Understanding
the
stability
characteristics
of
aquatic
ecosystems
under
different
steady
states
is
essential
for
effective
regulation
and
restoration
ecological
systems.
The
can
be
largely
affected
by
diversity
microbial
food
webs,
which
dominantly
contribute
to
biogeochemical
processes
substances.
However,
knowledge
three-dimensional
including
horizontal
(DH),
vertical
(DV)
range
(DR),
remains
limited.
In
this
study,
composition
abundance
combined
bacteria,
phytoplankton,
protozoan
metazoan,
were
investigated
in
both
a
reservoir
downstream
slow-flowing
rivers
via
microscopic
monitoring
DNA
metabarcoding
methods
separately,
then
calculated
based
on
webs.
results
showed
that
samples
from
respectively
displayed
two
three
distinct
clustering
states,
community
compositions,
was
consistent
their
dominant
influence
factor,
trophic
level
index.
Compared
reservoir,
averagely
higher
(DH=0.25,
DV=0.18,
DR=0.01),
but
relatively
lower
(robustness=0.97).
DV
DR
significantly
declined
with
increased
eutrophication
rivers,
DH
rivers.
structural
nitrogen
removal
ability
low-eutrophic
medium-eutrophic
river
state
than
those
high
eutrophic
respectively.
Mantel
test
indicated
positively
influenced
waters.
Structural
equation
modeling
function
webs
mainly
through
complex
structure
untangled
diversity,
clarified
web
various
provided
new
insights
into
ecosystems.
Environmental Science & Technology,
Journal Year:
2023,
Volume and Issue:
57(21), P. 8075 - 8084
Published: May 15, 2023
The
effects
of
nitrogen
deposition
reduction
on
nutrient
loading
in
freshwaters
have
been
widely
studied,
especially
remote
regions.
However,
understanding
the
ecological
is
still
rather
limited.
Herein,
we
re-estimated
deposition,
both
wet
and
dry
Lake
Taihu
with
monthly
monitoring
data
from
2010
to
2021.
Our
results
showed
that
atmospheric
reactive
(namely
NH4+
NO3-)
was
4.94-11.49
kton/yr,
which
equaled
13.9%-27.3%
riverine
loading.
Dry
NO3-
contributed
53.1%
bulk
Taihu.
Ammonium
main
component
may
due
strong
agriculture-related
activities
around
Nitrogen
explained
24.9%
variation
phytoplankton
community
succession
2021
highest
among
all
environmental
factors.
Atmospheric
offset
external
during
early
years
delayed
emergence
nitrogen-fixing
cyanobacterial
dominance
implied
a
decrease
fertilizer
use,
could
limit
diatoms
promote
non-nitrogen-fixing
dominance,
followed
by
taxa.
This
result
also
applied
other
shallow
eutrophic
lakes
middle
lower
reaches
Yangtze
River,
where
significant
use
recorded
last
decades.
Water Science & Technology,
Journal Year:
2023,
Volume and Issue:
88(1), P. 136 - 150
Published: June 30, 2023
Abstract
Cyanotoxins
produced
by
cyanobacteria
are
a
significant
threat
to
human
health.
However,
their
responses
nitrogen
(N)
supplies
could
differ
between
N-fixing
and
non-N-fixing
species,
which
has
been
poorly
understood.
This
study
aimed
compare
the
of
Microcystis
aeruginosa
Nostoc
sp.
varying
concentrations
nitrate
ammonium.
comparison
had
conducted
analyzing
chlorophyll-a
contents,
maximum
quantum
efficiencies
photosystem
II,
microcystin
production,
related
gene
expressions.
Our
findings
revealed
that
substantially
stimulated
growth
both
M.
with
biomass
increase
366.2
±
56.5
93.0
14.0%,
respectively,
at
16
mg-N/L.
In
contrast,
high
ammonium
suppressed
growth.
Furthermore,
intracellular
concentration
microcystins
was
higher
under
nitrate.
Extracellular
showed
an
opposite
trend
increases
in
Ammonium
production
releases
from
N
metabolism
genes
similar
toxin
formation
genes,
were
up-regulated
treatments.
provides
valuable
insights
into
impacts
on
growths
N-
cyanobacteria,
as
well
helps
develop
effective
strategies
for
managing
cyanobacterial
blooms.
Marine Life Science & Technology,
Journal Year:
2025,
Volume and Issue:
7(1), P. 157 - 175
Published: Jan. 7, 2025
The
interaction
of
riverine
inputs
and
ocean
current
systems
causes
complex
spatiotemporal
variations
in
phytoplankton
dynamics
marginal
seas
the
northwest
Pacific
Ocean,
yet
quantitative
assessments
these
their
remain
limited.
Here
we
evaluate
biomass
community
structure
changes
using
lipid
biomarkers,
accompanying
circulation
nutrient
surface
waters
collected
spring
summer
2017-2018
at
118
sites
East
China
Sea
off
Zhejiang
coast.
High
diatoms,
inferred
from
brassicasterol
concentrations,
shifted
south
to
north
summer,
while
high
dinoflagellate
biomass,
dinosterol
occurred
mainly
Changjiang
(Yangtze)
River
plume
adjacent
areas
both
seasons.
Seasonal
variation
distribution
was
linked
spatial
extents
water
masses
such
as
Diluted
Water
(CDW)
intrusion
Kuroshio
Subsurface
(KSSW).
A
three
end-member
mixing
model
applied
quantify
mass
contributions.
results
showed
that
an
increase
KSSW
(from
0
40%)
a
decrease
CDW
100
20%)
resulted
significant
(20%)
diatom
proportions
proportions.
Dinoflagellate
were
highest
CDW-dominated
region,
diatoms
total
higher
CDW-KSSW
region
KSSW-dominated
region.
This
study
highlights
dynamic
response
can
aid
coastal
ecosystem
management.
online
version
contains
supplementary
material
available
10.1007/s42995-024-00260-y.
Water,
Journal Year:
2025,
Volume and Issue:
17(4), P. 472 - 472
Published: Feb. 8, 2025
Lakes
are
essential
ecosystems
that
play
a
significant
role
in
water
quality
and
biodiversity,
particularly
nutrient
cycling.
Nitrogen
compounds,
including
ammonium
(NH4+),
nitrate
(NO3−),
nitrite
(NO2−),
critical
elements
lake
ecosystems,
influencing
productivity
quality.
This
study
aimed
to
investigate
nitrogen
compounds
Qinghai
Lake,
assess
soil
indicators,
evaluate
the
relationship
between
(N)
phosphorus
(P)
levels
soil.
Water
samples
from
17
locations
around
nine
sites
at
two
depths
were
analyzed
for
various
parameters.
Statistical
regression
analyses
performed
explore
correlations
N
forms
other
parameters
total
P,
N,
pH
soil,
as
well
their
interactions
with
environmental
variables.
The
mean
concentrations
of
NO3−-N,
NH4+-N,
NO2−-N
0.0189
mg/L,
0.112
0.595
mg/L
respectively.
models
revealed
P
along
factors,
crucial
roles
regulating
levels.
These
findings
contribute
our
understanding
cycling
high-altitude
lakes
provide
insight
into
managing
eutrophication
risks
Lake.
