图1 土壤微生物对植物多样性-生态系统功能关系的调控作用概念图。箭头表示路径。植物多样性直接影响生态系统功能(路径1); 植物多样性通过作用于土壤微生物进而影响生态系统功能(路径2); 土壤微生物介导植物多样性-生态系统功能关系(路径3)。AMF: 丛枝菌根真菌; EMF: 外生菌根真菌。

Fig. 1 Conceptual diagram illustrating the role of soil microorganisms in regulating the plant diversity-ecosystem functions relationships. The arrows indicate the pathways. Plant diversity directly influences ecosystem functions (pathway 1), and indirectly influences ecosystem functions through its effects on soil microorganisms (pathway 2). Soil microorganisms directly mediate the plant diversity-ecosystem functions relationships (pathway 3). AMF, Arbuscular mycorrhizal fungi; EMF, Ectomycorrhizal fungi.

图2 菌根真菌对植物多样性-生产力关系的驱动机制概念图。黑色和白色圆圈分别代表丛枝菌根真菌共生植物物种和外生菌根真菌共生植物物种, 不同的圆圈线条类型表示不同物种, 圆圈大小代表植物物种资源利用能力的相对强弱。对于丛枝菌根真菌共生植物而言, 高植物多样性条件下, 丛枝菌根真菌主要通过促进宿主间对资源的互补利用来加强植物多样性对生产力的促进作用(A); 对于外生菌根真菌共生植物而言, 尽管宿主间存在互补利用, 但其主要通过提高特定宿主的资源利用能力来加强植物多样性-生产力关系(B); 当宿主与两种菌根真菌共存时, 以上两种作用共存(C)。

Fig. 2 Conceptual figure illustrating the mechanisms by which mycorrhizal fungi drive plant diversity-productivity relationships. Black and white circles represent plant species associated with arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF), respectively, with varying line styles denoting different plant species, and the size of the circles indicating the relative strength of resource utilization capabilities of the plant species. For plants in association with arbuscular mycorrhizal fungi, under high plant diversity conditions, AM fungi primarily enhance the positive effect of plant diversity on productivity by promoting complementary resource use among hosts (A). For plants associated with ectomycorrhizal fungi, although complementary utilization among hosts is present, they primarily strengthen the relationship between plant diversity and productivity by enhancing the resource utilization capacity of specific hosts (B). When hosts coexist with both types of mycorrhizal fungi, both of these effects are concurrent (C).

图3 病原菌驱动植物多样性-生产力关系的3种假设。当病原菌对不同多样性植物群落的抑制作用相当时, 病原菌消失后植物多样性-生产力关系的斜率不变(A); 当高多样性的植物群落中某一物种占据主导地位时, 由于该物种相对多度较高, 导致病原菌对高多样性群落的抑制作用强于低多样性群落, 因此病原菌消失后植物多样性-生产力关系的斜率将会升高(B); 当病原菌宿主特异性和负密度依赖性发挥作用时, 病原菌对低多样性植物群落的抑制作用会强于对高多样性植物群落, 那么病原菌消失后植物多样性-生产力关系的斜率将会下降(C)。

Fig. 3 Three hypotheses on pathogen-driven plant diversity-productivity relationships. When pathogens exert equivalent suppressive effects on plant communities of varying diversities, the slope of the plant diversity-productivity relationship remains unchanged after the disappearance of pathogens (A). When a dominant species occupies a leading position in a high-diversity plant community, due to its relatively high abundance, the suppressive effect of pathogens on high-diversity communities is stronger than on low-diversity communities, thus the slope of the plant diversity-productivity relationship will increase after the disappearance of pathogens (B). When pathogen host specificity and negative density dependence effects function, the suppressive effect of pathogens on low-diversity plant communities is stronger than on high-diversity communities, then the slope of the plant diversity-productivity relationship will decrease after the disappearance of pathogens (C).