Biology subjects

Kempel, A.

Publications and source records attributed to Kempel, A..

3 recordsLinked to original sources

bioRxiv2019

Rare species perform worse than common species under changed climate

Predicting how species, particularly rare and endangered ones, will react to climate change is a major current challenge in ecology. Rare species are expected to have a narrower niche width than common species. However, we know little whether they are also less able to cope with new climatic conditions. To simulate climate change, we transplanted 35 plant species varying in rarity to five botanical gardens in Switzerland, differing in altitude. For each species we calculated the difference in climate between their natural habitats and the novel climate of the respective botanical garden. We found that rare species had generally lower survival and biomass production than common species. Moreover, rare plant species survived less when the amount of precipitation differed more from the one in their natural range, indicating a higher susceptibility to climate change. Common species, in contrast, survived equally well under all climates and even increased their biomass under wetter or drier conditions. Our study shows that rarer species are less able to cope with changes in climate compared to more widespread ones, which might even benefit from these changes. This indicates that already rare and endangered plant species might suffer strongly from future climate change.

ecology↗

bioRxiv2019

Sick plants in grassland communities: a growth-defense trade-off is the main driver of fungal pathogen abundance and impact

Aboveground fungal pathogens can substantially reduce biomass production in grasslands. However, we lack a mechanistic understanding of the drivers of fungal infection and impact. Using a global change biodiversity experiment we show that the trade-off between plant growth and defense is the main determinant of fungal infection in grasslands. Nitrogen addition only indirectly increased infection via shifting plant communities towards more fast growing species. Plant diversity did not decrease infection, likely because the spillover of generalist pathogens or dominance of susceptible species counteracted dilution effects. There was also evidence that fungal pathogens reduced biomass more strongly in diverse communities. Further, fungicide altered plant-pathogen interactions beyond just removing pathogens, probably by removing certain fungi more efficiently than others. Our results show that fungal pathogens have large effects on plant functional composition and biomass production and highlight the importance of considering changes in pathogen community composition to understand their effects.

ecology↗

bioRxiv2019

Context dependency of biotic interactions and its relation to plant rarity

AimBiotic interactions can determine rarity and commonness of species, however evidence that rare and common species respond differently to biotic stress is scarce. This is because biotic interactions are notoriously context-dependent and traits leading to success in one habitat might be costly or unimportant in another. We aim to identify plant characteristics that are related to biotic interactions and may drive patterns of rarity and commonness, taking environmental context into account.\n\nLocationSwitzerland\n\nMethodsIn a multi-species experiment, we compared the response to biotic interactions of 19 rare and 21 widespread congeneric plant species in Switzerland, while also accounting for variation in environmental conditions of the species origin.\n\nResultsOur results restrict the long-standing hypothesis that widespread species are superior competitors to rare species to only those species originating from resource rich habitats, in which competition is usually strong. Tolerance to herbivory and ambient herbivore damage on the other hand, did not differ between widespread and rare species. In accordance to the resource-availability hypothesis, widespread species from resource rich habitats where more damaged by herbivores (less defended) than widespread species from resource poor habitats - such a growth-defense tradeoff was lacking in rare species. This indicates that the evolutionary important tradeoff between traits increasing competitive-ability and defence is present in widespread species but may have been lost in rare species.\n\nMain conclusionsOur results indicate that biotic interactions, above all competition, might indeed set range limits, and underlines the importance of including context-dependency in studies comparing traits of common and rare or invasive and non-invasive species.

ecology↗