Korean Journal of Agricultural and Forest Meteorology (한국농림기상학회지)

Korean Society of Agricultural and Forest Meteorology (한국농림기상학회)
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The Effects of Elevated Atmoshpheric CO2 on Chemical Weathering of Forest Soils

대기 중 이산화탄소의 증가가 산림 토양의 화학적 풍화작용에 미치는 영향

  • Oh, Neung-Hwan (Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University)
  • 오능환 (서울대학교 환경대학원 환경계획학과)
  • Received : 2014.08.25
  • Accepted : 2014.09.26
  • Published : 2014.09.30
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Abstract

Chemical weathering of forest soils can reduce atmospheric $CO_2$ concentration over geologic time scales, providing many essential elements for life. Although many studies have been conducted on the effects of elevated atmospheric $CO_2$ on forest carbon storage using open top chambers and FACE (Free air $CO_2$ enrichment) facilities since the 1990s, studies on chemical weathering of forest soils under elevated $CO_2$ are relatively rare. Here I review on how elevated atmospheric $CO_2$ can affect the chemical weathering of forest soils and suggest directions on future research. Despite the recent advances in chemical weathering of forest soils under elevated atmospheric $CO_2$, it is still not clear how the large volume of forest soils would react under the condition. Future studies on weathering of forest soils covering large areas from the tropics to the polar regions with carefully monitored pre-treatment data would provide key information on how soils, the Earth's life sustaining engine, change under climate change.

산림토양의 화학적 풍화작용은 대기 중 $CO_2$의 농도를 지질학적 연대에 걸쳐 줄이는 기작일 뿐만 아니라 수목의 생장에 필요한 많은 영양소를 얻게해주는 중요한 반응이다. 대기 중 $CO_2$의 농도 증가($eCO_2$)가 산림의 탄소 저장 능력에 미치는 영향에 대한 연구는 1990년대부터 상부 개방형 온실(Open top chamber) 실험과 FACE(Free air $CO_2$ enrichment) 실험을 통해 활발히 이루어졌으나 $eCO_2$가 산림토양의 풍화작용에 미치는 영향에 대한 연구는 그 중요성에도 불구하고 상대적으로 드물다. 이 총설에서는 대기 중 $CO_2$의 증가가 산림토양의 화학적 풍화작용에 미치는 영향에 대한 기존의 연구 결과를 정리하고 앞으로 필요한 연구에 대해 제언한다. 산림토양의 풍화작용이 $eCO_2$ 하에서 어떻게 변화할 지에 대해 과거에 비해 진전된 연구 결과가 최근 보고되었으나 거대한 부피를 가진 산림 토양이 미래의 $eCO_2$ 대기 하에서 어떻게 반응할 지는 여전히 명확하지 않다. 연구 대상지의 실험군 처리 전 자료를 세밀히 분석하고, 열대 지방에서 극지에 이르는 넓은 지역을 포괄하는 산림토양의 풍화작용에 대한 연구를 진행하면 지구의 생명체를 지속시키는 동력인 토양이 기후변화 하에서 어떻게 변화할 지에 대한 중요한 정보를 얻을 수 있을 것이다.

Keywords

References

  1. Ainsworth, E. A., and S. P. Long, 2005: What have we learned from 15 years of free-air $CO_{2}$ enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy, New Phytologist 165(2), 351-371, doi:10.1111/j.1469-8137.2004.01224.x.
  2. Andrews, J. A., and W. H. Schlesinger, 2001: Soil $CO_{2}$ dynamics, acidification, and chemical weathering in a temperate forest with experimental $CO_{2}$ enrichment, Global Biogeochemical Cycles 15(1), 149-162. https://doi.org/10.1029/2000GB001278
  3. Bader, M. K. F., and C. Korner, 2010: No overall stimulation of soil respiration under mature deciduous forest trees after 7 years of $CO_{2}$ enrichment, Global Change Biology 16(10), 2830-2843, doi:10.1111/j.1365-2486.2010.02159.x.
  4. Bader, M. K. F., S. Leuzinger, S. G. Keel, R. T. W. Siegwolf, F. Hagedorn, P. Schleppi, and C. Korner, 2013: Central European hardwood trees in a high-$CO_{2}$ future: synthesis of an 8-year forest canopy $CO_{2}$ enrichment project, Journal of Ecology 101(6), 1509-1519, doi:10.1111/1365-2745.12149.
  5. Berner, E. K., R. A. Berner, and K. L. Moulton, 2004: Plants and mineral weathering: Present and past, in Surface and Ground Water, Weathering, and Soils, edited by J. I. Drever, Elsevier, San Diego.
  6. Berner, R. A. (2004): The Phanerozoic Carbon Cycle: $CO_{2}$ and $O_{2}$, Oxford University Press, Oxford ; New York.
  7. Berner, R. A., A. C. Lasaga, and R. M. Garrels, 1983: The carbonate-silicate geochemical cycle and its effect on atmospheric carbon-dioxide over the past 100 million years, Am. J. Sci. 283(7), 641-683. https://doi.org/10.2475/ajs.283.7.641
  8. Berner, R. A., J. L. Rao, S. Chang, R. O'Brien, and C. K. Keller, 1998: Seasonal variability of adsorption and exchange equilibria in soil waters, Aquatic Geochemistry 4(2), 273-290. https://doi.org/10.1023/A:1009680430757
  9. Blum, J. D., A. Klaue, C. A. Nezat, C. T. Driscoll, C. E. Johnson, T. G. Siccama, C. Eagar, T. J. Fahey, and G. E. Likens, 2002: Mycorrhizal weathering of apatite as an important calcium source in base-poor forest ecosystems, Nature 417(6890), 729-731. https://doi.org/10.1038/nature00793
  10. Bouchez, J., V. Galy, R. G. Hilton, J. Gaillardet, P. Moreira- Turcq, M. A. Perez, C. France-Lanord, and L. Maurice, 2014: Source, transport and fluxes of Amazon River particulate organic carbon: Insights from river sediment depth-profiles, Geochimica Et Cosmochimica Acta 133, 280-298, doi:10.1016/j.gca.2014.02.032.
  11. Brady, N. C., and R. R. Weil, 2008: The Nature and Properties of Soils, 14th ed., xiv, 965p, Pearson Prentice Hall, Upper Saddle River, N.J.
  12. Brantley, S. L., J. P. Megonigal, F. N. Scatena, Z. Balogh- Brunstad, R. T. Barnes, M. A. Bruns, P. Van Cappellen, K. Dontsova, H. E. Hartnett, A. S. Hartshorn, A. Heimsath, E. Herndon, L. Jin, C. K. Keller, J. R. Leake, W. H. McDowell, F. C. Meinzer, T. J. Mozdzer, S. Petsch, J. Pett-Ridge, K. S. Pregitzer, P. A. Raymond, C. S. Riebe, K. Shumaker, A. Sutton-Grier, R. Walter, and K. Yoo, 2011: Twelve testable hypotheses on the geobiology of weathering, Geobiology 9(2), 140-165, doi:10.1111/j.1472-4669.2010.00264.x.
  13. Byun, J., W.-K. Lee, S. Choi, S. Oh, S. Yoo, T. Kwon, J. Sung, and J. Woo, 2012: Vulnerability assessment for forest ecosystem to climate change based on spatiotemporal information, Korean Journal of Remote Sensing 28(1), 159-169. (In Korean with English abstract). https://doi.org/10.7780/kjrs.2012.28.1.159
  14. Cheng, L., J. Zhu, G. Chen, X. Zheng, N. H. Oh, T. W. Rufty, D. D. Richter, and S. Hu, 2010: Atmospheric $CO_{2}$ enrichment facilitates cation release from soil, Ecology Letters 13(3), 284-291, doi:10.1111/j.1461-0248.2009.01421.x.
  15. Cho, Y., C. T. Driscoll, and J. D. Blum, 2009: The effects of a whole-watershed calcium addition on the chemistry of stream storm events at the Hubbard Brook Experimental Forest in NH, USA, Science of the Total Environment 407(20), 5392-5401, doi:10.1016/j.scitotenv.2009.06.030.
  16. Cho, Y., C. T. Driscoll, C. E. Johnson, J. D. Blum, and T. J. Fahey, 2012: Watershed-Level Responses to Calcium Silicate Treatment in a Northern Hardwood Forest, Ecosystems 15(3), 416-434, doi:10.1007/s10021-012-9518-2.
  17. Cochran, M. F., and R. A. Berner, 1996: Promotion of chemical weathering by higher plants: Field observations on Hawaiian basalts, Chemical Geology 132(1-4), 71-77. https://doi.org/10.1016/S0009-2541(96)00042-3
  18. De Graaff, M.-A., K.-J. van Groenigen, J. Six, B. Hungate, and C. van Kessel, 2006: Interactions between plant growth and soil nutrient cycling under elevated $CO_{2}$: a meta-analysis, Global Change Biology 12(11), 2077-2091, doi:10.1111/j.1365-2486.2006.01240.x.
  19. Dorn, R. I., 2014: Ants as a powerful biotic agent of olivine and plagioclase dissolution, Geology 42, doi:10.1130/G35825.1.
  20. Drake, J. E., A. Gallet-Budynek, K. S. Hofmockel, E. S. Bernhardt, S. A. Billings, R. B. Jackson, K. S. Johnsen, J. Lichter, H. R. McCarthy, M. L. McCormack, D. J. P. Moore, R. Oren, S. Palmroth, R. P. Phillips, J. S. Pippen, S. G. Pritchard, K. K. Treseder, W. H. Schlesinger, E. H. DeLucia, and A. C. Finzi, 2011: Increases in the flux of carbon belowground stimulate nitrogen uptake and sustain the long-term enhancement of forest productivity under elevated $CO_{2}$, Ecology Letters 14(4), 349-357, doi:10.1111/j.1461-0248.2011.01593.x.
  21. Drever, J. I., and J. Zobrist, 1992: Chemical weathering of silicate rocks as a function of elevation in the southern Swiss Alps, Geochimica Et Cosmochimica Acta 56(8), 3209-3216, doi:10.1016/0016-7037(92)90298-w.
  22. Fontaine, S., S. Barot, P. Barre, N. Bdioui, B. Mary, and C. Rumpel, 2007: Stability of organic carbon in deep soil layers controlled by fresh carbon supply, Nature 450(7167), 277-U210, doi:10.1038/nature06275.
  23. Garten, C. T., Jr., C. M. Iversen, and R. J. Norby, 2011: Litterfall N-15 abundance indicates declining soil nitrogen availability in a free-air $CO_{2}$ enrichment experiment, Ecology 92(1), 133-139. https://doi.org/10.1890/10-0293.1
  24. Griffiths, R. P., J. E. Baham, and B. A. Caldwell, 1994: Soil solution chemistry of ectomycorrhizal mats in forest soil, Soil Biology & Biochemistry 26(3), 331-337, doi:10.1016/0038-0717(94)90282-8.
  25. Hartmann, J., A. J. West, P. Renforth, P. Kohler, C. L. De La Rocha, D. A. Wolf-Gladrow, H. H. Durr, and J. Scheffran, 2013: Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification, Reviews of Geophysics 51(2), 113-149, doi:10.1002/rog.20004.
  26. Hungate, B. A., K.-J. van Groenigen, J. Six, J. D. Jastrow, Y. Luo, M.-A. de Graaff, C. van Kessel, and C. W. Osenberg, 2009: Assessing the effect of elevated carbon dioxide on soil carbon: a comparison of four metaanalyses, Global Change Biology 15(8), 2020-2034, doi:10.1111/j.1365-2486.2009.01866.x.
  27. Iversen, C. M., T. D. Hooker, A. T. Classen, and R. J. Norby, 2011: Net mineralization of N at deeper soil depths as a potential mechanism for sustained forest production under elevated $CO_{2}$, Global Change Biology 17(2), 1130-1139, doi:10.1111/j.1365-2486.2010.02240.x.
  28. Iversen, C. M., J. K. Keller, C. T. Garten, and R. J. Norby, 2012: Soil carbon and nitrogen cycling and storage throughout the soil profile in a sweetgum plantation after 11 years of $CO_{2}$-enrichment, Global Change Biology 18(5), 1684-1697, doi:10.1111/j.1365-2486.2012.02643.x.
  29. Jackson, R. B., C. W. Cook, J. S. Pippen, and S. M. Palmer, 2009: Increased belowground biomass and soil $CO_{2}$ fluxes after a decade of carbon dioxide enrichment in a warm-temperate forest, Ecology 90(12), 3352-3366. https://doi.org/10.1890/08-1609.1
  30. Jandl, R., M. Rodeghiero, C. Martinez, M. F. Cotrufo, F. Bampa, B. van Wesemael, R. B. Harrison, I. A. Guerrini, D. D. Richter, L. Rustad, K. Lorenz, A. Chabbi, and F. Miglietta, 2014: Current status, uncertainty and future needs in soil organic carbon monitoring, Science of the Total Environment 468, 376-383, doi:10.1016/j.scitotenv.2013.08.026.
  31. Jastrow, J. D., R. M. Miller, R. Matamala, R. J. Norby, T. W. Boutton, C. W. Rice, and C. E. Owensby, 2005: Elevated atmospheric carbon dioxide increases soil carbon, Global Change Biology 11(12), 2057-2064, doi:10.1111/j.1365-2486.2005.01077.x.
  32. Jeong, J., C. Kim, K. Goo, C. Lee, H. Won, and J. Byun, 2003: Physico-chemical properties of Korean forest soils by parent rocks, Journal of Korean Forest Society 92(3), 254-262. (In Korean with English abstract).
  33. Jeong, J. H., K. S. Koo, C. H. Lee, and C. S. Kim, 2002: Physico-chemical properties of Korean forest soils by regions, Journal of Korean Forest Society 91(6), 694-700. (In Korean with English abstract).
  34. Karberg, N. J., K. S. Pregitzer, J. S. King, A. L. Friend, and J. R. Wood, 2005: Soil carbon dioxide partial pressure and dissolved inorganic carbonate chemistry under elevated carbon dioxide and ozone, Oecologia 142(2), 296-306. https://doi.org/10.1007/s00442-004-1665-5
  35. King, J. S., P. J. Hanson, E. Bernhardt, P. DeAngelis, R. J. Norby, and K. S. Pregitzer, 2004: A multiyear synthesis of soil respiration responses to elevated atmospheric $CO_{2}$ from four forest FACE experiments, Global Change Biology 10(6), 1027-1042. https://doi.org/10.1111/j.1529-8817.2003.00789.x
  36. Korner, C., 2006: Plant $CO_{2}$ responses: an issue of definition, time and resource supply, New Phytologist 172(3), 393-411, doi:10.1111/j.1469-8137.2006.01886.x.
  37. Lee, E.-H., J.-H. Lim, and J.-S. Lee, 2010: A review on soil respiration measurement and its application in Korea, Korean Journal of Agricultural and Forest Meteorology 12(4), 264-276. (In Korean with English abstract). https://doi.org/10.5532/KJAFM.2010.12.4.264
  38. Lee, J.-C., D.-H. Kim, G. N. Kim, P.-G. Kim, and S.-H. Han, 2012: Long-term climate change research facility for trees: $CO_{2}$-enrichend open top chamber system, Korean Journal of Agricultural and Forest Meteorology 14(1), 19-27. (In Korean with English abstract). https://doi.org/10.5532/KJAFM.2012.14.1.019
  39. Lee, J.-H., J.-S. Yi, Y.-M. Chun, N.-y. Chae, and J.-S. Lee, 2013: Discussion of soil respiration for understanding ecosystem carbon cycle in Korea, Korean Journal of Ecology and Environment 46(2), 310-318. (In Korean with English abstract). https://doi.org/10.11614/KSL.2013.46.2.310
  40. Leuzinger, S., Y. Q. Luo, C. Beier, W. Dieleman, S. Vicca, and C. Korner, 2011: Do global change experiments overestimate impacts on terrestrial ecosystems?, Trends in Ecology & Evolution 26(5), 236-241, doi:10.1016/j.tree.2011.02.011.
  41. Lichter, J., S. A. Billings, S. E. Ziegler, D. Gaindh, R. Ryals, A. C. Finzi, R. B. Jackson, E. A. Stemmler, and W. H. Schlesinger, 2008: Soil carbon sequestration in a pine forest after 9 years of atmospheric $CO_{2}$ enrichment, Global Change Biology 14(12), 2910-2922, doi:10.1111/j.1365-2486.2008.01701.x.
  42. Liu, J. X., D. Q. Zhang, W. J. Huang, G. Y. Zhou, Y. L. Li, and S. Z. Liu, 2014: Quantify the loss of major ions induced by $CO_{2}$ enrichment and nitrogen addition in subtropical model forest ecosystems, Journal of Geophysical Research-Biogeosciences 119(4), 676-686, doi:10.1002/2013jg002343.
  43. Luo, Y., B. Su, W. S. Currie, J. S. Dukes, A. C. Finzi, U. Hartwig, B. Hungate, R. E. McMurtrie, R. Oren, W. J. Parton, D. E. Pataki, M. R. Shaw, D. R. Zak, and C. B. Field, 2004: Progressive nitrogen limitation of ecosystem responses to rising atmospheric carbon dioxide, Bioscience 54(8), 731-739, doi:10.1641/0006-3568(2004)054[0731:pnloer]2.0.co;2.
  44. Luo, Y. Q., D. F. Hui, and D. Q. Zhang, 2006: Elevated $CO_{2}$ stimulates net accumulations of carbon and nitrogen in land ecosystems: A meta-analysis, Ecology 87(1), 53-63. https://doi.org/10.1890/04-1724
  45. Markewitz, D., and D. D. Richter, 2000: Long-term soil potassium availability from a Kanhapludult to an aggrading loblolly pine ecosystem, Forest Ecology and Management 130, 109-129. https://doi.org/10.1016/S0378-1127(99)00175-9
  46. Markewitz, D., D. D. Richter, H. L. Allen, and J. B. Urrego, 1998: Three decades of observed soil acidification in the calhoun experimental forest: Has acid rain made a difference?, Soil Science Society of America Journal 62(5), 1428-1439. https://doi.org/10.2136/sssaj1998.03615995006200050040x
  47. Moulton, K. L., J. West, and R. A. Berner, 2000: Solute flux and mineral mass balance approaches to the quantification of plant effects on silicate weathering, American Journal of Science 300(7), 539-570. https://doi.org/10.2475/ajs.300.7.539
  48. Newton, R. M., D. A. Burns, V. L. Blette, and C. T. Driscoll, 1996: Effect of whole catchment liming on the episodic acidification of two Adirondack streams, Biogeochemistry 32(3), 299-322. https://doi.org/10.1007/BF02187143
  49. Norby, R. J., E. H. DeLucia, B. Gielen, C. Calfapietra, C. P. Giardina, J. S. King, J. Ledford, H. R. McCarthy, D. J. P. Moore, R. Ceulemans, P. De Angelis, A. C. Finzi, D. F. Karnosky, M. E. Kubiske, M. Lukac, K. S. Pregitzer, G. E. Scarascia-Mugnozza, W. H. Schlesinger, and R. Oren, 2005: Forest response to elevated $CO_{2}$ is conserved across a broad range of productivity, Proceedings of the National Academy of Sciences of the United States of America 102(50), 18052-18056. https://doi.org/10.1073/pnas.0509478102
  50. Norby, R. J., J. M. Warren, C. M. Iversen, B. E. Medlyn, and R. E. McMurtrie, 2010: $CO_{2}$ enhancement of forest productivity constrained by limited nitrogen availability, Proceedings of the National Academy of Sciences of the United States of America 107(45), 19368-19373, doi:10.1073/pnas.1006463107.
  51. Norby, R. J., and D. R. Zak, 2011: Ecological Lessons from Free-Air $CO_{2}$ Enrichment (FACE) Experiments, in Annual Review of Ecology, Evolution, and Systematics, Vol 42, edited by D. J. Futuyma, H. B. Shaffer and D. Simberloff, pp. 181-203, doi:10.1146/annurev-ecolsys-102209-144647.
  52. Oh, N. H., M. Hofmockel, M. L. Lavine, and D. D. Richter, 2007: Did elevated atmospheric $CO_{2}$ alter soil mineral weathering?: an analysis of 5-year soil water chemistry data at Duke FACE study, Global Change Biology 13(12), 2626-2641. https://doi.org/10.1111/j.1365-2486.2007.01452.x
  53. Oh, N. H., H. S. Kim, and D. D. Richter, 2005: What regulates soil $CO_{2}$ concentrations? - A modeling approach to $CO_{2}$ diffusion in deep soil profiles, Environmental Engineering Science 22(1), 38-45. https://doi.org/10.1089/ees.2005.22.38
  54. Oh, N. H., and D. D. Richter, 2004: Soil acidification induced by elevated atmospheric $CO_{2}$, Global Change Biology 10(11), 1936-1946. https://doi.org/10.1111/j.1365-2486.2004.00864.x
  55. Oh, N. H., and D. D. Richter, 2005: Elemental translocation and loss from three highly weathered soil-bedrock profiles in the southeastern United States, Geoderma 126(1-2), 5-25. https://doi.org/10.1016/j.geoderma.2004.11.005
  56. Park, C.-w., J. Lee, M. Yi, C. Kim, G. S. Park, R. H. Kim, K. H. Lee, and Y. Son, 2013: Estimation of change in soil carbon stock of Pinus densiflora forests in Korea using KFSC model under RCP 8.5 climate change scenario, Climate Change Research 4(2), 77-93. (In Korean with English abstract).
  57. Raymond, P. A., and N. H. Oh, 2009: Long term changes of chemical weathering products in rivers heavily impacted from acid mine drainage: Insights on the impact of coal mining on regional and global carbon and sulfur budgets, Earth and Planetary Science Letters 284(1-2), 50-56, doi:10.1016/j.epsl.2009.04.006.
  58. Richter, D. D., and D. Markewitz, 1995: How deep is soil?, Bioscience 45, 600-609. https://doi.org/10.2307/1312764
  59. Richter, D. D., D. Markewitz, S. E. Trumbore, and C. G. Wells, 1999: Rapid accumulation and turnover of soil carbon in a re-establishing forest, Nature 400(6739), 56-58. https://doi.org/10.1038/21867
  60. Russell, L. M., P. J. Rasch, G. M. Mace, R. B. Jackson, J. Shepherd, P. Liss, M. Leinen, D. Schimel, N. E. Vaughan, A. C. Janetos, P. W. Boyd, R. J. Norby, K. Caldeira, J. Merikanto, P. Artaxo, J. Melillo, and M. G. Morgan, 2012: Ecosystem Impacts of Geoengineering: A Review for Developing a Science Plan, Ambio 41(4), 350-369, doi:10.1007/s13280-012-0258-5.
  61. Schleppi, P., I. Bucher-Wallin, F. Hagedorn, and C. Korner, 2012: Increased nitrate availability in the soil of a mixed mature temperate forest subjected to elevated $CO_{2}$ concentration (canopy FACE), Global Change Biology 18(2), 757-768, doi:10.1111/j.1365-2486.2011.02559.x.
  62. Schlesinger, W. H., and E. S. Bernhardt, 2013: Biogeochemistry: An Analysis of Global Change, 3rd ed., Academic Press, San Diego, California.
  63. Shukla, J., and Y. Mintz, 1982: Influence of land-surface evapotranspiration on the Earth's climate, Science 215(4539), 1498-1501, doi:10.1126/science.215.4539.1498.
  64. Siemens, J., A. Pacholski, K. Heiduk, A. Giesemann, U. Schulte, R. Dechow, M. Kaupenjohann, and H.-J. Weigel, 2012: Elevated air carbon dioxide concentrations increase dissolved carbon leaching from a cropland soil, Biogeochemistry 108(1-3), 135-148, doi:10.1007/s10533-011-9584-0.
  65. Stark, J. M., and S. C. Hart, 1997: High rates of nitrification and nitrate turnover in undisturbed coniferous forests, Nature 385(6611), 61-64, doi:10.1038/385061a0.
  66. Strobel, B. W., 2001: Influence of vegetation on lowmolecular- weight carboxylic acids in soil solution - a review, Geoderma 99(3-4), 169-198, doi:10.1016/s0016-7061(00)00102-6.
  67. Van Groenigen, K. J., J. Six, B. A. Hungate, M. A. de Graaff, N. van Breemen, and C. van Kessel, 2006: Element interactions limit soil carbon storage, Proceedings of the National Academy of Sciences of the United States of America 103(17), 6571-6574, doi:10.1073/pnas.0509038103.
  68. Williams, E. L., L. M. Walter, T. C. W. Ku, G. W. Kling, and D. R. Zak, 2003: Effects of $CO_{2}$ and nutrient availability on mineral weathering in controlled tree growth experiments, Global Biogeochemical Cycles 17(2), Art. No. 1041, doi:1010.1029/2002GB001925.