Soil C:N:P stoichiometry in plantations of N-fixing black locust and indigenous pine, and secondary oak forests in Northwest China
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Soil nutrient concentrations and stoichiometry are important indicators of plant growth, terrestrial productivity, and ecosystem functioning. Nevertheless, little is known about the vertical distribution and the environmental factors influencing the spatial patterns of different forest types under the “Grain for Green” program and the “Natural Forest Resources Protection” project in Northwest of China.
Materials and methods
We collected 114 soil profile samples within a 0–100-cm depth from black locust and Chinese pine plantations, and secondary oak forests. We determined the vertical distributions of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and their ratios along environmental gradients in Shaanxi Province, Northwest China.
Results and discussion
The results showed that both SOC and TN concentrations decreased exponentially within the soil profiles of the three forest types, but there was minimal change in TP. Significant differences in SOC, TN, and TP were found in the surface soil layers among the forest types. Both SOC and TN were relatively low in the N-fixing black locust plantations and TP was comparatively low in the Chinese pine plantations. The C:N:P ratios decreased with increasing soil depth for the three forest types. These ratios were comparatively high in the Chinese pine plantations, relatively low in the black locust plantations, and moderate in the oak forests. The differences in the ratios among the three forest types were more significant in surface soil than in deep soil. Precipitation was positively correlated with the concentrations of SOC and TN and the ratios of C:N:P. Temperature was negatively correlated with concentrations of SOC and TN and the ratios of C:N:P across all soil depths. A log-transformed linear C-N relationship was found for all three forest types, suggesting a well-constrained coupling between the levels of the two elements.
Our results demonstrated the effect of different tree species on soil C:N:P ratios and their controlling factors within soil profiles along environmental gradients. The secondary oak forest accumulated soil C and N more effectively than the plantations. The Chinese pine plantations were relatively more susceptible to P limitation. Therefore, the mechanism of different plant species on soil biogeochemical processes at the whole soil profile level must be considered when developing forest management strategies and implementing vegetation restoration projects.
KeywordsForest types Northwest China Soil nutrient status Spatial variability Vertical distribution
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Batjes NH (1996) Total carbon and nitrogen in the soils of the world. Eur J Soil Sci 47(2):151–163. https://doi.org/10.1111/j.1365-2389.1996.tb01386.x CrossRefGoogle Scholar
- Bing HJ, Wu YH, Zhou J, Sun HY, Luo J, Wang JP, Yu D (2016) Stoichiometric variation of carbon, nitrogen, and phosphorus in soils and its implication for nutrient limitation in alpine ecosystem of eastern Tibetan Plateau. J Soils Sediments 16(2):405–416. https://doi.org/10.1007/s11368-015-1200-9 CrossRefGoogle Scholar
- Bremner J, Mulvaney C (1982) Nitrogen-total, methods of soil analysis. Part 2. Chemical and microbiological properties, p 595–624Google Scholar
- Dawud SM, Raulund-Rasmussen K, Ratcliffe S, Domisch T, Finer L, Joly FX, Hattenschwiler S, Vesterdal L (2017) Tree species functional group is a more important driver of soil properties than tree species diversity across major European forest types. Funct Ecol 31(5):1153–1162. https://doi.org/10.1111/1365-2435.12821 CrossRefGoogle Scholar
- Epstein HE, Burke IC, Lauenroth WK (2002) Regional patterns of decomposition and primary production rates in the US Great Plains. Ecology 83:320–327Google Scholar
- Eswaran H, Vandenberg E, Reich P (1993) Organic-carbon in soils of the world. Soil Sci Soc Am J 57(1):192–194. https://doi.org/10.2136/sssaj1993.03615995005700010034x CrossRefGoogle Scholar
- Jobbagy EG, Jackson RB (2000) The vertical distribution of soil organic carbon and its relation to climate and vegetation. Ecol Appl 10(2):423–436. https://doi.org/10.1890/1051-0761(2000)010[0423:TVDOSO]2.0.CO;2 CrossRefGoogle Scholar
- Lemenih M, Olsson M, Karltun E (2004) Comparison of soil attributes under Cupressus lusitanica and Eucalyptus saligna established on abandoned farmlands with continuously cropped farmlands and natural forest in Ethiopia. For Ecol Manag 195(1-2):57–67. https://doi.org/10.1016/j.foreco.2004.02.055 CrossRefGoogle Scholar
- Li ZQ, Yang L, Lu W, Guo W, Gong XS, Xu J, Yu D (2015) Spatial patterns of leaf carbon, nitrogen stoichiometry and stable carbon isotope composition of Ranunculus natans CA Mey. (Ranunculaceae) in the arid zone of northwest China. Ecol Eng 77:9–17. https://doi.org/10.1016/j.ecoleng.2015.01.010 CrossRefGoogle Scholar
- Macedo MO, Resende AS, Garcia PC, Boddey RM, Jantalia CP, Urquiaga S, Campello EFC, Franco AA (2008) Changes in soil C and N stocks and nutrient dynamics 13 years after recovery of degraded land using leguminous nitrogen-fixing trees. For Ecol Manag 255(5-6):1516–1524. https://doi.org/10.1016/j.foreco.2007.11.007 CrossRefGoogle Scholar
- Nelson DW, Sommers LE, Sparks D, Page A, Helmke P, Loeppert R, Soltanpour P, Tabatabai M, Johnston C, Sumner M (1996) Total carbon, organic carbon, and organic matter. Methods of soil analysis. Part 3—chemical methods, p 961–1010Google Scholar
- Rice SK, Westerman B, Federici R (2004) Impacts of the exotic, nitrogen-fixing black locust (Robinia pseudoacacia) on nitrogen-cycling in a pine-oak ecosystem. Plant Ecol 174(1):97–107. https://doi.org/10.1023/B:VEGE.0000046049.21900.5a CrossRefGoogle Scholar
- Shan C, Liang Z, Hao W (2002) Review on growth of locust and soil water in Loess Plateau. Acta Botan Boreali-Occiden Sin 23:1341–1346Google Scholar
- Tateno R, Tokuchi N, Yamanaka N, Du S, Otsuki K, Shimamura T, Xue Z, Wang S, Hou Q (2007) Comparison of litterfall production and leaf litter decomposition between an exotic black locust plantation and an indigenous oak forest near Yan’an on the Loess Plateau, China. For Ecol Manag 241(1-3):84–90. https://doi.org/10.1016/j.foreco.2006.12.026 CrossRefGoogle Scholar
- Wang FM, Li ZA, Xia HP, Zou B, Li NY, Liu J, Zhu WX (2010) Effects of nitrogen-fixing and non-nitrogen-fixing tree species on soil properties and nitrogen transformation during forest restoration in southern China. Soil Sci Plant Nutr 56(2):297–306. https://doi.org/10.1111/j.1747-0765.2010.00454.x CrossRefGoogle Scholar
- Wiesmeier M, Sporlein P, Geuss U, Hangen E, Haug S, Reischl A, Schilling B, von Lutzow M, Kogel-Knabner I (2012) Soil organic carbon stocks in southeast Germany (Bavaria) as affected by land use, soil type and sampling depth. Glob Chang Biol 18(7):2233–2245. https://doi.org/10.1111/j.1365-2486.2012.02699.x CrossRefGoogle Scholar
- Wu HB, Guo ZT, Peng CH (2003) Distribution and storage of soil organic carbon in China. Glob Biogeochem Cycle 17:67–80Google Scholar