EARLY TRADE-OFFS OF ROOT TRAITS ON A MYCORRHIZAL COLLABORATION GRADIENT
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Date
2023-06
Authors
Villano, Lindsay
Journal Title
Journal ISSN
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Publisher
University of Oregon
Abstract
Aboveground plant traits exist on a spectrum defined by trade-offs between conservative and acquisitive resource uptake. However, belowground traits do not fit this axis because the uptake of soil nutrients can be outsourced to mycorrhizal mutualists. Thus, adding another axis in the root economic space that represents collaboration with arbuscular mycorrhizal (AM) fungi increases our understanding of fundamental variation in root traits. Mature roots exhibit trade-offs between investing in longer root structures that travel farther, or thicker roots that can better support mycorrhizae. Here, I explore whether young roots display trade-offs in collaboration intensity and if so, how long after germination species will begin to reflect niches on this axis. I hypothesize a negative correlation between root growth rate and colonization rate of AM fungi and that the relationship between these variables increases over time as plants refine their resource uptake strategy. I grew five native forb species for twenty-five days and sampled plants at eight time points after germination. Upon sampling, I recorded root length by analyzing the root's structure and then quantified percent colonization by AM fungi. I found that despite variation in species ' root length and colonization rates, they did not fo1m a negative relationship. The con elation of length and percent colonization did increase over time with intraspecific variation in the degree and direction of this correlation. The results of this study provide further insight on young root trait variation and benefit our understanding of species interactions in the rhizosphere that contribute to community dynamics.
Description
13 pages
Keywords
root traits, rhizosphere, trait variation