Abstract
Grasslands store substantial amounts of carbon in the form of organic matter in soil and roots. At high latitudes and elevation, turnover of these materials is slow due to various interacting biotic and abiotic constraints. Reliable estimates on the future of belowground carbon storage in cold grassland soils thus require quantitative understanding of these factors. We studied carbon turnover of roots, labile coarse particulate organic matter (cPOM) and older non-cPOM along a natural pH gradient (3.9–5.9) in a subalpine grassland by utilizing soil fractionation and radiocarbon dating. Soil carbon stocks and root biomass, turnover, and decomposability did not scale with soil pH whereas mean residence times of both soil organic matter fractions significantly increased with declining pH. The effect was twice as strong for non-cPOM, which was also stronger enriched in 15N at low pH. Considering roots as important precursors for cPOM, the weaker soil pH effect on cPOM turnover may have been driven by comparably high root pH values. At pH < 5, long non-cPOM mean residence times were probably related to pH dependent changes in substrate availability. Differences in turnover along the pH gradient were not reflected in soil carbon stocks because aboveground productivity was lower under acidic conditions and, in turn, higher inputs from aboveground plant residues compensated for faster soil carbon turnover at less acidic pH. In summary, the study provides evidence for a strong and differential regulatory role of pH on the turnover of soil organic matter that needs consideration in studies aiming to quantify effects of changing environmental conditions on belowground carbon storage.





Similar content being viewed by others
References
Anderson JM (1991) The effects of climate change on decomposition processes in grassland and coniferous forests. Ecol Appl 1:326–347
Bassin S, Volk M, Suter M, Buchmann N, Fuhrer J (2007) Nitrogen but not ozone affects productivity and species composition of subalpine grassland after 3 year of treatment. New Phytol 175:523–534
Bouma J, Hoeks J, van der Plas L, van Scherrenburg B (1969) Genesis and morphology of some alpine podzol profiles. J Soil Sci 20:384–398
Budge K, Leifeld J, Hiltbrunner E, Fuhrer J (2011) Alpine grassland soils contain large proportion of labile carbon but indicate long turnover times. Biogeosciences 8:1911–1923
Conen F, Zimmermann M, Leifeld J, Seth B, Alewell C (2008) Relative stability of soil carbon revealed by shifts in delta N-15 and C:N ratio. Biogeosciences 5:123–128
Denef K, Six J, Merckx R, Paustian K (2004) Carbon sequestration in microaggregates of no-tillage soils with different clay mineralogy. Soil Sci Soc Am J 68:1935–1944
Egli M, Mirabella A, Sartori G, Fitze P (2003) Weathering rates as a function of climate: results from a climosequence of the Val Genova (Trentino, Italian Alps). Geoderma 111:99–121
Eskelinen A, Stark S, Mannisto M (2009) Links between plant community composition, soil organic matter quality and microbial communities in contrasting tundra habitats. Oecologia 161:113–123
FAL (1998) Methodenbuch für Boden-, Pflanzen- und Lysimeterwasseruntersuchungen. Eidgenössische Forschungsanstalt für Agrarökologie und Landbau. Schriftenreihe der FAL, 27, Zurich, Switzerland
Guggenberger G, Glaser B, Zech W (1994) Heavy-metal binding by hydrophobic and hydrophilic dissolved organic carbon fractions in a Spodosol-A and Spodosol-B horizon. Water Air Soil Pollut 72:111–127
Harkness DD, Harrison AF, Bacon PJ (1986) The temporal distribution of bomb C-14 in a forest soil. Radiocarbon 28:328–337
Hobbie SE, Schimel JP, Trumbore SE, Randerson JR (2000) Controls over carbon storage and turnover in high-latitude soils. Glob Change Biol 6:196–210
Kaiser K, Guggenberger G (2007) Sorptive stabilization of organic matter by microporous goethite: sorption into small pores vs. surface complexation. Eur J Soil Sci 58:45–59
Kalbitz K, Solinger S, Park JH, Michalzik B, Matzner E (2000) Controls on the dynamics of dissolved organic matter in soils: a review. Soil Sci 165:277–304
Kleeberg R, Monecke T, Hillier S (2008) Preferred orientation of mineral grains in sample mounts for quantitative XRD measurements: how random are powder samples? Clays Clay Miner 56:404–415
Körner C (2003) Alpine plant life. Springer, Heidelberg
Kramer MG, Sollins P, Sletten RS, Swart PK (2003) N isotope fractionation and measures of organic matter alteration during decomposition. Ecology 84:2021–2025
Leifeld J, Fuhrer J (2009) Long-term management effects on soil organic matter in two cold, high-elevation grasslands: clues from fractionation and radiocarbon dating. Eur J Soil Sci 60:230–239
Leifeld J, Zimmermann M, Fuhrer J (2008) Simulating decomposition of labile soil organic carbon: effects of pH. Soil Biol Biochem 40:2948–2951
Leifeld J, Zimmermann M, Fuhrer J, Conen F (2009) Storage and turnover of carbon in grassland soils along an elevation gradient in the Swiss Alps. Glob Change Biol 15:668–679
Levin I, Kromer B (2004) The tropospheric (CO2)–C-14 level in mid-latitudes of the Northern Hemisphere (1959–2003). Radiocarbon 46:1261–1272
Mikutta R, Schaumann GE, Gildemeister D, Bonneville S, Kramer MG, Chorover J, Chadwick OA, Guggenberger G (2009) Biogeochemistry of mineral–organic associations across a long-term mineralogical soil gradient (0.3–4100 kyr), Hawaiian Islands. Geochim Cosmochim Acta 73:2034–2060
Neff JC, Townsend AR, Gleixner G, Lehman SJ, Turnbull J, Bowman WD (2002) Variable effects of nitrogen additions on the stability and turnover of soil carbon. Nature 419:915–917
Nilsson MC, Wardle DA, Zackrisson O, Jaderlund A (2002) Effects of alleviation of ecological stresses on an alpine tundra community over an eight-year period. Oikos 97:3–17
Pietri JCA, Brookes PC (2008) Nitrogen mineralisation along a pH gradient of a silty loam UK soil. Soil Biol Biochem 40:797–802
Rasse DP, Rumpel C, Dignac MF (2005) Is soil carbon mostly root carbon? Mechanisms for a specific stabilisation. Plant Soil 269:341–356
Scheel T, Dorfler C, Kalbitz K (2007) Precipitation of dissolved organic matter by aluminum stabilizes carbon in acidic forest soils. Soil Sci Soc Am J 71:64–74
Seeber J, Langel R, Meyer E, Traugott M (2009) Dwarf shrub litter as a food source for macro-decomposers in alpine pastureland. Appl Soil Ecol 41:178–184
Sinsabaugh RL, Lauber CL, Weintraub MN, Ahmed B, Allison SD, Crenshaw C, Contosta AR, Cusack D, Frey S, Gallo ME, Gartner TB, Hobbie SE, Holland K, Keeler BL, Powers JS, Stursova M, Takacs-Vesbach C, Waldrop MP, Wallenstein MD, Zak DR, Zeglin LH (2008) Stoichiometry of soil enzyme activity at global scale. Ecol Lett 11:1252–1264
Sjögersten-Turner S, Alewell C, Cécillon L, Hagedorn F, Jandl R, Leifeld J, Martinsen V, Schindlbacher A, Sebastià M-T, Van Miegroet H (2011) Mountain soils in a changing climate – vulnerability of carbon stocks and ecosystem feedbacks. In: Jandl R, Rodeghiero M, Olsson M (eds) Soil carbon in sensitive European ecosystems. From science to land management. Wiley-Blackwell, pp 118–148
Spiegelberger T, Hegg O, Matthies D, Hedlund K, Schaffner U (2006) Long-term effects of short-term perturbation in a subalpine grassland. Ecology 87:1939–1944
Stuiver M, Polach HA (1977) Reporting of C-14 data—discussion. Radiocarbon 19:355–363
Stuiver M, Reimer PJ, Braziunas TF (1998) High-precision radiocarbon age calibration for terrestrial and marine samples. Radiocarbon 40:1127–1151
Synal HA, Stocker M, Suter M (2007) MICADAS: a new compact radiocarbon AMS system. Nucl Instrum Methods Phys Res B 259:7–13
Tiessen H, Karamanos RE, Stewart JWB, Selles F (1984) Natural N-15 abundance as an indicator of soil organic-matter transformations in native and cultivated soils. Soil Sci Soc Am J 48:312–315
Torn MS, Swanston CW, Castanha C, Trumbore SE (2009) Storage and turnover of organic matter in soil. In: Senesi N, Xing B, Huang PM (eds) Biophysico–chemical processes involving natural nonliving organic matter in environmental systems. Wiley, New York, pp 219–272
Townsend AR, Vitousek PM, Trumbore SE (1995) Soil organic-matter dynamics along gradients in temperature and land-use on the Island of Hawaii. Ecology 76:721–733
Trumbore SE (1997) Potential responses of soil organic carbon to global environmental change. Proc Natl Acad Sci USA 94:8284–8291
Von Lützow M, Kögel-Knabner I, Ekschmitt K, Matzner E, Guggenberger G, Marschner B, Flessa H (2006) Stabilization of organic matter in temperate soils: mechanisms and their relevance under different soil conditions—a review. Eur J Soil Sci 57:426–445
Walse C, Berg B, Sverdrup H (1998) Review and synthesis of experimental data on organic matter decomposition with respect to the effect of temperature, moisture, and acidity. Environ Rev 6:25–40
Wang L, Ouyang H, Zhou CP, Zhang F, Song MH, Tian YQ (2005) Soil organic matter dynamics along a vertical vegetation gradient in the Gongga Mountain on the Tibetan Plateau. J Integr Plant Biol 47:411–420
Wang G, Li Y, Wang Y, Wu Q (2008) Effects of permafrost thawing on vegetation and soil carbon pool losses on the Qinghai-Tibet Plateau, China. Geoderma 143:143–152
Yano Y, Shaver GR, Giblin AE, Rastetter EB (2010) Depleted 15N in hydrolysable-N of arctic soils and its implication for mycorrhizal fungi–plant interaction. Biogeochemistry 97:183–194
Acknowledgments
We thank Robin Giger for soil fractionation and elemental analysis and Susanne Müller for assisting in root incubation experiments. Karen Budge helped to improve the language. Diane Bürge-Weirich and Johanna Rauwolf performed XRF measurements and Christian Mavris helped with XRD. We thank two anonymous reviewers and Phil Sollins for constructive comments on the manuscript.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Leifeld, J., Bassin, S., Conen, F. et al. Control of soil pH on turnover of belowground organic matter in subalpine grassland. Biogeochemistry 112, 59–69 (2013). https://doi.org/10.1007/s10533-011-9689-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10533-011-9689-5

