Lianas as a microhabitat for myxomycetes in tropical forests

Abstract

Woody vines (lianas) are common in tropical forests, where they reach the light by using other plants for support. Myxomycetes have been recorded from both living and dead lianas, but the microhabitat represented by these plants has never been examined in detail. In the present study, samples of lianas were obtained from a number of different types of tropical forest in Australia, Cuba, Ecuador, Mexico, Peru and Puerto Rico. Moist chamber cultures prepared with samples from these six study areas yielded several hundred collections representing 65 species of myxomycetes, and at least 87% of all cultures produced some evidence (either plasmodia or fruiting bodies) of these organisms. Arcyria cinerea, Diderma hemisphaericum, Didymium squamulosum, Physarum pusillum and Stemonitis fusca var. nigrescens appear to be among the more consistently abundant and widespread members of the assemblage of myxomycetes associated with lianas, but our cultures also have produced a number of noteworthy collections. Prominent examples are Perichaena dictyonema, a rare species described originally from Central Africa, Physarum hongkongense, Ceratiomyxa fruticulosa, Physarum melleum and Willkommlangea reticulata. In addition, the total assemblage of species we recorded includes three species (Physarum hongkongense, Stemonitis foliicola and Stemonaria gracilis) not previously known from the Neotropics along with six new records for Australia, 13 new records for Peru and 12 new records for Puerto Rico. Data are provided on the pH and water holding capacity of the samples we processed, and the ecology of lianas as a special microhabitat for myxomycetes is discussed.