The Vegetation of Footpaths, Sidewalks, Cart-Tracks and Gateways

THE contrast between the vegetation of footpaths traversing grassland and that of the surrounds has been commented upon by observers on numerous occasions, while graziers have recognised the fact that horses and sheep prefer to feed upon the footpath rather than the other parts of the field. Apart from a passing speculation by Darwin ((I), p. 10), no detailed examination of conditions or of the factors concerned appears to have been made, in spite of the possibility of the findings being of economic value. The vegetation of the path is usually shorter than that of the surrounding areas, though this varies with the intensity of grazing. The most outstanding phenomenon is the dark green colour of the path in comparison with the other herbage. This deep colour is maintained throughout the year and is most conspicuous in winter when the path stands out in vivid contrast to the dead remains of plant life on each side. With the exception of paths on very dry sandy soil, the dominant species are smooth-stalked meadow grass (Poa pratensis), perennial rye grass (Lolium perenne) and wild white clover (Trifolium repens). Poa pratensis is constant for all examples and Lolium perenne for the majority. Trifolium repens is extremely scarce in shaded positions, but is constant for all paths exposed to sunlight. Crested dogstail (Cynosurus cristatus), cocksfoot (Dactylis glomerata) and plantains (Plantago spp.) are fairly constant. A distinct and constant zonation is found. In the centre of the path, if much used, is an area of bare earth. This is adjoined on either side by a zone of Poa pratensis followed by zones of Lolium perenne and Trifolium repens. An example is shown in P1. XXXV, phot. 1, this being a path on a Lakeland fell. The surrounding vegetation is an Agrostis-Festuca association with Briza media, Vaccinium myrtillus, Molinia caerulea and Nardus stricta as sub-dominants. P1. XXXV, phot. 2 shows a small area of this and is a typical example of the contrast which occurs. On dry sandy heaths in districts of low rainfall the dominant species of the path are usually Festuca ovina, Agrostis stolonifera, Galium spp., Plantago spp. and Hieracium spp. On heavier soils and in moister situations, where puddling of the surface occurs in winter, it is notable that areas dominated by Poa