Fig 1.
Mean nectar sugar mass per 24h per floral unit for species in A. the annual seed mix, B. the perennial seed mix, and B. native weeds in either mix.
Values shown are ranked means in each group (mean values and standard errors are provided in S1 Table). Images of the top ranked species in each group are shown, with the highest-ranked at right. Images are provided by the project team with the exceptions of Echium vulgare (author: Ewan Cole) provided in 2016 under a (CCAL) CC BY 4.0 license from the Urban Flora of Scotland project.
Fig 2.
Mean pollen volume per 24h per floral unit for species in A. the annual seed mix, B. the perennial seed mix, and C. native weeds in either mix.
Values shown are ranked means in each group. Mean values and standard errors, longevity and pollen volume/floral unit are provided in S1 Table). Images of the top ranked species in each group are shown, with the highest-ranked at right. Images are provided by the project team with the exceptions of Chamerion angustifolium (author: Ewan Cole) provided in 2016 under a (CCAL) CC BY 4.0 license by the Urban Flora of Scotland project.
Fig 3.
Non-metric multidimensional scaling (NMDS) analyses of changes in the composition of floral meadows through time and among cities.
A. Perennial meadows across all cities, separated by survey round. B. Annual meadows across all cities, separated by survey round. In A and B, letters and ellipses show the centroid and 95% confidence limits for each survey round. C. Perennial meadows across all survey rounds, separated by city. D. Annual meadows across all survey rounds, separated by city. In C and D, letters and ellipses show the centroid and 95% confidence limits for each city. In D. the centroid for Bristol is hidden by, and almost identical to, the centroid for Leeds.
Table 1.
Mean, median and quartile values for nectar sugar mass/m2/day for each meadow treatment type across all cities and surveys, showing significant difference groups (p < 0.05) by the post-hoc Tukey-Kramer-Nemenyi test.
Fig 4.
Seasonal patterns in daily nectar sugar availability for individual Edinburgh meadows sown with A. perennial, B. annual A1, and C. annual A2 treatments.
Data were sampled at three-week intervals through 2013. Values at each time point are means based on 20x 1m2 quadrats, with dark shading showing 95% confidence limits. The poor performance of the Saughton perennial meadow was due to accidental mowing, and this replicate was excluded from statistical analyses.
Fig 5.
Seasonal patterns in the proportion of available daily nectar sugar contributed by individual plant species for Edinburgh meadows sown with A. perennial, B. annual A1, and C. annual A2 treatments.
The percentage of total meadow nectar sugar mass attributable to each species is indicated by the height of the filled polygon for that species at a given seasonal time point. Values at each time point are based on 100x 1m2 quadrats across 5 replicate meadows at each time point for each meadow treatment. Note that in both annual and perennial treatments, native perennial weeds provided up to 100% of nectar and pollen resources early in the year.
Fig 6.
Seasonal patterns in nectar sugar availability across four UK cities for meadows sown with A. perennial, B. annual A1, and C. annual A2 treatments, assessed at three-week intervals in 2013.
Values at each time point are means based on 7x 1m2 quadrats, with dark shading showing 95% confidence limits. Plots for individual sites are shown for Bristol, Reading and Leeds in S3 Fig.
Table 2.
Mean, median and quartile values for pollen volume /m2/day) for each meadow treatment type across all cities and surveys, showing significant difference groups (p < 0.05) by the post-hoc Tukey-Kramer-Nemenyi test.
Fig 7.
Seasonal patterns in daily pollen availability for individual Edinburgh meadows sown with A. perennial, B. annual A1, and C. annual A2 treatments.
Data were sampled at three-week intervals through 2013. Values each time point are means based on 20x 1m2 quadrats, with dark shading showing 95% confidence limits.
Fig 8.
Seasonal patterns in the proportion of available daily pollen contributed by individual plant species for Edinburgh meadows sown with A. perennial, B. annual A1, and C. annual A2 treatments.
The percentage of estimated total meadow pollen volume attributable to each species is indicated by the height of the filled polygon for that species at a given seasonal time point. Values at each time point are based on 100x 1m2 quadrats across 5 replicate meadows at each time point for each meadow treatment. Note that in both annual and perennial treatments, native perennial weeds contributed up to 100% of nectar and pollen resources early in the year.
Fig 9.
Seasonal patterns in pollen availability across four UK cities for meadows sown with A. perennial, B. annual A1, and C. annual A2 treatments, assessed at three-week intervals in 2013.
Values at each time point are means based on 7x 1m2 quadrats, with dark shading showing 95% confidence limits.
Fig 10.
Relationships between counts of floral units and A. nectar sugar mass/m2, and B. pollen volume/m2 across all Edinburgh meadow surveys.
Note that data have been loge transformed. The fitted lines are least squares regressions of the transformed data, with the darker shaded area showing standard errors of fitted values. The fitted lines (± standard errors of estimates, n = 80 in each case) for A is y = 0.721(±0.045)x– 1.556(±0.251), and for (b) is y = 0.748(±0.057)x– 1.439(±0.320).