Soil Aggregation and Organic Carbon Dynamics in Poplar Plantations
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Area and Sites
2.2. Sampling Design
2.3. Field Measurements and Sampling
2.4. Laboratory Analyses
2.4.1. Water-Stable Aggregates
2.4.2. SOC
2.4.3. Soil Microbial Biomass Carbon
2.4.4. Litterfall, Fine-Root Biomass, and SMBC
2.5. Statistical Analysis
3. Results
4. Discussion
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
- Amezketa, E. Soil aggregate stability: A review. J. Sustain. Agric. 1999, 14, 83–151. [Google Scholar] [CrossRef]
- Bronick, C.J.; Lal, R. Soil structure and management: A review. Geoderma 2005, 124, 3–22. [Google Scholar] [CrossRef]
- Plaza-Bonilla, D.; Cantero-Martínez, C.; Viñas, P.; Álvaro-Fuentes, J. Soil aggregation and organic carbon protection in a no-tillage chronosequence under Mediterranean conditions. Geoderma 2013, 193, 76–82. [Google Scholar] [CrossRef] [Green Version]
- Tisdall, J.; Oades, J.M. Organic matter and water-stable aggregates in soils. J. Soil Sci. 1982, 33, 141–163. [Google Scholar] [CrossRef]
- Spaccini, R.; Piccolo, A. Effects of field managements for soil organic matter stabilization on water-stable aggregate distribution and aggregate stability in three agricultural soils. J. Geochem. Explor. 2013, 129, 45–51. [Google Scholar] [CrossRef]
- Chai, Y.J.; Zeng, X.B.; E, S.Z.; Bai, L.Y.; Su, S.M.; Huang, T. Effects of freeze-thaw on aggregate stability and the organic carbon and nitrogen enrichment ratios in aggregate fractions. Soil Use Manag. 2014, 30, 507–516. [Google Scholar] [CrossRef]
- Chen, C.F.; Liu, W.J.; Jiang, X.J.; Wu, J.E. Effects of rubber-based agroforestry systems on soil aggregation and associated soil organic carbon: Implications for land use. Geoderma 2017, 299, 13–24. [Google Scholar] [CrossRef]
- Nzeyimana, I.; Hartemink, A.E.; Ritsema, C.; Stroosnijder, L.; Lwanga, E.H.; Geissen, V. Mulching as a strategy to improve soil properties and reduce soil erodibility in coffee farming systems of Rwanda. Catena 2017, 149, 43–51. [Google Scholar] [CrossRef]
- Wang, S.Q.; Li, T.X.; Zheng, Z.C. Distribution of microbial biomass and activity within soil aggregates as affected by tea plantation age. Catena 2017, 153, 1–8. [Google Scholar] [CrossRef]
- Zhong, X.L.; Li, J.T.; Li, X.J.; Ye, Y.C.; Liu, S.S.; Hallett, P.D.; Ogden, M.R.; Naveed, M. Physical protection by soil aggregates stabilizes soil organic carbon under simulated N deposition in a subtropical forest of China. Geoderma 2017, 285, 323–332. [Google Scholar] [CrossRef]
- Wu, H.; Guo, Z.; Peng, C. Land use induced changes of organic carbon storage in soils of China. Glob. Chang. Biol. 2003, 9, 305–315. [Google Scholar] [CrossRef]
- Meersmans, J.; De Ridder, F.; Canters, F.; De Baets, S.; Van Molle, M. A multiple regression approach to assess the spatial distribution of Soil Organic Carbon (SOC) at the regional scale (Flanders, Belgium). Geoderma 2008, 143, 1–13. [Google Scholar] [CrossRef]
- Hajabbasi, M.A.; Jalalian, A.; Karimzadeh, H.R. Deforestation effects on soil physical and chemical properties, Lordegan, Iran. Plant Soil 1997, 190, 301–308. [Google Scholar] [CrossRef]
- Zheng, F.L.; He, X.B.; Gao, X.T.; Zhang, C.E.; Tang, K.L. Effects of erosion patterns on nutrient loss following deforestation on the Loess Plateau of China. Agric. Ecosyst. Environ. 2005, 108, 85–97. [Google Scholar] [CrossRef]
- Karhu, K.; Wall, A.; Vanhala, P.; Liski, J.; Esala, M.; Regina, K. Effects of afforestation and deforestation on boreal soil carbon stocks—Comparison of measured C stocks with Yasso07 model results. Geoderma 2011, 164, 33–45. [Google Scholar] [CrossRef]
- Chen, H.Y.H.; Shrestha, B.M. Stand age, fire and clearcutting affect soil organic carbon and aggregation of mineral soils in boreal forests. Soil Biol. Biochem. 2012, 50, 149–157. [Google Scholar] [CrossRef]
- Murty, D.; Kirschbaum, M.U.F.; McMurtrie, R.E.; McGilvray, H. Does conversion of forest to agricultural land change soil carbon and nitrogen? A review of the literature. Glob. Chang. Biol. 2002, 8, 105–123. [Google Scholar] [CrossRef]
- Wei, X.; Li, X.; Jia, X.; Shao, M. Accumulation of soil organic carbon in aggregates after afforestation on abandoned farmland. Biol. Fertil. Soil 2013, 49, 637–646. [Google Scholar] [CrossRef]
- Blankinship, J.C.; Fonte, S.J.; Six, J.; Schimel, J.P. Plant versus microbial controls on soil aggregate stability in a seasonally dry ecosystem. Geoderma 2016, 272, 39–50. [Google Scholar] [CrossRef] [Green Version]
- Denef, K.; Six, J.; Bossuyt, H.; Frey, S.D.; Elliott, E.T.; Merckx, R.; Paustian, K. Influence of dry-wet cycles on the interrelationship between aggregate, particulate organic matter, and microbial community dynamics. Soil Biol. Biochem. 2001, 33, 1599–1611. [Google Scholar] [CrossRef]
- Garcia-Franco, N.; Albaladejo, J.; Almagro, M.; Martínez-Mena, M. Beneficial effects of reduced tillage and green manure on soil aggregation and stabilization of organic carbon in a Mediterranean agroecosystem. Soil Tillage Res. 2015, 153, 66–75. [Google Scholar] [CrossRef]
- Demenois, J.; Carriconde, F.; Bonaventure, P.; Maeght, J.L.; Stokes, A.; Rey, F. Impact of plant root functional traits and associated mycorrhizas on the aggregate stability of a tropical Ferralsol. Geoderma 2018, 312, 6–16. [Google Scholar] [CrossRef]
- Winsome, T.S.; Mccoll, J.G. Changes in chemistry and aggregation of a California forest soil worked by the earthworm Argilophilus papillifer eisen (megascolecidae). Soil Biol. Biochem. 1998, 30, 1677–1687. [Google Scholar] [CrossRef]
- Xiang, H.; Zhang, L.; Wen, D. Change of soil carbon fractions and water-stable aggregates in a forest ecosystem succession in South China. Forests 2015, 8, 2703–2718. [Google Scholar] [CrossRef]
- Zeglin, L.H.; Stursova, M.; Sinsabaugh, R.L.; Collins, S.L. Microbial responses to nitrogen addition in three contrasting grassland ecosystems. Oecologia 2007, 154, 349–359. [Google Scholar] [CrossRef] [PubMed]
- Bardgett, R.D.; Freeman, C.; Ostle, N.J. Microbial contributions to climate change through carbon cycle feedbacks. ISME J. 2008, 2, 805–814. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Zhou, Y.; Pei, Z.; Su, J.; Zhang, J.; Zheng, Y.; Ni, J.; Xiao, C.; Wang, R. Comparing soil organic carbon dynamics in perennial grasses and shrubs in a saline-alkaline arid region, northwestern China. PLoS ONE 2012, 7, e42927. [Google Scholar] [CrossRef] [PubMed]
- Lee, S.B.; Lee, C.H.; Jung, K.Y.; Park, K.D.; Lee, D.; Kim, P.J. Changes of soil organic carbon and its fractions in relation to soil physical properties in a long-term fertilized paddy. Soil Tillage Res. 2009, 104, 227–232. [Google Scholar] [CrossRef]
- Linsler, D.; Geisseler, D.; Loges, R.; Taube, F.; Ludwig, B. Temporal dynamics of soil organic matter composition and aggregate distribution in permanent grassland after a single tillage event in a temperate climate. Soil Tillage Res. 2013, 126, 90–99. [Google Scholar] [CrossRef]
- Six, J.; Elliott, E.; Paustian, K. Soil macroaggregate turnover and microaggregate formation: A mechanism for C sequestration under no-tillage agriculture. Soil Biol. Biochem. 2000, 32, 2099–2103. [Google Scholar] [CrossRef]
- Ussiri, D.; Lal, R.; Jacinthe, P. Soil properties and carbon sequestration of afforested pastures in reclaimed minesoils of Ohio. Soil Sci. Soc. Am. J. 2006, 70, 1797–1806. [Google Scholar] [CrossRef]
- Asaye, Z.; Zewdie, S. Fine root dynamics and soil carbon accretion under thinned and un-thinned Cupressus lusitanica stands in, Southern Ethiopia. Plant Soil 2013, 366, 261–271. [Google Scholar] [CrossRef]
- Lehmann, A.; Rillig, M.C. Are there temporal trends in root architecture and soil aggregation for Hordeum vulgare breeding lines? Appl. Soil Ecol. 2013, 65, 31–34. [Google Scholar] [CrossRef]
- Yuan, Z.Y.; Chen, H.Y.H. Fine root biomass, production, turnover rates, and nutrient contents in boreal forest ecosystems in relation to species, climate, fertility, and stand age: Literature review and meta-analyses. Crit. Rev. Plant Sci. 2010, 29, 204–221. [Google Scholar] [CrossRef]
- Brassard, B.W.; Chen, H.Y.H.; Cavard, X.; Laganière, J.; Reich, P.B.; Bergeron, Y.; Paré, D.; Yuan, Z.; Chen, H. Tree species diversity increases fine root productivity through increased soil volume filling. J. Ecol. 2013, 101, 210–219. [Google Scholar] [CrossRef]
- Barbhuiya, A.; Arunachalam, A.; Pandey, H.; Khan, M.; Arunachalam, K. Fine root dynamics in undisturbed and disturbed stands of a tropical wet evergreen forest in northeast India. Trop. Ecol. 2012, 53, 69–79. [Google Scholar]
- Miller, R.; Jastrow, J. Hierarchy of root and mycorrhizal fungal interactions with soil aggregation. Soil Biol. Biochem. 1990, 22, 579–584. [Google Scholar] [CrossRef]
- Ruiz-Peinado, R.; Bravo-Oviedo, A.; López-Senespleda, E.; Montero, G.; Río, M. Do thinnings influence biomass and soil carbon stocks in Mediterranean maritime pinewoods? Eur. J. For. Res. 2012, 132, 253–262. [Google Scholar] [CrossRef]
- Liang, W.; Hu, H.; Liu, F.; Zhang, D. Research advance of biomass and carbon storage of poplar in China. J. For. Res. 2006, 17, 75–79. [Google Scholar] [CrossRef]
- Li, Y.; Su, X.; Zhang, B.; Huang, Q.; Zhang, X.; Huang, R. Expression of jasmonic ethylene responsive factor gene in transgenic poplar tree leads to increased salt tolerance. Tree Physiol. 2009, 29, 273–279. [Google Scholar] [CrossRef] [PubMed]
- Qiu, S.; Ju, X. Effect of unrestricted nitrogen and irrigation application on soil carbon and nitrogen pools in greenhouse vegetable systems. Better Crops Plant Food 2010, 94, 29–31. [Google Scholar]
- National Meteorological Information Center. Annual Data Sets of Meteorological Observation in China. Available online: http://data.cma.cn/ (accessed on 4 May 2010).
- Johnson, E.A.; Miyanishi, K. Testing the assumptions of chronosequences in succession. Ecol. Lett. 2008, 11, 419–431. [Google Scholar] [CrossRef] [PubMed]
- Walker, L.R.; Wardle, D.A.; Bardgett, R.D.; Clarkson, B.D. The use of chronosequences in studies of ecological succession and soil development. J. Ecol. 2010, 98, 725–736. [Google Scholar] [CrossRef] [Green Version]
- Cavard, X.; Bergeron, Y.; Chen, H.Y.H.; Pare, D.; Laganiere, J.; Brassard, B. Competition and facilitation between tree species change with stand development. Oikos 2011, 120, 1683–1695. [Google Scholar] [CrossRef]
- Gee, G.W.; Bauder, J.W. Particle-Size Analysis—1; Soil Science Society of America, American Society of Agronomy: Madison, WI, USA, 1986; pp. 383–411. [Google Scholar]
- Jennings, S.B.; Brown, N.D.; Sheil, D. Assessing forest canopies and understorey illumination: Canopy closure, canopy cover and other measures. Forests 1999, 72, 59–74. [Google Scholar] [CrossRef]
- Franzluebbers, A.; Arshad, M. Soil microbial biomass and mineralizable carbon of water-stable aggregates. Soil Sci. Soc. Am. J. 1997, 61, 1090–1097. [Google Scholar]
- Su, Y.; Wang, F.; Suo, D.; Zhang, Z.; Du, M. Long-term effect of fertilizer and manure application on soil-carbon sequestration and soil fertility under the wheat–wheat–maize cropping system in northwest China. Nutr. Cycl. Agroecosyst. 2006, 75, 285–295. [Google Scholar] [CrossRef]
- Adesodun, J.; Adeyemi, E.; Oyegoke, C. Distribution of nutrient elements within water-stable aggregates of two tropical agro-ecological soils under different land uses. Soil Tillage Res. 2007, 92, 190–197. [Google Scholar] [CrossRef]
- Chen, G.S.; Yang, Z.J.; Gao, R.; Xie, J.S.; Guo, J.F.; Huang, Z.Q.; Yang, Y.S. Carbon storage in a chronosequence of Chinese fir plantations in southern China. For. Ecol. Manag. 2013, 300, 68–76. [Google Scholar] [CrossRef]
- Marin, S.; Andrea, L.E.; Ramona, S.L. Assessment of metals bioavailability to vegetables under field conditions using DGT, single extractions and multivariate statistics. Chem. Cent. J. 2012, 6, 119. [Google Scholar] [Green Version]
- Vance, E.; Brookes, P.; Jenkinson, D. An extraction method for measuring soil microbial biomass C. Soil Biol. Biochem. 1987, 19, 703–707. [Google Scholar] [CrossRef]
- Yuan, Z.Y.; Chen, H.Y.H.; Ostle, N. Fine root dynamics with stand development in the boreal forest. Funct. Ecol. 2012, 26, 991–998. [Google Scholar] [CrossRef] [Green Version]
- Beyer, F.; Hertel, D.; Jung, K.; Fender, A.C.; Leuschner, C. Competition effects on fine root survival of Fagus sylvatica and Fraxinus excelsior. For. Ecol. Manag. 2013, 302, 14–22. [Google Scholar] [CrossRef]
- Canty, A.; Ripley, B. Package ‘Boot’. Available online: http://cran.r-project.org/web/packages/boot/index.html (accessed on 1 March 2017).
- Bates, D.; Bolker, B.; Walker, S.; Christensen, R.H.B.; Singmann, H.; Dai, B.; Grothendieck, G. Lme4: Linear mixed-effects models using Eigen and S4. R Package Version 2017, 1, 1–13. [Google Scholar]
- Moritz, S.; Cule, E. Package ‘Ridge’: Ridge Regression with Automatic Selection of the Penalty Parameter. Available online: http://github.com/SteffenMoritz/ridge (accessed on 25 March 2017).
- R Development Core Team. R: A Language and Environment for Statistical Computing, Version 3.3.1; R Foundation for Statistical Computing: Vienna, Austria, 2016. [Google Scholar]
- Qiu, L.; Wei, X.; Gao, J.; Zhang, X. Dynamics of soil aggregate-associated organic carbon along an afforestation chronosequence. Plant Soil 2015, 391, 237–251. [Google Scholar] [CrossRef]
- Jackson, R.B.; Lajtha, K.; Crow, S.E.; Hugelius, G.; Kramer, M.G.; Piñeiro, G. The Ecology of Soil Carbon: Pools, Vulnerabilities, and Biotic and Abiotic Controls. Annu. Rev. Ecol. Evolut. Syst. 2017, 48, 419–445. [Google Scholar] [CrossRef] [Green Version]
- Olupot, G.; Daniel, H.; Lockwood, P.; Mchenry, M.; Mcleod, M.; Gilkes, R.J.; Prakongkep, N. Root contributions to long-term storage of soil organic carbon: Theories, mechanisms and gaps. In Proceedings of the 19th World Congress of Soil Science: Soil Solutions for a Changing World, Brisbane, Australia, 1–6 August 2010; pp. 112–115. [Google Scholar]
- Garcia-Franco, N.; Wiesmeier, M.; Goberna, M.; Martínez-Mena, M.; Albaladejo, J. Carbon dynamics after afforestation of semiarid shrublands: Implications of site preparation techniques. For. Ecol. Manag. 2014, 319, 107–115. [Google Scholar] [CrossRef]
- Querejeta, J.I.; Roldan, A.; Albaladejo, J.; Castillo, V. The role of mycorrhizae, site preparation, and organic amendment in the afforestation of a semi-arid Mediterranean site with Pinus halepensis. For. Sci. 1998, 44, 203–211. [Google Scholar]
- Jastrow, J. Soil aggregate formation and the accrual of particulate and mineral-associated organic matter. Soil Biol. Biochem. 1996, 28, 665–676. [Google Scholar] [CrossRef]
- Helfrich, M.; Ludwig, B.; Thoms, C.; Gleixner, G.; Flessa, H. The role of soil fungi and bacteria in plant litter decomposition and macroaggregate formation determined using phospholipid fatty acids. Appl. Soil Ecol. 2015, 96, 261–264. [Google Scholar] [CrossRef]
- Gupta, V.V.S.R.; Germida, J.J. Soil aggregation: Influence on microbial biomass and implications for biological processes. Soil Biol. Biochem. 2015, 80, A3–A9. [Google Scholar] [CrossRef]
- McNally, S.R.; Laughlin, D.C.; Rutledge, S.; Dodd, M.B.; Six, J.; Schipper, L.A. Root carbon inputs under moderately diverse sward and conventional ryegrass-clover pasture: Implications for soil carbon sequestration. Plant Soil 2015, 392, 289–299. [Google Scholar] [CrossRef]
- Mardhiah, U.; Caruso, T.; Gurnell, A.; Rillig, M.C. Just a matter of time: Fungi and roots significantly and rapidly aggregate soil over four decades along the Tagliamento River, NE Italy. Soil Biol. Biochem. 2014, 75, 133–142. [Google Scholar] [CrossRef]
- Imhoff, M.L.; Bounoua, L.; Ricketts, T.; Loucks, C.; Harriss, R.; Lawrence, W.T. Global patterns in human consumption of net primary production. Nature 2004, 429, 870–873. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Six, J.; Callewaert, P.; Lenders, S.; De Gryze, S.; Morris, S.; Gregorich, E.; Paul, E.; Paustian, K. Measuring and understanding carbon storage in afforested soils by physical fractionation. Soil Sci. Soc. Am. J. 2002, 66, 1981–1987. [Google Scholar] [CrossRef]
- Makkonen, K.; Helmisaari, H.S. Fine root biomass and production in Scots pine stands in relation to stand age. Tree Physiol. 2001, 21, 193–198. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Chen, L.; Mu, X.; Yuan, Z.; Deng, Q.; Chen, Y.; Yuan, L.Y.; Ryan, L.T.; Kallenbach, R.L. Soil nutrients and water affect the age-related fine root biomass but not production in two plantation forests on the Loess Plateau, China. J. Arid Environ. 2016, 135, 173–180. [Google Scholar] [CrossRef]
- Deng, Q.; Cheng, X.; Hui, D.; Zhang, Q.; Li, M.; Zhang, Q. Soil microbial community and its interaction with soil carbon and nitrogen dynamics following afforestation in central China. Sci. Total Environ. 2016, 541, 230–237. [Google Scholar] [CrossRef] [PubMed]
- Ma, Z.; Zhang, M.; Xiao, R.; Cui, Y.; Yu, F. Changes in soil microbial biomass and community composition in coastal wetlands affected by restoration projects in a Chinese delta. Geoderma 2017, 289, 124–134. [Google Scholar] [CrossRef]
- Gupta, V.V.S.R.; Germida, J.J. Distribution of microbial biomass and its activity in different soil aggregate size classes as affected by cultivation. Soil Biol. Biochem. 1988, 20, 777–786. [Google Scholar] [CrossRef]
- Mvan, G.; Merckx, R.; Vlassak, K. Spatial distribution of microbial biomass in microaggregates of a silty-loam soil and the relation with the resistance of microorganisms to soil drying. Soil Biol. Biochem. 1996, 28, 503–510. [Google Scholar]
- Handayani, I.P.; Coyne, M.S.; Tokosh, R.S. Soil organic matter fractions and aggregate distribution in response to tall fescue stands. Int. J. Soil Sci. 2010, 5, 1–10. [Google Scholar] [CrossRef]
- Manna, M.C.; Swarup, A.; Wanjari, R.H.; Singh, Y.V.; Ghosh, P.K.; Singh, K.N.; Tripathi, A.K.; Saha, M.N. Soil organic matter in a West Bengal Inceptisol after 30 years of multiple cropping and fertilization. Soil Sci. Soc. Am. J. 2006, 70, 121. [Google Scholar] [CrossRef]
- Six, J.; Paustian, K.; Elliott, E.T.; Combrink, C. Soil structure and organic matter. Soil Sci. Soc. Am. J. 2000, 64, 681–689. [Google Scholar] [CrossRef]
- Wang, Y.; Hu, N.; Ge, T.; Kuzyakov, Y.; Wang, Z.-L.; Li, Z.; Tang, Z.; Chen, Y.; Wu, C.; Lou, Y. Soil aggregation regulates distributions of carbon, microbial community and enzyme activities after 23-year manure amendment. Appl. Soil Ecol. 2017, 111, 65–72. [Google Scholar]
- Chen, X.; Li, Z.; Liu, M.; Jiang, C.; Che, Y. Microbial community and functional diversity associated with different aggregate fractions of a paddy soil fertilized with organic manure and/or NPK fertilizer for 20 years. J. Soils Sediment 2015, 15, 292–301. [Google Scholar] [CrossRef]
- Piao, H.C.; Liu, G.S.; Wu, Y.Y.; Xu, W.B. Relationships of soil microbial biomass carbon and organic carbon with environmental parameters in mountainous soils of southwest China. Biol. Fertil. Soil 2001, 33, 347–350. [Google Scholar] [CrossRef]
Age of Plantation (Years) | 5 | 9 | 16 |
---|---|---|---|
Height (m) | 18.1 ± 0.8 | 21.3 ± 1.7 | 23.6 ± 0.4 |
Diameter at breast height (cm) | 16.2 ± 0.5 | 23.1 ± 1.2 | 28.6 ± 1.7 |
Canopy closure (%) | 43.6 ± 4.8 | 53.6 ± 4.8 | 75.0 ± 4.1 |
Understory biomass (g/m2) | 101.0 ± 3.9 | 97.8 ± 2.3 | 98.7 ± 3.5 |
pH | 8.34 ± 0.15 | 8.25 ± 0.17 | 8.31 ± 0.13 |
C/N | 13.2 ± 0.16 | 13.5 ± 0.23 | 17.3 ± 0.20 |
Sand (g/kg) | 719.7 ± 17.2 | 719.0 ± 17.5 | 722.3 ± 23.5 |
Silt (g/kg) | 162.0 ± 12.8 | 153.0 ± 4.5 | 161.3 ± 6.3 |
Clay (g/kg) | 130.2 ± 0.8 | 119.8 ± 2.2 | 116.5 ± 1.7 |
Stand desity (stems/ha) | 625 | 313 | 305 |
Year of land reclamation | 1997 | 1993 | 1986 |
Year of plantation establishment | 2007 | 2003 | 1996 |
Attribute | Sum of Squares | df | f | p |
---|---|---|---|---|
Small aggregates | 1329.8 | 2, 6 | 17.61 | <0.001 |
Large aggregates | 374.4 | 2, 6 | 19.37 | <0.001 |
Total aggregates | 2962.2 | 2, 6 | 23.29 | <0.001 |
Mean weight diameter | 1.7 | 2, 6 | 23.92 | <0.001 |
Organic C content in bulk soil | 21.6 | 2, 6 | 26.12 | 0.001 |
Organic C content in fine aggregates | 191.5 | 2, 6 | 2.00 | 0.216 |
Organic C content in large aggregates | 841.6 | 2, 6 | 2.02 | 0.213 |
Attribute | n | Age | Date | Age × Date |
---|---|---|---|---|
Litterfall | 12 | 0.241 | ||
Fine-root biomass | 36 | <0.001 | <0.001 | 0.274 |
SMBC | 36 | <0.001 | <0.001 | <0.001 |
Predictor | Estimate | Scaled Estimate | Std. Error (Scaled) | t Value (Scaled) | Pr (>|t|) |
---|---|---|---|---|---|
Weighted percentage of fine aggregates | |||||
(Intercept) | 0.263 | ||||
Root | 3.628 | 2.582 | 2.806 | 0.920 | 0.357 |
SMBC | 29.631 | 14.485 | 2.820 | 5.136 | <0.001 |
Litterfall | −1.700 | −0.883 | 2.081 | 0.424 | 0.671 |
Weighted percentage of large aggregates | |||||
(Intercept) | 7.613 | ||||
Root | 5.088 | 3.622 | 1.753 | 2.066 | 0.039 |
SMBC | 8.269 | 4.042 | 1.753 | 2.306 | 0.021 |
Litterfall | −2.121 | −1.102 | 1.765 | 0.624 | 0.532 |
Organic C content in bulk soil | |||||
(Intercept) | 13.047 | ||||
Root | 5.319 | 3.786 | 0.797 | 4.751 | <0.001 |
SMBC | 0.559 | 0.273 | 0.800 | 0.341 | 0.733 |
Litterfall | −1.741 | −0.905 | 0.638 | 1.419 | 0.156 |
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Ge, Z.; Fang, S.; Chen, H.Y.H.; Zhu, R.; Peng, S.; Ruan, H. Soil Aggregation and Organic Carbon Dynamics in Poplar Plantations. Forests 2018, 9, 508. https://doi.org/10.3390/f9090508
Ge Z, Fang S, Chen HYH, Zhu R, Peng S, Ruan H. Soil Aggregation and Organic Carbon Dynamics in Poplar Plantations. Forests. 2018; 9(9):508. https://doi.org/10.3390/f9090508
Chicago/Turabian StyleGe, Zhiwei, Shuiyuan Fang, Han Y.H. Chen, Rongwei Zhu, Sili Peng, and Honghua Ruan. 2018. "Soil Aggregation and Organic Carbon Dynamics in Poplar Plantations" Forests 9, no. 9: 508. https://doi.org/10.3390/f9090508