TY  - JOUR
A1  - Guill, Christian
A1  - Hülsemann, Janne
A1  - Klauschies, Toni
T1  - Self-organised pattern formation increases local diversity in metacommunities
JF  - Ecology letters
N2  - Self-organised formation of spatial patterns is known from a variety of different ecosystems, yet little is known about how these patterns affect the diversity of communities. Here, we use a food chain model in which autotroph diversity is described by a continuous distribution of a trait that affects both growth and defence against heterotrophs. On isolated patches, diversity is always lost over time due to stabilising selection, and the local communities settle on one of two alternative stable community states that are characterised by a dominance of either defended or undefended species. In a metacommunity context, dispersal can destabilise these states and complex spatio-temporal patterns in the species' abundances emerge. The resulting biomass-trait feedback increases local diversity by an order of magnitude compared to scenarios without self-organised pattern formation, thereby maintaining the ability of communities to adapt to potential future changes in biotic or abiotic environmental conditions.
KW  - biomass-trait feedback
KW  - fitness gradient
KW  - food chain
KW  - functional
KW  - diversity
KW  - metacommunity
KW  - self-organisation
KW  - source-sink dynamics
KW  - spatio-temporal pattern
KW  - trait-based aggregate model
KW  - Turing instability
Y1  - 2021
U6  - https://doi.org/10.1111/ele.13880
SN  - 1461-023X
SN  - 1461-0248
VL  - 24
IS  - 12
SP  - 2624
EP  - 2634
PB  - Wiley-Blackwell
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Kiemel, Katrin
A1  - Weithoff, Guntram
A1  - Tiedemann, Ralph
T1  - DNA metabarcoding reveals impact of local recruitment, dispersal, and hydroperiod on assembly of a zooplankton metacommunity
JF  - Molecular ecology
N2  - Understanding the environmental impact on the assembly of local communities in relation to their spatial and temporal connectivity is still a challenge in metacommunity ecology. This study aims to unravel underlying metacommunity processes and environmental factors that result in observed zooplankton communities. Unlike most metacommunity studies, we jointly examine active and dormant zooplankton communities using a DNA metabarcoding approach to overcome limitations of morphological species identification. We applied two-fragment (COI and 18S) metabarcoding to monitor communities of 24 kettle holes over a two-year period to unravel (i) spatial and temporal connectivity of the communities, (ii) environmental factors influencing local communities, and (iii) dominant underlying metacommunity processes in this system. We found a strong separation of zooplankton communities from kettle holes of different hydroperiods (degree of permanency) throughout the season, while the community composition within single kettle holes did not differ between years. Species richness was primarily dependent on pH and permanency, while species diversity (Shannon Index) was influenced by kettle hole location. Community composition was impacted by kettle hole size and surrounding field crops. Environmental processes dominated temporal and spatial processes. Sediment communities showed a different composition compared to water samples but did not differ between ephemeral and permanent kettle holes. Our results suggest that communities are mainly structured by environmental filtering based on pH, kettle hole size, surrounding field crops, and permanency. Environmental filtering based on specific conditions in individual kettle holes seems to be the dominant process in community assembly in the studied zooplankton metacommunity.
KW  - bulk DNA
KW  - dispersal
KW  - DNA-metabarcoding
KW  - environmental filtering;
KW  - metacommunity
KW  - zooplankton
Y1  - 2022
U6  - https://doi.org/10.1111/mec.16627
SN  - 0962-1083
SN  - 1365-294X
VL  - 32
IS  - 23
PB  - Wiley
CY  - Hoboken
ER  -