LAUSR

ABSTRACT Common reed (Phragmites australis) is one of the most widely distributed, most abundant, and best-studied vascular plants worldwide but there has been no broad comparison of reed-associated biota on different continents. A survey of observational data on (mostly terrestrial) organisms using P. australis reedbeds revealed diverse biotas and some strong relationships to Phragmites in North America, Europe, and sub-Saharan Africa. I present examples for a selected group of 29 habitat functions (i.e., features of the reed plant or reedbed used in particular ways by groups of organisms). These functions include animals eating certain parts of reed, birds roosting in reedbeds, and insects mining within reed leaf blades. The diversity of reed users (associated species) and the similarities in habitat functions in biogeographically distinct world regions suggest a fundamental character of reed ecological relationships related to the large size, extensive stands, high productivity, deep litter layers, and other traits of reed. The data also underline the general importance of reed for biodiversity support, although on all three continents reed is considered desirable or undesirable depending on the site character and management goals. Managers can consider reed habitat functions and user guilds to prioritise and design management approaches and predict outcomes of conservation, management, or other environmental changes affecting reedbeds and their users, whether native or introduced, over-abundant or under-abundant.