Increasing the success of community transfer when creating species-rich meadows using green hay strewing

Abstract

Methods of increasing the number, diversity and evenness of plant species establishing in species-rich meadows created or enhanced with green hay from a semi-natural source meadow were studied. Three experiments were conducted on grasslands in Birmingham and Herefordshire: (i) Comparisons of species and community transfer resulting from green hay being strewn in consecutive years onto a glyphosated receiver meadow. (ii) The effect on species-richness of introducing green hay into a species-rich created meadow. (iii) The effect of different levels of disturbance in combination with grazing on the introduction of species into an existing created species-rich meadow. Strewing hay twice resulted in vegetation containing more species and species with higher frequencies compared with haying once. Hay strewing increased the number of species in an existing species-rich sward and also increased the frequency and abundance of existing species. Source species frequency, flowering/seed set date and established life strategy had an important influence on species transfer. In general, species that did not transfer were those found at low frequencies in MG5 Cynosurus cristatus – Centaurea nigra community meadows and with stress-tolerance as part of their life strategy. There was a statistically significant three-way interaction between haying, grazing and disturbance. As several terrestrial orchid species are associated with this habitat type, techniques and media for axenic seed germination and propagation of a selected local MG5 meadow orchid species (Dactylorhiza fuchsii) were assessed. Comparisons were made of two media types in combination with mycorrhizae and a source of complex carbohydrates. Of these, oats medium with fungi produced significantly higher germination rates than other tested media. Oats medium also proved the most suitable medium for protocorms when replated, producing the greatest increase in protocorm length compared with Western medium after 15 weeks of growth.