Fertilizer and herbicide alter nectar and pollen quality with consequences for pollinator floral choices

PeerJ

article

Laura Russo¹  Fabian Ruedenauer³  Angela Gronert⁴  Isabelle Van de Vreken⁵  Maryse Vanderplanck⁶  Denis Michez⁷  Alexandra Klein⁴  Sara Leonhardt³  Jane C. Stout² 

[1] University of Tennessee;Trinity College Dublin;Technische Universität München;Chair of Nature Conservation and Landscape Ecology, Albert-Ludwigs-University Freiburg;University of Liege;CEFE;University of Mons

关键词: Pollilnator health;    Floral resources;    Pollinator nutrition;    Agrochemicals;    Plant-pollinator interactions;    Pollen amino acids;    Pollen fatty acids;    Nectar sugars;    Nectar amino acids;   

DOI  :  10.7717/peerj.15452

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundPollinating insects provide economically and ecologically valuable services, but are threatened by a variety of anthropogenic changes. The availability and quality of floral resources may be affected by anthropogenic land use. For example, flower-visiting insects in agroecosystems rely on weeds on field edges for foraging resources, but these weeds are often exposed to agrochemicals that may compromise the quality of their floral resources.MethodsWe conducted complementary field and greenhouse experiments to evaluate the: (1) effect of low concentrations of agrochemical exposure on nectar and pollen quality and (2) relationship between floral resource quality and insect visitation. We applied the same agrochemcial treatments (low concentrations of fertilizer, low concentrations of herbicide, a combination of both, and a control of just water) to seven plant species in the field and greenhouse. We collected data on floral visitation by insects in the field experiment for two field seasons and collected pollen and nectar from focal plants in the greenhouse to avoid interfering with insect visitation in the field.ResultsWe found pollen amino acid concentrations were lower in plants exposed to low concentrations of herbicide, and pollen fatty acid concentrations were lower in plants exposed to low concentrations of fertilizer, while nectar amino acids were higher in plants exposed to low concentrations of either fertilizer or herbicide. Exposure to low fertilizer concentrations also increased the quantity of pollen and nectar produced per flower. The responses of plants exposed to the experimental treatments in the greenhouse helped explain insect visitation in the field study. The insect visitation rate correlated with nectar amino acids, pollen amino acids, and pollen fatty acids. An interaction between pollen protein and floral display suggested pollen amino acid concentrations drove insect preference among plant species when floral display sizes were large. We show that floral resource quality is sensitive to agrochemical exposure and that flower-visiting insects are sensitive to variation in floral resource quality.

【 授权许可】

CC BY