Evolution of soil microbial biomass in restoration process of plantations in an eroded environment

Abstract

Vegetation recovery is a key measure to improve ecosystems in the Loess Plateau in China. To understand the evolution of soil microorganisms in forest plantations in the hilly areas of the Loess Plateau, the soil microbial biomass, microbial respiration and physical and chemical properties of the soil of Robinia pseudoacacia plantations were studied. In this study, eight forest soils of different age classes were used to study the evolution of soil microbial biomass, while a farmland and a native forest community of Platycladus orientalis L. were chosen as controls. By measuring soil microbial biomass, metabolic quotient, and physical and chemical properties, it can be concluded that soil quality was improved steadily after planting. Soil microbial biomass of C, N and P (SMBC, SMBN and SMBP) increased significantly after 10 to 15 years of afforestation and vegetation recovery. A relatively stable state of soil microbial biomass was maintained in near-mature or mature plantations. There was an increase of soil microbial biomass appearing at the end of the mature stage. After 50 years of afforestation and vegetation recovery, compared with those in farmland, the soil microbial biomass of C, N and P increased by 213%, 201% and 83% respectively, but only accounting for 51%, 55% and 61% of the increase in P. orientalis forest. Microbial soil respiration was enhanced in the early stages, and then weakened in the later stage after restoration, which was different from the change of soil organic carbon. The metabolic quotient (qCO₂) was significantly higher in the soils of the P. orientalis forest than that in farmland at the early restoration stage and then decreased rapidly. After 25 years of afforestation and vegetation recovery, qCO₂ in soils of the R. pseudoacacia forest was lower than that in the farmland soil, and reached a minimum after 50 years, which was close to that of the P. orientalis forest. A significant relationship was found among soil microbial biomass, qCO₂ and physical and chemical properties and restoration duration. Therefore, we conclude that it is possible to artificially improve the ecological environment and soil quality in the hilly area of the Loess Plateau; a long time, even more than 100 years, is needed to reach the climax of the present natural forest.

References

1. Anderson T H Dormsch K H 1985 Maintenanceof carbon requirements of actively-metabolizing microbial populationsunder in situ conditionsSoil Biol Biochem17(2)197203. doi:10.1016/0038‐0717(85)90115‐4
2. Anderson T H Dormsch K H 1993 The metabolicquotient for CO₂ (qCO₂) as a specific activity parameter to assessthe effects of environmental conditions, such as pH, on the microbialbiomass of forest soilsSoil Biol Biochem25(3)393395. doi:10.1016/0038‐0717(93)90140‐7
3. Andrews J H Harris F 1986 r- and k-selection and microbial ecologyAdv MicrobEcol999147
4. Bauhus J Paré D Côté L 1998 Effects of tree speciesstand age and soil type on soil microbial biomass and its activityin a southern boreal forestSoil Biol Biochem3010771089. doi:10.1016/S0038‐0717(97)00213‐7
5. Brookes P C Andera L Jenkinson D S 1985 Chloroform fumigation and the releaseof soil nitrogen: A rapid direct extraction method to measure microbialbiomass nitrogen in soilSoil Biol Biochem17(6)837842. doi:10.1016/0038‐0717(85)90144‐0
6. Brookes P C 1995 The use of microbial parameters in monitoring soil pollutionby heavy metalsBiol Fert Soil19269279. doi:10.1007/BF00336094
7. Campbell B M Frost P King J A Mawanza M Mhlanga L 1994 The influence of treeson soil fertility on two contrasting semi arid types at Matopos, ZimbabweAgrofor Syst28(2)159172. doi:10.1007/BF00704827
8. Chen G C He Z L 1998 Study on differentland used patterns on red soil microbial biomassChin J Soil Sci29(6)276278 (in Chinese)
9. Garcia C Hernanderz T Roldan A Martin A 2002 Effect of plant cover decline on chemical and microbiological parametersunder Mediterranean climateSoil Biol Biochem34(5)635642. doi:10.1016/S0038‐0717(01)00225‐5
10. Gong J Chen L D Fu B J Hu C X Wei W 2005 Effects of vegetation restoration on soilnutrient in a small catchment in hilly Loess AreaJ Soil Water Conserv19(1)9396 (in Chinese)
11. Liu G B 1999 Soil conservation and sustainable agriculture on LoessPlateau: challenge and prospectiveAMBIO28(8)663668
12. Harris J A 2003 Measurements of the soil microbial community for estimatingthe success of restorationEur J Soil Sci54801808. doi:10.1046/j.1351‐0754.2003.0559.x
13. He Z L 1994 Method for measuring soil microbial biomass: present andfutureProg Soil Sci22(4)3644 (in Chinese)
14. Horwath W R Paul P A 1994 Soil biomassIn: Weaver R WMethods of Soil Analysis, Part 2. Chemical and Microbiological Methods.Agronomy Monograph No.9, 2nd edMadison WlAmerican Society ofAgronomy753761
15. Huang C Y Li B G Pan G X Xu J M Wang Q Y 2000 PedologyBeijingChina Agricultural Press5064 (in Chinese)
16. Jenkinson D S Ladd J N 1981 Microbialbiomass in soil: measurement and turnoverIn: Paul E ALadd J NSoil BiochemistryVol 5New YorkDekker414472
17. Jenkison D S 1987 An extraction method for measuring soil microbial biomassCSoil Biol Biochem19703707. doi:10.1016/0038‐0717(87)90052‐6
18. Jia G M Cao J Wang C Y Wang G 2005 Microbial biomass and nutrients in soil at the different stages ofsecondary forest succession in Ziwulin, northwest ChinaFor Ecol Manage217(1)117125. doi:10.1016/j.foreco.2005.05.055
19. Jiao F Wen Z M Jiao J Y Li R 2005 Heterogeneity of soil nutrients of cropland returning to forest onthe loess hilly regionPlant Nutr Fert Sci11(6)724730 (in Chinese)
20. Lamb D 1998 Large-scale ecological restoration of degraded tropicalforest lands: The potential role of timber plantationsRestor Ecol6271279. doi:10.1046/j.1526‐100X.1998.00632.x
21. Landgraf D 2001 Dynamics of microbial biomass in Cambisols under a 3 yearsuccession fallow in North Eastern SaxonyPlant Nutr Soil Sci164665671. doi:10.1002/1522‐2624(200112)164:6<665::AID‐JPLN665>3.0.CO;2‐N
22. Lu R K 1999 Analytical Methods for Soil and Agricultural ChemistryBeijingChinaAgricultural Science and Technology Press13169 (in Chinese)
23. Odum E 1985 Trends expected in stressed ecosystemsBioscience35419422. doi:10.2307/1310021
24. Paul E A Voroney R P 1980 Nutrient andEnergy Flow Through Soil Microbial BiomassIn: Ellwood D CHedger J NLutham M JContemporaryMicrobial EcologyLondonAcademic Press215237
25. Powlson D S Brookes P C Christensen B T 1987 Measurement of soil microbial biomassprovides an early indication of changes in total soil organic matterdue to straw incorporationSoil Biol Biochem19159164. doi:10.1016/0038‐0717(87)90076‐9
26. Rogers B F Tate R L 2001 Temporal analysisof the soil microbial community along a toposequence in Pineland soilsSoil Biol Biochem3313891401. doi:10.1016/S0038‐0717(01)00044‐X
27. Ross D J 1990 Estimation of soil microbial C by a fumigation extractionmethod: influence of seasons, soils and calibration with the fumigation-incubationprocedureSoil Biol Biochem22295300. doi:10.1016/0038‐0717(90)90103‐7
28. Rutigliano F A Ascoli R D De Santo A V 2004 Soil microbial metabolism and nutrientstatus in a Mediterranean area as affected by plant coverSoil Biol Biochem3617191729. doi:10.1016/j.soilbio.2004.04.029
29. Shi Y X Tang K L 1996 Soil nutrientdegradation under influence of forest land accelerated erosionJ Soil Eros Soil Water Conserv2(4)2633 (in Chinese)
30. Sparling G P Ross D J 1993 Biochemicalmethods to estimate soil microbial biomass: current developments andapplicationsIn: Mulongoy KMerckx RSoil OrganicMatter Dynamics and Sustainability of Tropical AgricultureLeuven, BelgiumWiley-Sayce1721
31. Sparling J P 1981 Microcalorimetry and other methods to assess biomass andactivity in soilSoil Biol Biochem139398. doi:10.1016/0038‐0717(81)90002‐X
32. Srivastava S C Singh S T 1991 MicrobialC and P in dry tropical forest soils: effects of alternate land useand nutrient fluxSoil Biol Biochem23117124. doi:10.1016/0038‐0717(91)90122‐Z
33. Wang Y Shen Q R Shi R H 1996 Soil microbial biomass and its ecologicaleffectsJ Nanjing Agric Univ19(4)4551 (in Chinese)
34. Wardle D A 1998 Controls of temporal variability of the soil microbialbiomass: A global synthesisSoil Bio Biochem30(13)16271637. doi:10.1016/S0038‐0717(97)00201‐0
35. Xu G H Zheng H Y 1986 AnalyticalHandbook of Soil MicrobesBeijingChina Agricultural Press (inChinese)
36. Yang W D Wang Z Q Sui G P Chen B L Xu K 1999 Impact of soil erosion on soil fertilityand land productivityChin J Appl Ecol10(2)175178 (in Chinese)
37. Zeller V Bardgett R D Tappeiner U 2001 Site and management effects on soil microbialproperties of subalpine meadows: A study of land abandonment alonga north-south gradient in the European AlpsSoil Biol Biochem33639649. doi:10.1016/S0038‐0717(00)00208‐X
38. Zha X Huang S Y 2001 Study on soilerosion process and evolution of soil physicochemisty characteristicson sloping farmlandJ Mt Res19(2)109114 (in Chinese)
39. Zhang C E Liang Y L He X B 2002 Effects of plastic cover cultivation onSoil microbial biomassActa Ecol Sin22(4)508512 (in Chinese)