Enhancing vegetation diversity in glades, rides and roads in plantation forests

Permanent open spaces in plantation forests provide an opportunity for enhancing biodiversity in plantations and in the wider landscape. We surveyed vegetation in 60 glades, rides and roads in 12 Irish plantation forests, and collected data on solar radiation, soil and management. Variation in species richness and diversity of vascular plants and bryophytes was determined principally by soil factors and open space management. Light levels were positively associated with vascular plant species richness and negatively associated with richness of bryophytes. In rides, the most important plantation feature in determining solar radiation levels and plant diversity was ride width. Increasing edge-to-area ratio corresponded with a decrease in β-diversity within glades. Roadside plots most strongly influenced by road gravel and disturbance supported the highest vascular plant, open-habitat and ruderal species richness and vegetation evenness. For open spaces to contribute significantly to the biodiversity of plantation forests, rides and roads should be a minimum of 15 m in width and glades should be a minimum of 625-900 m² in area.