title: Distribution and diversity of fungi in freshwater sediments on a river catchment scale.
abstract: Fungal communities perform essential functions in biogeochemical cycles. However, knowledge of fungal community structural changes in river ecosystems is still very limited. In the present study, we combined culture-dependent and culture-independent methods to investigate fungal distribution and diversity in sediment on a regional scale in the Songhua River catchment, located in North-East Asia. A total of 147 samples over the whole river catchment were analyzed. The results showed that compared to the mainstream, the tributaries have a higher fungal community organization and culturable fungal concentration, but possess lower community dynamics as assessed by denaturing gradient gel electrophoresis (DGGE). Furthermore, phylogenetic analysis of DGGE bands showed that Ascomycota and Basidiomycota were the predominant community in the Songhua River catchment. Redundancy analysis revealed that longitude was the primary factor determining the variation of fungal community structure, and fungal biomass was mainly related to the total nutrient content. Our findings provide new insights into the characteristics of fungal community distribution in a temperate zone river at a regional scale, and demonstrate that fungal dispersal is restricted by geographical barriers in a whole river catchment.
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University Tianjin, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Environmental Science and Engineering, Nankai University Binhai College Tianjin, China.
authors.forename: Jianan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University Tianjin, China.
authors.forename: Guanghai
authors.initials: G
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University Tianjin, China.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Bartlam
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University Tianjin, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Wang
keywords: DGGE; biogeography; fungal diversity; redundancy analysis (RDA); river catchment