While it is apparent from controlled studies that plant Si concentration is related to silicon availability of the growth medium, relatively little is known about how natural gradients influence plant silicification. I am probing this question at two different scales:
Landscape – I am utilizing the “natural laboratory” of Serengeti National Park to better understand which environmental factors, including soil Si availability, influence Si accumulation by grasses. I have built and tested structural equation models to understand the relationships between abiotic conditions, soil silicon pools, and grass silicon concentration. Results of this study were recently published in Plant and Soil.
Global – I am utilizing data from the Nutrient Network to investigate global patterns of grassland biosilicification across climatic gradients and in response to herbivore exclusion and soil nutrient (NPK) addition. Analytical methods for quantifying leaf Si were developed with George Donati (WFU chemistry) and published in Microchemical Journal. Collaborator and R guru, Daniel Griffith, has an R package under development which we are using for NIRS model calibration of leaf silicon. Check out the impressive body of work from the NutNet group here.