@article {KNZ002058, title = {Differential resilience of soil microbes and ecosystem functions following cessation of long-term fertilization}, journal = {Ecosystems}, volume = {24}, year = {2021}, pages = {2042{\textendash}2060}, abstract = {

Nitrogen (N) from anthropogenic sources has dramatically increased in terrestrial ecosystems globally. Although belowground microbial processes and events that release N into the atmosphere, such as fire, could support ecosystem resilience to eutrophication, little is known about how these factors might affect N loss following chronic fertilization, thus promoting ecosystem recovery. We studied how N pools, N-cycling potential rates and their affiliated microbial populations, and microbial community composition responded to the factorial effects of cessation of 30 years of chronic N fertilization and annual burning at a tallgrass prairie. Soil N availability in previously fertilized plots recovered by 86\% (using never-fertilized control plots as a 100\% recovery reference), while plant and microbial biomass did not change. Nitrification potential recovered (80\%), and denitrification potential partially recovered (50\%), in previously fertilized plots. There were differential responses among key groups of nitrifiers (archaea vs. bacteria) and denitrifiers (nosZ clade I vs. clade II from Anaeromyxobacter dehalogenans) to long-term N fertilization and cessation despite the whole microbial community composition not shifting significantly after fertilization ceased. Also, N-cycling potentials were consistently higher in unburned prairie. Together, results suggest that fire is a prominent mechanism for ecosystem N removal in annually burned prairie, while N-cycling microbes will have an important role in the absence of fire; however, the recovery to pre-fertilized condition, with or without fire, will take longer than 1 year. Overall, differential resilience of biotic populations and processes can potentially shape different outcomes of soil N loss and tallgrass prairie ecosystem recovery from long-term N fertilization.

}, keywords = {LTER-KNZ}, doi = {10.1007/s10021-021-00633-9}, url = {http://link.springer.com/10.1007/s10021-021-00633-9}, author = {Nieland, M.A. and P. Moley and J. Hanschu and L.H. Zeglin} }