TY - JOUR
T1 - The impact of plant diversity and fertilization on fitness of a generalist grasshopper
AU - Ebeling, Anne
AU - Allan, Eric
AU - Heimann, Juliane
AU - Köhler, Günter
AU - Scherer-Lorenzen, Michael
AU - Vogel, Anja
AU - Weigelt, Alexandra
AU - Weisser, Wolfgang W.
N1 - Funding Information:
We acknowledge E.-D. Schulze and B. Schmid for helping to establish “The Jena Experiment”. We thank all people helping with the management of “The Jena Experiment”, especially the gardeners S. Eismann, S. Hengelhaupt, U. Köber, K. Kunze, G. Kratzsch, and H. Scheffler and all the helpers during the weeding campaigns. “The Jena Experiment” is funded by the Deutsche Forschungsgemeinschaft (DFG, FOR 1451), with additional support from the Friedrich Schiller University of Jena and the Max Planck Society.
PY - 2013/5
Y1 - 2013/5
N2 - In many environments land use intensification is likely to result in a decrease in species richness and in an increase in eutrophication. Although the importance of both factors for higher trophic levels such as insect herbivores is well documented, their impact has rarely been studied in combination. Herbivorous insects have a strong impact on the functioning of ecosystems and it is therefore important to understand how they are affected by eutrophication in high or low diversity environments.We used a grassland biodiversity experiment to investigate the combined effect of fertilization and plant diversity loss on the fitness of the generalist grasshopper Chorthippus parallelus by rearing grasshopper nymphs for four weeks in cages on unfertilized or fertilized (NPK) subplots across a species richness gradient from 1 to 60 plant species. Survival, the number of oothecae, body mass and the number of hatchlings were measured separately for each cage. Plant diversity had no effect on any of the grasshopper fitness measures, neither in unfertilized nor in fertilized plots. NPK-fertilization reduced grasshopper survival but increased body mass of males and reproductive success of the surviving females. Fertilization effects were not mediated by plant community structure, productivity or composition, suggesting that higher food plant quality was one of the main drivers. There was no interaction between plant diversity and fertilization on any of the measures. In conclusion, an increase in eutrophication, in both species-rich and species-poor grasslands, could lead to higher reproductive success and therefore higher abundances of herbivorous insects including insect pests, with fertilization effects dominating plant diversity effects.
AB - In many environments land use intensification is likely to result in a decrease in species richness and in an increase in eutrophication. Although the importance of both factors for higher trophic levels such as insect herbivores is well documented, their impact has rarely been studied in combination. Herbivorous insects have a strong impact on the functioning of ecosystems and it is therefore important to understand how they are affected by eutrophication in high or low diversity environments.We used a grassland biodiversity experiment to investigate the combined effect of fertilization and plant diversity loss on the fitness of the generalist grasshopper Chorthippus parallelus by rearing grasshopper nymphs for four weeks in cages on unfertilized or fertilized (NPK) subplots across a species richness gradient from 1 to 60 plant species. Survival, the number of oothecae, body mass and the number of hatchlings were measured separately for each cage. Plant diversity had no effect on any of the grasshopper fitness measures, neither in unfertilized nor in fertilized plots. NPK-fertilization reduced grasshopper survival but increased body mass of males and reproductive success of the surviving females. Fertilization effects were not mediated by plant community structure, productivity or composition, suggesting that higher food plant quality was one of the main drivers. There was no interaction between plant diversity and fertilization on any of the measures. In conclusion, an increase in eutrophication, in both species-rich and species-poor grasslands, could lead to higher reproductive success and therefore higher abundances of herbivorous insects including insect pests, with fertilization effects dominating plant diversity effects.
KW - Body mass
KW - Chorthippus parallelus
KW - Food plant quality
KW - Reproductive success
KW - Survival
UR - http://www.scopus.com/inward/record.url?scp=84880040287&partnerID=8YFLogxK
U2 - 10.1016/j.baae.2013.01.006
DO - 10.1016/j.baae.2013.01.006
M3 - Article
AN - SCOPUS:84880040287
SN - 1439-1791
VL - 14
SP - 246
EP - 254
JO - Basic and Applied Ecology
JF - Basic and Applied Ecology
IS - 3
ER -