Biogeosciences www.biogeosciences.net 1726-4170 1726-4189 6 5 2009 10.5194/bg-6-795-2009 http://www.biogeosciences.net/6/795/2009/ http://www.biogeosciences.net/6/795/2009/bg-6-795-2009.html http://www.biogeosciences.net/6/795/2009/bg-6-795-2009.pdf 795 805 2009-05-11 Large regional-scale variation in C3/C4 distribution pattern of Inner Mongolia steppe is revealed by grazer wool carbon isotope composition K. Auerswald auerswald@wzw.tum.de M. H. O. M. Wittmer T. T. Männel Y. F. Bai R. Schäufele H. Schnyder Lehrstuhl für Grünlandlehre, Technische Universität München, Am Hochanger 1, 85350 Freising-Weihenstephan, Germany State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China now at: K. Deuring GmbH & Co KG, Seestraße 10, 6912 Hörbranz, Austria This work explored the spatial variation of C3/C4 distribution in the Inner Mongolia, P. R. China, steppe by geostatistical analysis of carbon isotope data of vegetation and sheep wool. Standing community biomass (<i>n</i>=118) and sheep wool (<i>n</i>=146) were sampled in a ~0.2 Mio km² area. Samples from ten consecutive years (1998–2007) were obtained. Community biomass samples represented the carbon isotopic composition of standing vegetation on about 1000 m² ("community-scale"), whereas the spatio-temporal scale of wool reflected the isotope composition of the entire area grazed by the herd during a 1-yr period (~5–10 km², "farm-scale"). Pair wise sampling of wool and vegetation revealed a ¹³C-enrichment of 2.7&plusmn;0.7&permil; (95% confidence interval) in wool relative to vegetation, but this shift exhibited no apparent relationships with environmental parameters or stocking rate. The proportion of C4 plants in above-ground biomass (P_C4, %) was estimated with a two-member mixing model of ¹³C discrimination by C3 and C4 vegetation (¹³Δ₃ and ¹³Δ₄, respectively), in accounting for the effects of changing ¹³C in atmospheric CO₂ on sample isotope composition, and of altitude and aridity on ¹³Δ₃. P_C4 averaged 19%, but the variation was enormous: full-scale (0% to 100%) at community-scale, and 0% to 85% at farm-scale. The farm-scale variation of P_C4 exhibited a clear regional pattern over a range of ~250 km. Importantly P_C4 was significantly higher above the 22&deg;C isotherm of the warmest month, which was obtained from annual high-resolution maps and averaged over the different sampling years. This is consistent with predictions from C3/C4 crossover temperature of quantum yield or light use efficiency in C3 and C4 plants. Still, temperature gradients accounted for only 10% of the farm-scale variation of P_C4, indicating that additional factors control P_C4 on this scale. Allen, G. A., Pereira, L. S., Raes, D., and Smith, M.: Crop Evapo-transpiration – Guidelines for Computing Crop Water Requirements, FAO Irrigation and Drainage Paper, 56, 78–86, 1998. Ayliffe, L. K., Cerling, T. E., Robinson, T., West, A. G., Sponheimer, M., Passey, B. H., Hammer, J., Roeder, B., Dearing, M. D., and Ehleringer, J. R.: Turnover of carbon isotopes in tail hair and breath CO₂ of horses fed an isotopically varied diet, Oecologia, 139, 11–22, 2004. Ayyub, B. M. and McCuen, R. H.: Optimum sampling for structural strength evaluation, J. Structural Eng., 116, 518–535, 1990. Bachmaier, M. and Backes, M.: Variogram or semivariogram? Understanding the variances in a variogram, Precision Agric., 9, 173–175, 2008. Bai, Y. F., Han, X. G., Wu, J. G., Chen, Z. Z., and Li, L. H.: Ecosystem stability and compensatory effects in the Inner Mongolian grassland, Nature, 431, 181–184, 2004. Barbehenn, R. V., Chen, Z., Karowe, D. N., and Spickard, A.: C3 grasses have higher nutritional quality than C4 grasses under ambient and elevated atmospheric CO₂, Global Change Biol., 10, 1565–1575, 2004. Bird, M. I. and Pousai, P.: Variations of $\delta^13$C in the surface soil organic carbon pool, Global Biogeochem. Cy., 11, 313–322, 1997. Cabido, M., Pons, E., Cantero, J. J., Lewis, J. P., and Anton, A.: Photosynthetic pathway variation among C₄ grasses along a precipitation gradient in Argentina, J. Biogeogr., 35, 131–140, 2008. Caswell, H., Reed, F., Stephens, S. N., and Werner, P. A.: Photosynthetic pathways and selective herbivory – hypothesis, Am. Nat., 107, 465–480, 1973. Chase, T. N., Pielke, R. A., Knaff, J. A., Kittel, T. G. F., and Eastman, J. L.: A comparison of regional trends in 1979–1997 depth-averaged tropospheric temperatures, Int. J. Climatol., 20, 503–518, 2000. Chen, S. P., Bai, Y. F., and Han, X. G.: Variation of water-use efficiency of Leymus chinensis and Cleistogenes squarrosa in different plant communities in Xilin River Basin, Nei Mongol, Acta Bot. Sin., 44, 1484–1490, 2002. Collatz, G. J., Berry, J. A., and Clark, J. S.: Effects of climate and atmospheric CO₂ partial pressure on the global distribution of C4 grasses: present, past, and future, Oecologia, 114, 441–454, 1998. Daly, C., Gibson, W. P., Taylor, G. H., Johnson, G. L., and Pasteris, P.: A knowledge-based approach to the statistical mapping of climate, Clim. Res., 22, 99–113, 2002. De Niro, M. J. and Epstein, S.: Influence of diet on distribution of carbon isotopes in animals, Geochim. Cosmochim. Acta, 42, 495–506, 1978. Ehleringer, J. R. and Bjorkman, O.: Quantum yields for CO₂ uptake in C3 and C4 plants - dependence on temperature, CO₂, and O₂ concentration, Plant Physiol., 59, 86–90, 1977. Ehleringer, J. R., Cerling, T. E., and Helliker, B. R.: C4 photosynthesis, atmospheric CO₂ and climate, Oecologia, 112, 285–299, 1997. Ehleringer, J. R., Buchmann, N., and Flanagan, L. B.: Carbon isotope ratios in belowground carbon cycle processes, Ecol. Appl., 10, 412–422, 2000. Epstein, H. E., Burke, I. C., and Mosier, A. R.: Plant effects on spatial and temporal patterns of nitrogen cycling in shortgrass steppe, Ecosystems, 1, 374–385, 1998. Farquhar, G. D., Ehleringer, J. R., and Hubick, K. T.: Carbon isotope discrimination and photosynthesis, Ann. Rev. Plant Phys., 40, 503–537, 1989. Fick, G. W., Wilkens, P. W., and Cherney, J. H.: Modeling forage quality changes in the growing crop, in: Forage Quality, Evaluation, and Utilization, edited by: Fahey, G. C. , Amer. Soc. Agron., Madison, WI, USA, 757–795, 1994. Hattersley, P. W.: The distribution of C3 and C4 grasses in Australia in relation to climate, Oecologia, 57, 113–128, 1983. Jones, R. J., Ludlow, M. M., Troughton, J. H., and Blunt, C. G.: Changes in the natural carbon isotope ratios of the hair from steers fed diets of C4, C3 and C4 species in sequence, Search, 12, 85–87, 1981. Körner, C., Farquhar, G. D., and Wong, S. C.: Carbon isotope discrimination by plants follows latitudinal and altitudinal trends, Oecologia, 88, 30–40, 1991. Liu, W. G., Feng, X. H., Ning, Y. F., Zhang, Q. L., Cao, Y. N., and An, Z. S.: $\delta^13$C variation of C3 and C4 plants across an Asian monsoon rainfall gradient in arid northwestern China, Global Change Biol., 11, 1094–1100, 2005. Männel, T. T., Auerswald, K., and Schnyder, H.: Altitudinal gradients of grassland carbon and nitrogen isotope composition are recorded in the hair of grazers, Global Ecol. Biogeogr., 16, 583–592, 2007. Minson, D. J., Ludlow, M. M., and Troughton, J. H.: Differences in natural carbon isotope ratios of milk and hair from cattle grazing tropical and temperate pastures, Nature, 256, 602–602, 1975. Murphy, B. R. and Bowman, D. M. J. S.: Seasonal water availability predicts the relative abundance of C3 and C4 grasses in Australia, Global Ecol. Biogeogr., 16, 160–169, 2007. Ni, J.: Plant functional types and climate along a precipitation gradient in temperate grasslands, north-east China and south-east Mongolia, J. Arid Environ., 53, 501–516, 2003. NOAA NCDC Climate Data Online: http://cdo.ncdc.noaa.gov/CDO/cdo, 2008. Norman, H. C., Wilmot, M. G., Thomas, D. T., Masters, D. G., and Revell, D. K.: Stable carbon isotopes accurately predict diet selection by sheep fed mixtures of C3 annual pastures and saltbush or C4 perennial grasses, Livest. Sci., 121, 162–172, 2009. Osborne, C. P.: Atmosphere, ecology and evolution: what drove the Miocene expansion of C₄ grasslands? J. Ecol., 96, 35–45, 2008. Paruelo, J. M. and Lauenroth, W. K.: Relative abundance of plant functional types in grasslands and shrublands of North America, Ecol. Appl., 6, 1212–1224, 1996. Pebesma, E. J.: Multivariable geostatistics in S: the gstat package, Comput. Geosci-UK, 30, 683–691, 2004. Pyankov, V. I., Gunin, P. D., Tsoog, S., and Black, C. C.: C4 plants in the vegetation of Mongolia: their natural occurrence and geographical distribution in relation to climate, Oecologia, 123, 15–31, 2000. R Development Core Team: R: A language and environment for statistical computing, R Foundation for Statistical Computing, ISBN: 3-900051-07-0, http://www.R-project.org, Vienna, Austria, 2008. Ribeiro, P. J. and Diggle, P. J.: geoR: a package for geostatistical analysis, R-NEWS, 1, 15–18, 2001. Rossi, R. E., Mulla, D. J., Journel, A. G., and Franz, E. H.: Geostatistical tools for modeling and interpreting ecological spatial dependence, Ecol. Monogr., 62, 277–314, 1992. Sachs, L. and Hedderich, J.: Angewandte Statistik, Methodensammlung mit R. Springer, Berlin, Germany, 702 pp., 2006. Sage, R. F. and Kubien, D. S.: Quo vadis C4? An ecophysiological perspective on global change and the future of C4 plants, Photosynth. Res., 77, 209–225, 2003. Scheirs, J., De Bruyn, L., and Verhagen, R.: A test of the C3-C4 hypothesis with two grass miners, Ecology, 82, 410–421, 2001. Schimel, D. S.: Terrestrial ecosystems and the carbon-cycle, Global Change Biol., 1, 77–91, 1995. Schnute, J., Boers, N., Haigh, R., et al.: PBSmapping: PBS Mapping 2.57, R package version 2.57, 2008. Schnyder, H., Schwertl, M., Auerswald, K., and Schäufele, R.: Hair of grazing cattle provides an integrated measure of the effects of site conditions and inter-annual weather variability on $\delta^13$ of temperate humid grassland, Global Change Biol., 12, 1315–1329, 2006 Schulze, E. D., Elis, R., Schulze, W., Trimborn, P., and Ziegler, H.: Diversity, metabolic types and $\delta^13$C carbon isotope ratios in the grass flora of Namibia in relation to growth form, precipitation and habitat conditions, Oecologia, 106, 352–369, 1996. Schulze, E. D., Williams, R. J., Farquhar, G. D., Schulze, W., Langridge, J., Miller, J. M., and Walker, B. H.: Carbon and nitrogen isotope discrimination and nitrogen nutrition of trees along a rainfall gradient in northern Australia, Aust. J. Plant Physiol., 25, 413–425, 1998. Schuurmans, J. M., Bierkens, F. P., and Pebesma, E. J.: Automatic prediction of high-resolution daily rainfall fields for multiple extents: the potential of operational radar, J. Hydrometerol., 8, 1204–1224, 2007. Schwertl, M., Auerswald, K., and Schnyder, H.: Reconstruction of the isotopic history of animal diets by hair segmental analysis, Rapid Commun. Mass Sp., 17, 1312-1318, 2003. Schwertl, M., Auerswald, K., Schäufele, R., and Schnyder, H.: Carbon and nitrogen stable isotope composition of cattle hair: ecological fingerprints of production systems? Agr. Ecosyst. Environ., 109, 153–165, 2005. Semmartin, M., Aguiar, M. R., Distel, R. A., Moretto, A. S., and Ghersa, C. M.: Litter quality and nutrient cycling affected by grazing-induced species replacements along a precipitation gradient, Oikos, 107, 148–160, 2004. Silverman, B. W.: Density estimation for statistics and data analysis, in: Monographs on Statistics and Applied Probability, 26, Chapman and Hall/CRC, London, UK, 1986. Sneath, D.: Ecology – State policy and pasture degradation in inner Asia, Science, 281, 1147–1148, 1998. Sponheimer, M., Robinson, T., Ayliffe, L. K., Passey, B. H., Roeder, B., Shipley, L., Lopez, E., Cerling, T. E., Dearing, M. D., and Ehleringer, J. R.: An experimental study of carbon-isotope fractionation between diet, hair, and feces of mammalian herbivores, Can. J. Zool., 81, 871–876, 2003a. Sponheimer, M., Robinson, T., Roeder, B., Passey, B. H., Ayliffe, L. K., Cerling, T. E., Dearing, M. D., and Ehleringer J. R.: Digestion and passage rates of grass hays by llamas, alpacas, goats, rabbits, and horses, Small Ruminant Res., 48, 149–154, 2003b. Still, C. J., Berry, J. A., Collatz, G. J., and DeFries, R. S: Global distribution of C3 and C4 vegetation: Carbon cycle implications, Global Biogeochem. Cy., 17, 1006, doi:10.1029/2001GB001807, 2003. Taub, D. R.: Climate and the U.S. distribution of C4 grass subfamilies and decarboxylation variants of C4 photosynthesis, Am. J. Bot., 87, 1211–1215, 2000. The Climate Source LLC: PRISM spatial climate datasets for Mongolia and Inner Mongolia. Corvallis, OR, USA, 2002. Tieszen, L. L., Reed, B. C., Bliss, N. B., Wylie, B. K., and Dejong, D. D.: NDVI, C3 and C4 production, and distributions in Great Plains grassland land cover classes, Ecol. Appl., 7, 59–78, 1997. Wang, R. Z.: Photosynthetic pathways, life forms, and reproductive types for forage species along the desertification gradient on Hunshandake desert, North China, Photosynthetica, 40, 321–329, 2002. Wang, R. Z.: Photosynthetic pathway and morphological functional types in the steppe vegetation from Inner Mongolia, North China, Photosynthetica, 41, 143–150, 2003. Wang, R. Z.: Photosynthetic and morphological functional types from different steppe communities in Inner Mongolia, North China, Photosynthetica, 42, 493–503, 2004. Wang, S. P., Wang, Y. F., and Chen, Z. Z.: Effect of climate change and grazing on populations of Cleistogenes squarrosa in Inner Mongolia Steppe, Acta Phytoecol. Sin., 27, 337–334, 2003. Wang, C. J., Tas, B. M., Glindemann, T., Rave, G., Schmidt, L., Weißbach, F., and Susenbeth. A.: Fecal crude protein content as an estimate for the digestiblity of forage in grazing sheep. Anim. Feed Sci. Technol., 149, 199–208, 2009. Wittmer, M. H. O. M., Auerswald, K., Tungalag, R., Bai, Y. F., Schäufele, R., and Schnyder, H.: Carbon isotope discrimination of C3 vegetation in Central Asian Grassland as related to long-term and short-term precipitation patterns, Biogeosciences, 5, 913–924, 2008. Xiao, X., Wang, Y. F., Jiang, S., Ojima, D. S., and Bonham, C. D.: Interannual variation in the climate and aboveground biomass of Leymus chinensis steppe and Stipa grandis steppe in the Xilin River Basin, Inner Mongolia, China, J. Arid Environ., 31, 283–299, 1995. Yu, F. F., Price, K. P., Ellis, J., and Shi, P. J.: Response of seasonal vegetation development to climatic variations in eastern central Asia, Remote Sens. Environ., 87, 42–54, 2003.