Search Results (6)

Mixed plantations of Pinus sylvestris var. mongolica with native shrubs are widely established in semiarid sandy landscapes, yet soil microbial responses may differ among mixed-planting modes depending on the companion shrub species. We compared soil bacterial and fungal communities across three approximately 9-year-old mixed-planting modes in the Mu Us Sandy Land, where P. sylvestris var. mongolica was combined with Juniperus sabina (Ps–Js), Salix psammophila (Ps–Sp), or Corethrodendron fruticosum (Ps–Cf). Planting configuration was associated with shifts in soil physicochemical conditions. Bacterial α-diversity did not differ among modes, whereas fungal α-diversity was higher in Ps–Sp. Community composition diverged across modes for both domains, and LEfSe identified configuration-specific taxa. Null-model analyses showed that bacterial assembly was consistently dominated by stochastic components, whereas the relative contributions of fungal assembly processes varied among mixed-planting modes. Functional inference further suggested mode-associated differences in fungal trophic guild composition, with Ps–Cf showing significantly higher ectomycorrhizal abundance and Ps–Sp showing higher representation of saprotroph-associated guilds; by contrast, predicted bacterial functional profiles were broadly comparable among modes. Together, these results indicate that bacterial and fungal communities showed different response patterns among mixed-planting modes: bacterial communities showed compositional differentiation but little variation in α-diversity and consistently stochastic assembly, whereas fungal communities showed mode-related changes in α-diversity, the relative contributions of assembly processes, and trophic guild composition. These findings provide a microbial basis for considering shrub-species selection when designing P. sylvestris var. mongolica mixed plantations in semiarid sandy ecosystems. Full article

In ecological restoration of arid/semi-arid sandy lands, micro-topographic variations and artificial shrub arrangement synergistically drive vegetation recovery and soil quality improvement. As a typical fragile ecosystem in northern China, the Mu Us Sandy Land has long suffered wind erosion, desertification, soil infertility, and vegetation degradation, demanding precise vegetation configuration for ecological rehabilitation. This study analyzed soil nutrients, plant diversity, and their correlations under various micro-topographic conditions across different types of artificial shrub plantations in the Mu Us Sandy Land. Employing one-way and two-way ANOVA, we compared the significant differences in soil nutrients and plant diversity indices among different micro-topographic conditions and shrub species. Additionally, redundancy analysis (RDA) was conducted to explore the direct and indirect relationships between micro-topography, shrub species, soil nutrients, and plant diversity. The results show the following: 1. The interdune depressions have the highest plant diversity and optimal soil nutrients, with relatively suitable pH values; the windward slopes and slope tops, due to severe wind erosion, have poor soil nutrients, high pH values, and the lowest plant diversity. Both micro-topography and vegetation can significantly affect soil nutrients and plant diversity (p < 0.05), and vegetation has a greater impact on soil nutrients. 2. The correlation between surface soil nutrients and plant diversity is the strongest, and the correlation weakens with increasing soil depth; under different micro-topographic conditions, the influence of soil nutrients on plant diversity varies. 3. In sandy land ecological restoration, a “vegetation type + terrain matching” strategy should be implemented, combining the characteristics of micro-topography and the ecological functions of shrubs for precise configuration, such as planting Corethrodendron fruticosum on windward slopes and slope tops to rapidly replenish nutrients, promoting Salix psammophila and mixed plantation in interdune depressions and leeward slopes to accumulate organic matter, and prioritizing Amorpha fruticosa in areas requiring soil pH adjustment. This study provides a scientific basis and management insights for the ecological restoration and vegetation configuration of the Mu Us Sandy Land. Full article

Litter serves as a crucial source of soil nutrients in sandy land ecosystems. Soil enzyme activities and their stoichiometric ratios act as essential “bridges” linking microbial metabolism with nutrient cycling, thereby reflecting the availability of soil nutrients and the sensitivity to microbial substrate limitations. To investigate the effects of litter quality changes on soil nutrients, enzyme activities, and stoichiometric ratios in sandy land, leaf litter and surface soil were collected from four sand-fixing forests in the Mu Us Sandy Land, including YC (Corethrodendron fruticosum), NT (Caragana korshinskii), ZSH (Amorpha fruticose), and SL (Salix cheilophila). These samples were then used for indoor cultivation. Experiments with these four leaf litter types were carried out; one treatment with no litter added served as the control. Our aim was to systematically study the changing characteristics of enzyme activities related to soil carbon, nitrogen, and phosphorus with different litter inputs. The results indicate the following: (1) Compared to the control treatment with no litter added (CK), the addition of all four types of litter significantly increased soil organic carbon, total nitrogen, and alkaline nitrogen contents. The addition of NT and YC litter significantly increased dissolved organic carbon, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN). (2) The addition of the four types of litter had different effects on the soil enzyme activity, showing increasing trends overall. A chemical analysis of the enzyme activity revealed that the soil was limited in nitrogen and phosphorus. After the addition of the ZSH, NT, and YC litter, the enzymatic C/P acquisition ratio (E_C/P) and enzymatic N/P acquisition ratio (E_N/P) decreased significantly, alleviating the limitation of phosphorus. After the addition of the NT litter, the enzymatic C/N acquisition ratio (E_C/N) increased significantly, alleviating the limitation of soil nitrogen. (3) A correlation analysis showed that the soil nutrients had varying degrees of correlation with enzyme activity and their stoichiometric ratio. The redundancy analysis results show that MBN, TN, MBC/MBN, organic carbon, and available nitrogen were key factors influencing soil enzyme activity and stoichiometric ratios. These results provide a reference for nutrient cycling during sandy soil restoration, and they provide essential data support for the development of fragile ecosystem models in the context of global change. Full article

Revegetation in arid and semi-arid regions is a pivotal strategy for mitigating desertification and controlling soil erosion by enhancing carbon storage in woody biomass and mitigating wind-induced erosion. Despite its recognized importance, a critical gap remains in understanding how biomass carbon is distributed across different plant compartments (leaves, stems, litter, and roots) and how this distribution influences soil carbon dynamics. In this study, we examined carbon allocation between aboveground (shoot and litterfall) and belowground (coarse and fine roots) components, as well as the composition and vertical distribution of soil carbon in three 20-year-old shrub plantations—Salix psammophila, Corethrodendron fruticosum, and Artemisia desertorum—in northwest China. Total biomass and litter carbon storage were highest in the S. psammophila plantation (3689.29 g m⁻²), followed by C. fruticosum (1462.83 g m⁻²) and A. desertorum (761.61 g m⁻²). In contrast, soil carbon storage at a 1 m depth was greatest in A. desertorum (12,831.18 g m⁻²), followed by C. fruticosum (7349.24 g m⁻²) and S. psammophila (5375.80 g m⁻²). Notably, A. desertorum also exhibited the highest proportions of stable soil organic carbon (heavy-fraction) and soil inorganic carbon, while S. psammophila had the lowest. Across all plantations, belowground biomass carbon and light-fraction soil organic carbon displayed distinct vertical distributions, while heavy-fraction soil organic carbon and soil inorganic carbon did not show significant spatial patterns. A strong correlation was found between soil carbon fractions and microbial biomass carbon and nitrogen, suggesting that microbial communities were key drivers of soil carbon stabilization and turnover. These findings underscore the importance of litter composition, root traits, and microbial activity in determining soil carbon accumulation following shrub revegetation. The study highlights the need to investigate species-specific mechanisms, such as rhizodeposition dynamics and microbial necromass stabilization, to elucidate carbon redistribution pathways in semi-arid ecosystems. Full article

Large-scale coal mine dumps are formed during the mining process of coal resources. These coal mine dumps comprise impoverished soil, posing significant challenges for vegetation restoration. To address this problem, soil microbial (EM) agents and fly ash have effectively improved soil quality. However, the effects of different application ratios on the quality of sandy soil in coal mine dumps are still unclear. This study aims to explore the applicable ratio for sandy soil in coal mine dumps. This study employed a field-based potted experiment design. A two-factor complete factorial experimental setup was utilized, with four levels of EM microbial agent to sandy soil weight ratio (0 g/kg, 0.1 g/kg, 0.2 g/kg, and 0.3 g/kg) and four levels of fly ash to sandy soil weight ratio (0 g/kg, 25 g/kg, 50 g/kg, and 75 g/kg), and the mixing of EM microbial agents and fly ash with the sandy soil was carried out at different ratios. Subsequently, the study examined the impacts of various dosages on the physicochemical properties of soil within the mine spoil heap, and a soil quality index was derived to quantify these effects. The application of EM microbial and fly ash resulted in significant improvements in the physicochemical properties of the soil compared to the control group. Notably, the combined application of EM microbial agent and fly ash exhibited superior effects on soil physicochemical properties compared to the individual applications of EM microbial agent or fly ash. Specifically, when the EM microbial agent concentration was 0.2 g/kg and the fly ash content was 75 g/kg, the enhancement in soil quality was most pronounced, with a soil quality index of 0.78. Mantel analysis revealed that the growth index and photosynthetic index of Corethrodendron fruticosum were primarily driven by soil total nitrogen and organic carbon. The research results can provide guidance and technical support for soil improvement in mining areas. Full article

Corethrodendron fruticosum is an endemic forage grasses in China with high ecological value. In this study, the complete chloroplast genome of C. fruticosum was sequenced using Illumina paired-end sequencing. The C. fruticosum chloroplast genome was 123,100 bp and comprised 105 genes, including 74 protein-coding genes, 4 rRNA-coding genes, and 27 tRNA-coding genes. The genome had a GC content of 34.53%, with 50 repetitive sequences and 63 simple repeat repetitive sequences that did not contain reverse repeats. The simple repeats included 45 single-nucleotide repeats, which accounted for the highest proportion and primarily comprised A/T repeats. A comparative analysis of C. fruticosum, C. multijugum, and four Hedysarum species revealed that the six genomes were highly conserved, with differentials primarily located in the conserved non-coding regions. Moreover, the accD and clpP genes in the coding regions exhibited high nucleotide variability. Accordingly, these genes may serve as molecular markers for the classification and phylogenetic analysis of Corethrodendron species. Phylogenetic analysis further revealed that C. fruticosum and C. multijugum appeared in different clades than the four Hedysarum species. The newly sequenced chloroplast genome provides further insights into the phylogenetic position of C. fruticosum, which is useful for the classification and identification of Corethrodendron. Full article