Effects of elevated CO2 concentration and increased temperature on leaf quality responses of rare and endangered plants

Background In the study, the effects of elevated CO2 and temperature on the nitrogen content, carbon content, and C:N ratio of seven rare and endangered species (Quercus gilva, Hibiscus hambo, Paliurus ramosissimus, Cicuta virosa, Bupleurum latissimum, Viola raddeana, and Iris dichotoma) were examined under control (ambient CO2 + ambient temperature) and treatment (elevated CO2 + elevated temperature) for 3 years (May 2008 and June 2011).