Plant-microbe competition for soil amino acids in the alpine tundra: effects of freeze-thaw and dry-rewet events

Amino acids have been shown to be a potentially significant N source for the alpine sedge, Kobresia myosuroides. We hypothesised that freeze-thaw and dry-rewet events allow this plant species increased access to amino acids by disrupting microbial cells, which decreases the size of competing microbial populations, but increases soil amino acid concentrations. To test this hypothesis, we characterized freeze-thaw and dry-rewet events in the field and simulated them in laboratory experiments on plant-soil microcosms. In one experiment, 15N,13C-[2]-glycine was added to microcosms that had previously been subjected to a freeze-thaw or dry-rewet event, and isotopic concentrations in the plant and microbial fractions...

Categories: Publication; Types: Citation, Journal Citation; Tags: Alpine tundra, Drying, Freezing, Kobresia myosuroides, Nitrogen cycle, All tags... Oecologia, Springer Berlin / Heidelberg, Fewer tags