When? How? Why?

Latipalpis margotana, beautifully green-glossy with brass lustre on the edges of the pronotum and elytra, at its flight hole in dead oak branch, S. Petres.

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WHEN? HOW? WHY?

A power line corridor!

When did they arrive here? How did they get here? And why do they still thrive here? Questions pile up as I slowly walk, with bent back and lowered gaze, along a power line corridor 14 km SE of Gävle. Just here, where Gästrikland and Uppland meet, along the narrow track that runs beneath the power lines, crowds an impressively large number of "old" meadow plants. It is a warm and sunny midsummer day and the flower display is overwhelming. Thousands of field gentians are seen here, and here and there grows its close relative, meadow gentian. In the hollows, typical calcareous wet meadow species dominate—cowslip, flax, meadowsweet, rosette mullein, tufted hairgrass, slender sedge, adder's tongue, eyebright, meadow sedge, glaucous sedge, primrose, and bistort. On leaner "heights", field gentian dominates together with meadow lousewort and polypody. On the Uppland side also grows the hoary plantain, which today is very uncommon inland. Long stretches of the track host pronounced dry meadow species such as meadow oat-grass, downy oat-grass, tufted hairgrass, sheep's fescue, cornflower, knapweed, maiden pink, red combs, black combs, small harebell, bugloss, pussy-toes, wild strawberry, deptford pink, hawksbeard, daisy, and yellow bedstraw. In a couple of places also grows buttercup. The list of beautiful and interesting plants can be made very long!

Threatened meadow plants

The track, at its broadest perhaps a couple of metres wide, provides along a stretch of approximately one and a half kilometres habitat for a very large number of meadow plants. Almost all the species mentioned above are pronounced indicator species for managed and unfertilized meadows and pastures. Many, perhaps most, are in decline and are today counted as threatened. Some of them are found elsewhere in the county at only a few localities. As far as I understand, our little track offers such a large number of threatened meadow plants within such a limited area that parallels become difficult to find in our county.

Rare butterflies

On this July day, innumerable butterflies flutter among all the flowers. I observe a couple of swallowtails, at least a dozen large whites, many green-veined whites, and some specimens of the rare and very fastidious germander speedwell fritillary. In the wetter areas flies the dark grayling. At the forest edge are seen marbled whites, spotted browns, and meadow browns, all typical meadow butterflies. Some worn mountain grasshoppers flutter along the forest edge where also a male of the beautifully glossy marbled white patrols.

It is also pleasing to find a few males of Donzel's blue. Still flying are some worn common blues together with countless specimens of common blue and chalk-hill blue. The silver-studded blue is also seen. Apart from all these butterflies, at least three different species of burnet moths fly among the flowers, namely the broad-bordered bee hawk-moth, the narrow-bordered bee hawk-moth, and the slender-winged bee hawk-moth. These very colourful slow-flying moths, together with the butterflies, truly bring life to the power line corridor.