view);
(2)
simultaneous
combining
multi-domain
radiative
transfer
models
machine
learning
methods;
(3)
assimilation
estimated
distinct
into
growth
As
outlook,
recommend
streams
model
schemes
build
up
Digital
Twins
agroecosystems,
which
may
most
efficient
way
detect
diversity
environmental
stresses
thus
enable
management
decisions.
Remote Sensing of Environment,
Journal Year:
2021,
Volume and Issue:
255, P. 112240 - 112240
Published: Jan. 20, 2021
The
European
spruce
bark
beetle
(Ips
typographus
[L.])
is
one
of
the
most
damaging
pest
insects
forests.
A
crucial
measure
in
control
removal
infested
trees
before
beetles
leave
bark,
which
generally
happens
end
June.
However,
stressed
tree
crowns
do
not
show
any
significant
color
changes
visible
spectrum
at
this
early-stage
infestation,
making
early
detection
difficult.
In
order
to
detect
related
forest
stress
an
stage,
we
investigated
differences
radar
and
spectral
signals
healthy
trees.
How
characteristics
changed
over
time
was
analyzed
for
whole
vegetation
season,
covered
period
attacks
(April),
infestation
(‘green-attacks’,
May
July),
middle
late-stage
(August
October).
results
that
already
existed
beginning
attacks.
separability
between
samples
did
change
significantly
during
‘green-attack’
stage.
indicate
were
had
signatures
differed
from
ones.
These
stress-induced
could
be
more
efficient
indicators
infestations
than
symptoms.
study
used
Sentinel-1
2
images
a
test
site
southern
Sweden
April
October
2018
2019.
red
SWIR
bands
Sentinel-2
showed
highest
samples.
backscatter
additional
contributed
only
slightly
Random
Forest
classification
models.
We
therefore
propose
Normalized
Distance
Red
&
(NDRS)
index
as
new
based
on
our
observations
linear
relationship
bands.
This
identified
with
accuracies
0.80
0.88
attacks,
0.82
0.81
0.91
middle-
infestations.
are
higher
those
attained
by
established
indices
aimed
detection,
such
Difference
Water
Index,
Ratio
Drought
Disease
Stress
Index.
By
using
proposed
method,
highlight
potential
NDRS
estimate
vulnerability
season.
Remote Sensing of Environment,
Journal Year:
2023,
Volume and Issue:
287, P. 113484 - 113484
Published: Feb. 3, 2023
Detecting
disease-
or
insect-infested
forests
as
early
possible
is
a
classic
application
of
remote
sensing.
Under
conditions
climate
change
and
global
warming,
outbreaks
the
European
spruce
bark
beetle
(Ips
typographus,
L.)
are
threatening
related
timber
industry
across
Europe,
detection
infestations
important
for
damage
control.
Infested
trees
without
visible
discoloration
(green
attack)
have
been
identified
using
multispectral
images,
but
how
green
attacks
can
be
detected
still
unknown.
This
study
aimed
to
determine
when
infested
start
show
an
abnormal
spectral
response
compared
with
healthy
trees,
quantify
detectability
during
infestation
process.
Pheromone
bags
were
used
attract
beetles
in
controlled
experiment,
subsequent
assessed
field
on
weekly
basis.
In
total,
977
monitored,
including
208
attacked
trees.
Multispectral
drone
images
obtained
before
insect
attacks,
representing
different
periods
infestation.
Individual
tree
crowns
(ITC)
delineated
by
marker-controlled
watershed
segmentation,
average
reflectance
ITCs
was
analyzed
based
duration
The
driving
factors
examined.
We
propose
new
Multiple
Ratio
Disease–Water
Stress
Indices
(MR-DSWIs)
vegetation
indices
(VI)
detecting
infestations.
defined
VI
range
5–95%
tree,
value
outside
that
tree.
Detection
rates
always
higher
than
observed
field,
newly
proposed
MR-DSWIs
more
established
VIs.
Infestations
detectable
at
5
10
weeks
after
attack
rate
15%
90%,
respectively,
from
images.
Weeks
5–10
therefore
represent
suitable
period
methodology
map
stage.
Forest Ecology and Management,
Journal Year:
2024,
Volume and Issue:
556, P. 121595 - 121595
Published: Feb. 16, 2024
Bark
beetle
disturbances
increasingly
threaten
structure
and
functionality
of
temperate
boreal
forests
globally.
The
early
detection
bark
beetle-infested
trees,
i.e.
before
beetles'
emergence
from
the
breeding
tree,
is
essential
for
an
effective
outbreak
mitigation.
Terrestrial
control
surveys
as
traditionally
employed
infestation
detection,
however,
are
resource-intensive
approach
their
limits
in
difficult
terrain
during
mass
outbreaks.
Developments
remote
sensing
algorithms
giving
hope
that
early-infested
trees
will
be
detectable
remotely,
thereby
improving
success
management
efficacy.
Yet,
a
comprehensive
quantitative
evaluation
approaches
currently
being
developed
lacking
to
date.
This
review
synthesises
state-of-the-art
recent
research
on
(or
green-attack)
by
sensing,
places
it
context
with
underlying
biological
constraints,
technical
opportunities
potential
applications.
Since
each
beetle-host
tree
system
has
specific
characteristics
detectability,
we
focus
greatest
impact
European
forests,
spruce
(Ips
typographus),
which
attacks
Norway
(Picea
abies).
By
screening
published
within
period
2000–2022,
included
26
studies
our
analyses.
All
reviewed
were
purely
exploratory,
testing
variety
data
and/or
classification
relatively
limited
spatial
temporal
coverage.
Among
tested
platforms
sensor
types,
satellite
multispectral
imagery
most
frequently
investigated.
Promising
spectral
wavelength
range
or
index
highly
varied
among
regions.
Timeliness
accuracy
found
insufficient
efficient
management,
regardless
platform,
type,
resolution
applied.
main
reasons
preventing
better
performance
include
rapid
development
I.
typographus
combination
delayed
variable
vitality
response
crown,
frequent
cloud
cover
spruce-dominated
regions
across
Europe.
In
conclusion,
current
survey
methods
cannot
yet
replace
terrestrial
timely
management.
Nevertheless,
they
might
supportive
either
back-up
regular
surveys,
situations,
e.g.
detect
hibernation
accessibility,
extensively
managed
without
sufficient
capacity.
We
suggest
term
'early
detection'
used
consistently
synonym
'pre-emergence
avoid
ambiguity.
Finally,
provide
recommendations
future
based
lessons
learned
analysed,
namely
use
more
rigorous
targeted
study
design,
ensure
interdisciplinarity,
communicate
results
explicitly.
International Journal of Applied Earth Observation and Geoinformation,
Journal Year:
2021,
Volume and Issue:
102, P. 102383 - 102383
Published: June 8, 2021
Although
coastal
aquaculture
ponds
provide
high-quality
fish
protein
for
billions
of
people,
they
are
threatened
by
urbanization,
pollution,
and
climate
change.
Moreover,
colossal
pose
damages
such
as
natural
wetland
shrinkage
water
quality
deterioration.
However,
understanding
the
trends
drivers
on
a
national
scale
remains
challenge.
In
this
study,
decision-tree
classifier
was
used
to
quantify
spatiotemporal
distribution
over
last
30
years
in
12
provinces
located
coast
China.
we
analyzed
their
drivers,
including
geographical
conditions,
socioeconomic
factors,
development
policies.
The
key
results
study
include
following:
(1)
from
1990
2020,
cumulative
area
holding
reached
21997.90
km2
9613.66
km2,
representing
3.7-fold
1.6-fold
increase,
respectively,
than
values.
Based
most
tend
be
plains
bays
following
low-lying
land.
(2)
Influenced
different
levels
changed
policies,
experienced
"rapidly
increasing
period"
2011,
growing
246
per
year;
"stable
between
2011
2017;
"sharply
shrinking
after
2017
declining
417
km2/year.
(3)
Coastal
land
reclamation
played
critical
role
expansion
cumulatively
contributing
approximately
22%
resource
past
years.
future,
result
competition,
extent
China
tends
decrease
continually.
International Journal of Applied Earth Observation and Geoinformation,
Journal Year:
2021,
Volume and Issue:
100, P. 102335 - 102335
Published: April 20, 2021
In
the
past
decade,
massive
outbreaks
of
bark
beetles
(Ips
spp.)
have
caused
large-scale
decline
coniferous-dominated,
prevailingly
managed
forests
Central
Europe.
Timely
detection
newly
infested
trees
is
important
for
minimizing
economic
losses
and
effectively
planning
forest
management
activities
to
stop
or
at
least
slow
outbreaks.
With
advancement
Copernicus
services,
a
pair
Sentinel-2
satellites
provides
unique
remote
sensing
data
source
multi-temporal
observations
in
high
spatial
resolution
on
scale
individual
stands
(although
not
allowing
tree
detection).
This
study
investigates
potential
using
seasonal
trajectories
bands
selected
vegetation
indices
early
beetle
infestation
(so–called
green-attack
stage
detection)
Norway
spruce
monoculture
Czech
Republic.
Spectral
nine
six
were
constructed
2018
season
14
satellite
from
April
November
distinguish
four
classes.
We
used
random
algorithm
classify
healthy
(i.e.,
infested)
with
various
decay.
The
separated
classes
better
than
did
bands.
Among
most
promising
we
identified
tasselled
cap
wetness
(TCW)
component
normalized
difference
index
near
shortwave
infrared
Analysing
inter-annual
change
was
more
single-date
classification.
It
achieved
96%
classification
accuracy
day
year
291
tested
set.
based
assessment
changes
TCW
applied
time
series
2019
its
outputs
verified
field
conditions
conducted
80
plots
(located
stands).
overall
78%
separation
Our
highlights
great
use
wavelengths
by
infestation.
Remote Sensing of Environment,
Journal Year:
2022,
Volume and Issue:
278, P. 113073 - 113073
Published: May 13, 2022
Land
disturbance
can
increase
carbon
emissions,
cause
detrimental
environmental
impacts,
and
threaten
human
life
property.
Monitoring
land
in
near-real-time
is
essential
to
mitigate
their
negative
effects
prevent
future
losses.
However,
rapid
timely
monitoring
of
at
a
high
spatial
resolution
its
infancy.
Here,
we
developed
an
algorithm
for
Near-Real-Time
MOnitoring
laNd
dIsturbance
based
on
Time-series
harmOnized
Reflectance
(NRT-MONITOR)
from
Landsats
7–8
Sentinel-2
data
30-m
resolution.
It
incorporates
online
recursive
called
Forgetting
Factor
improve
efficiency
the
determination
get
fast
detection
harmonized
data.
This
validated
by
using
1200
samples
created
time
series
2015
2019
within
conterminous
United
States
(CONUS).
An
overall
accuracy
70%
has
been
achieved
variety
types.
NRT-MONITOR
improves
processing
(11.5
times
faster)
compared
COLD
(Zhu
et
al.,
2020).
The
mean
lag
NRT-MONITOR,
defined
as
delta
days
confirming
after
occurrence,
only
35
days,
which
observations
reduced
number
clear
(from
six
four)
needed
confirm
disturbance.
Finally,
be
integrated
into
alerting
system
provide
potential
probability
maps
that
are
updated
every
three
days.
Remote Sensing,
Journal Year:
2022,
Volume and Issue:
14(13), P. 3135 - 3135
Published: June 29, 2022
Insect
outbreaks
affect
forests,
causing
the
deaths
of
trees
and
high
economic
loss.
In
this
study,
we
explored
detection
European
spruce
bark
beetle
(Ips
typographus,
L.)
at
individual
tree
crown
level
using
multispectral
satellite
images.
Moreover,
possibility
tracking
progression
outbreak
over
time
multitemporal
data.
Sentinel-2
data
acquired
during
summer
2020
a
beetle–infested
area
in
Italian
Alps
were
used
for
mapping
time,
while
airborne
lidar
to
automatically
detect
crowns
classify
species.
Mapping
carried
out
support
vector
machine
classifier
with
input
vegetation
indices
extracted
from
The
results
showed
that
it
was
possible
two
stages
(i.e.,
early,
late)
an
overall
accuracy
83.4%.
how
is
technically
track
evolution
almost
bi-weekly
period
crowns.
outcomes
paper
are
useful
both
management
ecological
perspective:
allows
forest
managers
map
different
spatial
accuracy,
maps
describing
could
be
further
studies
related
behavior
beetles.
Bark
beetle
infestations
are
among
the
most
substantial
forest
disturbance
agents
worldwide.
Moreover,
as
a
consequence
of
global
climate
change,
they
have
increased
in
frequency
and
size
number
affected
areas.
Controlling
bark
outbreaks
requires
consistent
operational
monitoring,
is
possible
using
satellite
data.
However,
while
many
satellite-based
approaches
been
developed,
full
potential
dense,
multi-sensor
time
series
has
yet
to
be
fully
explored.
Here,
for
first
time,
we
used
all
available
multispectral
data
from
Landsat
Sentinel-2,
Sentinel-1
SAR
data,
combinations
thereof
detect
Bavarian
Forest
National
Park.
Based
on
multi-year
reference
dataset
annual
infested
areas,
assessed
separability
between
healthy
forests
various
vegetation
indices
calculated
We
two
compute
infestation
probability
different
datasets:
Bayesian
conditional
probabilities,
based
best-separating
index
each
type,
random
regression,
type.
Five
sensor
configurations
were
tested
their
detection
capabilities:
alone,
Sentinel-2
combined,
types
combined.
The
best
overall
results
terms
spatial
accuracy
achieved
with
(max.
accuracy:
0.93).
detections
also
closest
onset
estimated
year.
detected
areas
larger
contiguous
patches
higher
reliability
compared
smaller
patches.
somewhat
inferior
those
0.89).
While
yielding
similar
results,
combination
did
not
provide
any
advantages
over
or
alone
0.87),
was
unable
0.62).
combined
three
achieve
satisfactory
either
0.67).
Spatial
accuracies
typically
probabilities
than
forest-derived
but
latter
resulted
earlier
detections.
approach
presented
herein
provides
flexible
pipeline
well-suited
monitoring
outbreaks.
Furthermore,
it
can
applied
other
types.