植被演替下植物组成多样性和群落稳定性与土壤团聚体的关系

为揭示植被自然恢复过程中植物组成多样性和群落稳定性与土壤团聚体的关系，防治水土流失，提高土壤质量.通过野外调查采样，确定并分析黄土高原近150年植被演替不同阶段的植被特征与土壤团聚体数据.结果表明：该过程共有种子植物39科99属128种，优势科是菊科、蔷薇科、禾本科和豆科，优势属是蒿属，单种属是该过程植物属的主体，出现频率较高的植物有大披针薹草、胡枝子、白刺花、水栒子、青蒿、虎榛子、辽东栎、茶条枫、油松、绣线菊、狗娃花等.植物地理成分在属级水平上有11个分布区类型8个变型，温带性质明显，热带性质（R值）与温带性质（T值）的比值（R/T）随恢复年限的增加而降低，R值与R/T值显著正相关，热带成分扩散分布受到限制.植物丰富度呈单峰曲线，在恢复年限为40~70年时最高.依照不同恢复年限对群落稳定性进行排序：70>120>135>150>40>10>20>0年.R值与植物种系分化度（SD值）极显著正相关，T值与稳定性极显著正相关.>5mm粒径团聚体与受热带性质物种驱动的植物丰富度有关.>0.25mm粒径团聚体总体上与群落稳定性保持一致，均受温带性质物种维持.大披针薹草、胡枝子、白刺花是该区植被演替过程中维持群落稳定性的关键种和具有潜在提高土壤大粒径团聚体比例的功能植物，植被近自然恢复、土壤质量提升和土壤侵蚀防治，可以考虑增加这3个物种.

Plant composition diversity and community stability under vegetation succession in relation to soil aggregates

In order to reveal the relationship between the diversity of plant composition, community stability, and soil aggregates in the process of natural vegetation restoration, and further to prevent soil erosion and improve soil quality, field survey and sampling were performed to determine vegetation characteristics and soil aggregation at different stages of vegetation succession on the Loess Plateau over the past 150 years. The results showed that there were 128 species of seed plants belonging to 39 families and 99 genera in the succession process. The dominant families were Asteraceae, Rosaceae, Gramineae, and Leguminosae, and the dominant genus was Artemisia. The plant genera in this process were characterized as monotypic genera. The plants with a high frequency of occurrence included Carex lanceolata, Lespedeza bicolor, Sophora davidii, Cotoneaster multiflorus, Artemisia caruifolia, Ostryopsis davidiana, Quercus wutaishanica, Acer tataricum subsp.ginnala, Pinus tabuliformis, Spiraea salicifolia, Aster hispidus, etc. At the genus level, the geographical composition had 11 types and 8 variants, in which the temperate geographical components had a distinguished superiority. The ratio (i.e., R/T values) of tropical (R-value) and temperate (T-value) properties decreased with increasing recovery years. The R-value correlated significantly with the R/T value, and the spread of tropical components was limited. The time series of plant diversity exhibited a single-peaked curve, with the maximum occurring between 40~70 years after restoration. The stability of the community could be ranked according to different restoration years as follows:70 > 120 > 135 > 150 > 40 > 10 > 20 > 0years. The R-value and the T-value were both significantly positively correlated with germline differentiation (i.e., SD values) and community stability, respectively. > 5mm particle size aggregates were related to the plant richness driven by tropical species, while community stability was associated with >0.25mm grain size clusters maintained by temperate species. As the key species to maintain community stability in the process of vegetation succession, Carex lanceolata, Lespedeza bicolor, and Sophora davidii are functional plants with the potential to increase the proportion of large-sized soil aggregates. These three species can be considered for near-natural vegetation restoration, soil quality improvement, and soil erosion control.