Mediterranean Botany,
Год журнала:
2023,
Номер
Online first
Опубликована: Сен. 20, 2023
The
water
content
of
vegetation
is
considered
a
key
parameter
for
ecological
analysis
as
well
agricultural
and
forestry
applications.
Remote
sensing
methods
offer
significant
advantages
over
traditional
field
determining
the
at
leaf,
canopy,
landscape
levels.
In
this
study,
potential
hyperspectral
indices
in
predicting
canopy
grasslands
was
evaluated.
For
purpose,
data
were
collected
from
3
several
located
~500
m,
~1200
m
~1400
altitudes.
71
samples
each
study
area,
total
213
analyzed.
context,
59
ratio-based
tested.
relationship
between
evaluated
with
linear,
exponential,
logarithmic
power
regression
models.
results
showed
that
NW-3
(920,970)
index
significantly
represents
variable.
It
determined
exponential
model
created
able
to
explain
variations
up
85%.
On
other
hand,
it
has
been
detected
high
level
creates
saturation
problem.
Another
finding
predictive
reaches
higher
levels
low
characteristics.
show
situ
very
grasslands.
Ecological Indicators,
Год журнала:
2024,
Номер
160, С. 111770 - 111770
Опубликована: Фев. 22, 2024
Drought
events
occur
frequently,
but
the
impact
of
drought
on
plant
autumn
phenology,
i.e.,
End
growing
Season
(EOS),
has
not
been
thoroughly
studied.
Considering
that
cumulative
and
lagged
effects
plants.
In
this
study,
we
quantified
two
EOS
in
China.
Our
results
indicated
affected
39.5%
70.1%
plants
China
over
past
decades.
Two
short
timescales
(2-
to
4-accumulated
month
1-
5-lagged
month)
largely
first
months
advanced
EOS,
while
fifth
before
caused
overcompensate
for
growth
delayed
senescence.
At
biome
level,
forests
were
more
resistant
than
grasslands
shrublands.
From
perspective
water
balance
gradient,
was
significant
humid
regions,
it
found
increased
loss
exacerbated
shortened
response
time.
study
reveals
phenology
provides
insights
into
predicting
future
vegetation
patterns
under
global
change.
Land,
Год журнала:
2025,
Номер
14(4), С. 758 - 758
Опубликована: Апрель 1, 2025
As
a
measure
of
the
accumulated
heat
deficit
during
growing
season
transition,
cooling
degree
days
(CDDs)
play
crucial
role
in
regulating
vegetation
phenology
and
ecosystem
dynamics.
However,
systematic
analyses
CDD
trends
their
driving
mechanisms
remain
limited,
particularly
high-altitude
regions
where
climate
variability
is
pronounced.
This
study
investigated
spatiotemporal
CDDs
from
1982
to
2022
alpine
grasslands
on
Qinghai–Tibetan
Plateau
(TP)
quantified
contributions
key
climatic
factors.
The
results
indicate
that
lower
values
(<350
°C-days)
were
predominantly
found
warm,
arid
regions,
whereas
higher
(>600
concentrated
colder,
wetter
areas.
Temporally,
area-averaged
exhibited
significant
decline,
decreasing
490.9
°C-days
495.8
at
rate
3.8
per
year.
Elevation
plays
critical
shaping
patterns,
displaying
nonlinear
relationship:
decrease
as
elevation
increases
up
4300
m,
beyond
which
they
increase,
suggesting
transition
global
climate-driven
warming
elevations
local
environmental
controls
elevations,
snow–albedo
feedback,
topographic
effects,
atmospheric
circulation
patterns
regulate
temperature
Tmax
was
identified
dominant
driver
variation,
above
while
radiation
showed
consistent
positive
influence
across
elevations.
In
contrast,
precipitation
had
limited
spatially
inconsistent
effect.
These
findings
emphasize
complex
interactions
between
elevation,
temperature,
radiation,
trends.
By
providing
long-term
perspective
variations
drivers,
this
enhances
our
understanding
vegetation–climate
ecosystems.
offer
scientific
basis
for
modeling
late-season
phenological
changes,
resilience,
land-use
planning
under
ongoing
change.
Global Ecology and Biogeography,
Год журнала:
2025,
Номер
34(5)
Опубликована: Май 1, 2025
ABSTRACT
Aim
Cold
degree
days
(CDD)
represent
the
heat
deficit
for
vegetation
leaf
senescence
in
autumn
and
serve
as
a
critical
parameter
modelling
senescence.
This
study
aimed
to
quantify
spatiotemporal
patterns
of
CDD
its
key
accumulation
processes
determinants.
Location
At
northern
middle
high
latitudes
(>
30°
N).
Period
2001–2022.
Major
Taxa
Studied
Vegetation.
Methods
We
estimate
cumulative
sum
difference
between
daily
mean
temperature
threshold
(12.75°C)
during
period
from
midsummer
end
growing
season.
To
identify
crucial
metric,
we
employ
combination
grey
relational
analysis,
random
forest
model
partial
correlation
analysis.
Results
The
average
increases
linearly
with
latitude
at
rate
5.9°C‐days
per
degree.
Higher
exhibit
larger
300.0°C‐days),
longer
periods
70
days)
faster
rates
6.0°C/day),
whereas
lower
show
smaller
(<
60.0°C‐days),
shorter
30
slower
1.0°C/day).
Temporally,
tended
decrease
2001
2022
−1.3°C
±
4.0°C‐days/year,
largely
attributed
climate
warming.
Precipitation
frequency
emerged
significant
climatic
variable
influencing
variations
across
>
46%
area,
especially
on
Tibetan
Plateau.
While
warming
generally
reduces
CDD,
an
increase
precipitation
can
counteract
this
trend
shape
relationship
amount
CDD.
effects
radiation
wind
speed
were
less
pronounced
than
those
frequency,
exerting
positive
(cooling)
effect
that
producing
negative
(heating)
decreases
accumulation.
Main
Conclusions
highlights
aspects
process
emphasises
importance
incorporating
into
CDD‐based
phenology
models
latitudes.
