University of Minnesota
University of Minnesota
College of Biological Sciences

E097 - Nitrogen Addition and Dynamics of Recovery from Cessation of N Addition




To determine the dynamics of recovery after cessation of N addition, N addition was halted in 3 plots per treatment randomly chosen from among the 6 total replicates per treatment in one of the 7 N addition sites in 1993. For a description of these plots, see E002 - Long-Term Nitrogen Deposition During Grassland Succession. Current work is in all plots in the E002 field are being recorded under experiment number E002

Key Results


Although nutrient enrichment frequently decreases biodiversity, it remains unclear whether such biodiversity losses are readily reversible, or are critical transitions between alternative low- and high-diversity stable states that could be difficult to reverse. Our 30-year grassland experiment shows that plant diversity decreased well below control levels after 10 years of chronic high rates (95–270 kg N ha-1 year-1) of nitrogen addition, and did not recover to control levels 20 years after nitrogen addition ceased. Thus, the regime shifts between alternative stable states that have been reported for some nutrient-enriched aquatic ecosystems may also occur in grasslands. Isbell et al. 2013 Ecology Letters

Methods for e097


Datasets for e097: Nitrogen Addition and Dynamics of Recovery from Cessation of N Addition

Dataset IDTitleRange of Years (# years with data)
lpe097Percent light penetration1982-1990 (9 years)
ple097Plant aboveground biomass data1982-2011 (23 years)
rbe097Root biomass data1988-1992 (4 years)
mse097Small mammal abundance1982-1985 (4 years)
cae097Soil Calcium1982-1982 (1 year)
care097Soil carbon1982-2011 (3 years)
mge097Soil magnesium1982-1982 (1 year)
nohe097Soil nitrate and ammonium1985-2002 (6 years)
ne097Soil nitrogen1982-2011 (4 years)
phe097Soil pH1982-1990 (5 years)
pe097Soil phosphorous1982-1982 (1 year)
ke097Soil potassium1982-1982 (1 year)

Selected Recent Publications

Hautier, Y.; Tilman, D.; Isbell, F.; Seabloom, E. W.; Borer, E. T.; Reich, P. B.; Anthropogenic environmental changes affect ecosystem stability via biodiversity. Science, 2015, 348, 6232, 336-340 DOI:10.1126/science.aaa1788 2015 [Full Text] e001 e002 e003 e012 e098 e120 e141 e245 e247 e248

Tilman, D.; Reich, P. B.; Isbell, F.; Biodiversity impacts ecosystem productivity as much as resources, disturbance, or herbivory; Proceedings of the National Academy of Sciences; 2012; 109, 26, 10394-10397 2012 [Full Text] e001 e002 e003 e004 e012 e062 e098 e120 e141 e172