Longitudinal and temporal variation in fish assemblage structure along lowland prairie Neotropical streams and relationships with environmental variables
Inland Waters,
Год журнала:
2025,
Номер
unknown, С. 1 - 30
Опубликована: Янв. 17, 2025
The
structure
of
fish
assemblages
in
lotic
systems
usually
varies
from
headwaters
to
the
mouth,
related
geomorphological
and
physicochemical
changes.
We
evaluated
main
processes
that
on
spatial,
seasonal,
decadal
(2009-2010;
2019-2020)
scales
relationships
with
environmental
variables
two
low-impacted
Neotropical
Pampean
streams
tributaries
Río
de
la
Plata
estuary
(RdlP).
Environmental
longitudinal
variation
assemblage
were
depth,
macrophyte
cover,
altitude,
showing
higher
values
headwater
compared
downstreams.
Species
richness
increased
towards
lower
stream
sectors
due
migration
riverine
species
RdlP.
Beta
diversity
partitioning
analysis
showed
greatest
proportion
variability
was
explained
by
turnover
component
both
seasonal
analyses.
a
more
stable
composition,
consisting
order
Characiformes
associated
aquatic
macrophytes,
while
downstream
recorded
greater
entry
migrant
Siluriformes
RdlP,
highlighting
essential
ecological
function
for
RldP
assemblages.
comparison
is
persistent
long
term
regardless
study
period.
Therefore,
consistent
pattern
its
explanatory
have
applicability
conservation
biomonitoring
lowland
streams,
serving
as
reference
recovery
efforts.
Язык: Английский
Transition to Agroecological Practices: Positive Effects on Streams and Biofilms
International Review of Hydrobiology,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 23, 2025
ABSTRACT
Transformations
in
agricultural
practices,
particularly
regarding
chemical
inputs
such
as
pesticides,
affect
physical
and
characteristics
biotic
communities
of
streams.
Currently,
many
conventional
production
systems
are
transitioning
to
economically
environmentally
more
sustainable
production,
which
aims
reduce
the
use
synthetic
inputs.
However,
it
remains
unclear
whether
agroecological
practices
positively
impact
environment.
Here,
we
compared
toxicity
sediments
from
streams
areas
transition
horticultural
well
reference
areas.
Additionally,
effects
on
stream
biofilms
were
assessed
7‐day
bioassays,
measuring
chlorophyll‐a,
extracellular
polymeric
substance
concentrations,
ash‐free
dry
weight,
diatom
motility.
In
with
horticulture,
pesticides
frequent
had
higher
concentrations
than
horticulture.
This
was
reflected
biofilms,
lower
algal
biomass
cell
motility
under
Our
study
suggested
that
even
early
stages,
positive
aquatic
ecosystems,
found
similarities
pesticide
biological
between
sites
horticulture
less‐impact
sites,
for
example,
grasslands
sites.
reports
integrates
a
complex
mixture
contaminants
used
intensive
providing
realistic
assessment
their
environmental
consequences.
Язык: Английский