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Journal of Arid Land  2024, Vol. 16 Issue (4): 567-579    DOI: 10.1007/s40333-024-0011-5     CSTR: 32276.14.s40333-024-0011-5
Research article     
Afforestation with an age-sequence of Mongolian pine plantation promotes soil microbial residue accumulation in the Horqin Sandy Land, China
GUO Jingwen1,2, SONG Xueshu1,2, WANG Xiao3, DU Zhangliu3, LU Sen1,2,*()
1State Key Laboratory of Efficient Production of Forest Resources, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
2Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
3College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
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Abstract  

Land use change affects the balance of organic carbon (C) reserves and the global C cycle. Microbial residues are essential constituents of stable soil organic C (SOC). However, it remains unclear how microbial residue changes over time following afforestation. In this study, 16-, 23-, 52-, and 62-year-old Mongolian pine stands and 16-year-old cropland were studied in the Horqin Sandy Land, China. We analyzed changes in SOC, amino sugar content, and microbial parameters to assess how microbial communities influence soil C transformation and preservation. The results showed that SOC storage increased with stand age in the early stage of afforestation but remained unchanged at about 1.27−1.29 kg/m2 after 52 a. Moreover, there were consistent increases in amino sugars and microbial residues with increasing stand age. As stand age increased from 16 to 62 a, soil pH decreased from 6.84 to 5.71, and the concentration of total amino sugars increased from 178.53 to 509.99 mg/kg. A significant negative correlation between soil pH and the concentration of specific and total amino sugars was observed, indicating that the effects of soil acidification promote amino sugar stabilization during afforestation. In contrast to the Mongolian pine plantation of the same age, the cropland accumulated more SOC and microbial residues because of fertilizer application. Across Mongolian pine plantation with different ages, there was no significant change in calculated contribution of bacterial or fungal residues to SOC, suggesting that fungi were consistently the dominant contributors to SOC with increasing time. Our results indicate that afforestation in the Horqin Sandy Land promotes efficient microbial growth and residue accumulation in SOC stocks and has a consistent positive impact on SOC persistence.



Key wordssoil organic matter      stand age      biomarker      amino sugars      microbial residues     
Received: 21 December 2023      Published: 30 April 2024
Corresponding Authors: *LU Sen (E-mail: asen205@cau.edu.cn)
Cite this article:

GUO Jingwen, SONG Xueshu, WANG Xiao, DU Zhangliu, LU Sen. Afforestation with an age-sequence of Mongolian pine plantation promotes soil microbial residue accumulation in the Horqin Sandy Land, China. Journal of Arid Land, 2024, 16(4): 567-579.

URL:

http://jal.xjegi.com/10.1007/s40333-024-0011-5     OR     http://jal.xjegi.com/Y2024/V16/I4/567

Age (a) Tree height (m) DBH (cm)
16 3.79±0.07 7.47±0.29
23 6.01±0.18 13.24±0.35
52 10.64±0.24 24.38±1.01
62 12.43±0.19 25.75±0.90
Table 1 Stand characteristics of Mongolian pine plantations with different ages
Land use BD (g/cm3) pH SOC concentration (g/kg) SOC storage (kg/m2)
CL16 1.51±0.02b 6.45±0.04b 4.75±0.39b 0.72±0.06bc
MP16 1.61±0.01a 6.84±0.04a 3.14±0.04c 0.50±0.01c
MP23 1.63±0.01a 6.76±0.04a 5.33±0.64b 0.86±0.11b
MP52 1.63±0.02a 5.85±0.11c 7.97±0.74a 1.29±0.12a
MP62 1.54±0.04b 5.71±0.12c 8.25±0.23a 1.27±0.04a
Table 2 Soil bulk density (BD), pH, soil organic carbon (SOC) concentration, and SOC storage at the 0-10 cm soil layer
Fig. 1 Concentrations of specific and total amino sugars under different land use patterns. (a), GluN (glucosamine); (b), GalN (galactosamine); (c), MurN (muramic acid); (d), total amino sugars. CL16 is the 16-year-old cropland; MP16, MP23, MP52, and MP62 are the 16-, 23-, 52-, and 62-year-old Mongolian pine plantations, respectively. Bars mean standard errors. Different lowercase letters represent significant differences among different land use patterns at P<0.050 level. The abbreviations are the same in the following figures.
Fig. 2 Microbial parameters under different land use patterns. (a), GluN/MurN (ratio of glucosamine to muramic acid); (b), GluN/GalN (ratio of glucosamine to galactosamine); (c), FRC/BRC (ratio of fungal residual C to bacterial residual C). Different lowercase letters represent significant differences among different land use patterns at P<0.050 level.
Fig. 3 Concentrations of microbial residual carbon (MRC) and their contributions to soil organic carbon (SOC) accumulation under different land use patterns. (a), BRC (bacterial residual carbon); (b), FRC (fungal residual carbon); (c), total MRC; (d), BRC/SOC; (e), FRC/SOC; (f), MRC/SOC. Different lowercase letters represent significant differences among different land use patterns at P<0.050 level.
Fig. 4 Correlations between soil pH and concentrations of specific and total amino sugars. (a), GluN (glucosamine); (b), GalN (galactosamine); (c), MurN (muramic acid); (d), total amino sugars.
[1]   Amelung W. 2001. Methods using amino sugars as markers for microbial residues in soil. Lewis Publishers Boca Raton, 100: 233-270.
[2]   Appuhn A, Joergensen R. 2006. Microbial colonisation of roots as a function of plant species. Soil Biology and Biochemistry, 38: 1040-1051.
doi: 10.1016/j.soilbio.2005.09.002
[3]   Bahram M, Hildebrand F, Forslund S K, et al. 2018. Structure and function of the global topsoil microbiome. Nature, 560: 233-237.
doi: 10.1038/s41586-018-0386-6
[4]   Baldock J A, Skjemstad J O. 2000. Role of the soil matrix and minerals in protecting natural organic materials against biological attack. Organic Geochemistry, 31(7-8): 697-710.
doi: 10.1016/S0146-6380(00)00049-8
[5]   Bailey V L, Smith J L, Bolton Jr H. 2002. Fungal-to-bacterial ratios in soils investigated for enhanced C sequestration. Soil Biology and Biochemistry, 34: 997-1007.
doi: 10.1016/S0038-0717(02)00033-0
[6]   Bárcena T G, Kiær L P, Vesterdal L, et al. 2014. Soil carbon stock change following afforestation in Northern Europe: A meta-analysis. Global Change Biology, 20: 2393-2405.
doi: 10.1111/gcb.12576 pmid: 24634314
[7]   Berthrong S T, Jobbágy E G, Jackson R B. 2009. A global meta-analysis of soil exchangeable cations, pH, carbon, and nitrogen with afforestation. Ecological Applications, 19: 2228-2241.
pmid: 20014590
[8]   Bouchoms S, Wang Z, Vanacker V, et al. 2017. Modelling long-term soil organic carbon dynamics under the impact of land cover change and soil redistribution. Catena, 151: 63-73.
doi: 10.1016/j.catena.2016.12.008
[9]   Campo J, Stijsiger R J, Nadal-Romero E, et al. 2019. The effects of land abandonment and long-term afforestation practices on the organic carbon stock and lignin content of Mediterranean humid mountain soils. European Journal of Soil Science, 70: 947-959.
doi: 10.1111/ejss.v70.5
[10]   Carvalho A L, Araújo-Neto R A, Lyra G B, et al. 2022. Impact of rainfed and irrigated agriculture systems on soil carbon stock under different climate scenarios in the semi-arid region of Brazil. Journal of Arid Land, 14(4): 359-373.
doi: 10.1007/s40333-022-0092-y
[11]   Chang X L, Lu C X, Gao Y B. 2003. Impact of human economic activities on wind and sand environment in Kerqin Sandy Land. Resources Science, 25: 78-83. (in Chinese)
[12]   Chapela I H, Osher L J, Horton T R, et al. 2001. Ectomycorrhizal fungi introduced with exotic pine plantations induce soil carbon depletion. Soil Biology and Biochemistry, 33: 1733-1740.
doi: 10.1016/S0038-0717(01)00098-0
[13]   Chen G, Ma S, Tian D, et al. 2020. Patterns and determinants of soil microbial residues from tropical to boreal forests. Soil Biology and Biochemistry, 151: 108059, doi: 10.1016/j.soilbio.2020.108059.
[14]   Cornwell W K, Cornelissen J H, Amatangelo K, et al. 2008. Plant species traits are the predominant control on litter decomposition rates within biomes worldwide. Ecology Letters, 11: 1065-1071.
doi: 10.1111/j.1461-0248.2008.01219.x pmid: 18627410
[15]   Cotrufo M F, Soong J L, Horton A J, et al. 2015. Formation of soil organic matter via biochemical and physical pathways of litter mass loss. Nature Geoscience, 8: 776-779.
doi: 10.1038/NGEO2520
[16]   Ding X, Zhang B, Wei Z, et al. 2020. Conversion of grassland into cropland affects microbial residue carbon retention in both surface and subsurface soils of a temperate agroecosystem. Biology and Fertility of Soils, 56: 137-143.
doi: 10.1007/s00374-019-01400-8
[17]   Engelking B, Flessa H, Joergensen R G. 2007. Shifts in amino sugar and ergosterol contents after addition of sucrose and cellulose to soil. Soil Biology and Biochemistry, 39: 2111-2118.
doi: 10.1016/j.soilbio.2007.03.020
[18]   Geiger P J, Hardy J P. 1971. Measurement of organic carbon in arid soils using hydrogen-flame ionization detector. Soil Science, 111: 175-181.
doi: 10.1097/00010694-197103000-00005
[19]   Glaser B, Turrión M B, Alef K. 2004. Amino sugars and muramic acid-biomarkers for soil microbial community structure analysis. Soil Biology and Biochemistry, 36: 399-407.
doi: 10.1016/j.soilbio.2003.10.013
[20]   Gougoulias C, Clark J M, Shaw L J. 2014. The role of soil microbes in the global carbon cycle: Tracking the below-ground microbial processing of plant-derived carbon for manipulating carbon dynamics in agricultural systems. Journal of the Science of Food and Agriculture, 94: 2362-2371.
doi: 10.1002/jsfa.6577 pmid: 24425529
[21]   Guggenberger G, Frey S D, Six J, et al. 1999. Bacterial and fungal cell-wall residues in conventional and no-tillage agroecosystems. Soil Science Society of America Journal, 63: 1188-1198.
doi: 10.2136/sssaj1999.6351188x
[22]   Hinsinger P, Plassard C, Tang C, et al. 2003. Origins of root-mediated pH changes in the rhizosphere and their responses to environmental constraints: A review. Plant and Soil, 248: 43-59.
doi: 10.1023/A:1022371130939
[23]   Hoover C M, Smith J E. 2023. Aboveground live tree carbon stock and change in forests of conterminous United States: Influence of stand age. Carbon Balance and Management, 18(1): 7, doi: 10.1186/s13021-023-00227-z.
pmid: 37062006
[24]   Hu Y, Zheng Q, Zhang S, et al. 2018. Significant release and microbial utilization of amino sugars and D-amino acid enantiomers from microbial cell wall decomposition in soils. Soil Biology and Biochemistry, 123: 115-125.
doi: 10.1016/j.soilbio.2018.04.024
[25]   Hu Y L, Zeng D H, Fan Z P, et al. 2008. Changes in ecosystem carbon stocks following grassland afforestation of semi-arid sandy soil in the southeastern Keerqin Sandy Lands, China. Journal of Arid Environments, 72: 2193-2200.
doi: 10.1016/j.jaridenv.2008.07.007
[26]   Jobbágy E G, Jackson R B. 2003. Patterns and mechanisms of soil acidification in the conversion of grasslands to forests. Biogeochemistry, 64: 205-229.
doi: 10.1023/A:1024985629259
[27]   Joergensen R G. 2018. Amino sugars as specific indices for fungal and bacterial residues in soil. Biology and Fertility of Soils, 54: 559-568.
doi: 10.1007/s00374-018-1288-3
[28]   Khan K S, Mack R, Castillo X, et al. 2016. Microbial biomass, fungal and bacterial residues, and their relationships to the soil organic matter C/N/P/S ratios. Geoderma, 271: 115-123.
doi: 10.1016/j.geoderma.2016.02.019
[29]   Kocyigit R, Demirci S. 2012. Long-term changes of aggregate-associated and labile soil organic carbon and nitrogen after conversion from forest to grassland and cropland in northern Turkey. Land Degradation & Development, 23: 475-482.
doi: 10.1002/ldr.v23.5
[30]   Lehmann J, Kleber M. 2015. The contentious nature of soil organic matter. Nature, 528: 60-68.
doi: 10.1038/nature16069
[31]   Lei Z, Yu D, Zhou F, Zhang Y, et al. 2019. Changes in soil organic carbon and its influencing factors in the growth of Pinus sylvestris var. mongolica plantation in Horqin Sandy Land, Northeast China. Scientific Reports, 9: 1-12.
doi: 10.1038/s41598-018-37186-2
[32]   Li T, Zhang J, Wang X, et al. 2022. Fungal necromass contributes more to soil organic carbon and more sensitive to land use intensity than bacterial necromass. Applied Soil Ecology, 176: 104492, doi: 10.1016/j.apsoil.2022.104492.
[33]   Liang C, Zhang X, Balser T C. 2007. Net microbial amino sugar accumulation process in soil as influenced by different plant material inputs. Biology and Fertility of Soils, 44: 1-7.
doi: 10.1007/s00374-007-0170-5
[34]   Liang C, Schimel J P, Jastrow J D. 2017. The importance of anabolism in microbial control over soil carbon storage. Nature Microbiology, 2: 17105, doi: 10.1038/nmicrobiol.2017.105.
pmid: 28741607
[35]   Liu X, He Y, Zhao X, et al. 2015. Characteristics of deep drainage and soil water in the mobile sandy lands of Inner Mongolia, northern China. Journal of Arid Land, 7: 238-250.
doi: 10.1007/s40333-014-0095-4
[36]   Liu Y Y, Wang A Y, An Y N, et al. 2018. Hydraulics play an important role in causing low growth rate and dieback of aging Pinus sylvestris var. mongolica trees in plantations of Northeast China. Plant, Cell & Environment, 41: 1500-1511.
[37]   Maillard F, Kennedy P G, Adamczyk B, et al. 2021. Root presence modifies the long-term decomposition dynamics of fungal necromass and the associated microbial communities in a boreal forest. Molecular Ecology, 30: 1921-1935.
doi: 10.1111/mec.15828 pmid: 33544953
[38]   Manna M C, Swarup A, Wanjari R H, et al. 2007. Long-term fertilization, manure and liming effects on soil organic matter and crop yields. Soil and Tillage Research, 94: 397-409.
doi: 10.1016/j.still.2006.08.013
[39]   McLean E O. 1983. Soil pH and lime requirement. In: PageA L, MillnerRH, KeeneyD R. 2 Chemical and Microbiological Properties. Methods of Soil Analysis:Part Madison: American Society of Agronomy, 199-224.
[40]   Miltner A, Bombach P, Schmidt-Brücken B, et al. 2012. SOM genesis: Microbial biomass as a significant source. Biogeochemistry, 111: 41-55.
doi: 10.1007/s10533-011-9658-z
[41]   Mondini C, Cayuela M L, Sanchez-Monedero M A, et al. 2006. Soil microbial biomass activation by trace amounts of readily available substrate. Biology and Fertility of Soils, 42: 542-549.
doi: 10.1007/s00374-005-0049-2
[42]   Mueller K E, Eissenstat D M, Hobbie S E, et al. 2012. Tree species effects on coupled cycles of carbon, nitrogen, and acidity in mineral soils at a common garden experiment. Biogeochemistry, 111: 601-614.
doi: 10.1007/s10533-011-9695-7
[43]   Murugan R, Loges R, Taube F, et al. 2014. Changes in soil microbial biomass and residual indices as ecological indicators of land use change in temperate permanent grassland. Microbial Ecology, 67: 907-918.
doi: 10.1007/s00248-014-0383-8 pmid: 24549746
[44]   Perron T, Mareschal L, Laclau J P, et al. 2021. Dynamics of biomass and nutrient accumulation in rubber (Hevea brasiliensis) plantations established on two soil types: Implications for nutrient management over the immature phase. Industrial Crops and Products, 159: 113084, doi: 10.1016/j.indcrop.2020.113084.
[45]   Poeplau C, Don A, Vesterdal L, et al. 2011. Temporal dynamics of soil organic carbon after land-use change in the temperate zone-carbon response functions as a model approach. Global Change Biology, 17: 2415-2427.
doi: 10.1111/j.1365-2486.2011.02408.x
[46]   Poeplau C, Don A. 2013. Sensitivity of soil organic carbon stocks and fractions to different land-use changes across Europe. Geoderma, 192: 189-201.
doi: 10.1016/j.geoderma.2012.08.003
[47]   Post W M, King A W, Wullschleger S D. 1996. Soil organic matter models and global estimates of soil organic carbon. In: PowlsonD S, SmithP, SmithJ U. Evaluation of Soil Organic Matter Models:Using Existing Long-Term Datasets. Heidelberg: Springer, 201-222.
[48]   Roberts P, Bol R, Jones D L. 2007. Free amino sugar reactions in soil in relation to soil carbon and nitrogen cycling. Soil Biology and Biochemistry, 39: 3081-3092.
doi: 10.1016/j.soilbio.2007.07.001
[49]   Rousk J, Brookes P C, Bååth E. 2009. Contrasting soil pH effects on fungal and bacterial growth suggest functional redundancy in carbon mineralization. Applied and Environmental Microbiology, 75: 1589-1596.
doi: 10.1128/AEM.02775-08 pmid: 19151179
[50]   Rytter R M. 2016. Afforestation of former agricultural land with Salicaceae species-Initial effects on soil organic carbon, mineral nutrients, C: N and pH. Forest Ecology and Management, 363: 21-30.
doi: 10.1016/j.foreco.2015.12.026
[51]   Sauer T J, James D E, Cambardella C A, et al. 2012. Soil properties following reforestation or afforestation of marginal cropland. Plant and Soil, 360: 375-390.
doi: 10.1007/s11104-012-1258-8
[52]   Schimel J, Balser T C, Wallenstein M. 2007. Microbial stress-response physiology and its implications for ecosystem function. Ecology, 88: 1386-1394.
doi: 10.1890/06-0219 pmid: 17601131
[53]   Shao P, Liang C, Lynch L, et al. 2019. Reforestation accelerates soil organic carbon accumulation: Evidence from microbial biomarkers. Soil Biology and Biochemistry, 131: 182-190.
doi: 10.1016/j.soilbio.2019.01.012
[54]   Simpson A J, Simpson M J, Smith E, et al. 2007. Microbially derived inputs to soil organic matter: Are current estimates too low? Environmental Science & Technology, 41: 8070-8076.
doi: 10.1021/es071217x
[55]   Sokol N W, Sanderman J, Bradford M A. 2019. Pathways of mineral-associated soil organic matter formation: Integrating the role of plant carbon source, chemistry, and point of entry. Global Change Biology, 25: 12-24.
doi: 10.1111/gcb.14482 pmid: 30338884
[56]   Soleimani A, Hosseini S M, Bavani A R M, et al. 2019. Influence of land use and land cover change on soil organic carbon and microbial activity in the forests of northern Iran. Catena, 177: 227-237.
doi: 10.1016/j.catena.2019.02.018
[57]   Solomon D, Fritzsche F, Tekalign M, et al. 2002. Soil organic matter composition in the subhumid Ethiopian highlands as influenced by deforestation and agricultural management. Soil Science Society of America Journal, 66: 68-82.
doi: 10.2136/sssaj2002.6800
[58]   Song L, Zhu J, Li M, et al. 2016a. Water use patterns of Pinus sylvestris var. mongolica trees of different ages in a semiarid sandy lands of Northeast China. Environmental and Experimental Botany, 129: 94-107.
doi: 10.1016/j.envexpbot.2016.02.006
[59]   Song L, Zhu J, Li M, et al. 2016b. Sources of water used by Pinus sylvestris var. mongolica trees based on stable isotope measurements in a semiarid sandy region of Northeast China. Agricultural Water Management, 164: 281-290.
doi: 10.1016/j.agwat.2015.10.018
[60]   Spohn M, Klaus K, Wanek W, et al. 2016. Microbial carbon use efficiency and biomass turnover times depending on soil depth-Implications for carbon cycling. Soil Biology and Biochemistry, 96: 74-81.
doi: 10.1016/j.soilbio.2016.01.016
[61]   Tew E R, Vanguelova E I, Sutherland W J. 2021. Alternative afforestation options on sandy heathland result in minimal long-term changes in mineral soil layers. Forest Ecology and Management, 483: 118906, doi: 10.1016/j.foreco.2020.118906.
[62]   Throckmorton H M, Bird J A, Dane L, et al. 2012. The source of microbial C has little impact on soil organic matter stabilisation in forest ecosystems. Ecology Letters, 15: 1257-1265.
doi: 10.1111/j.1461-0248.2012.01848.x pmid: 22897121
[63]   Usmani Z, Kumar V, Gupta P, et al. 2019. Enhanced soil fertility, plant growth promotion and microbial enzymatic activities of vermicomposted fly ash. Scientific Reports, 9: 10455, doi: 10.1038/s41598-019-46821-5.
[64]   Wang B, An S, Liang C, et al. 2021. Microbial necromass as the source of soil organic carbon in global ecosystems. Soil Biology and Biochemistry, 162: 108422, doi: 10.1016/j.soilbio.2021.108422.
[65]   Weedon J T, Kowalchuk G A, Aerts R, et al. 2012. Summer warming accelerates sub-arctic peatland nitrogen cycling without changing enzyme pools or microbial community structure. Global Change Biology, 18: 138-150.
doi: 10.1111/gcb.2011.18.issue-1
[66]   Wright I J, Reich P B, Cornelissen J H, et al. 2005. Modulation of leaf economic traits and trait relationships by climate. Global Ecology and Biogeography, 14: 411-421.
doi: 10.1111/geb.2005.14.issue-5
[67]   Zhang W, He H B, Xie H T, et al. 2010. Amino sugars mineralization and its responses to exogenous substances in black soil of Northeast China. Chinese Journal of Applied Ecology, 21(10): 2593-2598. (in Chinese)
pmid: 21328948
[68]   Zhang X, Amelung W. 1996. Gas chromatographic determination of muramic acid, glucosamine, mannosamine, and galactosamine in soils. Soil Biology and Biochemistry, 28: 1201-1206.
doi: 10.1016/0038-0717(96)00117-4
[69]   Zhang X, Zhang X, Han H, et al. 2019. Biomass accumulation and carbon sequestration in an age-sequence of Mongolian pine plantations in Horqin Sandy Land, China. Forests, 10(2): 197, doi: 10.3390/f10020197.
[70]   Zeng X, Zhang W, Cao J, et al. 2014. Changes in soil organic carbon, nitrogen, phosphorus, and bulk density after afforestation of the ''Beijing-Tianjin Sandstorm Source Control'' program in China. Catena, 118: 186-194.
doi: 10.1016/j.catena.2014.01.005
[71]   Zhu J J, Li F Q, Xu M L, et al. 2008. The role of ectomycorrhizal fungi in alleviating pine decline in semiarid sandy soil of northern China: An experimental approach. Annals of Forest Science, 65: 304, doi: 10.1051/forest:2008007.
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