Stabilization and destabilization of soil organic matter and the impact of agricultural management and global warming on those processes
Physical and chemical characteristics of organo-mineral associations at different spatial/temporal scales
Soil processes and ecosystem functioning (nutrient cycling, microbial ecology, pedology)
Academic Record
Ph.D.
Ecology and Environmental Sciences, 2005, University of Maine-Orono, ME, USA
M.S.
Forest Science, 1999, Oregon State University, Corvallis, OR
B.S.
Forest Ecology and Management, 1996, University of Wisconsin-Madison, Madison, WI
Publication
20) Asano, M, and R. Wagai. (2014) Evidence of aggregate hierarchy at micro to submicron scales in an allophanic Andisol. Geoderma 216: 62-74.
19) Shirato, Y, M. Jomura, R. Wagai, M. Kondo, K. Tanabe, M. Uchida (2014) Deviations between observed and RothC-simulated Δ14C values despite improved IOM initialization. European Journal of Soil Science, 64(5), 576-585
18) Wagai, R. A.W. Kishimoto-Mo, S. Yonemura, Y. Shirato, S. Hiradate, Y. Yagasaki. (2013) Linking temperature sensitivity of soil organic matter decomposition to its molecular structure, accessibility, and microbial physiology. Global Change Biology 19: 1114-1125.
17) Wagai, R. L.M. Mayer, K. Kitayama, Y. Shirato (2013) Association of organic matter with iron and aluminum across a range of soils determined via selective dissolution techniques coupled with dissolved nitrogen analysis. Biogeochemistry 112:95-109
16) Wagai, R. and K. Kitayama (2012) Soil organic matter storage in the tropical forests of Borneo: pedogenic controls and ecological implications. In: International Symposia: Land Degradation and Pedology; Land Degradation and Management Pedologist 55(3): 392-402
15) Fushimi, A., R. Wagai, M. Uchida, S. Hasegawa, K. Takahashi, M. Kondo, M. Hirabayashi, Y. Morino, Y. Shibata, T. Ohara, S. Kobayashi, K. Tanabe (2011) Radiocarbon (14C) diurnal variations in fine particles at sites downwind from Tokyo, Japan in summer, Environmental Science and Technology 45: 6784-6792.
14) Wagai, R., K. Kitayama, T. Satomura, R. Fujinuma, and T.C. Balser (2011) Interactive influences of climate and parent material on soil microbial community structure in Bornean tropical forest ecosystems. Ecological Research 26: 627-636.
13) Sollins, P., M.G. Kramer, C. Swanston, K. Lajtha, T. Filley, A.K. Aufdenkampe, R. Wagai, and R.D. Bowden (2009) Organic C and N stabilization across soils of contrasting mineralogy: further evidence from sequential density fractionation. Biogeochemistry 96:209-231.
12) Moritz, L.K., C. Liang, R. Wagai, K. Kitayama, and T.C. Balser (2009) Vertical distribution and accumulation of microbial residues in tropical forest soils formed from distinct parent materials. Biogeochemistry 92:83-94.
11) Wagai, R., L.M. Mayer, and K. Kitayama (2009) Nature of “occluded” low-density fraction in soil organic matter studies: a critical review. Soil Science and Plant Nutrition 55: 13-25.
10) Wagai, R., L.M. Mayer, and K. Kitayama (2009) Extent and nature of organic coverage of soil mineral surfaces assessed by a gas sorption approach. Geoderma 149: 152-160.
9) Ushio, M., R. Wagai, T. Balser, and K. Kitayama (2008) Variations in the soil microbial community composition of a tropical montane forest ecosystem : does tree species matter? Soil Biology and Biochemistry 40: 2699-2702.
8) Wagai, R., L.M. Mayer, K. Kitayama, and H. Knicker (2008) Climate and parent material controls on organic matter storage in surface soils: A three-pool, density-separation approach. Geoderma 147: 23-33.
7) Wagai, R. and L.M. Mayer (2007) Significance of hydrous iron oxides for sorptive stabilization of organic carbon in a range of soils. Geochimica et Cosmochimica Acta 71: 25-35.
6) Mayer, L.M., L.L. Schick, K. Hardy, R. Wagai, and J.F. McCarthy (2004) Organic matter content of small mesopores in sediments and soils. Geochimica et Cosmochimica Acta 68: 3863-3872.
5) Kitayama, K., S. Aiba, M. Takyu, N. Majalap-Lee, and R. Wagai (2004) Soil phosphorus fractionation and phosphorus-use efficiency of a Bornean tropical montane rain forest during soil ageing with podozolization. Ecosystems 7:259-274.
4) Wagai, R. and P. Sollins (2002) Biodegradation and regeneration of water-soluble organic carbon in a forest soil: leaching column study. Biology and Fertility of Soils 35:18-26.
3) Ohno, T., M.Y. Horesh, K. Merritt, and R. Wagai (2002) Calcium and pH effects on salicylic acid phytotoxicity. Allelopathy Journal 9: 19-25.
2) Norton, S., R. Wagai, T. Navratil, J.M. Kaste, and F.A. Rissberger (2000) Response of a first-order stream in Maine to short-term in-situ acidification. Hydrology and Earth System Sciences 4: 383-391.
1) Wagai, R., K. Brye, S.T. Gower, J.M. Norman, and L. Bundy (1998) Land use and environmental factors influencing soil surface CO2 flux and microbial biomass in natural and managed ecosystems in southern Wisconsin. Soil Biology and Biochemistry 30: 1501-1509.