Plants vary enormously in the morphology and physiology of their roots. We have only begun to understand the diversity in root form and function and the major role they play in ecosystem processes. At the physiological level, the primary function of mycorrhizal fine roots is water and nutrient absorption. Ecologically, roots have a major influence on plant competition, nutrient cycling, soil development and the complex web of soil microorganism. Lifespans of the finest roots of a plant may range from no more than a week to more that three years. Root diameters of the finest roots of a plant species can range from only 40 microns to nearly 1000 microns. Some species construct roots that are unresponsive to changes in soil water or nutrient status; others build roots that grow rapidly when soil is favorable and shed quickly when soil conditions become unfavorable. We are interested in linking a better understanding of root biology and ecology to improved predictions on factors influencing species distribution and abundance. Studies are conducted under controlled greenhouse and growth chamber conditions as well as common garden plantings in the field and natural patterns in the forest. Field sites include forests in Pennsylvania, tallgrass prairie in Minnesota, tundra in Greenland, and forest plantations near Harbin, China.

Current projects include:

• An investigation of species variation in root lifespan and the factors that influence root lifespan
• Factors controlling root respiration, particularly associated with soil moisture and temperature of species from different latitudes
• Factors controlling the decomposition of roots and variation among species

Grape roots in respiration chamber

Root Box Technique