Fig. 6. Change in functional evenness across soil nutrient amendments and major bacterial phyla.

Cumulative contribution of bacteria to total relativized carbon (C) use (the sum of μg C–CO₂ respired and μg MBC produced per taxon relativized by total C use across all taxa, both per g dry soil per week [wk]) across soil amendment. Points represent averages across soil replicates from four ecosystems (mixed conifer forest, ponderosa pine forest, piñon pine-juniper scrubland, and desert grassland) (n = 3 experimental replicates). Color indicates soil treatment (Control = no amendment, C = carbon—glucose—only, C + N = carbon and nitrogen—[NH₄]₂SO₄). Taxa were ranked by individual contribution to C use.