title: Long-lasting effects of land use history on soil fungal communities in second-growth tropical rain forests.
abstract: Our understanding of the long-lasting effects of human land use on soil fungal communities in tropical forests is limited. Yet, over 70% of all remaining tropical forests are growing in former agricultural or logged areas. We investigated the relationship among land use history, biotic and abiotic factors, and soil fungal community composition and diversity in a second-growth tropical forest in Puerto Rico. We coupled high-throughput DNA sequencing with tree community and environmental data to determine whether land use history had an effect on soil fungal community descriptors. We also investigated the biotic and abiotic factors that underlie such differences and asked whether the relative importance of biotic (tree diversity, basal tree area, and litterfall biomass) and abiotic (soil type, pH, iron, and total carbon, water flow, and canopy openness) factors in structuring soil fungal communities differed according to land use history. We demonstrated long-lasting effects of land use history on soil fungal communities. At our research site, most of the explained variation in soil fungal composition (R2= 18.6%), richness (R2= 11.4%), and evenness (R2= 10%) was associated with edaphic factors. Areas previously subject to both logging and farming had a soil fungal community with lower beta diversity and greater evenness of fungal operational taxonomic units (OTUs) than areas subject to light logging. Yet, fungal richness was similar between the two areas of historical land use. Together, these results suggest that fungal communities in disturbed areas are more homogeneous and diverse than in areas subject to light logging. Edaphic factors were the most strongly correlated with soil fungal composition, especially in areas subject to light logging, where soils are more heterogenous. High functional tree diversity in areas subject to both logging and farming led to stronger correlations between biotic factors and fungal composition than in areas subject to light logging. In contrast, fungal richness and evenness were more strongly correlated with biotic factors in areas of light logging, suggesting that these metrics might reflect long-term associations in old-growth forests. The large amount of unexplained variance in fungal composition suggests that these communities are structured by both stochastic and niche assemblage processes.
authors.affiliation: Department of Ecology, Evolution and Environmental Biology, Columbia University, 1200 Amsterdam Avenue, New York, New York, 10027, USA. bmb43@duke.edu.
authors.forename: Benedicte
authors.initials: B
authors.lastname: Bachelot
authors.affiliation: Department of Ecology, Evolution and Environmental Biology, Columbia University, 1200 Amsterdam Avenue, New York, New York, 10027, USA.
authors.forename: María
authors.initials: M
authors.lastname: Uriarte
authors.affiliation: Department of Environmental Sciences, University of Puerto Rico, Río Piedras Campus, San Juan, Puerto Rico, 00936, USA.
authors.forename: Jess K
authors.initials: JK
authors.lastname: Zimmerman
authors.affiliation: Department of Environmental Sciences, University of Puerto Rico, Río Piedras Campus, San Juan, Puerto Rico, 00936, USA.|Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK.
authors.forename: Jill
authors.initials: J
authors.lastname: Thompson
authors.affiliation: Department of Ecology and Evolutionary Biology, Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, 1900 Pleasant street, 334 UCB, Boulder, Colorado, 80309, USA.
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Leff
authors.affiliation: Department of Biology, Barnard College, Columbia University, New York, New York, 10027, USA.
authors.forename: Ava
authors.initials: A
authors.lastname: Asiaii
authors.affiliation: Department of Biology, Barnard College, Columbia University, New York, New York, 10027, USA.
authors.forename: Jenny
authors.initials: J
authors.lastname: Koshner
authors.affiliation: Department of Ecology, Evolution and Environmental Biology, Columbia University, 1200 Amsterdam Avenue, New York, New York, 10027, USA.|Department of Biology, Barnard College, Columbia University, New York, New York, 10027, USA.
authors.forename: Krista
authors.initials: K
authors.lastname: McGuire
mesh_terms: D005658:Fungi / Q000145:classification* / Q000502:physiology*; D011647:Puerto Rico; D065947:Rainforest; D012988:Soil Microbiology; D013997:Time Factors; D014329:Tropical Climate
keywords: Luquillo Forest Dynamics Plot (LFDP); Puerto Rico; forest soil fungi; high-throughput sequencing; land use history; tropical forest