Everwand, Georg

[["dc.bibliographiccitation.firstpage","584"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Ecology"],["dc.bibliographiccitation.lastpage","594"],["dc.bibliographiccitation.volume","102"],["dc.contributor.author","Didiano, Teresa J."],["dc.contributor.author","Turley, Nash E."],["dc.contributor.author","Everwand, Georg"],["dc.contributor.author","Schaefer, Hanno"],["dc.contributor.author","Crawley, Michael J."],["dc.contributor.author","Johnson, Marc T. J."],["dc.date.accessioned","2018-11-07T09:41:04Z"],["dc.date.available","2018-11-07T09:41:04Z"],["dc.date.issued","2014"],["dc.description.abstract","Plant defence traits have evolved over macro- and microevolutionary time-scales in response to herbivores. Although a number of studies have investigated the evolutionary impacts of herbivores over short time-scales, few studies have experimentally examined what defence traits most commonly evolve and whether multiple coexisting species exhibit similar evolutionary responses to herbivores. We addressed these questions using a long-term experiment at Silwood Park, England, United Kingdom, where we excluded rabbits from 38 grassland plots for <1-34years. To assess the evolutionary impacts of rabbits on plant defence traits, we collected seeds from plots containing the following perennial species: Anthoxanthum odoratum (Poaceae), Festuca rubra ssp. rubra (Poaceae), Holcus lanatus (Poaceae) and Stellaria graminea (Caryophyllaceae). We then grew these plants in a common garden and measured defensive and morphological traits. We found some evidence for evolutionary change of defence traits in three of the four species following the exclusion of rabbits. We observed the clearest changes in F.rubra, which showed a 9% decline in tolerance to herbivory and a 26% decline in leaf number. We also observed weak evidence for a change in all grass species towards a more erect growth form suggesting that grazing selects for plants that grow close to the ground. Although our results are most consistent with evolution due to changes in the frequency of alleles and genotypes, we cannot rule out that epigenetic changes (e.g. methylation) or maternal environmental effects also contributed to or caused the observed long-term phenotypic responses. Synthesis. Our study provides an experimental test of the evolutionary effects of an ecologically important herbivore. We found evidence for plant defence evolution following >20years of rabbit exclusion. However, the evidence was only strong in one species for multiple traits, weak in all three grass species for avoidance and absent in an herb species. This suggests that the evolutionary effects of an ecologically important herbivore on plants will be variable and difficult to predict in nature."],["dc.identifier.doi","10.1111/1365-2745.12227"],["dc.identifier.isi","000334588300004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33642"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1365-2745"],["dc.relation.issn","0022-0477"],["dc.title","Experimental test of plant defence evolution in four species using long-term rabbit exclosures"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","S21"],["dc.bibliographiccitation.journal","The American Naturalist"],["dc.bibliographiccitation.lastpage","S34"],["dc.bibliographiccitation.volume","181"],["dc.contributor.author","Turley, Nash E."],["dc.contributor.author","Odell, Walter C."],["dc.contributor.author","Schaefer, Hanno"],["dc.contributor.author","Everwand, Georg"],["dc.contributor.author","Crawley, Michael J."],["dc.contributor.author","Johnson, Marc T. J."],["dc.date.accessioned","2018-11-07T09:25:28Z"],["dc.date.available","2018-11-07T09:25:28Z"],["dc.date.issued","2013"],["dc.description.abstract","Herbivores are credited with driving the evolutionary diversification of plant defensive strategies over macroevolutionary time. For this to be true, herbivores must also cause short-term evolution within plant populations, but few studies have experimentally tested this prediction. We addressed this gap using a long-term manipulative field experiment where exclosures protected 22 plant populations from natural rabbit herbivory for <1 to 26 years. We collected seeds of Rumex acetosa L. (Polygonaceae) from our plots and grew them in a common greenhouse environment to quantify evolved differences among populations in individual plant growth rate, tolerance to herbivory, competitive ability, and the concentration of secondary metabolites (tannins and oxalate) implicated in defense against herbivores. In 26 years without rabbit herbivory, plant growth rate decreased linearly by 30%. We argue that plant growth rate has evolved as a defense against intense rabbit herbivory. In contrast, we found no change in tolerance to herbivory or concentrations of secondary metabolites. We also found no change in competitive ability, suggesting that contemporary evolution may not feed back to alter ecological interactions within this plant community. Our results combined with those of other studies show that the evolution of gross morphological traits such as growth rate in response to herbivory may be common, which calls into question assumptions about some of the most popular theories of plant defense."],["dc.identifier.doi","10.1086/668075"],["dc.identifier.isi","000317840400003"],["dc.identifier.pmid","23598357"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/30074"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Univ Chicago Press"],["dc.relation.issn","0003-0147"],["dc.title","Contemporary Evolution of Plant Growth Rate Following Experimental Removal of Herbivores"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1095"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Ecosystems"],["dc.bibliographiccitation.lastpage","1108"],["dc.bibliographiccitation.volume","17"],["dc.contributor.author","Everwand, Georg"],["dc.contributor.author","Fry, Ellen L."],["dc.contributor.author","Eggers, Till"],["dc.contributor.author","Manning, Pete"],["dc.date.accessioned","2018-11-07T09:36:14Z"],["dc.date.available","2018-11-07T09:36:14Z"],["dc.date.issued","2014"],["dc.description.abstract","There is a need for accurate predictions of ecosystem carbon (C) and water fluxes in field conditions. Previous research has shown that ecosystem properties can be predicted from community abundance-weighted means (CWM) of plant functional traits and measures of trait variability within a community (FDvar). The capacity for traits to predict carbon (C) and water fluxes, and the seasonal dependency of these trait-function relationships has not been fully explored. Here we measured daytime C and water fluxes over four seasons in grasslands of a range of successional ages in southern England. In a model selection procedure, we related these fluxes to environmental covariates and plant biomass measures before adding CWM and FDvar plant trait measures that were scaled up from measures of individual plants grown in greenhouse conditions. Models describing fluxes in periods of low biological activity contained few predictors, which were usually abiotic factors. In more biologically active periods, models contained more predictors, including plant trait measures. Field-based plant biomass measures were generally better predictors of fluxes than CWM and FDvar traits. However, when these measures were used in combination traits accounted for additional variation. Where traits were significant predictors their identity often reflected seasonal vegetation dynamics. These results suggest that database derived trait measures can improve the prediction of ecosystem C and water fluxes. Controlled studies and those involving more detailed flux measurements are required to validate and explore these findings, a worthwhile effort given the potential for using simple vegetation measures to help predict landscape-scale fluxes."],["dc.identifier.doi","10.1007/s10021-014-9779-z"],["dc.identifier.isi","000340554700012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32566"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","1435-0629"],["dc.relation.issn","1432-9840"],["dc.title","Seasonal Variation in the Capacity for Plant Trait Measures to Predict Grassland Carbon and Water Fluxes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","62"],["dc.bibliographiccitation.journal","Acta Oecologica"],["dc.bibliographiccitation.lastpage","68"],["dc.bibliographiccitation.volume","48"],["dc.contributor.author","Everwand, Georg"],["dc.contributor.author","Scherber, Christoph"],["dc.contributor.author","Tscharntke, Teja"],["dc.date.accessioned","2017-09-07T11:50:54Z"],["dc.date.available","2017-09-07T11:50:54Z"],["dc.date.issued","2013"],["dc.description.abstract","Current studies on trophic interactions in biodiversity experiments have largely relied on artificially sown gradients in plant diversity, but removal experiments with their more natural plant community composition are more realistic. Slugs are a major part of the invertebrate herbivore community, with some species being common pests in agriculture. We therefore investigated how strongly slugs are influenced by grassland management, plant biodiversity and composition. Here we analysed the effects of cutting frequency, fertilizer application and plant functional group composition on slug densities and their contribution to herbivory on Rumex acetosa in a removal experiment within a >100-year old grassland in Northern Germany. The experiment was laid out as a Latin rectangle with full factorial combinations of (i) plant functional group removal (3 levels) using herbicides, (ii) fertilizer application (2 levels) and (iii) cutting frequency (2 levels). The resulting 12 treatment combinations were replicated 6 times, resulting in 72 plots. We collected a total of 1020 individuals belonging to three species Arion distinctus (60.4% of individuals), Deroceras reticulatum (34.7%) and Arion lusitanicus (4.9%) using a cover board technique and additionally measured herbivore damage to R. acetosa. We found the highest slug abundance on plots with a low cutting frequency and high food resource availability (increased cover of forbs and taller vegetation). Fertilizer application had no significant effect on slug abundance, but caused higher herbivore damage to on R. acetosa, possibly as a result of increased tissue quality. The negative effect of higher cutting frequency on slug abundance was lowest in control plots with their naturally developed graminoid-forb communities (cutting reduced slug density by 6% in the control vs. 29% in herbicide plots). Our experiments therefore support the idea that more natural plant species compositions reduce the impact of disturbances (e.g. through cutting or grazing) on invertebrates."],["dc.identifier.doi","10.1016/j.actao.2013.01.015"],["dc.identifier.gro","3149939"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6651"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.relation.issn","1146-609X"],["dc.subject","Biodiversity experiment; Management intensity; Mollusc; Gastropod; Mowing; Invertebrate"],["dc.title","Slug responses to grassland cutting and fertilizer application under plant functional group removal"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]