@article {KNZ001668,
	title = {Mycorrhizal phenotypes and the law of the minimum},
	journal = {New Phytologist},
	volume = {205},
	year = {2015},
	pages = {1473 -1484},
	abstract = {<p>Mycorrhizal phenotypes arise from interactions among plant and fungal genotypes and the environment. Differences in the stoichiometry and uptake capacity of fungi and plants make arbuscular mycorrhizal (AM) fungi inherently more nitrogen (N) limited and less phosphorus (P) limited than their host plants. Mutualistic phenotypes are most likely in P-limited systems and commensal or parasitic phenotypes in N-limited systems. Carbon (C) limitation is expected to cause phenotypes to shift from mutualism to commensalism and even parasitism. Two experiments compared the influence of fertilizer and shade on mycorrhizas in Andropogon gerardii across three naturally N-limited or P-limited grasslands. A third experiment examined the interactive effects of N and P enrichment and shade on A. gerardii mycorrhizas. Our experiments generated the full spectrum of mycorrhizal phenotypes. These findings support the hypothesis that mutualism is likely in P-limited systems and commensalism or parasitism is likely in N-limited systems. Furthermore, shade decreased C-assimilation and generated less mutualistic mycorrhizal phenotypes with reduced plant and fungal biomass. Soil fertility is a key controller of mycorrhizal costs and benefits and the Law of the Minimum is a useful predictor of mycorrhizal phenotype. In our experimental grasslands arbuscular mycorrhizas can ameliorate P-limitation but not N-limitation.</p>},
	keywords = {LTER-KNZ, stoichiometry},
	doi = {10.1111/nph.13172},
	url = {https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.13172},
	author = {Johnson, N.C. and G.T. Wilson and Wilson, J.A. and Miller, R.M. and M. Bowker}
}
@article {KNZ001314,
	title = {Resource limitation is a driver of local adaptation in mycorrhizal symbioses},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {107},
	year = {2010},
	pages = {2093 -2098},
	abstract = {<p>Symbioses may be important mechanisms of plant adaptation to their environment. We conducted a reciprocal inoculation experiment to test the hypothesis that soil fertility is a key driver of local adaptation in arbuscular mycorrhizal (AM) symbioses. Ecotypes of Andropogon gerardii from phosphorus-limited and nitrogen-limited grasslands were grown with all possible \&ldquo;home and away\&rdquo; combinations of soils and AM fungal communities. Our results indicate that Andropogon ecotypes adapt to their local soil and indigenous AM fungal communities such that mycorrhizal exchange of the most limiting resource is maximized. Grasses grown in home soil and inoculated with home AM fungi produced more arbuscules (symbiotic exchange structures) in their roots than those grown in away combinations. Also, regardless of the host ecotype, AM fungi produced more extraradical hyphae in their home soil, and locally adapted AM fungi were, therefore, able to sequester more carbon compared with nonlocal fungi. Locally adapted mycorrhizal associations were more mutualistic in the two phosphorus-limited sites and less parasitic at the nitrogen-limited site compared with novel combinations of plants, fungi, and soils. To our knowledge, these findings provide the strongest evidence to date that resource availability generates evolved geographic structure in symbioses among plants and soil organisms. Thus, edaphic origin of AM fungi should be considered when managing for their benefits in agriculture, ecosystem restoration, and soil-carbon sequestration.</p>},
	keywords = {LTER-KNZ, coevolution, geographic mosaics, mutualism, parasitism},
	doi = {10.1073/pnas.0906710107},
	url = {https://www.pnas.org/content/107/5/2093},
	author = {Johnson, N.C. and G.T. Wilson and M. Bowker and Wilson, J.A. and Miller, R.M.}
}
