Diurnal variation in methyl halide emission rates from tropical ferns

We measured foliar emission rates of methyl chloride (CH3Cl) and methyl bromide (CH3Br) from tropical ferns. The diurnal variation in methyl halide emission rates was quite different between tropical ferns of the same genus: Cyathea podophylla showed diurnal cycles with a midday maximum, whereas Cyathea lepifera showed a midday decline in emission rates. It is likely that the efficiency of methylation of halide ions in the leaves is affected positively or negatively by environmental factors such as temperature and solar radiation, depending on the species. These unique diurnal variations in methyl halide emission rates could be important keys to our understanding of the production of these compounds.