Carbon and Nitrogen Pools in a Tallgrass Prairie Soil under Elevated Carbon Dioxide Export

@article{citeulike:523201, abstract = {Soil is a potential C sink and could offset rising atmospheric CO2. The capacity of soils to store and sequester C will depend on the rate of C inputs from plant productivity relative to C exports controlled by microbial decomposition. Our objective was to measure pools of soil C and N to assess the potential for C accrual and changes to N stocks as influenced by elevated atmospheric CO2. Treatments (three replications, randomized complete block design) were ambient CO2--no chamber (NC), ambient CO2--chamber (AC), and two times ambient CO2--chamber (EC). Long-term (290 d) incubations (35{degrees}C) were conducted to assess changes in the slow soil fractions of potentially mineralizable C (PMC) and potentially mineralizable N (PMN). Potentially mineralizable C was enhanced (P < 0.1) by 19 and 24\% in EC relative to AC and NC soil at the 0- to 5- and 5- to 15-cm depths, respectively. Potentially mineralizable N was significantly greater by 14\% at the 0- to 5-cm depth in EC relative to AC, but decreased by 12\% in EC relative to NC (P < 0.1). Measurements of PMC indicate that increases in total soil C under elevated CO2 in a previous study were a consequence of accrual into the slow pool. Relatively large amounts of new C deposited as a result of elevated CO2 (Cnew) remained in the soil after the 290-d incubation. In contrast to accumulation of C into the slow fraction, Cnew was integrated into a passive fraction of soil organic matter (SOM). Accumulation of N was also detected in the whole soil, which cannot be explained by current estimates of ecosystem N flux.}, author = {Williams, M. A. and Rice, C. W. and Omay, A. and Owensby, C.}, citeulike-article-id = {523201}, citeulike-linkout-0 = {http://soil.scijournals.org/cgi/content/abstract/68/1/148}, citeulike-linkout-1 = {http://soil.scijournals.org/cgi/content/full/68/1/148?maxtoshow=&#38;HITS=&#38;hits=&#38;RESULTFORMAT=&#38;andorexactfulltext=and&#38;searchid=1&#38;FIRSTINDEX=0&#38;volume=68&#38;firstpage=148&#38;resourcetype=HWCIT}, day = {1}, journal = {Soil Sci Soc Am J}, keywords = {climate\_change, co2, science, soil}, month = {January}, number = {1}, pages = {148--153}, posted-at = {2006-02-27 06:37:39}, priority = {3}, title = {Carbon and Nitrogen Pools in a Tallgrass Prairie Soil under Elevated Carbon Dioxide}, url = {http://soil.scijournals.org/cgi/content/abstract/68/1/148}, volume = {68}, year = {2004} }

TY - JOUR ID - citeulike:523201 L3 - citeulike-article-id:523201 N2 - Soil is a potential C sink and could offset rising atmospheric CO2. The capacity of soils to store and sequester C will depend on the rate of C inputs from plant productivity relative to C exports controlled by microbial decomposition. Our objective was to measure pools of soil C and N to assess the potential for C accrual and changes to N stocks as influenced by elevated atmospheric CO2. Treatments (three replications, randomized complete block design) were ambient CO2--no chamber (NC), ambient CO2--chamber (AC), and two times ambient CO2--chamber (EC). Long-term (290 d) incubations (35{degrees}C) were conducted to assess changes in the slow soil fractions of potentially mineralizable C (PMC) and potentially mineralizable N (PMN). Potentially mineralizable C was enhanced (P < 0.1) by 19 and 24% in EC relative to AC and NC soil at the 0- to 5- and 5- to 15-cm depths, respectively. Potentially mineralizable N was significantly greater by 14% at the 0- to 5-cm depth in EC relative to AC, but decreased by 12% in EC relative to NC (P < 0.1). Measurements of PMC indicate that increases in total soil C under elevated CO2 in a previous study were a consequence of accrual into the slow pool. Relatively large amounts of new C deposited as a result of elevated CO2 (Cnew) remained in the soil after the 290-d incubation. In contrast to accumulation of C into the slow fraction, Cnew was integrated into a passive fraction of soil organic matter (SOM). Accumulation of N was also detected in the whole soil, which cannot be explained by current estimates of ecosystem N flux. IS - 1 JF - Soil Sci Soc Am J EP - 153 TI - Carbon and Nitrogen Pools in a Tallgrass Prairie Soil under Elevated Carbon Dioxide VL - 68 SP - 148 KW - climate_change KW - co2 KW - science KW - soil AU - Williams, MA AU - Rice, CW AU - Omay, A AU - Owensby, C PY - 2004/01/01/ UR - http://soil.scijournals.org/cgi/content/abstract/68/1/148 ER -