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Plant diversity shapes microbe‐rhizosphere effects on P mobilisation from organic matter in soil

Hacker, Nina, Ebeling, Anne, Gessler, Arthur, Gleixner, Gerd, González Macé, Odette, Kroon, Hans, Lange, Markus, Mommer, Liesje, Eisenhauer, Nico, Ravenek, Janneke, Scheu, Stefan, Weigelt, Alexandra, Wagg, Cameron, Wilcke, Wolfgang, Oelmann, Yvonne, Cleland, Elsa
Ecology letters 2015 v.18 no.12 pp. 1356-1365
carbon, exudation, microorganisms, nutrient uptake, phosphorus, probability, soil, soil nutrient dynamics, soil organic matter, species diversity
Plant species richness (PSR) increases nutrient uptake which depletes bioavailable nutrient pools in soil. No such relationship between plant uptake and availability in soil was found for phosphorus (P). We explored PSR effects on P mobilisation [phosphatase activity (PA)] in soil. PA increased with PSR. The positive PSR effect was not solely due to an increase in Cₒᵣg concentrations because PSR remained significant if related to PA:Cₒᵣg. An increase in PA per unit Cₒᵣg increases the probability of the temporal and spatial match between substrate, enzyme and microorganism potentially serving as an adaption to competition. Carbon use efficiency of microorganisms (Cₘᵢc:Cₒᵣg) increased with increasing PSR while enzyme exudation efficiency (PA:Cₘᵢc) remained constant. These findings suggest the need for efficient C rather than P cycling underlying the relationship between PSR and PA. Our results indicate that the coupling between C and P cycling in soil becomes tighter with increasing PSR.