TY - JOUR A1 - Bukovinszky, Tibor A1 - Verschoor, Antonie M. A1 - Helmsing, Nico R. A1 - Bezemer, T. Martijn A1 - Bakker, Elisabeth S. A1 - Vos, Matthijs A1 - Domis, Lisette Nicole de Senerpont T1 - The Good, the bad and the plenty Interactive effects of food quality and quantity on the growth of different daphnia species JF - PLoS one N2 - Effects of food quality and quantity on consumers are neither independent nor interchangeable. Although consumer growth and reproduction show strong variation in relation to both food quality and quantity, the effects of food quality or food quantity have usually been studied in isolation. In two experiments, we studied the growth and reproduction in three filter-feeding freshwater zooplankton species, i.e. Daphnia galeata x hyalina, D. pulicaria and D. magna, on their algal food (Scenedesmus obliquus), varying in carbon to phosphorus (C:P) ratios and quantities (concentrations). In the first experiment, we found a strong positive effect of the phosphorus content of food on growth of Daphnia, both in their early and late juvenile development. Variation in the relationship between the P-content of animals and their growth rate reflected interspecific differences in nutrient requirements. Although growth rates typically decreased as development neared maturation, this did not affect these species-specific couplings between growth rate and Daphnia P-content. In the second experiment, we examined the effects of food quality on Daphnia growth at different levels of food quantity. With the same decrease in P-content of food, species with higher estimated P-content at zero growth showed a larger increase in threshold food concentrations (i.e. food concentration sufficient to meet metabolic requirements but not growth). These results suggest that physiological processes such as maintenance and growth may in combination explain effects of food quality and quantity on consumers. Our study shows that differences in response to variation in food quality and quantity exist between species. As a consequence, species-specific effects of food quality on consumer growth will also determine how species deal with varying food levels, which has implications for resource-consumer interactions. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0042966 SN - 1932-6203 VL - 7 IS - 9 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Meyer, Katrin M. A1 - Vos, Matthijs A1 - Mooij, Wolf M. A1 - Hol, W. H. Gera A1 - Termorshuizen, Aad J. A1 - van der Putten, Wim H. T1 - Testing the paradox of enrichment along a land use gradient in a multitrophic aboveground and belowground community JF - PLoS one N2 - In the light of ongoing land use changes, it is important to understand how multitrophic communities perform at different land use intensities. The paradox of enrichment predicts that fertilization leads to destabilization and extinction of predator-prey systems. We tested this prediction for a land use intensity gradient from natural to highly fertilized agricultural ecosystems. We included multiple aboveground and belowground trophic levels and land use-dependent searching efficiencies of insects. To overcome logistic constraints of field experiments, we used a successfully validated simulation model to investigate plant responses to removal of herbivores and their enemies. Consistent with our predictions, instability measured by herbivore-induced plant mortality increased with increasing land use intensity. Simultaneously, the balance between herbivores and natural enemies turned increasingly towards herbivore dominance and natural enemy failure. Under natural conditions, there were more frequently significant effects of belowground herbivores and their natural enemies on plant performance, whereas there were more aboveground effects in agroecosystems. This result was partly due to the "boom-bust'' behavior of the shoot herbivore population. Plant responses to herbivore or natural enemy removal were much more abrupt than the imposed smooth land use intensity gradient. This may be due to the presence of multiple trophic levels aboveground and belowground. Our model suggests that destabilization and extinction are more likely to occur in agroecosystems than in natural communities, but the shape of the relationship is nonlinear under the influence of multiple trophic interactions. Citation: Meyer KM, Vos M, Mooij WM, Hol WHG, Termorshuizen AJ, et al. (2012) Testing the Paradox of Enrichment along a Land Use Gradient in a Multitrophic Aboveground and Belowground Community. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0049034 SN - 1932-6203 VL - 7 IS - 11 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Seifert, Linda I. A1 - de Castro, Francisco A1 - Marquart, Arnim A1 - Gaedke, Ursula A1 - Weithoff, Guntram A1 - Vos, Matthijs T1 - Heated relations: temperature-mediated shifts in consumption across trophic levels JF - PLoS one N2 - A rise in temperature will intensify the feeding links involving ectotherms in food webs. However, it is unclear how the effects will quantitatively differ between the plant-herbivore and herbivore-carnivore interface. To test how warming could differentially affect rates of herbivory and carnivory, we studied trophic interaction strength in a food chain comprised of green algae, herbivorous rotifers and carnivorous rotifers at 10, 15, 20 and 25 degrees C. We found significant warming-induced changes in feeding by both herbivorous and carnivorous rotifers, but these responses occurred at different parts of the entire temperature gradient. The strongest response of the per capita herbivore's ingestion rate occurred due to an increase in temperature from 15 to 20 degrees C (1.9 fold: from 834 to 1611 algal cells per h(-1)) and of the per capita carnivore's ingestion rate from 20 to 25 degrees C (1.6 fold: from 1.5 to 2.5 prey h(-1)). Handling time, an important component of a consumer's functional response, significantly decreased from 15 to 20 degrees C in herbivorous rotifers. In contrast, it decreased from 20 to 25 degrees C in carnivorous rotifers. Attack rates significantly and strongly increased from 10 to 25 degrees C in the herbivorous animals, but not at all in the carnivores. Our results exemplify how the relative forces of top-down control exerted by herbivores and carnivores may strongly shift under global warming. But warming, and its magnitude, are not the only issue: If our results would prove to be representative, shifts in ectotherm interactions will quantitatively differ when a 5 degrees C increase starts out from a low, intermediate or high initial temperature. This would imply that warming could have different effects on the relative forces of carnivory and herbivory in habitats differing in average temperature, as would exist at different altitudes and latitudes. Y1 - 2014 U6 - https://doi.org/10.1371/journal.pone.0095046 SN - 1932-6203 VL - 9 IS - 5 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Seifert, Linda I. A1 - Weithoff, Guntram A1 - Vos, Matthijs T1 - Extreme heat changes post-heat wave community reassembly JF - Ecology and evolution N2 - Climate forecasts project further increases in extremely high-temperature events. These present threats to biodiversity, as they promote population declines and local species extinctions. This implies that ecological communities will need to rely more strongly on recovery processes, such as recolonization from a meta-community context. It is poorly understood how differences in extreme event intensity change the outcome of subsequent community reassembly and if such extremes modify the biotic environment in ways that would prevent the successful re-establishment of lost species. We studied replicated aquatic communities consisting of algae and herbivorous rotifers in a design that involved a control and two different heat wave intensity treatments (29 degrees C and 39 degrees C). Animal species that suffered heat-induced extinction were subsequently re-introduced at the same time and density, in each of the two treatments. The 39 degrees C treatment led to community closure in all replicates, meaning that a previously successful herbivore species could not re-establish itself in the postheat wave community. In contrast, such closure never occurred after a 29 degrees C event. Heat wave intensity determined the number of herbivore extinctions and strongly affected algal relative abundances. Re-introduced herbivore species were thus confronted with significantly different food environments. This ecological legacy generated by heat wave intensity led to differences in the failure or success of herbivore species re-introductions. Reassembly was significantly more variable, and hence less predictable, after an extreme heat wave, and was more canalized after a moderate one. Our results pertain to relatively simple communities, but they suggest that ecological legacies introduced by extremely high-temperature events may change subsequent ecological recovery and even prevent the successful re-establishment of lost species. Knowing the processes promoting and preventing ecological recovery is crucial to the success of species re-introduction programs and to our ability to restore ecosystems damaged by environmental extremes. KW - Biodiversity KW - climate change KW - conservation KW - ecological restoration KW - extinction KW - extreme temperature events KW - global warming KW - maximum temperature KW - variability Y1 - 2015 U6 - https://doi.org/10.1002/ece3.1490 SN - 2045-7758 VL - 5 IS - 11 SP - 2140 EP - 2148 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Bauer, Barbara A1 - Vos, Matthijs A1 - Klauschies, Toni A1 - Gaedke, Ursula T1 - Diversity, functional similarity, and top-down control drive synchronization and the reliability of ecosystem function JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - The concept that diversity promotes reliability of ecosystem function depends on the pattern that community-level biomass shows lower temporal variability than species-level biomasses. However, this pattern is not universal, as it relies on compensatory or independent species dynamics. When in contrast within--trophic level synchronization occurs, variability of community biomass will approach population-level variability. Current knowledge fails to integrate how species richness, functional distance between species, and the relative importance of predation and competition combine to drive synchronization at different trophic levels. Here we clarify these mechanisms. Intense competition promotes compensatory dynamics in prey, but predators may at the same time increasingly synchronize, under increasing species richness and functional similarity. In contrast, predators and prey both show perfect synchronization under strong top-down control, which is promoted by a combination of low functional distance and high net growth potential of predators. Under such conditions, community-level biomass variability peaks, with major negative consequences for reliability of ecosystem function. KW - biodiversity KW - ecosystem services KW - population dynamics KW - predator-prey system KW - species richness KW - synchrony Y1 - 2014 U6 - https://doi.org/10.1086/674906 SN - 0003-0147 SN - 1537-5323 VL - 183 IS - 3 SP - 394 EP - 409 PB - Univ. of Chicago Press CY - Chicago ER - TY - JOUR A1 - Bukovinszky, Tibor A1 - Helmsing, Nico R. A1 - Grau, R. A. A1 - Bakker, Elisabeth S. A1 - Bezemer, T. Martijn A1 - Vos, Matthijs A1 - Uittenhout, H. A1 - Verschoor, A. M. T1 - A device to study the behavioral responses of zooplankton to food quality and quantity JF - Journal of insect behavior N2 - In order to explore the behavioral mechanisms underlying aggregation of foragers on local resource patches, it is necessary to manipulate the location, quality and quantity of food patches. This requires careful control over the conditions in the foraging arena, which may be a challenging task in the case of aquatic resource-consumer systems, like that of freshwater zooplankton feeding on suspended algal cells. We present an experimental tool designed to aid behavioral ecologists in exploring the consequences of resource characteristics for zooplankton aggregation behavior and movement decisions under conditions where the boundaries and characteristics (quantity and quality) of food patches can be standardized. The aggregation behavior of Daphnia magna and D. galeata x hyalina was tested in relation to i) the presence or absence of food or ii) food quality, where algae of high or low nutrient (phosphorus) content were offered in distinct patches. Individuals of both Daphnia species chose tubes containing food patches and D. galeata x hyalina also showed a preference towards food patches of high nutrient content. We discuss how the described equipment complements other behavioral approaches providing a useful tool to understand animal foraging decisions in environments with heterogeneous resource distributions. KW - Foraging behavior KW - behavioral choice KW - food preference KW - Daphnia KW - flow-through vessel Y1 - 2013 U6 - https://doi.org/10.1007/s10905-012-9366-0 SN - 0892-7553 VL - 26 IS - 4 SP - 453 EP - 465 PB - Springer CY - New York ER -