Many plants attract insect pollinators with floral nectar (FN) and ant “bodyguards” with extrafloral nectar (EFN). If nectar production is costly or physiologically linked across glands, investment in one mutualism may trade off with investment in the other. We confirmed that changes in FN and EFN availability alter pollination and ant defense mutualisms in a field population of Turnera ulmifolia. Plants with additional FN tended to produce more seeds, while plants with reduced EFN production experienced less florivory. We then mimicked the consumptive effects of mutualists by removing FN or EFN daily for 50 days in a full factorial design using three Turnera species (T. joelii, T. subulata, and T. ulmifolia) in a glasshouse experiment. For T. ulmifolia and T. subulata, but not T. joelii, removing either nectar reduced production of the other, showing for the first time that EFN and FN production can trade off. In T. subulata, increased investment in FN decreased seed set, suggesting that nectar production can have direct fitness costs. Through the linked expression of EFN and FN, floral visitors may negatively affect biotic defense, and extrafloral nectary visitors may negatively affect pollination.
Field Experiment: FN Addition
This data was collected from a population of Turnera ulmifolia, in Key Largo, Florida. Seed set was measured on plants with ambient floral nectar or with an aditional 10 uL. Plant ID is an identifier to distinguish different plants. Treatment can be "Normal FN," i.e. ambient floral nectar available, or "Plus FN," i.e. an additional 10 uL was added to flowers. Leafs is a count of the number of leaves on the plant. AvgSS is the average seed set for all flowers produced on the plant over a six day period.
FN_experiment2.csv
Glasshouse: FN Addition
The purpose of this experiment was to check if adding floral nectar could increase seed set in hand pollinated Turnera ulmifolia flowers due to increased resource availability. PlantID is an identifier to distinguish different plants. Treatment can either be "Control" (no floral nectar added) or "FN plus" (10uL added). AvgSeed is the average seed set across all flowers produced by the plant over three days.
FN_extra_check.csv
Field Experiment: EFN Reduction (Flowers)
The purpose of this experiment was to determine if preventing plants from producing EFN decreased seed set and fruit production or increased florivory. The experiment was conducted at John Pennekamp Coral Reef State Park in Key Largo, Florida. Plant is an identifier to distinguish specific plants. Treatment can be either "EFN glued" (extrafloral nectaries were covered with clear nail polish to stop extrafloral nectar secretion) or "EFN Normal" (clear nail polish was placed near but not on the extrafloral nectaries allowing ambient production). PropFlowHerb is the proportion of flowers herbivorized over seven days. AvgSeed is the average seed set for flowers produced over seven days. Ltotal is the number of leaves on the plant.
EFN_seed.csv
Field Experiment: EFN Reduction (Fruit)
This is a 2x2 contingency table reporting the number of fruits produced on florivorized and non-florivorized flowers from the EFN reduction field experiment.
fishers.csv
Field Experiment: EFN Reduction (Leaves)
The purpose of this experiment was to determine if preventing plants from producing EFN decreased ant visitation and increased leaf herbivory. The experiment was conducted at John Pennekamp Coral Reef State Park in Key Largo, Florida. Plant is an identifier to distinguish specific plants. Treatment can be either "EFN glued" (extrafloral nectaries were covered with clear nail polish to stop extrafloral nectar secretion) or "EFN normal" (clear nail polish was placed near but not on the extrafloral nectaries allowing ambient production). AntCount is the average number of ants counted on the plants daily for seven days. Ltotal is the number of leaves on the plant. PLHerb is the proportion of leaves herbivorized after seven days of experimental treatment. The remaining columns are species of ants observed on plants over the seven day period, with "1" indicating they were observed at least once and "0" indicating they were not observed on the plant.
EFN_ants.csv
EFN Nectar Stimulation
The purpose of this experiment was to confirm that removing extrafloral nectar stimulated further production. It was conducted under glasshouse conditions. Species lists the species of Turnera. Code is an identifier to distinguish specific plants. EFNsugar_exp_per is the mass (mg sucrose equivalent) of extrafloral nectar collected per extrafloral nectary pair in the morning and afternoon from the experimental treatment (nectar removed morning + afternoon). EFNsugar_cont_per is the mass (mg sucrose equivalent) of extrafloral nectar collected per extrafloral nectary pair in the afternoon from the control treatment (nectar removed afternoon only).
assumption_all_EFN.csv
FN Reabsorption
The purpose of this experiment was to determine if Turnera flowers reabsorb nectar that is not removed by pollinators. It was conducted under glasshouse conditions. Species identifies the species of Turnera being investigated Hour is the time nectar was removed from the flower. Time is the period of the day when nectar was removed. FNvol is the volume (uL) of floral nectar removed from the flower. FNconc is the concentration (Brix) of floral nectar removed from the flower. FNsugar is the mass of floral nectar (mg sucrose equivalent) removed from the flower. Each measurement is from a different plant and flower.
FN_time_r.csv
Nectar Removal Experiment: Endpoint
The purpose of this experiment was to determine if extrafloral and floral nectar production trade off. The experiment was conducted under glasshouse conditions. Values represent endpoint data from a 50 day experiment. Plant ID is an identifier to distinguish individual plants. Species is the species of Turnera. Treatment is the experimental treatment applied to the plant. EFN is a yes/no variable answering if extrafloral nectar was removed for the duration of the experiment. FN is a yes/no variable answering if floral nectar was removed for the duration of the experiment. Leaves is the number of leaves on the plant. Buds is the number of buds on the plants. nFlowers is the average number of flowers produced each day over three days. FNvol is the three-day average floral nectar volume (uL) produced by the plant. FNconc is the three-day average floral nectar concentration (Brix). FNsugar is the three-day average mass of floral nectar sugar (mg sucrose equivalent) produced by the plant. FNvol_per is the three-day average floral nectar volume (uL) per flower. FNsugar_per is the three-day average mass of floral nectar sugar (mg sucrose equivalent) per flower. nEFN is the three-day average number of active EFN pairs per plant. EFNvol is the three-day average extrafloral nectar volume (uL) produced by the plant. EFNconc is the three-day average extrafloral nectar concentration (Brix). EFNsugar is the three-day average mass of extrafloral nectar sugar (mg sucrose equivalent) produced by the plant. EFNvol_per is the three-day average extrafloral nectar volume (uL) per active extrafloral nectary pair. EFNsugar_per is the three-day average extrafloral nectar sugar mass (mg sucrose equivalent) per active extrafloral nectary pair.
endpoint_avg_all.csv
Nectar Removal Experiment: Repeated Measures- Extrafloral nectar
The purpose of this experiment was to determine if extrafloral and floral nectar production trade off. The endpoint data included in a different spreadsheet was recorded from the last three days of this experiment. Species identifies the species being studied. id is a identifier to distinguish individual plants. Treatment is the experimental treatment applied to the plant (EFN=extrafloral nectar removed; EFN+FN=extrafloral and floral nectar removed). Day is the day of the experiment (Calendar day of each Day 1 for each species differs because species had different start times). EFNsugar is the mass of extrafloral nectar sugar removed (mg sucrose equivalent). Temp is the average temperature (C) of the greenhouse from 6pm the previous evening to 6pm on the day of the removal, with temperature being measured every 15 minutes.
EFN_rm_all.csv
Nectar Removal Experiment: Repeated Measures- Floral Nectar
The purpose of this experiment was to determine if extrafloral and floral nectar production trade off. The endpoint data included in a different spreadsheet was recorded from the last three days of this experiment. Species identifies the species being studied. id is a identifier to distinguish individual plants. Treatment is the experimental treatment applied to the plant (FN=floral nectar removed; EFN+FN=extrafloral and floral nectar removed). Day is the day of the experiment (Calendar day of each Day 1 for each species differs because species had different start times). EFNsugar is the mass of extrafloral nectar sugar removed (mg sucrose equivalent). Temp is the average temperature (C) of the greenhouse from 6pm the previous evening to 6pm on the day of the removal, with temperature being measured every 15 minutes.
FN_rm_all.csv
Nectar Removal Experiment: Seed Set
The purpose of this experiment was to determine if removing extrafloral or floral nectar decreased seed set under glasshouse conditions. This experiment was conducted on the plants from the nectar removal experiment, after applying the treatment for 50 days. PlantID is an identifier to distinguish between different individuals. Species is the species of Turnera being studied. Treatment is the treatment that each plant was exposed to for 50 days. FN is a yes/no variable answering if floral nectar was removed. EFN is a yes.no variable answering if extrafloral nectar was removed. nSeeds is the average number of seeds produced by hand pollinating seven flowers following the nectar removal experiment. A maximum of one flower was pollinated per day. Leaves is the number of leaves on the plant.
seed_set_all.csv