title: Nutrient addition dramatically accelerates microbial community succession.
abstract: The ecological mechanisms driving community succession are widely debated, particularly for microorganisms. While successional soil microbial communities are known to undergo predictable changes in structure concomitant with shifts in a variety of edaphic properties, the causal mechanisms underlying these patterns are poorly understood. Thus, to specifically isolate how nutrients--important drivers of plant succession--affect soil microbial succession, we established a full factorial nitrogen (N) and phosphorus (P) fertilization plot experiment in recently deglaciated (∼3 years since exposure), unvegetated soils of the Puca Glacier forefield in Southeastern Peru. We evaluated soil properties and examined bacterial community composition in plots before and one year after fertilization. Fertilized soils were then compared to samples from three reference successional transects representing advancing stages of soil development ranging from 5 years to 85 years since exposure. We found that a single application of +NP fertilizer caused the soil bacterial community structure of the three-year old soils to most resemble the 85-year old soils after one year. Despite differences in a variety of soil edaphic properties between fertilizer plots and late successional soils, bacterial community composition of +NP plots converged with late successional communities. Thus, our work suggests a mechanism for microbial succession whereby changes in resource availability drive shifts in community composition, supporting a role for nutrient colimitation in primary succession. These results suggest that nutrients alone, independent of other edaphic factors that change with succession, act as an important control over soil microbial community development, greatly accelerating the rate of succession.
authors: Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, United States of America; Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, United States of America.
authors: Joseph E
authors: JE
authors: Knelman
authors: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, United States of America.
authors: Steven K
authors: SK
authors: Schmidt
authors: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, United States of America.
authors: Ryan C
authors: RC
authors: Lynch
authors: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, United States of America.
authors: John L
authors: JL
authors: Darcy
authors: Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, Montana, United States of America.
authors: Sarah C
authors: SC
authors: Castle
authors: Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, Montana, United States of America.
authors: Cory C
authors: CC
authors: Cleveland
authors: Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, United States of America; Environmental Studies Program, University of Colorado, Boulder, Colorado, United States of America.
authors: Diana R
authors: DR
authors: Nemergut
mesh_terms: D005308:Fertilizers; D046448:Ice Cover; D064307:Microbiota / Q000235:genetics*; D058889:Molecular Typing; D010568:Peru; D010802:Phylogeny; D012988:Soil Microbiology
chemical_list: D005308:Fertilizers