The value of wet leaves
An often overlooked, yet common, feature of all plants is that their leaf surfaces are wet for very significant periods over their lifetimes. My talk will present the results of a meta-analysis that shows on a global basis, all leaves spend >37% of their lifetimes wet. Further analyses therefore focused on identifying important reasons for why enhancing our understanding of wet leaves can be critical for biologists to not only acknowledge, but also to quantify and incorporate into their investigations at a host of scales.
The meta-analysis of over 100 different plant species from a wide range of ecosystems reveals that among the most important affects the value leaf wetting events has is on physiological functions from the scale of the leaf itself to the ecosystem, including improvements in leaf-level carbon fixation (by 4 to 17%) and water relations (as changes in relative water content and water potential and their pressure volume relations), that translate to increased rates of plant growth (by 3 to 34%) and survival (by up to 19%), as well as changes to ecosystem biogeochemical cycling. Moreover, there is growing recognition and a few investigations that demonstrate how leaf-wetting events can result in new or diversified trophic interactions, either directly affecting endophytic microbes or epiphylls inhabiting leaf surfaces or indirectly the mycorrhizal-root interactions in the soil. Given projected scenarios of global environmental changes, it is critical to consider how this underappreciated aspect of plant biology, leaf wetting, and its interactions with and on climate is likely to affect plants and their communities now and in the future.