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Auteur Christina Fischer
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Can rare arable plants benefit biological pest control potential of cereal aphids in croplands? / Alina Twerski in Basic and applied ecology, Online (12 December 2022)
Titre : Can rare arable plants benefit biological pest control potential of cereal aphids in croplands? Type de document : Imprimé Auteurs : Alina Twerski ; Harald Albrecht ; Róbert Gallé ; Fabian Sauter ; Péter Császár ; Christina Fischer Année de publication : 2022 Article en page(s) : 1-46 Langues : Anglais (eng) Catégories : [Thématique] Messicole Résumé : In agricultural landscapes, arable plants are negatively affected by management intensification. These species can fulfill various ecosystem functions, such as biological pest control, by supporting predators. The ecosystem functions of common plant species are widely known. By contrast, the contribution of rare arable plants (RAPs) to biocontrol in cereal fields remains poorly understood. This study investigated the effect of RAPs on biocontrol potential. We compared cropped plots with and without sowing of rare and threatened arable plant species and investigated the effects on cereal aphids and their antagonistic predators, active hunting, and web-building spiders, as well as carnivorous/omnivorous carabids. We counted the total number of aphids on cereal shoots and trapped ground-dwelling arthropods on an experimental field and on 10 agricultural farms in the vicinity of Munich, Germany, in 2018 and 2019. The effects of the presence of RAP were analyzed using linear mixed-effect models, whereas cover of RAPs was analyzed using structural equation models. Linear models revealed that the presence of RAPs did not significantly affect the aphid density and the activity densities of spiders and carabids. Structural equation models revealed direct negative effects of RAP cover on aphid density. However, no indirect effects via the predators of aphids were detected. Direct negative effects of active hunting spiders on aphids were determined, but not of the other potential predators. The weak impact of RAPs on spiders and carabids suggests that the species richness of plant communities exerts only little influence on organisms at higher trophic levels. Our results suggest that RAPs may indirectly impact aphid infestation, however, the activity density of spiders and carabids were unsuitable indicators for such interactions. Lien pérenne : DOI : 10.1016/j.baae.2022.12.003
in Basic and applied ecology > Online (12 December 2022) . - 1-46Twerski, A., Albrecht, H., Gallé, R., Sauter, F., Császár, P., Fischer, C. 2022. Can rare arable plants benefit biological pest control potential of cereal aphids in croplands? Basic and applied ecology, Online: 1-46.
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Reintroduction of rare arable plants by seed transfer. What are the optimal sowing rates? / Marion Lang in Ecology and evolution, 6 (15) (2016)
Titre : Reintroduction of rare arable plants by seed transfer. What are the optimal sowing rates? Type de document : Imprimé Auteurs : Marion Lang ; Julia W. Prestele ; Christina Fischer ; Johannes Kollmann (1963-) ; Harald Albrecht Année de publication : 2016 Article en page(s) : 5506-5516 Langues : Anglais (eng) Catégories : [Thématique] Messicole Résumé : During the past decades, agro-biodiversity has markedly declined and some species are close to extinction in large parts of Europe. Reintroduction of rare arable plant species in suitable habitats could counteract this negative trend. The study investigates optimal sowing rates of three endangered species (Legousia speculum-veneris (L.) Chaix, Consolida regalis Gray, and Lithospermum arvense L.), in terms of establishment success, seed production, and crop yield losses.A field experiment with partial additive design was performed in an organically managed winter rye stand with study species added in ten sowing rates of 5-10,000 seeds m(-2). They were sown as a single species or as a three-species mixture (pure vs. mixed sowing) and with vs. without removal of spontaneous weeds. Winter rye was sown at a fixed rate of 350 grains m(-2). Performance of the study species was assessed as plant establishment and seed production. Crop response was determined as grain yield.Plant numbers and seed production were significantly affected by the sowing rate, but not by sowing type (pure vs. mixed sowing of the three study species), and weed removal. All rare arable plant species established and reproduced at sowing rates >25 seeds m(-2), with best performance of L. speculum-veneris. Negative density effects occurred to some extent for plant establishment and more markedly for seed production.The impact of the three study species on crop yield followed sigmoidal functions. Depending on the species, a yield loss of 10% occurred at >100 seeds m(-2). Synthesis and applications: The study shows that reintroduction of rare arable plants by seed transfer is a suitable method to establish them on extensively managed fields, for example, in organic farms with low nutrient level and without mechanical weed control. Sowing rates of 100 seeds m(-2) for C. regalis and L. arvense, and 50 seeds m(-2) for L. speculum-veneris are recommended, to achieve successful establishment with negligible crop yield losses. Lien pérenne : DOI : 10.1002/ece3.2303
in Ecology and evolution > 6 (15) (2016) . - 5506-5516Lang, M., Prestele, JW., Fischer, C., Kollmann, J., Albrecht, H. 2016. Reintroduction of rare arable plants by seed transfer. What are the optimal sowing rates? Ecology and evolution, 6(15): 5506-5516.
The β-diversity of arable weed communities on organic and conventional cereal farms in two contrasting regions / Laura Armengot in Applied vegetation science, 15 (4) (October 2012)
Titre : The β-diversity of arable weed communities on organic and conventional cereal farms in two contrasting regions Type de document : Imprimé Auteurs : Laura Armengot ; Francesc Xavier Sans ; Christina Fischer ; Andreas Flohre ; Laura José-María ; Teja Tscharntke (1952-) ; Carsten Thies Année de publication : 2012 Article en page(s) : 571-579 Catégories : [Thématique] Messicole Lien pérenne : DOI : 10.1111/j.1654-109X.2012.01190.x
in Applied vegetation science > 15 (4) (October 2012) . - 571-579Armengot, L., Sans, F.X., Fischer, C., Flohre, A., José-María, L., Tscharntke, T., Thies, C. 2012. The β-diversity of arable weed communities on organic and conventional cereal farms in two contrasting regions. Applied vegetation science, 15(4): 571-579.