Distribution characteristics and influencing factors of soil organic carbon in alpine ecosystems on the Tibetan Plateau transect, China

Abstract

The undisturbed regions along the Qinghai-Tibet Highway crossing the natural zones of montane desert, alpine meadow-steppe, and montane shrub-coniferous forest were chosen as the study areas. Soil samples were collected at 23 sites and the relations between the influencing factors and distribution of soil organic carbon (SOC) content were studied. The results indicated that the order of SOC content for the whole soil profile with different vegetations and in the horizontal direction was shown as below: forest > shrub > meadow > steppe > desert. All the SOC contents of the top 10 cm soil layers of forest, shrub and meadow vegetations, as well as that of the top 20 cm soil layers in steppe, in the vertical direction, were higher than those of corresponding lower soil layers. However, the SOC content in the desert soil was in accordance. The grey correlative analysis between the climatic factors and SOC content in the top soil show that precipitation was the dominant climatic factor affecting the distribution of SOC in the Tibetan Plateau transect. The influence of precipitation on the horizontal distribution of SOC decreased with the increase of precipitation in the horizontal direction. The vertical distribution of SOC along the soil profile was greatly affected by precipitation or the soil clay content in top soil layers, and was clearly influenced by soil silt content or sand content in lower soil layers, as well. The influences of both soil bulk density and soil pH on the vertical distribution of SOC along the soil profile gradually declined. The plant biomass was the most important biotic factors affecting the distribution of the SOC.

References

1. Balesdent J, Besnard E, Arrouays D, Chenu C (1998). The dynamics of carbon in particle-size fractions of soil in a forest-cultivationsequence. Plant and Soil, 201(1): 49–57. doi:10.1023/A:1004337314970
2. Batjes N H (1996). Total carbon and nitrogen in the soils of the world. European Journal of Soil Science, 47: 151–163. doi:10.1111/j.1365-2389.1996.tb01386.x
3. Cao G M, Zhang J X, Bao X K, Zhou D X (1999). The phosphorus cycling in an alpine meadow ecosystem. Acta Ecologica Sinica, 19(4): 514–518 (in Chinese)
4. Ciais P, Tans P P, Trolier M, White J W C, Francey R J (1995). A large NorthernHemisphere terrestrial CO₂ sink indicated bythe ¹³C/¹²Cratio of atmospheric CO₂. Science, 269: 1098–1102. doi:10.1126/science.269.5227.1098
5. Daly C, Neilson R P, Phillips D L (1994). A statistical-topographic model formapping climatologic precipitation over mountainous terrain. Journal of Applied Meteorology, 33: 140–158. doi:10.1175/1520-0450(1994)033<0140:ASTMFM>2.0.CO;2
6. Fan S, Gloor M, Mahlman J, Pacala S, Sarmiento J, Takahashi T, Tans P (1998). A largeterrestrial carbon sink in North America implied by atmospheric andoceanic carbon dioxide data and models. Science, 282: 442–446. doi:10.1126/science.282.5388.442
7. Fang J Y, Chen A P, Peng C H, Zhao S Q, Ci L J (2001). Changes in forestbiomass carbon storage in China between 1949 and 1998. Science, 292: 2320–2322. doi:10.1126/science.1058629
8. Gao Y X, Chen H Z, Wu Z D, Sun H L, Li M S (1985). The Soil in XizangAutonomous Region. The scientific exploration team of Qing-Hai WeatherBureau. Beijing: Scientific Publishers (in Chinese)
9. Houghton R A, Hackler J L, Lawrence K T (1999). The U S carbon budget: Contributionsfrom land-use change. Science, 285: 574–578. doi:10.1126/science.285.5427.574
10. Huang C Y (2000). Pedology. Beijing: Chinese Agricultural Publishing House (in Chinese)
11. Institute of botany,the Chinese Academy of Sciences. (1988). The Vegetationin Xizang Autonomous Region. The series books of scientific exploration on the Tibetan Plateau. Beijing: Scientific Publishers (in Chinese)
12. Jobbágy E G, Jackson R B (2000). The verticaldistribution of soil organic carbon and relation to climate and vegetation. Ecological Applications, 10(2): 423–436. doi:10.1890/1051-0761(2000)010[0423:TVDOSO]2.0.CO;2
13. Jobbágy E G, Jackson R B (2001). The distributionof soil nutrients with depth: global patterns and imprint of plants. Biogeochemistry, 53: 51–77. doi:10.1023/A:1010760720215
14. Kauppi P E, Mielikäinen K, Kuusela K (1992). Biomass and carbon budget of Europeanforests 1971 to 1990. Science, 256: 70–74. doi:10.1126/science.256.5053.70
15. Lal R, Kimble J M, Levine E, Stewart B A (1995). Soil Management and Greenhouse Effect. Boca Raton, FL: Lewis Publishers, 1–7
16. Li B Y (1987). The boundary and area of the Tibetan Plateau in China. Geographical Research, 6(3): 57–63 (in Chinese)
17. Liu S Q, Li J P (1992). The SoilSpecies of Xizang Autonomous Region. Beijing: Scientific PublishingHouse (in Chinese)
18. Liu Y F, Ouyang H, Cao G M, Luo J, Zhang X Z, Zhao X Q, Yang Q W (2001). Soilcarbon emission from ecosystems of eastern Qinghai-Tibetan Plateau. Journal of Natural Resources, 16(2): 152–160 (in Chinese)
19. Lu R K (1999). The Analysis of Soil Science and Agricultural Chemistry. Beijing: Chinese Agricultural Scientific Technology Publishers (in Chinese)
20. Luo T X, Li W H, Luo J, Wang Q J (1999). A comparative study on biological production of major vegetationtypes on the Tibetan Plateau. Acta EcologicaSinica, 19(6): 823–831 (in Chinese)
21. Luo T X, Li W H, Luo J, Zhu H Z (2002b). Estimated biomass and productivity of natural vegetation on the TibetanPlateau. Ecological Applications, 12(4): 980–997. doi:10.1890/1051-0761(2002)012[0980:EBAPON]2.0.CO;2
22. Luo T X, Shi P L, Luo J, Ouyang H (2002a). Distribution patterns of aboveground biomass in Tibetan alpine vegetationtransects. Acta Phytoecologica Sinica, 26(6): 668–676 (in Chinese)
23. Ma L (1960). The Precipitation on the Tibetan Plateau. The scientific exploration team of Qing-Hai Weather Bureau (in Chinese)
24. Paul E A (1984). Dynamics of soil organic matter. Plant and Soil, 76: 275–285. doi:10.1007/BF02205586
25. Pei Z Y, Ouyang H, Zhou C P (2003). A study on carbon fluxes from alpinegrassland ecosystem on Tibetan Plateau. Acta Ecologica Sinica, 23(2): 231–236 (in Chinese)
26. Post W M, Emanuel W R, Zinke P J, Stangenberger A G (1982). Soil carbon pools and life zones. Nature, 298: 156–159. doi:10.1038/298156a0
27. Post W M, Peng T H, Emanuel W R, King A W, Dale V H, DeAngelis D L (1990). The global carbon cycle. American Scientist, 78: 310–326
28. Schlesinger W H (1990). Evidence from chronosequence studies for a low carbon-storagepotential of soil. Nature, 48: 232–234. doi:10.1038/348232a0
29. Thompson M V, Randerson J T, Malmstrom C M, Field C E (1996). Change in net primary production and net heterotrophic respiration:How much is necessary to sustain the terrestrial carbon sink. Global Biogeochemical Cycles, 10(4): 711–726. doi:10.1029/96GB01667
30. Wang G X, Cheng G D, Shen Y P (2002). Soil organic carbon pool of grasslandson the Tibetan Plateau and its global implication. Journal of Glaciology and Geocryology, 24(6): 693–700 (in Chinese)
31. Wang L, Ouyang H, Zhou C P, Zhang F, Bai J H, Peng K (2004). Distribution characteristics of soil organic matterand nitrogen on eastern slope of Mt. Gongga. Acta Geographica Sinica, 59(6): 1012–1019 (in Chinese)
32. Wang L, Ouyang H, Zhou C P, Zhang F, Song M H, Tian Y Q (2005). Soil organic matter dynamics along a vertical vegetationgradient in the Gongga Mountain on the Tibetan Plateau. Journal of Integrative Plant Biology, 47(4): 411–420. doi:10.1111/j.1744-7909.2005.00085.x
33. Wu H B, Guo Z T, Peng C H (2003). Distribution and storage of soilorganic carbon in China. Global BiogeochemicalCycle, 17(2): 1–11
34. Xu J H (2002). Mathematical Methods in Contemporary Geography. 2nded. Beijing: Higher Education Press (in Chinese)
35. Xu X L, Ouyang H, Pei Z Y, Zhou C P (2003). Fate of ¹⁵N labeled nitrate and ammoniumsalts added to an alpine meadow in the Qinghai-Xizang Plateau. Acta Botanica Sinica, 45(3): 276–281
36. Zhang J X, Cao G M (1999). The nitrogencycle in an alpine meadow ecosystem. ActaEcologica Sinica, 19(4): 509–513 (in Chinese)
37. Zhang Y L, Li B Y, Zheng D (2002). A discussion on the boundary andarea of the Tibetan Plateau in China. GeographicalResearch, 21(1): 1–8 (in Chinese)
38. Zheng D (1996). The study of the natural zone system on the TibetanPlateau. Science in China (Series D), 26(4): 336–341 (in Chinese)
39. Zheng D, Zhang R Z, Yang Q Y (1979). On the natural zone in the Qinghai-XizangPlateau. Acta Geographica Sinica, 34(1): 1–11 (in Chinese)
40. Zhu H Z, Luo T X, Daly C (2003). Validation of simulated grid datasets of China's temperature and precipitation with high spatial resolution. Geographical Research, 22(3): 349–359 (in Chinese)