Table 4.

Plant species strengths (the sum of pollinator dependencies) across all interactions observed in transmission corridors, semi-natural grasslands and over all habitats combined. Rankings are in parentheses because raw numbers cannot be compared among habitats. Plant species with high strengths are the most important in supporting a combination of provider and threatened species. Strength values can be high because a plant species support several bumblebee species with low dependence on it, or because it supports bumblebee species that are dependent on the plant species for foraging.

plant speciesstrength (all habitats)strength (corridors)strength (grasslands)
Centaurea jacea3.49 (1)4.71 (2)1.00 (6)
Trifolium pratense2.85 (2)0.36 (8)2.82 (2)
Carduus crispus2.28 (3)6.43 (1)0.63 (7)
Cirsium arvense1.80 (4)0.85 (6)3.09 (1)
Calluna vulgaris1.31 (5)2.42 (3)
Lythranceae salcaria1.12 (6)1.35 (4)
Trifolium hybridum0.75 (7)0.27 (9)1.14 (5)
Satureja vulgaris0.71 (8)0.02 (12)1.35 (4)
Centaurea scabiosa0.70 (9)
Succisa pratensis0.67 (10)0.96 (5)
Trifolium repens0.54 (11)
Lathyrus pratensis0.44 (12)0.05 (11)0.56 (8)
Leontodon autumnalis0.43 (13)1.81 (3)
Campanulaceae rapunculoides0.32 (14)
Filipendula ulmaria0.24 (15)0.44 (7)0.08 (10)
Melampyrum pratense0.17 (16)0.43 (9)
Centaurea cyanus0.16 (17)
Carduus helenioides0.14 (18)
Arctium tomentosum0.12 (19)
Malva spp.0.11 (20)
Campanulaceae rotundifolia0.11 (21)
Crepis tectorum0.10 (22)
Prunella vulgaris0.07 (23)
Epilobium adenocaulon0.06 (24)
Vicia cracca0.06 (25)0.05 (11)
Lamium maculatum0.06 (26)
Trifolium medium0.05 (27)
Galeopsis terrahit0.04 (28)
Carduus arvense0.03 (29)0.12 (10)
Solidago virgaurea0.03 (30)
Lamiastrum galeobdolon0.02 (31)
Hypericum maculatum0.01 (32)
Taraxacum spp.0.01 (33)
Sonchus glabrescens0.01 (34)