國際森林土壤研討會課件Zhang Jing-SCBGCAS

1、Whether mycorrhizae promoted soil organic carbon is controversial.Plants allocated a considerable photosynthate to AMAM turnover fast (5-7 days )3Physical protectionBSAGRSPCarboxyl CAromatic CSchindler et al. 2007; Soil Biology & biochemistry Lovelock et al. 2004; Journal of EcologyHypothesis:Ri

2、ch proportion of recalcitrant chemical structure of GRSP is important for SOC sequestration.4Study siteSuccessional seriesPFMFMEBFPF: the young forest, pine forestMF: secondary forest, mixed pine and monsoon evergreen broadleaved forestMEBF: primary forest, monsoon evergreen broadleaved forestLocate

3、d in Dinghushan Biosphere reserve (23o10N, 112o32E) in southern China5The monsoon evergreen broadleaved forest accumulated soil organic carbon at the rate of 61 g m-2 year-1 T h e m o n s o o n e v e r g r e e n broadleaved forest accumulated soil organic carbon resulted from the accumulated of non-

4、readily oxidizable organic carbon (NROC).Zhou et al. 2006; ScienceChen et al. 2021; Journal of Plant Ecology6Forest TypeEctomycorrhizal Plants (EM)Arbuscular mycorrhizal plants (AMF)SpeciesNumber/haDBH/cmHeight/m SpeciesNumber/haDBH/cmHeight/m PF338021.08.76.72.52130653.01.93.81.6MF668716.19.89.73.9

5、4122854.65.44.83.5MEBF1046110.715.37.85.95745973.24.14.22.7Primary forestPlanted forestT h e m o n s o o n e v e r g r e e n broadleaved forest (60%) allocated more carbon to belowgroud than the young forest (45%).Tang et al. 2021; Plant EcologyZheng et al. 2021; Ecology and Environmental SciencesAM

6、 is the dominant mycorrhizal type in subtropical forests; AMF plants in MEBF are higher than in MF and PF.7Scientific questions1.Does GRSP has a higher contribution to SOC in MEBF and MF than PF?2. Are the carbon functional group of GRSP and of SOC different among forests?3.Is recalcitrant C compone

7、nt ratio of GRSP higher than that of SOC? Net primary production ( N P P ) a l l o c a t e d t o mycorrhizal fungi correlated with relative belowground allocation in culture studies (n=37, r2=0.55， P0.001). Hobbie, 2006; ecology8MethodExtractionColorimetryCollectionCentrifugeDryDialysisElement Analy

8、sisNMR9ResultsContribution of GRSP to SOC in subtropical forestsMechanism of GRSP promote the recalcitrant SOC accumulation10ResultsSoil layer (cm)PFMFMEBFGRSP (mg g-1)0-103.330.47 c4.610.33 b5.300.61 a10-202.240.20 b3.020.40 a3.400.43 aC concentration of GRSP (%) 0-1019.50.88 a14.501.54 b15.471.29

9、b10-207.190.86 b9.150.27 a6.830.95 bSOC (mg g-1)0-1017.732.25 c27.283.65 b32.684.66 a10-206.861.19 c11.732.73 b14.191.52 aTable 1 Concentrations of GRSP and SOC in subtropical forests.IncreasedecreaseIncreasePart 1 Contribution of GRSP to SOC in subtropical forests11Figure 1 Relationship between GRS

10、P and SOC of subtropical forests. Part 1 Contribution of GRSP to SOC in subtropical forestsFigure 2 Contribution of microbial biomass C and GRSP-C to SOC. The error bar represented standard deviation (n=7). * or * indicated contribution of microbial C to SOC significantly different from contribution

11、 of GRSP-C to SOC at P=0.05 or P=0.01. Lowercases above bar meant GRSP-C/SOC or microbial biomass C/SOC significant difference among forests at P0.05 level.PFMFMEBF0-10 cm10-20 cm12Alkyl C0-50 ppmmethyl, long chain aliphatics, waxes, cutins, lipidsO-alkyl C50-110 ppmamino acid, carbohydrates, alcoho

12、ls, amino sugars and tannin componentAromatic C110-160 ppmlignin, olefinic C, Phenols, PolyphenolsCarboxyl C160-212 ppmcarboxylic acid (-COOH), amide and ester C, carbonyl C groups (C=O), organic acids, Recalcitrant index=(alkyl C+aromatic C)/(O-alkyl C+carboxyl C)Part 2 Mechanism of GRSP promote th

13、e recalcitrant SOC accumulationFigure 3 Functional group and the recalcitrant index of GRSP and SOC in subtropical forests. GRSP had a significant different chemical structure compared with SOC. The recalcitrant index of GRSP significant higher than that of SOC, which is very important for SOC seque

14、stration.PFMEBFMF14Part 2 Mechanism of GRSP promote the recalcitrant SOC accumulationFigure 4 Relationship between recalcitrant C in SOC and GRSP of three different forests. Recalcitrant C in GRSP displayed a significant positive linear correlation with recalcitrant C in SOC. Variation of recalcitrant C in GRSP explained 83% of soil recalcitrant C variations in the MEBF, 74% in the MF, and 9