Predicted global warming will be most pronounced in the Arctic and will severely affect permafrost environments. Due to its large spatial extent and large stocks of soil organic carbon, changes to organic matter decomposition rates and associated carbon fluxes in Arctic permafrost soils will significantly impact the global carbon cycle. We explore the potential of soil spectroscopy to estimate soil carbon properties and investigate the relation between soil properties and vegetation composition. Soil samples are collected in Siberia, and vegetation descriptions are made at each sample point. First, laboratory-determined soil properties are related to the spectral reflectance of wet and dried samples using partial least squares regression (PLSR) and stepwise multiple linear regression (SMLR). SMLR, using selected wavelengths related with C and N, yields high calibration accuracies for C and N. PLSR yields a good prediction model for K and a moderate model for pH. Using these models, soil properties are determined for a larger number of samples, and soil properties are related to plant species composition. This analysis shows that variation of soil properties is large within vegetation classes, but vegetation composition can be used for qualitative estimation of soil properties. 1. Introduction The Arctic is experiencing the highest rates of warming compared with other world regions [1] that will likely have great impacts on high-latitude ecosystems [2, 3]. The large and potentially volatile carbon pools stored in Arctic soils have the potential for large emissions of greenhouse gases in the form of both CO2 and CH4 under warmer and potentially drier conditions, resulting in a positive feedback to global warming [4]. Further, climatic changes may impact vegetation development and affect water and energy exchange in tundra ecosystems, with consequences for permafrost thaw depth [5, 6] and concomitant soil carbon release to the atmosphere [7–9]. The response of soil organic matter decomposition to increasing temperature is a critical aspect of ecosystem responses to global change [10]. It has been suggested that a warmer and drier climate in Arctic regions might increase the decomposition rate and, hence, release more CO2 to the atmosphere than at present [11, 12]. Besides expected changes within the soil itself, changes on the vegetation development are observed and expected for future warming. Plant species composition may greatly affect rates of soil processes, including decomposition [13]. In general, species within a growth form (graminoids, evergreen
References
[1]
IPCC, “Climate change 2007: the physical science basis,” in Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, S. Solomon, D. Qin, M. Manning, et al., Eds., p. 996, Cambridge University Press, Cambridge, UK, 2007.
[2]
E. Post, M. C. Forchhammer, M. S. Bret-Harte et al., “Ecological dynamics across the arctic associated with recent climate change,” Science, vol. 325, no. 5946, pp. 1355–1358, 2009.
[3]
ACIA, in Arctic Climate Impact Assessment, Impacts of a Warming Arctic, V. M. Kattsov and E. K？llén, Eds., pp. 99–150, Cambridge University Press, Cambridge, UK, 2004.
[4]
C. D. Koven, B. Ringeval, P. Friedlingstein et al., “Permafrost carbon-climate feedbacks accelerate global warming,” Proceedings of the National Academy of Sciences of the United States of America, vol. 108, no. 36, pp. 14769–14774, 2011.
[5]
V. E. Romanovsky, D. S. Drozdov, N. G. Oberman et al., “Thermal state of permafrost in Russia,” Permafrost and Periglacial Processes, vol. 21, no. 2, pp. 136–155, 2010.
[6]
D. Blok, M. M. P. D. Heijmans, G. Schaepman-Strub, A. V. Kononov, T. C. Maximov, and F. Berendse, “Shrub expansion may reduce summer permafrost thaw in Siberian tundra,” Global Change Biology, vol. 16, no. 4, pp. 1296–1305, 2010.
[7]
E. A. G. Schuur, J. G. Vogel, K. G. Crummer, H. Lee, J. O. Sickman, and T. E. Osterkamp, “The effect of permafrost thaw on old carbon release and net carbon exchange from tundra,” Nature, vol. 459, no. 7246, pp. 556–559, 2009.
[8]
N. S. Zimov, S. A. Zimov, A. E. Zimová, G. M. Zimová, V. I. Chuprynin, and F. S. Chapin, “Carbon storage in permafrost and soils of the mammoth tundra-steppe biome: role in the global carbon budget,” Geophysical Research Letters, vol. 36, no. 2, Article ID L02502, 6 pages, 2009.
[9]
E. Dorrepaal, S. Toet, R. S. P. Van Logtestijn et al., “Carbon respiration from subsurface peat accelerated by climate warming in the subarctic,” Nature, vol. 460, no. 7255, pp. 616–619, 2009.
[10]
R. T. Conant, M. G. Ryan, G. I. ？gren, et al., “Temperature and soil organic matter decomposition rates—synthesis of current knowledge and a way forward,” Global Change Biology, vol. 17, no. 11, pp. 3392–3404, 2011.
[11]
W. D. Billings, J. O. Luken, D. A. Mortensen, and K. M. Peterson, “Arctic tundra: a source or sink for atmospheric carbon dioxide in a changing environment?” Oecologia, vol. 53, no. 1, pp. 7–11, 1982.
[12]
W. D. Billings, J. O. Luken, D. A. Mortensen, and K. M. Peterson, “Increasing atmospheric carbon dioxide: possible effects on arctic tundra,” Oecologia, vol. 58, no. 3, pp. 286–289, 1983.
[13]
S. E. Hobbie and L. Gough, “Litter decomposition in moist acidic and non-acidic tundra with different glacial histories,” Oecologia, vol. 140, no. 1, pp. 113–124, 2004.
[14]
S. E. Hobbie, “Temperature and plant species control over litter decomposition in Alaskan tundra,” Ecological Monographs, vol. 66, no. 4, pp. 503–522, 1996.
[15]
J. H. C. Cornelissen, P. M. Van Bodegom, R. Aerts et al., “Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes,” Ecology Letters, vol. 10, no. 7, pp. 619–627, 2007.
[16]
L. Gough, G. R. Shaver, J. Carroll, D. L. Royer, and J. A. Laundre, “Vascular plant species richness in Alaskan arctic tundra: the importance of soil pH,” Journal of Ecology, vol. 88, no. 1, pp. 54–66, 2000.
[17]
F. S. Chapin, G. R. Shaver, A. E. Giblin, K. J. Nadelhoffer, and J. A. Laundre, “Responses of Arctic tundra to experimental and observed changes in climate,” Ecology, vol. 76, no. 3, pp. 694–711, 1995.
[18]
M. D. Walker, C. H. Wahren, R. D. Hollister et al., “Plant community responses to experimental warming across the tundra biome,” Proceedings of the National Academy of Sciences of the United States of America, vol. 103, no. 5, pp. 1342–1346, 2006.
[19]
D. Blok, G. Schaepman-Strub, H. Bartholomeus, M. M. P. D. Heijmans, T. C. Maximov, and F. Berendse, “The response of Arctic vegetation to the summer climate: relation between shrub cover, NDVI, surface albedo and temperature,” Environmental Research Letters, vol. 6, no. 3, Article ID 035502, 2011.
[20]
F. S. Chapin, M. Sturm, M. C. Serreze et al., “Role of land-surface changes in arctic summer warming,” Science, vol. 310, no. 5748, pp. 657–660, 2005.
[21]
C. W. Chang, D. A. Laird, M. J. Mausbach, and C. R. Hurburgh, “Near-infrared reflectance spectroscopy—principal components regression analyses of soil properties,” Soil Science Society of America Journal, vol. 65, no. 2, pp. 480–490, 2001.
[22]
R. A. Viscarra Rossel, D. J. J. Walvoort, A. B. McBratney, L. J. Janik, and J. O. Skjemstad, “Visible, near infrared, mid infrared or combined diffuse reflectance spectroscopy for simultaneous assessment of various soil properties,” Geoderma, vol. 131, no. 1-2, pp. 59–75, 2006.
[23]
A. Stevens, B. van Wesemael, H. Bartholomeus, D. Rosillon, B. Tychon, and E. Ben-Dor, “Laboratory, field and airborne spectroscopy for monitoring organic carbon content in agricultural soils,” Geoderma, vol. 144, no. 1-2, pp. 395–404, 2008.
[24]
B. Stenberg, R. A. Viscarra Rossel, A. M. Mouazen, and J. Wetterlind, “Visible and Near Infrared Spectroscopy in Soil Science,” Advances in Agronomy, vol. 107, pp. 163–215, 2010.
[25]
M. K. Van Der Molen, J. Van Huissteden, F. J. W. Parmentier et al., “The growing season greenhouse gas balance of a continental tundra site in the Indigirka lowlands, NE Siberia,” Biogeosciences, vol. 4, no. 6, pp. 985–1003, 2007.
[26]
D. A. Walker, M. K. Reynolds, F. J. A. Dani？ls et al., “The Circumpolar Arctic vegetation map,” Journal of Vegetation Science, vol. 16, no. 3, pp. 267–282, 2005.
[27]
P. H. Fidêncio, R. J. Poppi, J. C. De Andrade, and H. Cantarella, “Determination of organic matter in soil using near-infrared spectroscopy and partial least squares regression,” Communications in Soil Science and Plant Analysis, vol. 33, no. 9-10, pp. 1607–1615, 2002.
[28]
T. Udelhoven, C. Emmerling, and T. Jarmer, “Quantitative analysis of soil chemical properties with diffuse reflectance spectrometry and partial least-square regression: a feasibility study,” Plant and Soil, vol. 251, no. 2, pp. 319–329, 2003.
[29]
H. Bartholomeus, L. Kooistra, A. Stevens et al., “Soil Organic Carbon mapping of partially vegetated agricultural fields with imaging spectroscopy,” International Journal of Applied Earth Observation and Geoinformation, vol. 13, no. 1, pp. 81–88, 2011.
[30]
R. A. Viscarra Rossel, “ParLeS: software for chemometric analysis of spectroscopic data,” Chemometrics and Intelligent Laboratory Systems, vol. 90, no. 1, pp. 72–83, 2008.
[31]
P. J. Curran, “Remote sensing of foliar chemistry,” Remote Sensing of Environment, vol. 30, no. 3, pp. 271–278, 1989.
[32]
R. Ihaka and R. Gentleman, “R: a language for data analysis and graphics,” Journal of Computational and Graphical Statistics, vol. 5, no. 3, pp. 299–314, 1996.
[33]
C. W. Chang and D. A. Laird, “Near-infrared reflectance spectroscopic analysis of soil C and N,” Soil Science, vol. 167, no. 2, pp. 110–116, 2002.
[34]
M. O. Hill and P. ？milauer, TWINSPAN for Windows Version 2.3, Centre for Ecology & Hydrology and University of South Bohemia, Huntingdon, UK, 2005.
[35]
D. Blok, Shrubs in the Cold: Interactions between Vegetation, Permafrost and Climate in Siberian Tundra, Wageningen University, Wageningen, The Netherlands, 2011.
[36]
S. A. Zimov, S. P. Davydov, G. M. Zimova et al., “Permafrost carbon: stock and decomposability of a globally significant carbon pool,” Geophysical Research Letters, vol. 33, no. 20, Article ID L20502, 5 pages, 2006.
[37]
E. Ben-Dor, “Quantitative remote sensing of soil properties,” Advances in Agronomy, vol. 75, pp. 173–243, 2002.
[38]
M. Knadel, A. Thomsen, and M. H. Greve, “Multisensor on-the-go mapping of soil organic carbon content,” Soil Science Society of America Journal, vol. 75, no. 5, pp. 1799–1806, 2011.
[39]
G. J. Michaelson, C. L. Ping, and J. M. Kimble, “Carbon storage and distribution in tundra soils of Arctic Alaska, U.S.A,” Arctic and Alpine Research, vol. 28, no. 4, pp. 414–424, 1996.
[40]
H. Lee, E. A. G. Schuur, K. S. Inglett, M. Lavoie, and J. P. Chanton, “The rate of permafrost carbon release under aerobic and anaerobic conditions and its potential effects on climate,” Global Change Biology, vol. 18, no. 2, pp. 515–527, 2012.
[41]
P. Dunfield, R. knowles, R. Dumont, and T. R. Moore, “Methane production and consumption in temperate and subarctic peat soils: response to temperature and pH,” Soil Biology and Biochemistry, vol. 25, no. 3, pp. 321–326, 1993.
[42]
R. T. Williams and R. L. Crawford, “Methanogenic Bacteria, including an acid-tolerant strain, from peatlands,” Applied and Environmental Microbiology, vol. 50, no. 6, pp. 1542–1544, 1985.
[43]
M. S. Bret-Harte, G. R. Shaver, J. P. Zoerner et al., “Developmental plasticity allows betula nana to dominate tundra subjected to an altered environment,” Ecology, vol. 82, no. 1, pp. 18–32, 2001.
[44]
D. Blok, U. Sass-Klaassen, G. Schaepman-Strub, M. M. P. D. Heijmans, P. Sauren, and F. Berendse, “What are the main climate drivers for shrub growth in Northeastern Siberian tundra?” Biogeosciences, vol. 8, no. 5, pp. 1169–1179, 2011.
[45]
I. H. Myers-Smith, B. C. Forbes, M. Wilmking et al., “Shrub expansion in tundra ecosystems: dynamics, impacts and research priorities,” Environmental Research Letters, vol. 6, no. 4, Article ID 045509, 2011.
[46]
D. Blok, G. Schaepman-Strub, M. Heijmans et al., Climate Change Effects on Vegetation in Northeastern Siberian Tundra—How Does Shrub Growth Relate to Local Climate and What Are Potential Effects of Shurb Expansion on Permafrost Thawing?EGU General Assembly, Vienna, Austria, 2010.
[47]
F. E. Nelson, N. I. Shiklomanov, G. R. Mueller, K. M. Hinkel, D. A. Walker, and J. G. Bockheim, “Estimating active-layer thickness over a large region: Kuparuk river basin, Alaska, U.S.A,” Arctic and Alpine Research, vol. 29, no. 4, pp. 367–378, 1997.
[48]
G. Schaepman-Strub, J. Limpens, M. Menken, H. M. Bartholomeus, and M. E. Schaepman, “Towards spatial assessment of carbon sequestration in peatlands: spectroscopy based estimation of fractional cover of three plant functional types,” Biogeosciences, vol. 6, no. 2, pp. 275–284, 2009.
