title: Nutrient enrichment effects on mycorrhizal fungi in an Andean tropical montane Forest.
abstract: Nitrogen (N) and phosphorus (P) deposition are increasing worldwide largely due to increased fertilizer use and fossil fuel combustion. Most work with N and P deposition in natural ecosystems has focused on temperate, highly industrialized, regions. Tropical regions are becoming more developed, releasing large amounts of these nutrients into the atmosphere. Nutrient enrichment in nutrient-poor systems such as tropical montane forest can represent a relatively large shift in nutrient availability, especially for sensitive microorganisms such as arbuscular mycorrhizal fungi (AMF). These symbiotic fungi are particularly critical, given their key role in ecosystem processes affecting plant community structure and function.To better understand the consequences of nutrient deposition in plant communities, a long-term nutrient addition experiment was set up in a tropical montane forest in the Andes of southern Ecuador. In this study, we investigated the impacts of 7 years of elevated N and P on AMF root colonization potential (AMF-RCP) through a greenhouse bait plant method in which we quantified root colonization. We also examined the relationship between AMF-RCP and rarefied tree diversity.After 7 years of nutrient addition, AMF-RCP was negatively correlated with soil P, positively correlated with soil N, and positively correlated with rarefied tree diversity. Our results show that AMF in this tropical montane forest are directly affected by soil N and P concentrations, but may also be indirectly impacted by shifts in rarefied tree diversity. Our research also highlights the need to fully understand the benefits and drawbacks of using different sampling methods (e.g., AMF-RCP versus direct root sampling) to robustly examine AMF-plant interactions in the future.
authors.affiliation: Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect St, New Haven, CT, 06511, USA. camille.delavaux@ku.edu.|Ecology and Evolutionary Biology, University of Kansas, Room 9, Takeru Higuchi Hall, Lawrence, KS, 66047, USA. camille.delavaux@ku.edu.
authors.forename: Camille S
authors.initials: CS
authors.lastname: Delavaux
authors.affiliation: Institute of Biology, Freie Universität Berlin, Altensteinstr. 6, 14195, Berlin, Germany.|Berlin- Brandenburg Institute of Advanced Biodiversity Research, Plant Ecology, 14195, Berlin, Germany.
authors.forename: Tessa
authors.initials: T
authors.lastname: Camenzind
authors.affiliation: Albrecht von Haller Institute of Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Homeier
authors.affiliation: Laboratorio de Ecología de Plantas, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de octubre 1076 y Roca, Apdo. 17-01-2184, Quito, Ecuador.
authors.forename: Rosa
authors.initials: R
authors.lastname: Jiménez-Paz
authors.affiliation: Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect St, New Haven, CT, 06511, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Ashton
authors.affiliation: Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect St, New Haven, CT, 06511, USA.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Queenborough
mesh_terms: D004484:Ecuador; D065928:Forests; D005658:Fungi; D038821:Mycorrhizae / Q000502:physiology*; D009584:Nitrogen / Q000502:physiology*; D010758:Phosphorus / Q000502:physiology*; D018517:Plant Roots / Q000382:microbiology; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D012987:Soil; D010758:Phosphorus; D009584:Nitrogen
keywords: Arbuscular mycorrhizas; Ecuador; Nitrogen fertilization; Phosphorus fertilization; Tropical