This Dissertation Improvement Grant award will provide funds to develop quantitative linkages between plant form, function and climate. Leaf venation is highly correlated with key climate variables, such as mean annual temperature, atmospheric CO2 and aridity. Climate is a key determinant of plant form and function, but a strong mechanistic linkage between these factors remains lacking. Identifying this mechanism will improve scaling-up of individual plant measurements to climate variation, and scaling-down of climate models to their impact on local ecosystems. A quantitative model will be developed and parameterized. The model will be tested on community weighted leaf venation measurements gathered along two elevational gradients, one in Costa Rica and one in Colorado. Preliminary results suggest strong correlations between vein density and growing season mean temperature along these gradients. The model and analyses will elucidate a mechanistic basis for predicting how variation in climate affects living systems. The analysis will be expanded by applying these quantitative methods to venation patterns in fossil leaves from well-described paleo-communities. Historically, leaf margins from fossil leaves have been used to link morphology to past climate. The research proposes to substantiate that leaf venation provides an accurate mechanism to reconstruct paleo-climate than leaf margins. An innovative approach to broader impacts is proposed by using crowd sourcing approaches to analyze leaf venation. A web portal to enable citizen-science participation in data analysis, and will provide lesson plans for teachers to integrate climate and leaves into their classrooms. These lessons will be developed and tested through a partnership with Miles Exploratory Learning Center (Tucson) and disseminated to hundreds of teachers through an existing relationship with the University of Arizona's College of Science K-12 outreach programs.
