Seasonal Occurrence and Distribution of Fungi Associated with Spartina Alterniflora from a Rhode Island Estuary

SUMMARY

The seasonal occurrence and distribution of filamentous fungi on the aerial parts of salt marsh cordgrass, Spartina alterniflora, along a Rhode Island estuary were studied over a 26-mon period. Fungal fruiting bodies were observed on freshly collected standing plants and their frequency varied with the season. Frequency patterns were similar over the two growth-death cycles studied and indicate there may be a characteristic mycota associated with S. alterniflora. The Ascomycetes Buergenerula spartinae and Phaeosphaeria typharum were found to invade early during the growing season and the Deuteromycetes Alternaria alternata, Epicoccum nigrum, and Stagonospora sp. reached their highest frequencies at the time of seed production. Species of Leptosphaeria and Pleospora were found primarily on dead standing culms. A combination of both marine and terrestrial fungi can be observed on S. alterniflora, with the marine species occurring on the lower portion of standing plants. The number of observations of fungal species/plant was the greatest at the time of seed production, senescence, and death (September-January). The mycota at the three sampling stations, which differed in salinity, was similar and, in general, the fungi which occurred at the highest frequencies were found at all the sampling stations.