De Micco, V.,Arena, C., Vitale, L., Aronne, G. and De Santo, A.V. 2011. Anatomy and photochemical behavior of Mediterranean Cistus incanus winter leaves under natural outdoor and warmer indoor conditions. Botany 89: 677-688.
The authors write that "climate change simulations for the Mediterranean region report a temperature increase of more than 5°C by the end of the twenty-first century (Giorgi and Lionello, 2008: Hertig and Jacobeit, 2008)," but they indicate that very few studies have focused on the consequences of winter warming in Mediterranean environments for the types of plants that live there, and they thus set out to help fill that void.
What was done
Focusing on the semi-deciduous pink roserock (Cistus incanus) - which relies on phenological and morphological features to protect its leaves from excessive light loads and reduce the need for investment in physiological mechanisms to avoid or limit photoinhibition - De Micco et al. compared leaf anatomy and photochemical activity in winter leaves of Cistus plants grown out-of-doors under winter temperatures characteristically experienced in Mediterranean ecosystems, as well as indoors at 5°C-higher-than-outside temperatures simulating expected winter warming.
What was learned
The first thing the five researchers report about their findings is that "the leaves of C. incanus plants grown indoors showed a rise of quantum yield of PSII [photosystem II] compared with that of outdoor leaves, attributable to a greater allocation of absorbed light to photochemistry, likely due to an increase of carbon fixation under the higher indoor temperature conditions," additionally citing the supportive prior work of Savitch et al. (2002), Oliveira and Penuelas (2004) and Gorsuch et al. (2010).
What it means
"Our overall analysis, combining the study of anatomical and ecophysiological traits of the winter leaves of C. incanus," as De Micco et al. describe it, indicates that in addition to currently being well-suited to its Mediterranean environment, "this species might be also able to adjust to the environmental conditions expected in the future."
Giorgi, F. and Lionello, P. 2008. Climate change projections for the Mediterranean region. Global and Planetary Change 63: 90-104.
Gorsuch, P.A., Pandey, S. and Atkin, O.K. 2010. Thermal de-acclimation: how permanent are leaf phenotypes when cold-acclimated plants experience warming? Plant, Cell and Environment 33: 1124-1137.
Hertig, E. and Jacobeit, J. 2008. Downscaling future climate change: temperature scenarios for the Mediterranean area. Global and Planetary Change 63: 127-131.
Oliveira, G. and Penuelas, J. 2004. Effects of winter cold stress on photosynthesis and photochemical efficiency of PSII of the Mediterranean Cistus albidus L. and Quercus ilex L. Plant Ecology 174: 179-191.
Savitch, L.V., Leonardos, E.D., Krol, M., Jansson, S., Grodzinski, B., Huner, N.P.A. and Oquist, G. 2002. Two different strategies for light utilization in photosynthesis in relation to growth and cold acclimation. Plant, Cell and Environment 25: 761-771.Reviewed 2 May 2012