Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: Feb. 19, 2024
Abstract
The
Holocene
temperature
conundrum,
the
discrepancy
between
proxy-based
global
cooling
and
simulated
annual
warming
trends,
remains
controversial.
Meanwhile,
reconstructions
simulations
show
inconsistent
spatial
patterns
of
terrestrial
changes.
Here
we
report
alkenone
records
to
address
over
mid-latitude
Eurasia.
In
contrast
with
long-term
trends
in
warm
season
temperatures
northeastern
China,
from
southwestern
Siberia
are
characterized
by
colder
conditions
before
~6,000
years
ago,
thus
trends.
Together
existing
surrounding
regions,
infer
that
airmass
might
have
prevailed
interior
Eurasian
continent
during
early
mid-Holocene,
perhaps
associated
atmospheric
response
remnant
ice
sheets.
Our
results
challenge
proposed
seasonality
bias
proxies
modeled
study
region,
highlighting
changes
should
be
re-considered
record
integrations
model
simulations,
important
implications
for
hydroclimate
Paleoceanography and Paleoclimatology,
Journal Year:
2023,
Volume and Issue:
38(10)
Published: Sept. 28, 2023
Abstract
Foraminiferal
isotopes
are
widely
used
to
study
past
oceans,
with
different
species
recording
conditions
at
depths.
Their
δ
18
O
values
record
both
seawater
oxygen‐18
and
temperature
according
species‐specific
fractionation
factors,
while
their
Δ
47
signatures
likely
depend
only
on
temperature.
We
describe
an
open‐source
framework
collect/combine
data
relevant
foraminiferal
isotopes,
by
constraining
factors
(
α
)
based
culture
experiments,
stratified
plankton
tows
or
core‐top
sediments;
compiling
tow
constraints
living
depths
for
planktic
species;
extracting
temperature,
O,
chemistry
from
existing
databases
any
latitude,
longitude,
depth‐range;
inferring
calcification
temperatures
the
above
data.
find
that
although
differs
between
species,
its
sensitivity
remains
indistinguishable
inorganic
calcite.
Based
>
2,600
observations
we
show
that,
most
consistent
over
expected
depths,
a
sizable
minority
(12%–24%)
have
heavier‐than‐predicted
best
explained
in
deeper
waters.
use
this
revisit
three
recent
calibration
studies
of
planktic/benthic
foraminifera,
confirming
varies
systematically
oxygen‐18‐derived
estimates,
even
samples
whose
disagrees
assumed
climatological
conditions,
demonstrating
excellent
agreement
foraminifera
modern,
largely
calibrations.
Benthic
remain
ambiguous:
modern
benthic
appear
offset
ones,
yet
applying
equilibrium
Cenozoic
foraminifer
Meckler
et
al.
(2022,
https://doi.org/10.1126/science.abk0604
reconciles
it
O‐derived
temperatures,
discrete
/δ
discrepancies
persisting
Late
Paleocene/Eocene/Plio‐Pleistocene.
Abstract
Climate
warming
threatens
to
destabilize
vast
northern
permafrost
areas,
potentially
releasing
large
quantities
of
organic
carbon
that
could
further
disrupt
the
climate.
Here
we
synthesize
paleorecords
past
permafrost-carbon
dynamics
contextualize
future
stability
and
feedbacks.
We
identify
key
landscape
differences
between
last
deglaciation
today
influence
response
atmospheric
warming,
as
well
landscape-level
limit
subsequent
uptake.
show
current
magnitude
thaw
has
not
yet
exceeded
previous
deglaciations,
but
release
potential
exert
a
strong
feedback
on
Arctic
climate
temperatures
exceed
those
Pleistocene.
Better
constraints
extent
subsea
its
pool,
from
range
processes,
including
blowout
craters
megaslumps,
are
needed
help
quantify
permafrost-carbon-climate
Mycosphere,
Journal Year:
2023,
Volume and Issue:
14(1), P. 815 - 917
Published: Jan. 1, 2023
Trichaptum
sensu
lato
is
a
widespread
wood-decay
fungal
group
important
for
the
transfer
of
energy
and
recycling
nutrients
in
forest
ecosystems.The
taxonomy
s.l.
was
previously
mostly
based
on
morphology,
phylogenetic
relationships
among
taxa
are
poorly
known.The
systematics
revised
using
molecular
study
which
analysed
combined
datasets
ITS+nLSU+mt-SSU+nuc-SSU+TEF1
from
256
samples.Maximum
Likelihood
(ML)
Bayesian
Inference
(BI)
were
employed
to
perform
analyses
these
datasets.The
traditional
polyphyletic.Two
main
clades,
distantly
related,
recognized
two
new
families,
Hirschioporaceae
Trichaptaceae,
proposed
represent
clades.All
analyzed
samples
formed
seven
independent
clades
representing
genera,
them
five
newly
proposed.38
lineages
nested
10
described
as
species.In
addition,
total
49
identified
by
morphological
examination
625
specimens
19
countries,
28
combinations
proposed.To
support
our
results,
divergence
time
estimation
historical
biogeography
analyzed.Photos
illustrations
ten
species
presented,
full
description
each
given.This
recognizes
genera
belonging
Hymenochaetales
provides
modern
global
treatment
s.l.Keys
families
provided,
identification
keys
accepted
worldwide
given.Keywords
-38
taxadivergence
estimationphylogenypolyporetaxonomy
s.l.based
around
world.Combined
with
sequences
type
specimen
or
localities
GenBank,
available
DNA
involved
sequence
dataset
ITS+nLSU+mt-SSU+nuc-SSU+TEF1.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: Feb. 19, 2024
Abstract
The
Holocene
temperature
conundrum,
the
discrepancy
between
proxy-based
global
cooling
and
simulated
annual
warming
trends,
remains
controversial.
Meanwhile,
reconstructions
simulations
show
inconsistent
spatial
patterns
of
terrestrial
changes.
Here
we
report
alkenone
records
to
address
over
mid-latitude
Eurasia.
In
contrast
with
long-term
trends
in
warm
season
temperatures
northeastern
China,
from
southwestern
Siberia
are
characterized
by
colder
conditions
before
~6,000
years
ago,
thus
trends.
Together
existing
surrounding
regions,
infer
that
airmass
might
have
prevailed
interior
Eurasian
continent
during
early
mid-Holocene,
perhaps
associated
atmospheric
response
remnant
ice
sheets.
Our
results
challenge
proposed
seasonality
bias
proxies
modeled
study
region,
highlighting
changes
should
be
re-considered
record
integrations
model
simulations,
important
implications
for
hydroclimate
