Elevated CO2 Changes Plant Dynamics in a Forest Ecosystem


DOE has developed and supported a number of long-term Free-Air CO2 Enrichment (FACE) studies to evaluate the response of entire ecosystems to increased CO2 associated with a changing climate. Oak Ridge National Laboratory has managed one of those sites for over 11 years and reports a set of findings in a recent issue of the Journal of Plant Ecology. Over the course of the experiment, the understory plant community changed dramatically. Above ground biomass was ~25% greater in plots exposed to elevated concentrations of carbon dioxide. Early in the study (2001-2003), herbaceous species made up 94% of the total understory biomass. After multiple years of treatments (2008), woody shrubs and saplings comprised 39% of total understory biomass in plots not receiving additional CO2 treatments and 67% in plots receiving elevated CO2 treatments. Understory communities in plots receiving elevated CO2 treatments also showed more rapid transition from herbaceous to woody-dominated communities, indicating faster succession. These results suggest that rising atmospheric CO2 concentration could accelerate ecosystem succession and have long-term impacts on forest dynamics.


Souza L, Belote RT, Kardol P, Weltzin JF, Norby RJ (2010) “CO2 enrichment accelerates successional development of an understory plant community,” Journal of Plant Ecology 3(1): 33-39.