| The purpose of this experiment was to elucidate the effects of different plants on soil water nutrient and soil enzyme activities in the forest of A.pedunculata.This study was conducted on the five herb-shrub soils which concluded the A.pedunculata.+Astragalus adsurgens(SC),A.pedunculata.+Melilotus suaveolens(CC),A.pedunculata.+Medicago sativa(MC),A.pedunculata.+Onobrychis viciaefolia(HC),A.pedunculata.+Coronilla varia +(XC)and chosen A.pedunculata.pure stand as a control group(CK)laid in the A.pedunculata.base of Weijiamao Village,Bulanghe Township,Yulin.Three shrub-shrub which concluded the A.pedunculata.+Amorpha fruticosa(ZSC),A.pedunculata.+ Artemisia desertorum(SHC),A.pedunculata.+ Sabina procumbens(PDC),and A.pedunculata.+ Pinus sylvestnis var.mongolica(ZZC)arbor-shrub of the forest of A.pedunculata.and wild A.pedunculata.pure stand as a control group(YCK)laid in the A.pedunculata.base of Balasu Town.Taking sampling analysis were used to determine the changes of soil moisture,physical properties and chemical properties with the type of composite configuration and soil depth from 0-60 cm in the forest of A.pedunculata and selected the eco-economic optimal configuration suitable mode A.pedunculata.The main conclusions as follows:(1)Different composite allocation patterns can significantly affect the soil moisture status of the forest of A.pedunculata.With the increase of soil depth,the soil water content has an increasing trend.As the seasons and rainfall change,the soil water content changes accordingly.The analysis of variance showed that the soil water content in the herb-shrub combined model was significantly different from that in the control.The average soil water content change was MC<CC<HC<SC<XC< CK.And the change trend of soil water content in shrub-shrub combined mode was YCK<ZSC <SHC<PDC,and the ZZC in the arbor-shrub complex mode increased by 13.17% compared with the control.The influence range of the water interface between MC and ZSC modes is narrowed and narrowed by moving water window method.It is suggested that the composite pattern of Medicago sativa + A.pedunculata.can be reduced to 60 cm.The spacing pattern of the Amorpha fruticosa + A.pedunculata.can be set at 90 cm.(2)Different herb-shrub composite configuration modes have certain adjustment effects on soil physical properties.Under the same conditions,the more developed the plant roots,the more obvious the effect of soil bulk density improvement.The soil bulk density of MC mode was 9.17% lower than that of the control,and the average porosity increased by 14.34%.The SC mode reduced cosmid 8.38%,powder 8.19%,and increased sand 16.55%.(3)In the composite configuration mode,the soil pH average is 8.71,which is slightly alkaline.The herb-shrub composite mode order of regulation ability was: MC>XC>SC>CC>HC>CK.The ZSC mode in the shrub-shrub compound had the best adjustment effect on soil pH,and the arbor-shrub composite ZZC mode increased by 3.27% compared with the control.According to the results of different composite allocation patterns on soil nutrients in the A.pedunculata.forest.The nitrogen content in the herb-shrub compound increased significantly.The total nitrogen and alkaline nitrogen solution increased by 1.24 and 0.48 times compared with the control.The available phosphorus and available potassium showed the same trend.The MC,CC and SC modes increased significantly.the organic matter content was MC>CC>SC>XC>HC>CK.In the shrub-shrub compound,the trend of organic matter change is ZSC>SHC>PDC>YCK.In the arbor-shrub complex mode,total nitrogen,alkali nitrogen,available phosphorus and available potassium increased by 0.77,0.27,0.87 and 0.34 times,respectively.(4)There were significant differences in soil enzyme activities in different soil layers.The invertase activities of SC,CC and MC in the herb-shrub combined model increased by 111.21%,75.76% and 34.82%,respectively.The trend of alkaline phosphatase and sucrase was consistent,and the order was MC>SC>CC>XC>CK>HC.The activities of soil catalase and urease were lower than those of the control;in the compound-distribution mode of arbor-shrub and shrub-shrub,the characteristics of the four soil enzyme activities were lower than the control,and the difference was significant.There was no significant improvement in soil enzyme activity in forest land.(5)The grass-shrub composite configuration mode has a certain promoting effect on the growth of A.pedunculata..The order is CC>SC>MC>XC>HC>CK.The best growth promotion effect is CC model.In the arbor-shrub and shrub-shrub combined configuration,the ZSC model grew better than the other composite models.The average growth rate of the crown was 93.27% higher than that of the control,and the new average was 21.88 cm,which was 28.87% higher than the control,and the leaf area control was 3.40% higher.I(6)Through the principal component analysis method,the comprehensive results show that the MC,SC and CC models have improved the ecological environment of the soil of the A.pedunculata.forest due to the mutually beneficial symbiotic relationship with Medicago sativa,Astragalus adsurgens,and Melilotus suaveolens.And its comprehensive score is ranked as MC(3.208)>SC(1.802)>CC(0.751).The shrub-shrub showed that ZSC and PDC model had the best effect on improving the soil ecological effects of the A.pedunculata.\ which was 5.562 points higher than the control.The score of the comprehensive analysis of the arbor-shrub ZZC mode composite model was 1.014,which was 5.221 points higher than the control.Therefore,in the subsidence area of Yulin Coal Mine,the herb-shrub composite model which include the Astragalus adsurgens + A.pedunculata.,Melilotus suaveolens + A.pedunculata.and Medicago sativa + A.pedunculata.,the shrub-shrub composite model the Amorpha fruticosa + A.pedunculata.and Sabina procumbens(Endl.)Iwata et + A.pedunculata.,and the Pinus sylvestnis var.mongolica + A.pedunculata.arbor-shrub composite model can be used to construct the A.pedunculata.vegetation ecological economic forest. |
PDF Full Text Request