|A list including citations is available via Google scholar|
Martín Vélez, V; Van Leeuwen, C.H.A.; Sánchez, M.; Hortas, F.; Shamoun-Baranes, J.; Thaxter, C.; Lens, L.; Camphuysen, C. & A. J. Green (accepted)
Spatial patterns of weed dispersal by wintering gulls within and beyond an agricultural landscape
Journal of Ecology https://doi.org/10.1111/1365-2745.13619
Mulder, A.J.E., van Aalderen, R. & C.H.A. van Leeuwen (2021)
Tracking temperate fish reveals their relevance for plant seed dispersal
Functional Ecology https://doi.org/10.1111/1365-2435.13757 pdf
Content: We calculated the first realistic dispersal kernels for plant seeds dispersed by temperate fish species, by combining acoustic tracking with laboratory experiments. This novel approach increases our understanding of plant-animal interactions in an understudied system. We draw conclusions about maximum dispersal distances, intraspecific variation, seasonality and effects of anthropogenic barriers.
Petruzzella, A., T.A. da S. S. R. Rodrigues, C.H.A. van Leeuwen, F. de Assis Esteves, M. Paulo Figueiredo-Barros & E.S. Bakker (2020)
Species identity and diversity effects on invasion resistance of tropical freshwater plant communities
Scientific Reports 10, 5626 doi: 10.1038/s41598-020-62660-1 pdf
Content: We investigated how native plant community presence and diversity - and the presence of native phylogenetically closely related species to invading plant species - affect the establishment success of invading tropical freshwater submerged plant species. The presence of a native plant community suppressed the growth of the invading species (Hydrilla verticillata), but did not prevent its colonisation. Invader growth was negatively affected by native plant productivity, but independent of native species richness and phylogenetic relatedness to the invader. This illustrates that resistance provided by tropical freshwater submerged plant communities to invasive species contrasts to resistance described for other ecosystem types.
Zhang, P., van Leeuwen, C.H.A., Bogers, D. Poelman, M. Xu, J. & E.S. Bakker (2020)
Ectothermic omnivores increase herbivory in response to rising temperatures
Oikos doi: 10.1111/oik.07082 pdf
Content: Ectothermic herbivores and carnivores generally ingest more food with rising temperature as their metabolic rates increase with rising temperature. We hypothesized that rising temperature would increase herbivory of ectothermic omnivores, and confirmed this hypothesis in a freshwater model system with the pond snail Lymnaea stagnalis. A literature survey furthermore suggested that aquatic ectothermic omnivores might commonly increase herbivory with rising temperatureWe conclude that future global warming will most likely alter food webs by increasing the top–down control of aquatic herbivores and omnivores on primary producers.
Petruzzella, A., van Leeuwen, C.H.A., van Donk, E. & E.S. Bakker (2020)
Direct and indirect effects of native plants and herbivores on biotic resistance to alien aquatic plant invasions
Journal of Ecology doi: 10.1111/1365-2745.13380 pdf
Content: Biotic resistance to alien plant invasions is mainly determined by ecological interactions in two layers of the food web: competition with native plant species and herbivory by native herbivores. While the direct effect of native plants on alien plant performance via competition has been well documented across ecosystems, less is known about the direct and indirect effects of herbivores in providing biotic resistance. We found experimental evidence for biotic resistance through competition by native plant species. However, we show that in freshwater ecosystems herbivores can indirectly facilitate invasions by promoting invader growth through selective feeding on filamentous algae. This illustrates the importance of indirect interactions to understand biotic resistance in natural ecosystems.
Van Leeuwen, C.H.A., Tella, J. L. & Green, A. J. (2020)
Animal-Mediated Dispersal in Understudied Systems.
Frontiers in Ecology and Evolution Ebook available here
Content: Animals disperse smaller organisms by ingesting, transporting and egesting propagules such as plant seeds, fruits, small invertebrates and algae (internal transport), or by carrying propagules attached to their exterior (external transport). Animal-mediated dispersal is generally well studied, but most previous work focused on only a handful of species networks. We initiated a Research Topic in which we gathered studies on animal-mediated dispersal that involved poorly studied and previously overlooked propagules and disperser animals. We hope this collection of 14 new papers will broaden our knowledge beyond the currently most-studied systems, and will inspire future work on contrasts and similarities across study systems.
Zhang P., Kuramae A., van Leeuwen C.H.A., Velthuis M., van Donk E., Xu J. and Bakker E.S. (2020)
Interactive effects of rising temperature and nutrient enrichment on aquatic plant growth, stoichiometry, and palatability
Frontiers in Plant Science 11:58. doi: 10.3389/fpls.2020.00058 pdf
Content: Temperature rise and eutrophication are global environmental changes that can affect aquatic plants and their palatability to herbivores. However, these factors often change simultaneoulsy. We studied how temperature rise and eutrophication interactively affect aquatic plants. We tested the hypotheses that (1) plant growth rates increase faster with rising temperature in nutrient-rich than nutrient-poor sediments; (2) plant carbon to nutrient ratios respond differently to rising temperatures at contrasting nutrient conditions of the sediment; (3) external nutrient loading to the water column limits the growth of plants and decreases plant C:nutrient ratios; and that (4) changes in plant stoichiometry affect plant palatability.
Van Leeuwen, C.H.A., Tella, J. L. & Green, A. J. (2020)
Editorial: Animal-Mediated Dispersal in Understudied Systems.
Frontiers in Ecology and Evolution doi: 10.3389/fevo.2019.00508 pdf
Content: Editorial publication outlining seven key lessons we can learn from the 14 new publications we published in our Special Issue on "Animal-mediated dispersal in understudied systems".
Martín-Vélez, V., Mohring, B., van Leeuwen, C. H. A., Shamoun-Baranes, J., Thaxter, C. B., Baert, J. M., Camphuysen, C. J. & Green, A. J. (2019)
Functional connectivity network between terrestrial and aquatic habitats by a generalist waterbird, and implications for biovectoring.
Science of the Total Environment 135886. pdf
Content: The functional connectivity network of gulls wintering in Southern Spain was found to functionally link seven habitat types. Dominant habitat types were ricefields and rubbish dumps (landfills). High connectivity of terrestrial landfills with wetlands suggests that waterbirds can transport nutrients, contaminants and antibiotic resistance to and from protected wetland habitats.
J.P van Zuidam*, C.H.A. van Leeuwen*, E.S. Bakker, J.T.A. Verhoeven, S. IJff, E.T.H.M. Peeters, B.G. van Zuidam, M.B. Soons (2019) *shared first authors
Plant functional diversity and nutrient availability can improve restoration of floating fens via facilitation, complementarity and selection effects
Journal of Applied Ecology pdf
Content: Peat‐forming wetlands, and particularly floating fens forming the initial stages of these ecosystems, are globally declining due to excavation, dehydration and eutrophication. Restoration of these valuable ecosystems typically involves re‐establishment of early‐successional open‐water stages with oligotrophic conditions that are characteristic for these systems. However, restoration success is notoriously limited. We experimentally tested how (1) increasing functional diversity of introduced species and (2) nutrient availability would possibly stimulate resotration success, using 36 artificial outdoor ponds for 2 years. We found that restoration of floating fen communities (1) can be stimulated by introducing a high functional diversity of plant species, including fast‐growing clonal species, clonal stress‐tolerators and interstitials, which facilitate each other, (2) is dependent on the presence of clonal stress‐tolerators such as Calla palustris, Comarum palustre and Menyanthes trifoliata for expansion onto the open water, (3) can start under a wide range of water nutrient levels, including eutrophic conditions.
Zhang, P., B.M. Grutters, C.H.A. van Leeuwen, J. Xu, A Petruzzella, R.F. van den Berg, E.S. Bakker (2018)
Effects of rising temperature on the growth, stoichiometry and palatability of aquatic plants
Frontiers in Plant Science pdf
Content: We experimentally investigated how rising water temperatures - as an important component of global changes - may affect plant chemical traits and plant palatability in freshwater ecosystems. If warming water would increase plant palatability to herbivores, this could subsequently increase top-down control of aquatic vegetation in the future. We found that warming generally stimulated the growth of the investigated aquatic plant species, but also that any changes in plant traits and palatability were highly species-specific. This implies that species identity is an important factor to take into account when predicting how global change may affect aquatic vegetation in the future.
PLoS ONE pdf
Content: Eutrophication in aquatic ecosystems increases plant nutrient concentrations. We experimentally showed that aquatic omivores shift to a more plant-based diet in more eutrophied aquatic systems, because plants become relatively more attractive food sources. Because most aquatic consumers are omnivores, increased nutrient loadings into aquatic systems may increase top-down control on aquatic plants.
Strong pair bonds and high site fidelity in a subarctic-breeding migratory shorebird
The Wilson Journal of Ornithology 130(1):140-151 pdf
Content: We investgated mate and site fidelity of the migratory shorebird Pacific Dunlin (Calidris alpina pacifica) breeding at the subarctic Yukon-Kuskokwim Delta, Alaska, USA. We found subarctic-breeding Dunlin to strongly prefer previous breeding locations and previous mates when these were available in consecutive breeding attempts. However, if sites or mates were unavailable for breeding, their behavior prioritized early nest initiation and fast renesting over mate and site fidelity. This study illustrates the high importance of timing for migratory birds nesting in the short subarctic summer.
Mechanisms of invasion resistance of aquatic plant communities
Ecology and Evolution 6(8):2414-2425 pdf
Content: Fishways with restricted seasonal operation times were found to affect upstream spawning migrations of both spring and autumn spawning salmonid fish. We discuss possible effects of late opening and early closing of fish passages in a theoretical framework, in which we propose that movement restrictions of migratory individuals in partially migratory populations can also indirectly affect conditions for resident fish in the same river system.
Internal transport of alien and native plants by geese and ducks - an experimental study
Freshwater Biology 60(7): 1316-1329 pdf
Content: Experiments on the transport of plant seeds by waterbirds revealed that: i) smaller ducks differ from larger geese in their role as dispersal vectors ii) invasive water primrose Ludwigia grandiflora has a greater dispersal potential than invasive cordgrass Spartina densiflora, which is consistent with its faster range expansion across Europe, and iii) maximum retention times of wetland seeds have been underestimated in previous experimental studies that lasted only 1–2 days, as intact seeds were retrieved from faeces for up to 4 days after ingestion. More attention should be paid to the role of waterbirds as vectors of alien plants and to the role of migratory geese as vectors of plants in general.
Hydrology, shore morphology and species traits affect seed dispersal, germination and community assembly in riparian plant communities.
Journal of Ecology 102: 998-1007 pdf
Content: Seed dispersal and germination of plants on the shores of wetlands is influenced by water level fluctuations, shore morphology and seed characteristics. Active water level management and shore restoration can contribute to the creation of rich riparian plant communities.
Van Leeuwen, C.H.A., N. Huig, G. van der Velde, T.A. van Alen, C.A.M. Wagemaker, C.D.H. Sherman, M. Klaassen and J. Figuerola (2013)
How did this snail get here? Multiple dispersal vectors inferred for an aquatic invasive species.
Freshwater Biology 58(1): 88-99 pdf
Content: Microsatellite analyses reveal how invasive aquatic snails (Physa acuta) can colonize isolated freshwater ponds in Doñana National Park (Spain) by using a multitude of passive dispersal vectors: water currents, waterbirds and large mammals.
Van Leeuwen, C.H.A., G. van der Velde, J.M. van Groenendael and M. Klaassen (2012)
Gut travellers: internal dispersal of aquatic organisms by waterfowl.
Content: This is the first quantitative meta-analysis on internal transport of aquatic invertebrates and wetland plant seeds by waterbirds. Analysis of over 80 publications (which can be found in supplementary 1) indicates the state of the art on bird-mediated dispersal, and is used to present the first calculations on the quantitative and qualitative importance of endozoochory as a long distance dispersal mechanism.
Van Leeuwen, C.H.A. and G. van der Velde (2012)
Prerequisites for flying snails: external transport potential of aquatic snails by waterbirds.
Freshwater Science 31(3): 963-972 pdf
Content: This study experimentally addresses dispersal of snails on the outside of birds, known as ectozoochory. A large selection of aquatic snail species is highly tolerant to desiccation, will attach readily to the exterior of waterbirds, and can stay attached for over 8 hours in drying mud. Aquatic snails appear to have all the necessary prerequisites for successful zoochory by birds or other large animals.
Van Leeuwen, C.H.A., M.L. Tollenaar, and M. Klaassen (2012)
Vector activity and propagule size affect dispersal potential by vertebrates.
Oecologia 170(1): 101-109 pdf
Content: In this paper we describe how physical activity of mallards (Anas platyrhynchos), in the form of swimming, alters their digestive physiology. This has implications for the construction of seed dispersal kernels by zoochory, which have to date always been based on seed release patterns obtained from experiments with resting animals. We show for the first time that modelling dispersal kernels to predict seed dispersal distances by zoochory should incorporate potential digestive changes induced by the physical movement of animal vectors.
Van Leeuwen, C.H.A., G. Van der Velde, B. Van Lith, and M. Klaassen (2012)
Experimental quantification of long distance dispersal potential of aquatic snails in the gut of migratory birds.
PLoS ONE 7:e32292 pdf
Content: This publication shows how aquatic snails can survive digestion of waterbirds. In a feeding experiment, snails were retrieved over five hours after ingestion, indicating for the first time that long distance endozoochory of aquatic snails is possible.
Dietz M.W., B. Spaans, A. Dekinga, M. Klaassen, H. Korthals, C.H.A. van Leeuwen, and T. Piersma (2010)
Do red knots (Calidris canutus islandica) routinely skip Iceland during southward migration?
Condor 112(1): 48-55 pdf
Content: Stable isotope analyses of red knots (Calidris canutus islandica) reveal that these birds do not always use all available stopover sites on migration, but that direct migration from Greenland to Western-Europe occurs without a stopover in Iceland, even for juveniles.
Klaassen, R.H.G., B.A. Nolet, and C.H.A. van Leeuwen (2007)
Prior knowledge about spatial pattern affects patch assessment rather than movement between patches in tactile-feeding mallard.
Journal of Animal Ecology 76(1): 20-29 pdf
Content: This experiment with mallards (Anas platyrhynchos) reveals that birds searching for cryptic food items can make use spatial patterns to optimize their food intake over time.