Publications from the Frey Lab

Anthony, M., K.A. Stinson, A.N. Trautwig, E. Coates-Connor, S.D. Frey. 2019. Fungal communities do not recover after removing invasive Alliaria petioata (garlic mustard). Biological Invasions 21, 3085-3099.

Bray, N., J. Kao-Kniffin, S.D. Frey, T. Fahey, K. Wickings. 2019. Soil macroinvertebrates shape microbial communities and stimulate microbial activity in the rhizosphere. Frontiers in Microbiology 10, 256.

Frey, S.D. 2019. Mycorrhizal fungi as mediators of soil organic matter dynamics. Annual Review of Ecology, Evolution and Systematics 50, 237–259.

Geyer, K.M., P. Dijkstra, R. Sinsabaugh, and S.D. Frey. 2019. Clarifying the interpretation of carbon use efficiency estimates in soil through methods comparison. Soil Biology & Biochemistry 128, 79-88.

Gilliam, F.S., D.A. Burns, C.T. Driscoll, S.D. Frey, G.M. Lovett, and S.A. Watmough. 2019. Responses of forest ecosystems of eastern North America to decreased nitrogen deposition. Environmental Pollution 244, 560-574.

Morrison, E.W., A. Pringle, L.T.A. van Diepen, A.S. Grandy, J.M. Melillo, and S.D. Frey. 2019. Warming alters fungal communities and litter chemistry with implications for soil carbon stocks. Soil Biology & Biochemistry 132, 120-130.

Asbjornsen, H. J. Campbell, K. Jennings, M. Vadeboncoeur, C. McIntire, P. Templer, Pamela, R. Phillips, T. Bauerle, M. Dietze, S.D. Frey, P. Groffman, R. Guerrieri, P. Hanson, E. Kelsey, A. Knapp, N. McDowell, P. Meir, K. Novick, S. Ollinger, W. Pockman, P. Schaberg, S. Wullschleger, M. Smith, and L. Rustad. 2018. Guidelines and considerations for designing field experiments simulating precipitation extremes in forest ecosystems. Methods in Ecology and Evolution 9, 2310-2325.

Haines, D.F., J.A. Aylward, S.D. Frey, and K.A. Stinson. 2018. Regional Patterns of Floristic Diversity and Composition in Forests Invaded by Garlic Mustard (Alliaria petiolata). Northeastern Naturalist 25, 399-417.

Heuck, C., G. Smolka, Georg, E. Whalen, S.D. Frey, P. Gundersen, F. Moldan, and M. Spohn. 2018. Effects of long-term nitrogen addition on phosphorus cycling in temperate forest floors. Biogeochemistry 141(2), 167-181.

Jilling, A., Contosta, A.R., Frey, S.D., Schimel, J., Schnecker, J., Smith, R.G., Tiemann, L., and A.S. Grandy. 2018. Minerals in the rhizosphere: overlooked mediators of soil nitrogen availability to plants and microbes. Biogeochemistry 139, 103-122.

Li, J, G. Wang, M.A. Mayes, S.D. Allison, S.D. Frey, Z. Shi, X.M. Hu, Y. Luo, J.M. Mellilo. Reduced carbon use efficiency and increased microbial turnover with two-decades of soil warming. 2018. Global Change Biology 10.1111/gcb.14517

Maynard, D.S., K.R. Covey, T.W. Crowther, N.W. Sokol, E.W. Morrison, S.D. Frey, L.T.A. van Diepen, Mark A. Bradford. 2018. Fungal associations overwhelm abiotic conditions as drivers of community structure and function. Ecology 99(4), 801-811.

Morrison, E.W., A. Pringle, L.T.A. van Diepen, and S.D. Frey. 2018. Simulated nitrogen deposition favors stress-tolerant fungi with low potential for decomposition. Soil Biology & Biochemistry 125: 75-85.

Stinson, K.A., S.D. Frey, M.R. Jackson, E. Coates-Connor, M. Anthony, and K. Martinez. 2018. More than meets the eye: Responses of exotic earthworms to experimental eradication of Alliaria petiolata and interactive effects of co-invasion on forest understory plants. Ecosphere 9(7), Article e02353.

vandenEnden, L., S.D. Frey, K. Nadelhoffer, K. Lajtha, J. LeMoine, and M. Simpson. 2018. Molecular-level changes in soil organic matter composition after 10 years of litter, root and nitrogen manipulation in a temperate forest. Biogeochemistry (in press).

Whalen, E.D., R.G. Smith, A. S. Grandy, and S.D. Frey. 2018. Manganese limitation as a mechanism for reduced decomposition in soils under atmospheric nitrogen deposition. Soil Biology & Biochemistry 127, 252-263.

Melillo, J.M., S.D. Frey, K.M. DeAngelis, W. Werner, M. Bernard, F.P. Bowles, G. Pold, M.A. Knorr, and A.S. Grandy. 2017. Long-term Pattern and Magnitude of Soil Carbon Feedback to the Climate System in a Warming World. Science 358, 101-105.

Anthony, M.A., S.D., Frey, and K.S., Stinson. 2017. Fungal community homogenization, shift in dominant trophic guild, and appearance of novel taxa in forests invaded by an exotic plant. Ecosphere 8(9), Article e01951.

Contosta, A.R., E.A. Burakowski, R.K. Varner, and S.D. Frey. 2017. Winter soil respiration in a temperate forest: the role of moisture, temperature, snowpack, and wind. Journal of Geophysical –Biogeosciences (in press).

Maynard, D.S., M.A. Bradford, D.L. Lindner, L.T.A. van Diepen, S.D. Frey, J.A. Glaeser, and T.W. Crowther. 2017. Diversity begets diversity in competition for space. Nature Ecology and Evolution 1, 0156.

Parker, T.C. J. Sadowsky, H. Dunleavy, J.A. Subke, S.D. Frey, and P.A. Wookey. 2017. Slowed biogeochemical cycling in sub-arctic birch forest linked to reduced mycorrhizal growth and community change after a defoliation event. Ecosystems 20, 316-330.

Wheeler, J.A., S.D. Frey and K. Stinson. 2017. Responses of red maple seedlings to multiple environmental stresses: interactive effects of invasion, warming, and nitrogen deposition. Forest Ecology and Management 403, 44-51.

van Diepen, L.T.A., S.D. Frey, E.A. Landis, E.W. Morrison, A. Pringle. 2017. Fungi exposed to chronic nitrogen enrichment are less able to decay leaf litter. Ecology 98(1), 5-11.

Creer, S. K. Deiner, Kristy, S.D. Frey, D. Porazinska, P. Taberlet, K. Thomas, C. Potter, and H. Bik, Holly. 2016. The ecologist’s field guide to sequence-based identification of biodiversity. Methods in Ecology and Evolution 7, 1008-1018.

Crowther, T.W., Todd-Brown, K.E.O., Rowe, C.W., Wieder, W.R., Carey, J.C., Machmuller, M.B., Todd-Brown, K.E.O., Snoek, B.L., Fang, S., Zhou, G., Allison, S.D., Burton, A.J., Carrillo, Y., Dijkstra, F.A., Elberling, B., Emmett, B., Estiarte, M., Frey, S.D., Harte, A.J., Jiang, L., Kröel-Dulay, G., Larsen, K.S., Laudon, H., Lavallee, J.M., Luo, Y., Ma, L.N., Marhan, S., Michelsen, A., Niu, S., Pendell, E., Peñuelas, J., Poll, C., Reinsch, S., Reynolds, L.L., Schmidt, I.K., Sistla, S., Sokol, N., Templer, P.H., Treseder, K.K., Reich, P., & Bradford, M.A. 2016. Quantifying global soil carbon losses in response to warming. Nature 540, 104-108.

Geyer, K.M., E. Kyker-Snowman, A.S. Grandy, and S.D. Frey. 2016. Microbial carbon use efficiency: Accounting for population, community, and ecosystem-scale controls over the fate of metabolized organic matter. Biogeochemistry DOI 10.1007/s10533-016-0191-y

Carey, J.C. J. Tang, P.H. Templer, K.D. Kroeger, T.W. Crowther, A. Burton, J.S. Dukes, B. Emmett, S.D. Frey et al. 2016. Uniform response of soil respiration to experimental temperature manipulation. PNAS 113(48) 13797-13802.

Kallenbach, C.M., A.S. Grandy, and S.D. Frey. 2016. Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls. Nature Communications 7:13630 | DOI: 10.1038/ncomms13630.

Morrison, E.W., S.D. Frey, J.J. Sadowsky, L. van Diepen, W.K. Thomas, and A. Pringle. 2016. Chronic nitrogen additions fundamentally restructure the soil fungal community in a temperate forest. Fungal Ecology 23, 48-57.

Pold, G. A.F. Billings, J.L. Blanchard, D.B. Burkhardt, S.D. Frey, J.M. Melillo, J. Schnabel, L.T.A. van Diepen, and K.M. DeAngelis. 2016. Long-term warming alters carbohydrate degradation potential in temperate forest soils. Applied Environmental Microbiology 82, 6518-6530.

Andrews, S. and S.D. Frey. 2015. Studio structure improves student performance in an undergraduate introductory soil science course. Natural Sciences Education 40, 60-68.

Burd, A.B., S.D. Frey, A.Cabre, T. Ito, N.M. Levine, C. Lonborg, M. Long, M. Mauritz, R.Q. Thomas, B.M. Stephens, T. Vanwalleghem, and N. Zeng. Terrestrial and marine perspectives on modeling organic matter degradation pathways. 2015. Global Change Biology. 22, 121-136.

Contosta, A.R., S.D. Frey, A.B. Cooper. 2015. Soil microbial communities vary as much over time as with chronic warming and nitrogen additions. Soil Biology & Biochem. 88, 19-24.

Crowther, T.W., S.M. Thomas, D.S. Maynard, P. Baldrian, K. Covey, S.D. Frey, L.T.A. van Diepen, and M.A. Bradford. 2015. Biotic interactions mitigate soil microbial feedbacks to climate change. PNAS 112 (22), 7033-7038. doi: 10.1073/pnas.1502956112

DeAngelis, K.M., G. Pold, B.D. Topcuoglu, L.T.A. van Diepen, R. Varney, J. Blanchard, J. Melillo, S.D. Frey. 2015. Long-term forest soil warming alters microbial communities in temperate forest soils. Frontiers in Microbiology 6:104. doi: 10.3389/fmicb.2015.00104

Kallenbach, C.M., A.S. Grandy, S.D. Frey, and A.F. Diefendorf. 2015. Microbial physiology and nectomass regulate agricultural soil carbon accumulation. Soil Biology & Biochemistry 91, 279-290.

Pisani, O., S.D. Frey, A.J. Simpson, and M.J. Simpson. 2015. Soil warming and nitrogen deposition alter soil organic matter composition at the molecular-level. Biogeochemistry 123(3), 391-469.

Rousk, J. and S.D. Frey. 2015. Revisiting the hypothesis that fungal-to-bacterial dominance characterises turnover of soil organic matter and nutrients. Ecological Monographs 85(3), 457-472.

Smith, M.D., K. La Pierre, S.L. Collins, A.K. Knapp, K.L. Gross, J.E. Barrett, S.D. Frey, L. Gough, R. Miller, J.T. Morris, L.E. Rustad, and J. Yarie. 2015. Global environmental change and the nature of aboveground net primary productivity responses: Insights from long-term experiments. Oecologia 177(4), 935-947.

van Diepen, L.T.A., S.D. Frey, C.M. Sthultz, E.W. Morrison, R. Minocha, and A. Pringle. 2015. Changes in litter quality caused by simulated nitrogen deposition reinforce the N-induced suppression of litter decay. Ecosphere 6(10), art205.

Frey S.D., Ollinger S, Nadelhoffer K, Bowden R, Brzostek E, Burton A, Caldwell B, Crow S, Goodale C, Grandy S, Finzi A, Kramer M, Lajtha K, Martin M, McDowell W, Minocha R, Templer P, Wicking K. 2014. Chronic nitrogen additions suppress decomposition and sequester soil carbon in a temperate forest. Biogeochemistry 121, 305-316.

Andrews, S.E., R. Schultz, S.D. Frey, V. Bouchard, R. Varner, and M.J. Ducey. 2013. Plant community structure mediates potential methane production and iron reduction in wetland mesocosms. Ecosphere 4:art44.

Contosta, A.R., S.D. Frey, S.V. Ollinger, and A.B. Cooper. 2013. Soil respiration does not acclimatize to warmer temperatures when modeled over seasonal timescales. Biogeochemistry 12, 555-570.

Savage, K. W.J. Parton, E.A. Davidson, S.E. Trumbore, S.D. Frey. 2013. Long-term changes in forest carbon under temperature and nitrogen amendments in a temperate northern hardwood forest. Global Change Biology 19, 2389-2400.

Tonitto, C., C. Goodale, M.S. Weiss, S.D. Frey, S. Ollinger. 2013. The effect of nitrogen addition on soil organic matter dynamics: A model analysis of the Harvard Forest Chronic Nitrogen Amendment experiment and soil carbon response to anthropogenic N deposition. Biogeochemistry 10.1007/s10533-013-9887-4.

Frey, S.D., J. Lee, J. Melillo, and J.W. Six. 2013. The temperature response of soil microbial efficiency and its feedback to climate. Nature Climate Change 3, 395-398.

Giasson, M.A., A.M. Ellison, R.D. Bowden, P.M. Crill, E.A. Davidson, J.E. Drake, S.D. Frey, J. L. Hadley, M. Lavine, J.M. Melillo, J.W. Munger, K.J. Nadelhoffer, E. Nicoll, S.V. Ollinger, K.E. Savage, P.A. Steudler, J. Tang, R.K. Varner, S.C. Wofsy, D.R. Foster, and A.C. Finzi. 2013. Soil respiration in a northeastern US temperate forest: a 22-year synthesis. Ecosphere 4(11): 140

Kamble, P.N., J. Rousk, S.D. Frey, and E. Baath. 2013. Bacterial growth and growth limiting nutrients following chronic nitrogen additions to a hardwood forest soil. Soil Biology & Biochemistry 10.1016/j.soilbio.2012.12.017.

Brzostek, E.R., J.M. Blair, J.S. Dukes, S.D. Frey, S.E. Hobbie, J.M. Melillo, R.J. Mitchell, E. Pendall, P.B. Reich, G.R. Shaver, A. Stefanski, M.G. Tjoelker, and A.C. Finzi. 2012. The effect of experimental warming and precipitation change on proteolytic enzyme activity: positive feedbacks to nitrogen availability are not universal. Global Change Biology 18 (8), 2617-2625.

Garland, J.L., M.C. Zabaloy, M. Birmele, C.L. Mackowiak, R.M. Lehman, S.D. Frey. 2012. Examining N-limited soil microbial activity using community-level physiological profiling based on O2 consumption. Soil Biology & Biochemistry 47, 46-52.

Rousk, J., S.D. Frey, and E. Baath. 2012. Temperature adaptation of bacterial communities in experimentally warmed forest soils. Global Change Biology 18(10), 3252-3258.

Schultz, R.E., V.L. Bouchard, S.D. Frey. 2012. Overyielding and the role of complementary use of nitrogen in wetland plant communities. Aquatic Botany 97, 1-9.

Sierra, C.A., S.E. Trumbore, E.A. Davidson, S.D. Frey, K.E. Savage, and F.M. Hopkins. 2012. Predicting decadal trends and transient responses of radiocarbon storage and fluxes in a temperate forest soil. Biogeosciences 9, 3013-3028.

Conant, R.T., M.G. Ryan, G.I. Ågren, H.E. Birge, M.A. Bradford, E.A. Davidson, P.E. Eliasson, S.E. Evans, S.D. Frey, C.P. Giardina, F. Hopkins, R. Hyvönen, M.U.F. Kirschbaum, J.M. Lavallee, J. Leifeld, W.J. Parton, J. M. Steinweg, M.D. Wallenstein, J.A.M. Wetterstedt 2011. Temperature and soil carbon decomposition – synthesis of current knowledge and a way forward. Global Change Biology 17, 3392-3404.

Contosta, A.R., S. D. Frey, and A. B. Cooper. 2011. Seasonal dynamics of soil respiration and nitrogen mineralization in chronically warmed and fertilized soils. Ecosphere 2(3), 1-21.

Finzi, A.C., A.T Austin, E.E. Cleland, S.D. Frey, B.Z. Houlton, and M.D. Wallenstein. 2011. Alteration of coupled biogeochemical cycles in response to global change in the terrestrial biosphere. Frontiers in Ecology and the Environment 9(1), 61-67.

Hossler, K., V. Bouchard, M.S. Fennessy, S.D. Frey, E. Anemaet, and E. Herbert. 2011. No-net-loss not met for nutrient function in freshwater marshes: recommendations for wetland mitigation policies. Ecosphere 2:art82 [doi:10.1890/ES11-00009.1].

Montecchia, M.S., O.S. Correa, M.A. Soria, S.D. Frey, A.F. Garcia, and J.L. Garland. 2011. Multivariate approach to characterizing soil microbial communities in pristine and agricultural sites in Northwest Argentina . Applied Soil Ecology 47(3), 176-183 DOI: 10.1016/j.apsoil.2010.12.008

Schultz, R.**, S. Andrews*, L. O’Reilly, V. Bouchard, S.D. Frey. 2011. Plant community composition more predictive than diversity of carbon cycling in freshwater wetlands. Wetlands DOI: 10.1007/s13157-011-0211-6.

Bradford, M.A., M.D. Wallenstein, S.D. Allison, K.K. Treseder, S.D. Frey, B.W. Watts, C.A. Davies, T.R. Maddox, J.M. Melillo, J.E. Mohan, J.F. Reynolds. 2009. Decreased mass specific respiration under experimental warming is robust to the microbial biomass method employed. Ecology Letters 12, E15-E18.

Bradford, M.A., C.A. Davies, S.D. Frey, T.R. Maddox, J.M. Melillo, J.E. Mohan, J.F. Reynolds, K.K. Treseder, and M.D. Wallenstein. 2008. Acclimation of soil microbial respiration to elevated temperature. Ecology Letters 11, 1316-1327.

Burton, A.J., J.M. Melillo, and S.D. Frey. 2008. Adjustment of forest ecosystem root respiration as temperature warms. Journal of Integrative Plant Biology 50(11), 1467-1483.

Frey, S.D., R. Drijber, H. Smith, and J. Melillo. 2008. Microbial biomass, functional capacity, and community composition after twelve years of soil warming. Soil Biology & Biochemistry 40, 2904-2907.

Olchin, G.P., S. Ogle, S.D. Frey, T.R. Filley, K. Paustian, and J. Six. 2008. Residue carbon stabilization in soil aggregates of no-till and tillage management of dryland cropping systems. Soil Science Society of America Journal 72(2), 507-513.

Sinsabaugh, R.L., C.L. Lauber, M.N Weintraub, B. Ahmed, S.D. Allison, C. Crenshaw, A.R. Contosta, D. Cusack, S. Frey, M.E. Gallo, T.B. Gartner, S.E. Hobbie, K. Holland, B.L. Keeler, J.S. Powers, M. Stursova, C. Takacs-Vesbach, M. Waldrop, M.Wallenstein, D.R. Zak, L.H. Zeglin. 2008. Stoichiometry of soil enzyme activity at global scale. Ecology Letters 11, 1252-1264.

Zabaloy, M.C., S.D. Frey, R.M. Lehman, and J.L. Garland. 2008. Optimization and validation of an oxygen-based approach for community-level physiological profiling of soils. Soil Biology & Biochemistry 40:2960-2969.

Bouchard, V., S.D. Frey, J.M Gilbert, and S. Reed. 2007. Effects of macrophyte functional group richness on emergent freshwater wetland functions. Ecology 88(11), 2903-2914.

Frey, S.D. 2006. Forest ecosystem responses to chronic nitrogen additions. Teaching Issues and Experiments in Ecology Volume 4, April 2006 (

Johnson, V.S., J.A. Litvaitis, T.D. Lee, and S.D. Frey. 2006. The role of spatial and temporal scale in colonization and spread of invasive shrubs in early successional habitats. Forest Ecology & Management 228, 124-134.

Six, J., S.D. Frey, R.K. Thiet, and K.M. Batten. 2006. Bacterial and fungal contributions to carbon sequestration in agroecosystems. Soil Science Society of America Journal 70, 555-569.

Thiet, R.K., S.D. Frey, and J. Six. 2006. Growth yield efficiencies of soil microbial communities with different fungal:bacterial ratios. Soil Biology & Biochemistry 38, 837-844.

Knorr, M., S.D. Frey, and P.S. Curtis. 2005. Nitrogen additions and litter decomposition: a meta-analysis. Ecology 86, 3252-3257.

Väisänen, R.K., M.S. Roberts, J.L. Garland, S.D. Frey, and L.A. Dawson. 2005. Physiological and molecular characterization of microbial communities associated with different water-stable aggregate size fractions. Soil Biology & Biochemistry 37, 2007-2016.

Averett, J.M., R.A. Klips, L.E. Nave, S.D. Frey, and P.S. Curtis. 2004. The effects of soil carbon amendment on nitrogen availability and plant growth in an experimental tallgrass prairie restoration. Restoration Ecology 12, 567-573.

Frey, S.D., M. Knorr, J. Parrent, and R.T. Simpson. 2004. Chronic nitrogen enrichment affects the structure and function of the soil microbial community in a forest ecosystem. Forest Ecology and Management 196, 159-171.

Simpson, R.T.*, S.D. Frey, J. Six, and R.K. Thiet. 2004. Preferential accumulation of microbial carbon in aggregate structures of no-tillage soils. Soil Science Society of America Journal 68, 1249-1255.

Paul, E.A., H.P. Collins, KI. Paustian, E.T. Elliott, S. Frey, N. Juma, H. Janzen, C.A. Campbell, R.P. Zentner, G.P. Lafond, and A.P. Moulin. 2004. Management effects on the dynamics and storage capacity of soil organic matter in the Canadian prairies. Canadian Journal of Soil Science 84, 49-61.

Frey, S.D., J. Six and E.T. Elliott. 2003. Reciprocal transfer of carbon and nitrogen by decomposer fungi at the soil-litter interface. Soil Biology & Biochemistry 35, 1001-1004.

Bossuyt, H., K. Denef, J. Six, S.D. Frey and R. Merckx. 2001. Influence of microbial populations and residue quality on aggregate stability. Applied Soil Ecology 16, 195-208.

Denef K., Six J., Bossuyt H., Frey S.D., Elliott E.T., Merckx R., and Paustian K. 2001. Influence of dry-wet cycles on aggregate, particulate organic matter, and microbial community dynamics. Soil Biology & Biochemistry 33, 1599-1611.

Frey, S.D., V.V.S.R. Gupta, E.T. Elliott and K. Paustian. 2001. Protozoan grazing affects estimates of carbon utilization efficiency of the soil microbial community. Soil Biology & Biochemistry 33, 1759-1768.

Frey, S.D., E.T. Elliott, K. Paustian and G. Peterson. 2000. Fungal translocation as a mechanism of exogenous nitrogen inputs to decomposing surface residues in a no-tillage agroecosystem. Soil Biology & Biochemistry 32, 689-698.

Frey, S.D., E.T. Elliott and K. Paustian. 1999. Bacterial and fungal abundance and biomass in conventional and no-tillage agroecosystems along two climatic gradients. Soil Biology & Biochemistry 31, 573-585.

Frey, S.D., E.T. Elliott and K. Paustian. 1999. Application of the hexokinase/glucose-6-phosphate-dehydrogenase enzymatic assay for measurement of glucose in soil. Soil Biology & Biochemistry 31, 933-935.

Guggenberger, G., S.D. Frey, J. Six, E.T. Elliott, and K. Paustian. 1999. Glucosamine and muramic acid patterns in conventional and no-tillage agroecosystems. Soil Science Society of America Journal 63, 1188-1198.

Guggenberger, G., E.T. Elliott, S.D. Frey, J. Six and K. Paustian. 1998. Microbial contributions to the aggregation of a cultivated grassland soil amended with starch. Soil Biology & Biochemistry 31(3), 407-419.

Motavalli, P.P., S.D. Frey and N.A. Scott. 1995. Effects of filter type and extraction efficiency on nitrogen mineralization measurements using the aerobic leaching soil incubation method. Biology and Fertility of Soils 20, 197-204.

Motavalli, P.P., C.A. Palm, W.J. Parton, E.T. Elliott and S.D. Frey. 1995. Soil pH and organic C dynamics in tropical forest soils: evidence from laboratory and simulation studies. Soil Biology & Biochemistry 27, 1589-1599.

Motavalli, P.P., C.A. Palm, W.J. Parton, E.T. Elliott and S.D. Frey. 1995. Nitrogen mineralization in humid tropical forest soils: mineralogy, texture, and measured nitrogen fractions. Soil Science Society of America Journal 59:1168-1175.

Frey, S.D. and L.K. Blum. 1994. The effect of soil pH on competitive ability of type I and type II strains of Rhizobium leguminosarum biovar phaseoli. Plant and Soil 163, 157-164.

Motavalli, P.P., C.A. Palm, W.J. Parton, E.T. Elliott, and S.D. Frey. 1994. A comparison of laboratory and modeling simulation methods for estimating soil carbon pools in tropical forest soils with differing mineralogies and textures. Soil Biology & Biochemistry 26, 935-944.