Abundance, diversity, and species composition of fungal communities in a temperate forest affected by excreta of the Great Cormorant Phalacrocorax carbo

Abstract

The possible effects of excreta of the Great Cormorant Phalacrocorax carbo on abundance, diversity, and species composition of fungal communities were investigated in a temperate evergreen coniferous forest near Lake Biwa in central Japan. Samples were collected at three study sites that had the same vegetation composition, but which had been influenced by different stages of breeding colony establishment: Site C (control site), Site 2 (colonizing site), and Site 3 (post-colony site). In forest floor samples and in needles and twigs of Chamaecyparis obtusa, total hyphal length was lowest at Site 3, and clamp-bearing hyphal length (biomass of basidiomycetous fungi) was lower at Sites 2 and 3 than at Site C. Dark-pigmented hyphal length was highest at Site 2. Dilution plating of forest floor samples and mineral soil revealed: (i) species richness was higher at Sites 2 and 3 than at Site C, (ii) diversity was higher at Site 3 than at Sites C and 2, and that (iii) species composition differed among the sites. Surface sterilization of needles and twigs of C. obtusa revealed (i) with the exception of species richness in twigs, species richness and diversity were higher at Site 3 than at Sites C and 2, and that (ii) species composition differed markedly among the sites. In twig samples white rot Marasmius-like fungus and Geniculosporium sp. 1 were dominant at Site C and reduced at Sites 2 and 3. A coprophilous species, Sordaria sp. 1, showed a marked increase at Site 2 in needle and twig samples.