Supplemental Literature Cited Ambus, P. and S. Christensen. 1995. Spatial and seasonal nitrous oxide and methane fluxes in Danish forest-, grassland-, and agroecosystems. Journal of Environmental Quality 24: 993-1001. Bowden, R.D., P.A. Steudler, and J.M. Melillo. 1990. Annual nitrous oxide fluxes from temperate forest soils in the northeastern United States. Journal of Geophysical Research 96: 13997-14005. Bowden, R.D. J.M. Melillo, P.A. Steudler, et al. 1991. Effects of nitrogen additions on annual nitrous oxide fluxes from temperate forest soils in the northeastern United States. Journal of Geophysical Research 96: 9321-9328. Breuer, L., H. Papen and K. Butterbach-Bahl. 2000. N2O emission from tropical forest soils of Australia. Journal of Geophysical Research 105: 26353-26367. Brown, J.R., J.C. Blankinship, A. Niboyet, K. J. van Groenigen, P. Dijkstra, X. Le Roux, P.W. Leadley, and B.A. Hungate. 2012. Effects of multiple global change treatments on soil N2O fluxes. Biogeochemistry 109: 85-100. Bruemmer, C., N. Brueggeman, K. Butterbach-Bahl, et al. 2008. Soil-atmosphere exchange of N2O and NO in near-natural savanna and agricultural land in Burkina Faso (W. Africa). Ecosystems 11: 582-600. Burgin, A.J. and P.M. Groffman. 2012. Soil O2 controls denitrification rates and N2O yield in a riparian wetland. Journal of Geophysical Research 117: doi:10.1029/2011JG001799 Butterbach-Bahl, K., R. Gasche, C. Huber, K. Kreutzer and H. Papen. 1998. Impact of N-input by wet deposition on N-trace gas fluxes and CH4-oxidation in spruce forest ecosystems of the temperate zone. Atmospheric Environment 32: 559-564. Butterbach-Bahl, K., L. Breuer, R. Gasche, G. Willibald, and H. Papen. 2002a. Exchange of trace gases between soils and the atmosphere in Scots pine forest ecosystems of the northeastern German lowlands. I. Fluxes of N2O, NO/NO2 and CH4 at forest sites with different N-deposition. Forest Ecology and Management 167: 123-134. Butterbach-Bahl, K., G. Willibald, and H. Papen. 2002b. Soil core method for direct simultaneous determination of N2 and N2O emissions from forest soils. Plant and Soil 240: 105-116. Cantarel, A.M., J.M.G. Bloor, N Deltroy, et al. 2011. Effects of climate change drivers on nitrous oxide fluxes in an upland temperate grassland. Ecosystems 14: 223-233. Castaldi, S., T. Bertolini, A. Valente, T. Chiti, and R. Valentini. 2012. Nitrous oxide emissions from soil of an African rain forest in Ghana. Biogeosciences Discussion 9: 16565-16588. Castro, M.S., P.A. Steudler, J.M. Melillo, J.D. Aber, and S. Millham. 1992. Exchange of N2O and CH4 between the atmosphere and soils in spruce-fir forests in the northeastern United States. Biogeochemistry 18: 119-135. Christiansen, J.R., P. Gundersen, P. Frederiksen, and L. Vesterdal. 2012. Influence of hydromorphic soil conditions on greenhouse gas emissions and soil carbon stocks in a Danish temperate forest. Forest Ecology and Management 284: 185-195. Couwenberg, J., R. Dommain, and H. Joosten. 2010. Greenhouse gas fluxes from tropical peatlands in south-east Asia. Global Change Biology 16: 1715-1732. Czóbel, S., L. Horvath, and O. Szimai, et al. 2010. Comparison of N2O and CH4 fluxes from Pannonian natural ecosystems. European Journal of Soil Science 61: 671-682. Dannenman, M., R. Gasche, and H. Papen. 2007. Nitrogen turnover and N2O production in the forest floor of beech stands as influenced by forest management. Journal of Plant Nutrition and Soil Science 170: 134-144. DiSimone, J., M.L. Macrae, and R.A. Bourbonniere. 2010. Spatial variability in surface N2O fluxes across a riparian zone and relationships with soil environmental conditions and nutrient supply. Agriculture, Ecosystems and Environment 138: 1-9. Dong, Y., D. Scharffe, J.M. Lobert, et al. 1998. Fluxes of CO2, CH4, and N2O from a temperate forest soil: the effects of leaves and humus layers. Tellus 50B: 243-252. Donoso, L., R. Santana, and E. Sanhueza. 1993. Seasonal variation of N2O fluxes at a tropical savannah site: Soil consumption of N2O during the dry season. Geophysical Research Letters 20: 1379-1382. Eickenscheidt, N. and R. Brumme. 2012. NOx and N2O fluxes in a nitrogen-enriched European spruce forest soil under experimental long-term reduction of nitrogen deposition. Atmospheric Environment 60: 51-58. Erickson, H., E.A. Davidson, and M. Keller. 2002. Former land use and tree species affect nitrogen oxide emissions from a tropical dry forest. Oecologia 130: 297-308. Flechard, C.R., A. Neftel, M. Jocher, C. Ammann, and J. Fuhrer. 2005. Bi-directional soil/atmosphere N2O exchange over two mown grassland systems with contrasting management practices. Global Change Biology 11: 2114-2127. Frasier, R., S. Ullah, and T.R. Moore. 2010. Nitrous oxide consumption potential of well-drained forest soils in southern Quebec, Canada. Geomicrobiology Journal 27: 53-60. Garcia-Mendez, G., J.M. Maass, P.A. Matson, and P.M. Vitousek. 1991. Nitrogen transformations and nitrous oxide flux in a tropical deciduous forest in Mexico. Oecologia 88: 362-366. Garcia-Montiel, D., P. Steudler, M. Piccolo, et al. 2001. Controls on soil nitrogen oxide emissions from forest and pastures in the Brazilian Amazon. Global Biogeochemical Cycles 15: 1021-1030. Glatzel, S. and K. Stahr. 2001. Methane and nitrous oxide exchange in differently fertilized grassland in southern Germany. Plant and Soil 231: 21-35 Goldberg, S.D. and G. Gebauer. 2009. Drought turns a central European Norway spruce forest soil from an N2O source to a transient N2O sink. Global Change Biology 15: 850-860. Goosens, A., A. de Visscher, P. Boeckx, and O. van Cleemput. 2001. Two-year field study on the emission of N2O from coarse and middle-textured Belgian soils with different land use. Nutrient Cycling in Agroecosystems 40: 23-34. Groffman, P.M., J.P. Hardy, C.T. Driscoll, and T.J. Fahey. 2006. Snow depth, soil freezing, and fluxes of carbon dioxide, nitrous oxide and methane in a northern hardwood forest. Global Change Biology 12: 1748-1760. Guilbault, M.R. and A.D. Matthias. 1998. Emissions of N2O from Sonoran desert and effluent-irrigated grass ecosystems. Journal of Arid Environments 38: 87-98. Hadi, A., K. Inubushi, E. Purnomo, et al. 2000. Effects of land use changes on nitrous oxide (N2O) emission from tropical peatlands. Chemosphere-Global Change Science 2: 347. Hartley, A.E. 1997. Environmental controls on nitrogen cycling in northern Chihuahuan desert soils. Ph.D. Dissertation, Duke University, Durham, NC. Holtgrieve, G.W., P.K. Jewett, and P.A. Matson. 2006. Variation in soil N cycling and trace gas emissions in wet tropical forests. Oecologia 146: 584-594. Hopfensperger, K.N., C.M. Gault, and P.M. Groffman. 2009. Influence of plant communities and soil properties on trace gas fluxes in riparian northern hardwood forests. Forest Ecology and Management 258: 2076-2082. Horvath, L., G. Grosz, A. Machon, et al. 2010. Estimation of nitrous oxide emission from Hungarian semi-arid sandy and loess grasslands: effect of soil parameters, grazing, irrigation and land use. Agriculture, Ecosystems and Environment 139: 255-263. Inubushi, K., Y. Furukawa, A. Hadi, et al. 2003. Seasonal changes of CO2, CH4, and N2O fluxes in relation to land-use change in tropical peatlands located in coastal area of South Kalimantan. Chemosphere 52: 603-608. Inclan, R., C. Uribe, L. Sanchez, D.M. Sanchez, A. Clavero, A.M. Fernandez, R. Morante, A. Blanco, and R. Jandl. 2012. N2O and CH4 fluxes in undisturbed and burned holm oak, Scots pine and Pyrenean oak forests in central Spain. Biogeochemistry 107: 19-41. Jambert, C., R.L. Delmas, L. Labrouse, and P. Chassin. 1994. Nitrogen compound emissions from fertilized soils in a maize field pine tree forest agrosystem in the southwest of France. Journal of Geophysical Research 99: 16523-16530. Jordan, T.E., D.E. Weller, and D.L. Correll. 1998. Denitrification in surface soils of a riparian forest: effects of water, nitrate and sucrose additions. Soil Biology and Biochemistry 30: 833-843. Jorgensen, C.J. and B. Elberling. 2012. Effects of flooding-induced N2O production, consumption and emission dynamics on the annual N2O emission budget in wetland soil. Soil Biology and Biochemistry 53: 9-17. Jungkunst, H.F., A. Bargsten, and M. Timme, et al. 2012. Spatial variability of nitrous oxide emissions in an unmanaged old-growth beech forest. Journal of Plant Nutrition and Soil Science 175: 739-749. Kellman, L. and K. Kavanaugh. 2008. Nitrous oxide dynamics in managed northern forest soil profiles: is production offset by consumption? Biogeochemistry 90: 115-128. Livesley, S.J., S. Gover, L.B. Hutley, H. Jamali, K. Butterbach-Bahl, B. Fest, J. Beringer, and S.K. Arndt. 2011. Seasonal variation and fire effects on CH4, N2O and CO2 exchange in savanna soils of northern Australia. Agricultural and Forest Meteorology 151: 1440-1452. Lohila, A., M. Aurela, and J. Hatakka, et al. 2010. Responses of N2O fluxes to temperature, water table, and N deposition in a northern boreal fen. European Journal of Soil Science 61: 651-661. MacDonald, J.A., U. Skiba, L.J. Sheppard, B. Ball, J.D. Roberts, K.A. Smith, and D. Fowler. 1997. The effect of nitrogen deposition and seasonal variability on methane oxidation and nitrous oxide emission rates in an upland spruce plantation and moorland. Atmospheric Environment 31: 3693-3706. Maljanen, M., N. Shurpali, and J. Hytonen, et al. 2012. Afforestation does not necessarily reduce nitrous oxide emissions from managed boreal peat soils. Biogeochemistry 108: 199-218. Matson, P.A. and P.M. Vitousek. 1987. Cross-system comparisons of soil nitrogen transformations and nitrous oxide flux in tropical forest ecosystems. Global Biogeochemical Cycles 1: 163-170 Matson, P.A., C. Volkmann, K. Coppinger, and W.A. Reiners. 1991. Annual nitrous oxide flux and soil nitrogen characteristics in sagebrush steppe ecosystems. Biogeochemistry 14: 1-12. Morishita, T., T. Sakata, M. Takahashi, et al. 2007. Methane uptake and nitrous oxide emission in Japanese forest soils and their relationship to soil and vegetation types. Soil Science and Plant Nutrition 53: 678-691. Morse, J.L., M. Ardon, and E.S. Bernhardt. 2012. Using environmental variables and soil processes to forecast denitrification potential and nitrous oxide fluxes in coastal plain wetlands across different land uses. Journal of Geophysical Research 117: doi:10.1029/2011JG001923 Neftel, A., C. Flechard, C. Ammann, F. Conen, L. Emmenegger, and K. Zeyer. 2007. Experimental assessment of N2O background fluxes in grassland systems. Tellus 59B: 470-482. Palm, C.A., J.C. Alegre, L. Arevalo, P.K. Mutuo, A.R. Mosier, and R. Coe. 2002. Nitrous oxide and methane fluxes in six different land use systems in the Peruvian Amazon. Global Biogeochemical Cycles 16: doi: 10.1029/2001GB001855 Passianoto, C., T. Ahrens, B. Feigl, et al. 2003. Emissions of CO2, N2O and NO in conventional and no-till management practices in Rondonia, Brazil. Biology and Fertility of Soils 38: 200-208. Peichl, M., M. Arain, S. Ullah, et al. 2010. Carbon dioxide, methane, and nitrous oxide exchanges in an age-sequence of temperate pine forests. Global Change Biology 16: 2198-2212. Phillips, R.L., S.C. Whalen, and W.H. Schlesinger. 2001. Influence of atmospheric CO2 enrichment on nitrous oxide flux in a temperate forest ecosystem. Global Biogeochemical Cycles 15: 741-752. Pihlatie, M. J. Pumpanen, J. Rinne, H. Ilvesniemi, A. Simojoki, P. Hari, and T. Vesala. 2007. Gas concentration driven fluxes of nitrous oxide and carbon dioxide in boreal forest soil. Tellus 59: 458-469. Pinto, A., M.M.C. Bustamante, M.R.S.S. da Silva, et al. 2006. Effects of different treatments of pasture restoration on soil trace gas emissions in the Cerrados of central Brazil. Earth Interactions 10: 1-26. Regina, K., H. Nykanen, J. Silvola, and P.J. Martikainen. 1996. Fluxes of nitrous oxide from boreal peatlands as affected by peatland type, water table level, and nitrification capacity. Biogeochemistry 35: 401-418. Rennenberg, H., K. Kreutzer, H. Papen, and P. Weber. 1998. Consequences of high loads of nitrogen for spruce (Picea abies) and beech (Fagus sylvatica) forests. New Phytologist 139: 71-86. Rodrigues, R.de A.R. and W.Z. de Mello. 2012. Nitrous oxide fluxes in montane tropical rainforest soil in Serra Dos Órgãos, RJ. Quim Nova 35: 1549-1553. Rosenkranz, P., N. Bruggemann, H. Papen, et al. 2005. NO and CH4 exchange and microbial N turnover over a Mediterranean pine forest soil. Biogeosciences Discussions 2: 673-702. Ryden, J.C. 1981. N2O exchange between a grassland soil and the atmosphere. Nature 282: 235-237. Sanhueza, E., W.M. Hao, D. Scharffe, L. Donoso, and P.J. Crutzen. 1990. N2O and NO emissions from soils of the northern part of the Guayana Shield, Venezuela. Journal of Geophysical Research 95:2248122488. Schaefer, K., J. Boettcher, D. Weymann, et al. 2012. Evaluation of a closed tunnel for field-scale measurements of nitrous oxide fluxes from an unfertilized grassland soil. Journal of Environmental Quality 41: 1383-1392. Schiller, C.L. and D.R. Hastie. 1996. Nitrous oxide and methane fluxes from perturbed and unperturbed boreal forest sites in northern Ontario. Journal of Geophysical Research 101: 22767-22774. Skiba, U.M., L.J. Sheppard, C.E.R. Pitcairn, S. Van Duk, and M.J. Rossal. 1999. The effect of N deposition on nitrous oxide and nitric oxide emissions from temperate forest soils. Water, Air and Soil Pollution 116: 89-98. Stewart, K.J., M.E. Brummell, R.E. Farrell, and S.D. Siciliano. 2012. N2O flux from plant-soil systems in polar deserts switch between sources and sinks under different light conditions. Soil Biology and Biochemistry 48:69-77. Ullah, S. and T.R. Moore. 2011. Biogeochemical controls on methane, nitrous oxide, and carbon dioxide fluxes from deciduous forest soils in eastern Canada. Journal of Geophysical Research-Biogeosciences 116: doi: 10.1029/2010JG001525 Vanitchung, S., R. Conrad, N.W. Harvey, and A. Chidthaisong. 2011. Fluxes and production pathways of nitrous oxide in different types of tropical forest soils in Thailand. Soil Science and Plant Nutrition 57: 650-658. Velthof, G.L. and O. Oenema. 1995. Nitrous oxide fluxes from grassland in the Netherlands. I. Statistical analysis of flux-chamber measurements. European Journal of Soil Science 46: 533-540. Verchot, L.V., E.A. Davidson, J.H. Cattanio, I.L. Ackerman, H.E. Erickson, and M. Keller. 1999. Land use change and biogeochemical controls of nitrogen oxide emissions from soils in eastern Amazonia. Global Biogeochemical Cycles 13: 31-46. Wagner-Riddle, C., G.W. Thurtell, G.K. Kidd, et al. 1997. Estimates of nitrous oxide emissions from agricultural fields over 28 months. Canadian Journal of Soil Science 77: 135-146. Werner, C., R. Kiese, and K. Butterbach-Bahl. 2007. Soil-atmosphere exchange of N2O, CH4, and CO2 and controlling environmental factors for tropical rain forest sites in western Kenya. Journal of Geophysical Research 112: doi: 10.1029 Wu, X., N. Bruggemann, R. Gasche, Z. Shen, B. Wolf, and K. Butterbach-Bahl. 2010. Environmental controls over soil-atmosphere exchange of N2O, NO and CO2 in a temperate Norway spruce forest. Global Biogeochemical Cycles 24: doi: 10.1029/2009GB003616 Yamulki, S., R. Anderson, A. Peace, and J.I.L. Morison. 2013. Soil CO2, CH4, and N2O fluxes from an afforested lowland raised peatbog in Scotland: Implications for drainage and restoration. Biogeosciences 10: 1051-1065. Yao, Z., X. Wu, B. Wolf, et al. 2010. Soil-atmosphere exchange potential of NO and N2O in different land use types of Inner Mongolia as affected by soil temperature, soil moisture, freeze-thaw, and dryingwetting events. Journal of Geophysical Research-Atmospheres 115: doi: 10.1029/2009JD013528 Zhu, R., Q. Chen, W. Ding, and H. Xu. 2012. Impact of seabird activity on nitrous oxide and methane from high arctic tundra in Svalbard, Norway. Journal of Geophysical Research 117: doi: 10.1029