caa a22 4500 477109543 CHVBK 20180405111604.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF00010451 doi (NATIONALLICENCE)springer-10.1007/BF00010451 Responses of soil microbiota of a late successional alpine grassland to long term CO2 enrichment [Elektronische Daten] [Pascal Niklaus, Christian Körner] We investigated microbial responses in a late successional sedge-dominated alpine grassland to four seasons of CO2 enrichment. Part of the plots received fertilizer equivalent to 4.5g N m−2 a−1. Soil basal respiration (R mic ), the metabolic quotient for CO2 (qCO2=R mic /C mic ), microbial C and N (C mic and N mic ) as well as total soil organic C and N showed no response to CO2 enrichment alone. However, when the CO2 treatment was combined with fertilizer addition R mic and qCO2 were statistically significantly higher under elevated CO2 than under ambient conditions (+57% and +71%, respectively). Fertilizer addition increased microbial N pools by 17%, but this was not influenced by elevated CO2. Microbial C was neither affected by elevated CO2 nor fertilizer. The lack of a CO2-effect in unfertilized plots was suprising in the light of our evidence (based on C balance) that enhanced soil C inputs must have occurred under elevated CO2 regardless of fertilizer treatment. Based on these data and other published work we suggest that microbial responses to elevated CO2 in such stable, late-successional ecosystems are limited by the availability of mineral nutrients and that results obtained with fertile or heavily disturbed substrates are unsuitable to predict future microbial responses to elevated CO2 in natural systems. However, when nutrient limitation is removed (e.g. by wet nitrogen deposition) microbes make use of the additional carbon introduced into the soil system. We believe that the response of natural ecosystems to elevated CO2 must be studied in situ in natural, undisturbed systems. Kluwer Academic Publishers, 1996 carbon sequestration nationallicence elevated CO2 nationallicence metabolic quotient nationallicence microbial biomass nationallicence nutrient limitation nationallicence respiration nationallicence Niklaus Pascal Institute of Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland aut Körner Christian Institute of Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland aut Plant and Soil Kluwer Academic Publishers; gopher://gopher:wkap.nl 184/2(1996-06-01), 219-229 0032-079X 184:2<219 1996 184 11104 https://doi.org/10.1007/BF00010451 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00010451 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Niklaus Pascal Institute of Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland aut NATIONALLICENCE 700 1- Körner Christian Institute of Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland aut NATIONALLICENCE 773 0- Plant and Soil Kluwer Academic Publishers; gopher://gopher:wkap.nl/ 184/2(1996-06-01), 219-229 0032-079X 184:2<219 1996 184 11104 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer