Víztudományi és Vízbiztonsági Nemzeti Laboratórium(RRF-2.3.1-21-2022-00008) Támogató:
NKFIH
FFT NP FTA(MTA Fenntartható Fejlődés és Technológiák Nemzeti Program) Támogató: MTA
((138296) OTKA PD) Támogató: NKFIH
The assembly of real‐world ecological communities in human‐modified landscapes is
influenced by a complex interplay of spatial, temporal, environmental and invasion
gradients. However, understanding the relative importance of these drivers and their
interactions in shaping functional assembly remains elusive. Our study aimed to investigate
the relative influence of these drivers on the functional assembly of a stream fish
metacommunity.LocationStreams
of the Lake Balaton catchment, Hungary.MethodsWe
analysed a long‐term (18‐year) dataset of the stream fish metacommunity, focusing
on changes in functional diversity (Q), redundancy (R) and species dominance (D).
Ternary diagrams were utilized to decompose functional diversity into Q, R and D components
and to visualize diversity patterns. Linear mixed‐effect regression and separate structural
equation models were employed to identify significant drivers of Q, R and D.ResultsNative
fish communities exhibited low functional diversity (Q) but high redundancy (R) and
dominance (D), indicating functional convergence and dominance. Stream habitat size,
network position and associated spatial, physical and chemical gradients emerged as
consistently significant drivers of D and R. Changes in Q were additionally linked
to non‐native community properties and subtle shifts in land use and within‐stream
habitat characteristics.Main ConclusionsOur
findings suggest that both environmental filtering and interspecies interactions,
particularly trait similarity between invaders and natives shape functional assembly
of stream fish metacommunities. Despite minimal temporal directional changes, environmental
drivers predominantly influence long‐term diversity patterns of native fish communities,
overshadowing invasion effects. Our findings underscore the importance of considering
both environmental filtering mechanisms and interspecies interactions in understanding
functional assembly. Additionally, the joint application of diversity decomposition
frameworks with predictive modelling provides comprehensive insight into patterns
of functional diversity and assembly across ecological communities.
