An Unanticipated Benefit of Drought in Certain Forests
Wurzburger, N. and Miniat, C.F. 2014. Drought enhances symbiotic dinitrogen fixation and competitive ability of a temperate forest tree. Oecologia 174: 1117-1126.
The two U.S. researchers discovered that "under drought, growth declined across all species." However, they say that it "triggered an 80% increase in nodule biomass and N accrual for R. pseudoacacia, improving its growth relative to other species." Wurzburger and Miniat say their results suggest that "drought intensified soil N deficiency and that R. pseudoacacia's ability to fix N2 facilitated competition with non-fixing species when both water and N were limiting." Under scenarios of moderate drought, therefore, they conclude that "N2 fixation may alleviate the N constraints resulting from low soil moisture and improve the competitive ability of N2-fixing species, and as a result, supply more new nitrogen to the [entire] ecosystem."
Burke, E.J., Brown, S.J. and Christidis, N. 2006. Modeling the recent evolution of global drought and projections for the twenty-first century with the Hadley Center climate model. Journal of Hydrometeorology 7: 1113-1125.
Carnicer, J., Coll, M., Ninyerola, M., Pons, X., Sanchez, G. and Penuelas, J. 2011. Widespread crown condition decline, food web disruption, and amplified tree mortality with increased climate change-type drought. Proceedings of the National Academy of Sciences USA 108: 1474-1478.