How did the swiss cheese plant get its holes?
Adult leaf fenestration in "Swiss cheese" plants (Monstera Adans.) is an unusual leaf shape trait lacking a convincing evolutionary explanation. Monstera are secondary hemiepiphytes that inhabit the understory of tropical rainforests, where photosynthesis from sunflecks often makes up a large proportion of daily carbon assimilation. Here I present a simple model of leaf-level photosynthesis and whole-plant canopy dynamics in a stochastic light environment. The model demonstrates that leaf fenestration can reduce the variance in plant growth and thereby increase geometric mean fitness. This growth-variance hypothesis also suggests explanations for conspicuous ontogenetic changes in leaf morphology (heteroblasty) in Monstera, as well as the absence of leaf fenestration in co-occurring juvenile tree species. The model provides a testable hypothesis of the adaptive significance of a unique leaf shape and illustrates how variance in growth rate could be an important factor shaping plant morphology and physiology.
Department of Biology, Indiana University, Bloomington, Indiana 47405, USA. cdmuir@indiana.edu
Christopher D
CD
Muir
D000220:Adaptation, Biological / Q000502:physiology*; D029064:Araceae / Q000033:anatomy & histology* / Q000254:growth & development; D005075:Biological Evolution; D017753:Ecosystem; D056084:Genetic Fitness / Q000235:genetics; D008027:Light; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology*; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000502:physiology