To reveal the full complexity of biotic interactions in the high arctic food web of Zackenberg, we show a quantitative representation of ecological interactions involving a single plant taxon,
Dryas octopetala ×
integrifolia. The interactions depicted involve both antagonistic ones (
green
(1),
blue
(2),
purple
(3), and
red
(4) connectors) and mutualistic ones (
yellow
5 connectors). Each
block represents one species at a trophic level. Note that for practical reasons, the information used to quantify interaction strength varies between interaction types. (1)
Green blocks represent Lepidopteran larvae (herbivores) found in visual searches conducted from 2009 to 2012. Only individuals found actively feeding are included here, with the widths of the
blocks representing the numbers of individuals detected (extracted from Roslin et al.
2013). The widths of the
light green connectors show the proportion of each herbivore taxa found feeding on
Dryas, i.e. the relative dependence of this herbivore taxon on
Dryas. (2)
Blue blocks represent parasitoid species attacking the lepidopteran herbivores feeding on
Dryas (extracted from Wirta et al.
2014). Here, the widths of the
blocks represent the total number of interactions in which the species was involved, as detected with three different methods (MAPL-AP, MAPL-LH, and rearing; see Wirta et al.
2014). The widths of the
light blue connectors represent the numbers of feeding events involving each herbivore. (3)
Purple blocks represent three spider species (extracted from Wirta et al.
2014). The widths of these
blocks represent the total numbers of feeding events involving each species, as identified with CO1 DNA barcodes, with connector width proportional to the specific predator-by-prey interaction. (4)
Red blocks represent feeding interactions involving three bird species studied by Wirta et al. (
2015a).
Blocks on the upper level show the total numbers of feeding events detected for each bird species, and
blocks on the two lower levels represent the total number of interactions involving each
Dryas-affiliated prey taxon. The widths of the
light red connectors represent the numbers of feeding events for each predator-by-prey combination. (5)
Yellow blocks represent taxa visiting
Dryas flowers (i.e. potential pollinators) as trapped by sticky flower mimics (from Tiusanen et al.
2016). Again, the widths of the
blocks represent the numbers of individuals found, with widths scaled to 1/6 of those of the other
colours, to accommodate all 185 taxa detected