Site: Cedar Creek Ecosystem Science Reserve

CDR Experiment E002 – Long-Term Nitrogen Addition to Disturbed Vegetation.
Credit: Jacob Miller

Chronic N addition reduced plant species richness and led to the local extinction of species with efficient N use. Species richness returned to its original level after ceasing the addition of low levels of N. These changes in composition were readily reversed after low levels of N were no longer added. However, species richness did not recover two decades after ceasing the addition of high levels of N. Network-wide synthesis projects are testing how applicable this observation may be across different ecosystem types.