Fungi colonising and sporulating on submerged wood in the River Severn, UK

Test blocks of Fagus sylvatica and Pinus sylvestris were submerged in the River Severn, England, UK, for 92 weeks and recovered at frequent intervals. Recovered samples were incubated in moist chambers and sporulating fungi on the test blocks were recorded. Fifty fungi consisting of 35 anamorphic species, 13 Ascomycota and 2 Basidiomycota were identified. Species diversity (40) was greatest on the beech test blocks, while only 28 species occurred on the Scots pine test blocks. The most common fungi on beech were Camposporium pellucidum, Dictyochaeta parva, Pseudohalonectria lignicola (each with 95% occurrence) and Trichocladium lignicola (89%). On Scots pine T. lignicola occurred on 95% of the test blocks. A succession of sporulating fungi was observed on the wood over a 3 month incubation period in the laboratory. The results are compared with other studies on lignicolous aquatic fungi from temperate and tropical locations. These indicate that different fungal communities occur in different geographical locations.