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  - 
TY  - JOUR
A1  - Kiemel, Katrin
A1  - Gurke, Marie
A1  - Paraskevopoulou, Sofia
A1  - Havenstein, Katja
A1  - Weithoff, Guntram
A1  - Tiedemann, Ralph
T1  - Variation in heat shock protein 40 kDa relates to divergence in thermotolerance among cryptic rotifer species
JF  - Scientific reports
N2  - Genetic divergence and the frequency of hybridization are central for defining species delimitations, especially among cryptic species where morphological differences are merely absent. Rotifers are known for their high cryptic diversity and therefore are ideal model organisms to investigate such patterns. Here, we used the recently resolved Brachionus calyciflorus species complex to investigate whether previously observed between species differences in thermotolerance and gene expression are also reflected in their genomic footprint. We identified a Heat Shock Protein gene (HSP 40 kDa) which exhibits cross species pronounced sequence variation. This gene exhibits species-specific fixed sites, alleles, and sites putatively under positive selection. These sites are located in protein binding regions involved in chaperoning and may therefore reflect adaptive diversification. By comparing three genetic markers (ITS, COI, HSP 40 kDa), we revealed hybridization events between the cryptic species. The low frequency of introgressive haplotypes/alleles suggest a tight, but not fully impermeable boundary between the cryptic species.
Y1  - 2022
U6  - https://doi.org/10.1038/s41598-022-27137-3
SN  - 2045-2322
VL  - 12
IS  - 1
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - GEN
A1  - Cahsan, Binia De
A1  - Kiemel, Katrin
A1  - Westbury, Michael V.
A1  - Lauritsen, Maike
A1  - Autenrieth, Marijke
A1  - Gollmann, Günter
A1  - Schweiger, Silke
A1  - Stenberg, Marika
A1  - Nyström, Per
A1  - Drews, Hauke
A1  - Tiedemann, Ralph
T1  - Southern introgression increases adaptive immune gene variability in northern range margin populations of Fire-bellied toad
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Northern range margin populations of the European fire-bellied toad (Bombina bombina) have rapidly declined during recent decades. Extensive agricultural land use has fragmented the landscape, leading to habitat disruption and loss, as well as eutrophication of ponds. In Northern Germany (Schleswig-Holstein) and Southern Sweden (Skåne), this population decline resulted in decreased gene flow from surrounding populations, low genetic diversity, and a putative reduction in adaptive potential, leaving populations vulnerable to future environmental and climatic changes. Previous studies using mitochondrial control region and nuclear transcriptome-wide SNP data detected introgressive hybridization in multiple northern B. bombina populations after unreported release of toads from Austria. Here, we determine the impact of this introgression by comparing the body conditions (proxy for fitness) of introgressed and nonintrogressed populations and the genetic consequences in two candidate genes for putative local adaptation (the MHC II gene as part of the adaptive immune system and the stress response gene HSP70 kDa). We detected regional differences in body condition and observed significantly elevated levels of within individual MHC allele counts in introgressed Swedish populations, associated with a tendency toward higher body weight, relative to regional nonintrogressed populations. These differences were not observed among introgressed and nonintrogressed German populations. Genetic diversity in both MHC and HSP was generally lower in northern than Austrian populations. Our study sheds light on the potential benefits of translocations of more distantly related conspecifics as a means to increase adaptive genetic variability and fitness of genetically depauperate range margin populations without distortion of local adaptation.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1177 
KW  - Bombina bombina
KW  - heat shock protein
KW  - introgression
KW  - major histocompatibility complex
KW  - scaled mass index
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-523883
SN  - 1866-8372
IS  - 14
ER  - 
TY  - GEN
A1  - Kiemel, Katrin
A1  - Gurke, Marie
A1  - Paraskevopoulou, Sofia
A1  - Havenstein, Katja
A1  - Weithoff, Guntram
A1  - Tiedemann, Ralph
T1  - Variation in heat shock protein 40 kDa relates to divergence in thermotolerance among cryptic rotifer species
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Genetic divergence and the frequency of hybridization are central for defining species delimitations, especially among cryptic species where morphological differences are merely absent. Rotifers are known for their high cryptic diversity and therefore are ideal model organisms to investigate such patterns. Here, we used the recently resolved Brachionus calyciflorus species complex to investigate whether previously observed between species differences in thermotolerance and gene expression are also reflected in their genomic footprint. We identified a Heat Shock Protein gene (HSP 40 kDa) which exhibits cross species pronounced sequence variation. This gene exhibits species-specific fixed sites, alleles, and sites putatively under positive selection. These sites are located in protein binding regions involved in chaperoning and may therefore reflect adaptive diversification. By comparing three genetic markers (ITS, COI, HSP 40 kDa), we revealed hybridization events between the cryptic species. The low frequency of introgressive haplotypes/alleles suggest a tight, but not fully impermeable boundary between the cryptic species.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1305 
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-578635
SN  - 1866-8372
IS  - 1305
ER  - 
TY  - THES
A1  - Kiemel, Katrin
T1  - Zooplankton adaptations and community dynamics in space and time
N2  - In times of ongoing biodiversity loss, understanding how communities are structured and what mechanisms and local adaptations underlie the patterns we observe in nature is crucial for predicting how future ecological and anthropogenic changes might affect local and regional biodiversity. Aquatic zooplankton are a group of primary consumers that represent a critical link in the food chain, providing nutrients for the entire food web. Thus, understanding the adaptability and structure of zooplankton communities is essential. In this work, the genetic basis for the different temperature adaptations of two seasonally shifted (i.e., temperature-dependent) occurring freshwater rotifers of a formerly cryptic species complex (Brachionus calyciflorus) was investigated to understand the overall genetic diversity and evolutionary scenario for putative adaptations to different temperature regimes. Furthermore, this work aimed to clarify to what extent the different temperature adaptations may represent a niche partitioning process thus enabling co-existence. The findings were then embedded in a metacommunity context to understand how zooplankton communities assemble in a kettle hole metacommunity located in the northeastern German "Uckermark" and which underlying processes contribute to the biodiversity patterns we observe. Using a combined approach of newly generated mitochondrial resources (genomes/cds) and the analysis of a candidate gene (Heat Shock Protein 40kDa) for temperature adaptation, I showed that the global representatives of B. calyciflorus s.s.. are genetically more similar than B. fernandoi (average pairwise nucleotide diversity: 0.079 intraspecific vs. 0.257 interspecific) indicating that both species carry different standing genetic variation. In addition to differential expression in the thermotolerant B. calyciflorus s.s. and thermosensitive B. fernandoi, the HSP 40kDa also showed structural variation with eleven fixed and six positively selected sites, some of which are located in functional areas of the protein. The estimated divergence time of ~ 25-29 Myr combined with the fixed sites and a prevalence of ancestral amino acids in B. calyciflorus s.s. indicate that B. calyciflorus s.s. remained in the ancestral niche, while B. fernandoi partitioned into a new niche. The comparison of mitochondrial and nuclear markers (HPS 40kDa, ITS1, COI) revealed a hybridisation event between the two species. However, as hybridisation between the two species is rare, it can be concluded that the temporally isolated niches (i.e., seasonal-shifted occurrence) they inhabit based on their different temperature preferences most likely represent a pre-zygotic isolation mechanism that allows sympatric occurrence while maintaining species boundaries. To determine the processes underlying zooplankton community assembly, a zooplankton metacommunity comprising 24 kettle holes was sampled over a two-year period. Active (i.e., water samples) and dormant communities (i.e., dormant eggs hatched from sediment) were identified using a two-fragment DNA metabarcoding approach (COI and 18S). Species richness and diversity as well as community composition were analysed considering spatial, temporal and environmental parameters. The analysis revealed that environmental filtering based on parameters such as pH, size and location of the habitat patch (i.e., kettle hole) and surrounding field crops largely determined zooplankton community composition (explained variance: Bray-Curtis dissimilarities: 10.5%; Jaccard dissimilarities: 12.9%), indicating that adaptation to a particular habitat is a key feature of zooplankton species in this system. While the spatial configuration of the kettle holes played a minor role (explained variance: Bray-Curtis dissimilarities: 2.8% and Jaccard dissimilarities: 5.5%), the individual kettle hole sites had a significant influence on the community composition. This suggests monopolisation/priority effects (i.e., dormant communities) of certain species in individual kettle holes. As environmental filtering is the dominating process structuring zooplankton communities, this system could be significantly influenced by future land-use change, pollution and climate change.
N2  - In Zeiten des fortschreitenden Verlusts biologischer Vielfalt ist es von entscheidender Bedeutung zu verstehen, wie natürliche Gemeinschaften strukturiert sind und welche Mechanismen und lokalen Anpassungen den beobachteten Biodiversitätsmustern zugrunde liegen, um eine wissenschaftliche Grundlage für die Vorhersage künftiger Veränderungen der lokalen und regionalen biologische Vielfalt zu schaffen. Aquatisches Zooplankton ist eine artenreiche Gruppe Primärkonsumenten, die ein entscheidendes Glied in der Nahrungskette darstellen, indem sie Nährstoffe für das gesamte Nahrungsnetz bereitstellen. Daher ist es von entscheidender Bedeutung, die Anpassungsfähigkeit und Struktur von Zooplanktongemeinschaften zu verstehen. In dieser Arbeit wurden die genetischen Grundlagen für die unterschiedliche Temperaturanpassung zweier saisonal-versetzt (d.h. temperaturabhängig) vorkommender limnischen Rädertierarten eines ehemals kryptischen Artenkomplexes (Brachionus calyciflorus) untersucht, um die genetische Variation und das evolutionäre Divergenz-Szenario sowie Grundlagen für die mutmaßliche Anpassungen an unterschiedliche Temperaturregime zu verstehen. Weiterhin sollte untersucht werden, ob die Temperaturanpassungen als Prozess der Nischenaufteilung verstanden werden können die die Koexistenz der Arten ermöglicht. Diese Ergebnisse wurden dann in einen Metagemeinschaftskontext eingebettet, um zu verstehen, wie sich Zooplanktongemeinschaften in einer Soll-Metagemeinschaft, welche sich in der nordostdeutschen Region "Uckermark" befindet, zusammensetzen und welche zugrundeliegenden Prozesse zu den beobachteten Biodiversitätsmustern führen. Eine Kombination aus neu generierten mitochondrialen Ressourcen (Genome/codierende Sequenzen) und der Analyse eines Kandidatengens (HSP 40kDa Gen) für die Temperaturanpassung ergab zum einen, dass die globalen Vertreter von B. calyciflorus s.s. einander genetisch ähnlicher sind als B. fernandoi (Nukleotiddiversität: 0,079 intraspezifisch vs. 0,257 interspezifisch) und beide Arten somit eine unterschiedliche genetische Variation besitzen. Zum anderen wird das HSP 40kDa wird nicht nur in dem wärmetoleranten B. calyciflorus s.s. und wärmeempfindlichen B. fernandoi unterschiedlich exprimiert, sondern weist auch strukturelle Variationen mit elf fixierten und sechs positiv selektierten Positionen auf, von denen einige in funktionellen Regionen des HSP 40kDa liegen. Die geschätzte Divergenzzeit von ca. 25-29 Millionen Jahren sowie die fixierten Positionen und die Dominanz anzestraler Aminosäuren in B. calyciflorus s.s. legen nahe, dass B. calyciflorus s.s. in der anzestralen Nische verblieb, während B. fernandoi eine neue Nische besetzte. Der Vergleich von mitochondrialen und nukleären Markern (HSP 40kDa, ITS1, COI) ergab ein Hybridisierungsereignis zwischen beiden Arten. Da Hybridisierung jedoch selten ist, können die zeitlich isolierten Nischen (d.h. saisonal-versetztes Auftreten), die sie aufgrund ihrer unterschiedlichen Temperaturpräferenzen bewohnen, als prä-zygotischer Isolationsmechanismus verstanden werden, der ein sympatrisches Vorkommen der Arten unter Aufrechterhaltung der Artgrenzen ermöglicht. Um die Prozesse zu bestimmen, die der Strukturierung von Zooplanktongemeinschaften zugrunde liegen, wurde über einen Zeitraum von zwei Jahren eine Zooplankton-Metagemeinschaft, bestehend aus 24 Söllen beprobt. Aktive (d.h. Wasserproben) und ruhende Gemeinschaften (d.h. aus dem Sediment geschlüpfte Gemeinschaften) wurden mit einem Zwei-Fragment-DNA-Metabarcoding-Ansatz (COI und 18S) bestimmt. Die Artenzahl und Abundanz sowie die Zusammensetzung der Gemeinschaften wurden unter Berücksichtigung räumlicher, zeitlicher und umweltbezogener Parameter analysiert. Die Analyse ergab, dass Umweltfilterung basierend auf Parametern wie pH-Wert, Größe, Lage und Typ des Habitats (d.h. des Solls) und der umgebenden Feldfrüchte die Zusammensetzung der Zooplanktongemeinschaft weitgehend bestimmt (erklärte Varianz: Bray-Curtis-Dissimilaritäten: 10,5%; Jaccard-Dissimilaritäten: 12,9%), was darauf hindeutet, dass die Anpassung an einen bestimmten Lebensraum ein wichtiges Merkmal der Zooplanktonarten in diesem System ist. Während die räumliche Struktur der Sölle eine geringe Rolle spielte (erklärte Varianz: Bray-Curtis-Dissimilaritäten: 2,8% und Jaccard-Dissimilaritäten: 5,5%), hatten die einzelnen Standorte einen erheblichen Einfluss auf die Zusammensetzung der Gemeinschaft. Dies deutet auf Monopolisierung/Prioritätseffekte (d.h. ruhende Gemeinschaften) bestimmter Arten in einzelnen Söllen hin. Da Umweltfilterung der dominierende Prozess für die Strukturierung der Zooplanktongemeinschaften ist, könnte dieses System durch künftige Landnutzungsänderungen, Verschmutzung und Klimawandel erheblich beeinflusst werden.
KW  - Zooplankton
KW  - Metacommunity
KW  - B. calyciflorus species complex
KW  - adaptation
KW  - hybridization
KW  - Metagemeinschaft
KW  - Anpassung
KW  - Hybridisierung
Y1  - 2023
ER  - 
TY  - JOUR
A1  - Cahsan, Binia De
A1  - Kiemel, Katrin
A1  - Westbury, Michael V.
A1  - Lauritsen, Maike
A1  - Autenrieth, Marijke
A1  - Gollmann, Günter
A1  - Schweiger, Silke
A1  - Stenberg, Marika
A1  - Nyström, Per
A1  - Drews, Hauke
A1  - Tiedemann, Ralph
T1  - Southern introgression increases adaptive immune gene variability in northern range margin populations of Fire-bellied toad
JF  - Ecology and Evolution
N2  - Northern range margin populations of the European fire-bellied toad (Bombina bombina) have rapidly declined during recent decades. Extensive agricultural land use has fragmented the landscape, leading to habitat disruption and loss, as well as eutrophication of ponds. In Northern Germany (Schleswig-Holstein) and Southern Sweden (Skåne), this population decline resulted in decreased gene flow from surrounding populations, low genetic diversity, and a putative reduction in adaptive potential, leaving populations vulnerable to future environmental and climatic changes. Previous studies using mitochondrial control region and nuclear transcriptome-wide SNP data detected introgressive hybridization in multiple northern B. bombina populations after unreported release of toads from Austria. Here, we determine the impact of this introgression by comparing the body conditions (proxy for fitness) of introgressed and nonintrogressed populations and the genetic consequences in two candidate genes for putative local adaptation (the MHC II gene as part of the adaptive immune system and the stress response gene HSP70 kDa). We detected regional differences in body condition and observed significantly elevated levels of within individual MHC allele counts in introgressed Swedish populations, associated with a tendency toward higher body weight, relative to regional nonintrogressed populations. These differences were not observed among introgressed and nonintrogressed German populations. Genetic diversity in both MHC and HSP was generally lower in northern than Austrian populations. Our study sheds light on the potential benefits of translocations of more distantly related conspecifics as a means to increase adaptive genetic variability and fitness of genetically depauperate range margin populations without distortion of local adaptation.
KW  - Bombina bombina
KW  - heat shock protein
KW  - introgression
KW  - major histocompatibility complex
KW  - scaled mass index
Y1  - 2021
SN  - 2045-7758
VL  - 11
IS  - 14
PB  - John Wiley & Sons, Inc.
CY  - New Jersey
ER  - 
TY  - JOUR
A1  - Kiemel, Katrin
A1  - Gurke, Marie
A1  - Paraskevopoulou, Sofia
A1  - Havenstein, Katja
A1  - Weithoff, Guntram
A1  - Tiedemann, Ralph
T1  - Variation in heat shock protein 40 kDa relates to divergence in thermotolerance among cryptic rotifer species
JF  - Scientific Reports
N2  - Genetic divergence and the frequency of hybridization are central for defining species delimitations, especially among cryptic species where morphological differences are merely absent. Rotifers are known for their high cryptic diversity and therefore are ideal model organisms to investigate such patterns. Here, we used the recently resolved Brachionus calyciflorus species complex to investigate whether previously observed between species differences in thermotolerance and gene expression are also reflected in their genomic footprint. We identified a Heat Shock Protein gene (HSP 40 kDa) which exhibits cross species pronounced sequence variation. This gene exhibits species-specific fixed sites, alleles, and sites putatively under positive selection. These sites are located in protein binding regions involved in chaperoning and may therefore reflect adaptive diversification. By comparing three genetic markers (ITS, COI, HSP 40 kDa), we revealed hybridization events between the cryptic species. The low frequency of introgressive haplotypes/alleles suggest a tight, but not fully impermeable boundary between the cryptic species.
Y1  - 2022
U6  - https://doi.org/10.1038/s41598-022-27137-3
SN  - 2045-2322
VL  - 12
PB  - Springer Nature
CY  - London
ER  - 
TY  - GEN
A1  - Stiegler, Jonas
A1  - Kiemel, Katrin
A1  - Eccard, Jana
A1  - Fischer, Christina
A1  - Hering, Robert
A1  - Ortmann, Sylvia
A1  - Strigl, Lea
A1  - Tiedemann, Ralph
T1  - Seed traits matter
BT  - Endozoochoric dispersal through a pervasive mobile linker
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co-evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile linkers as zoochorous seed dispersers are critical for the population dynamics of numerous plant species. However, knowledge about the quali- or quantification of such mobile link processes, especially in agricultural landscapes, is still limited. In a controlled feeding experiment, we recorded the seed intake and germination success after complete digestion by the European brown hare (Lepus europaeus) and explored its mobile link potential as an endozoochoric seed disperser. Utilizing a suite of common, rare, and potentially invasive plant species, we disentangled the effects of seed morphological traits on germination success while controlling for phylogenetic relatedness. Further, we measured the landscape connectivity via hares in two contrasting agricultural landscapes (simple: few natural and semi-natural structures, large fields; complex: high amount of natural and semi-natural structures, small fields) using GPS-based movement data. With 34,710 seeds of 44 plant species fed, one of 200 seeds (0.51%) with seedlings of 33 species germinated from feces. Germination after complete digestion was positively related to denser seeds with comparatively small surface area and a relatively slender and elongated shape, suggesting that, for hares, the most critical seed characteristics for successful endozoochorous seed dispersal minimize exposure of the seed to the stomach and the associated digestive system. Furthermore, we could show that a hare's retention time is long enough to interconnect different habitats, especially grasslands and fields. Thus, besides other seed dispersal mechanisms, this most likely allows hares to act as effective mobile linkers contributing to ecosystem stability in times of agricultural intensification, not only in complex but also in simple landscapes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1229 
KW  - agricultural landscapes
KW  - endozoochory
KW  - Lepus europaeus
KW  - mobile links
KW  - seed dispersal
KW  - seed dispersal syndrome
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-544265
SN  - 1866-8372
SP  - 18477
EP  - 18491
ER  - 
TY  - JOUR
A1  - Stiegler, Jonas
A1  - Kiemel, Katrin
A1  - Eccard, Jana
A1  - Fischer, Christina
A1  - Hering, Robert
A1  - Ortmann, Sylvia
A1  - Strigl, Lea
A1  - Tiedemann, Ralph
T1  - Seed traits matter
BT  - Endozoochoric dispersal through a pervasive mobile linker
JF  - Ecology and Evolution
N2  - Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co-evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile linkers as zoochorous seed dispersers are critical for the population dynamics of numerous plant species. However, knowledge about the quali- or quantification of such mobile link processes, especially in agricultural landscapes, is still limited. In a controlled feeding experiment, we recorded the seed intake and germination success after complete digestion by the European brown hare (Lepus europaeus) and explored its mobile link potential as an endozoochoric seed disperser. Utilizing a suite of common, rare, and potentially invasive plant species, we disentangled the effects of seed morphological traits on germination success while controlling for phylogenetic relatedness. Further, we measured the landscape connectivity via hares in two contrasting agricultural landscapes (simple: few natural and semi-natural structures, large fields; complex: high amount of natural and semi-natural structures, small fields) using GPS-based movement data. With 34,710 seeds of 44 plant species fed, one of 200 seeds (0.51%) with seedlings of 33 species germinated from feces. Germination after complete digestion was positively related to denser seeds with comparatively small surface area and a relatively slender and elongated shape, suggesting that, for hares, the most critical seed characteristics for successful endozoochorous seed dispersal minimize exposure of the seed to the stomach and the associated digestive system. Furthermore, we could show that a hare's retention time is long enough to interconnect different habitats, especially grasslands and fields. Thus, besides other seed dispersal mechanisms, this most likely allows hares to act as effective mobile linkers contributing to ecosystem stability in times of agricultural intensification, not only in complex but also in simple landscapes.
KW  - agricultural landscapes
KW  - endozoochory
KW  - Lepus europaeus
KW  - mobile links
KW  - seed dispersal
KW  - seed dispersal syndrome
Y1  - 2021
U6  - https://doi.org/10.1002/ece3.8440
SN  - 2045-7758
VL  - 11
IS  - 24
SP  - 18477
EP  - 18491
PB  - John Wiley & Sons, Inc.
ER  - 
TY  - JOUR
A1  - Stiegler, Jonas
A1  - Kiemel, Katrin
A1  - Eccard, Jana
A1  - Fischer, Christina
A1  - Hering, Robert
A1  - Ortmann, Sylvia
A1  - Strigl, Lea
A1  - Tiedemann, Ralph
A1  - Ullmann, Wiebke
A1  - Blaum, Niels
T1  - Seed traits matter
BT  - endozoochoric dispersal through a pervasive mobile linker
JF  - Ecology and evolution
N2  - Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co-evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile linkers as zoochorous seed dispersers are critical for the population dynamics of numerous plant species. However, knowledge about the quali- or quantification of such mobile link processes, especially in agricultural landscapes, is still limited. In a controlled feeding experiment, we recorded the seed intake and germination success after complete digestion by the European brown hare (Lepus europaeus) and explored its mobile link potential as an endozoochoric seed disperser. Utilizing a suite of common, rare, and potentially invasive plant species, we disentangled the effects of seed morphological traits on germination success while controlling for phylogenetic relatedness. Further, we measured the landscape connectivity via hares in two contrasting agricultural landscapes (simple: few natural and semi-natural structures, large fields; complex: high amount of natural and semi-natural structures, small fields) using GPS-based movement data. With 34,710 seeds of 44 plant species fed, one of 200 seeds (0.51%) with seedlings of 33 species germinated from feces. Germination after complete digestion was positively related to denser seeds with comparatively small surface area and a relatively slender and elongated shape, suggesting that, for hares, the most critical seed characteristics for successful endozoochorous seed dispersal minimize exposure of the seed to the stomach and the associated digestive system. Furthermore, we could show that a hare's retention time is long enough to interconnect different habitats, especially grasslands and fields. Thus, besides other seed dispersal mechanisms, this most likely allows hares to act as effective mobile linkers contributing to ecosystem stability in times of agricultural intensification, not only in complex but also in simple landscapes.
KW  - agricultural landscapes
KW  - endozoochory
KW  - Lepus europaeus
KW  - mobile links
KW  - seed dispersal
KW  - seed dispersal syndrome
Y1  - 2021
U6  - https://doi.org/10.1002/ece3.8440
SN  - 2045-7758
VL  - 11
IS  - 24
SP  - 18477
EP  - 18491
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Kiemel, Katrin
A1  - De Cahsan, Binia
A1  - Paraskevopoulou, Sofia
A1  - Weithoff, Guntram
A1  - Tiedemann, Ralph
T1  - Mitochondrial genomes of the freshwater monogonont rotifer Brachionus fernandoi and of two additional B. calyciflorus sensu stricto lineages from Germany and the USA (Rotifera, Brachionidae)
JF  - Mitochondrial DNA. Part B-Resources
N2  - The Brachionus calyciflorus species complex was recently subdivided into four species, but genetic resources to resolve phylogenetic relationships within this complex are still lacking. We provide two complete mitochondrial (mt) genomes from B. calyciflorus sensu stricto (Germany, USA) and the mt coding sequences (cds) from a German B. fernandoi. Phylogenetic analysis placed our B. calyciflorus sensu stricto strains close to the published genomes of B. calyciflorus, forming the putative sister species to B. fernandoi. Global representatives of B. calyciflorus sensu stricto (i.e. Europe, USA, and China) are genetically closer related to each other than to B. fernandoi (average pairwise nucleotide diversity 0.079 intraspecific vs. 0.254 interspecific).
KW  - Mitogenome
KW  - cryptic species
KW  - Brachionus calyciflorus s
KW  - Brachionus
KW  - fernandoi
KW  - monogonont rotifer
Y1  - 2022
U6  - https://doi.org/10.1080/23802359.2022.2060765
SN  - 2380-2359
VL  - 7
IS  - 4
SP  - 646
EP  - 648
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  -