Warming, CO2, and nitrogen deposition interactively affect a plant-pollinator mutualism

• Published in: Ecology letters Vol. 15; no. 3; pp. 227 - 234
• Main Authors: Hoover, Shelley E. R., Ladley, Jenny J., Shchepetkina, Anastasia A., Tisch, Maggie, Gieseg, Steven P., Tylianakis, Jason M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.03.2012; Blackwell
• Subjects: Amino acids; Amino Acids - analysis; analysis; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Bees; Bees - physiology; Biological and medical sciences; Bombus; bottom-up; Carbon Dioxide; chemistry; Climate change; Climatology. Bioclimatology. Climate change; Cucurbita; Cucurbita - physiology; Earth, ocean, space; Ecosystem; ecosystem service; Ecosystem services; ecosystems; Environmental changes; Exact sciences and technology; External geophysics; Flowers; Flowers - chemistry; Flowers - growth & development; Flowers - physiology; Fundamental and applied biological sciences. Psychology; General aspects; global change; Global Warming; growth & development; higher-order effects; Land use; Meteorology; Morphology; Mutualism; nectar; Nitrogen; Phenology; physiology; plant biochemistry; Plant Nectar; Plant Nectar - chemistry; Plant Physiological Phenomena; Plant reproduction; Pollination; Pollinators; pumpkins; Species diversity; species interactions; sugars; Survival Rate; temperature; Modification; ecosystem service; Temperature; Insecta; Carbon dioxide; Apidae; Mutualism; Bombus; Bottom up control; Cucurbita; bottom-up; Apoidea; Dicotyledones; species interactions; Angiospermae; Planetary scale; Ecosystem services; Aculeata; Warming; Atmospheric fallout; Cucurbitaceae; Nitrogen; higher-order effects; Pollination; Dynamical climatology; Climate change; Pollinator; global warming; Arthropoda; Global change; Spermatophyta; Hymenoptera; Invertebrata; Interspecific relation
• ISSN: 1461-023X; 1461-0248; 1461-0248
• DOI: 10.1111/j.1461-0248.2011.01729.x

Environmental changes threaten plant‐pollinator mutualisms and their critical ecosystem service. Drivers such as land use, invasions and climate change can affect pollinator diversity or species encounter rates. However, nitrogen deposition, climate warming and CO2 enrichment could interact to disrupt this crucial mutualism by altering plant chemistry in ways that alter floral attractiveness or even nutritional rewards for pollinators. Using a pumpkin model system, we show that these drivers non‐additively affect flower morphology, phenology, flower sex ratios and nectar chemistry (sugar and amino acids), thereby altering the attractiveness of nectar to bumble bee pollinators and reducing worker longevity. Alarmingly, bees were attracted to, and consumed more, nectar from a treatment that reduced their survival by 22%. Thus, three of the five major drivers of global environmental change have previously unknown interactive effects on plant‐pollinator mutualisms that could not be predicted from studies of individual drivers in isolation.