To analyze the correlation between plant species diversity and sampling area in different types of artificial lawn ecosystems, this study used a nested sampling method to track and investigate the plant species diversity of six commonly used artificial lawn ecosystems in China constructed by six different turf grasses. Two experimental treatments of manually removing weeds (MRW) and maintaining natural state (MNS) were set, and the changing patterns of plant species diversity with the increasing sampling area were analyzed. The results showed that the plant species diversity in the six different types of lawn ecosystems treated with MRW was significantly lower than that in the MNS experimental research plot, and the difference between these two experimental treatments became gradually greater as the sampling area increased, indicating that MRW management measures had a significant effect on maintaining the singularity of plant species and the evenness of plant growth in various types of lawn ecosystems. Both plant species diversity in the unit area and change rate of plant species diversity with the increased sampling area gradually decreased with the increase of construction years, indicating that the material cycle and energy flow inside the ecosystems tended to be stable, and the plant species composition and the functional structure of lawn ecosystems both were in the dynamic equilibrium states with the development and succession of lawn ecosystems. However, the maintenance mechanisms of this dynamic equilibrium state were different in the two experimental treatments of MRW and MNS, the former was that the regular artificial impurity removal management measure inhibited weed invasion and growth, while the latter was that the dominant plant species suppressed the growth and reproduction of the other types of plant species. The research results indicated that although various management measures had a strong intervention intensity on the lawn ecosystems, they still could not completely eliminate the continuous invasion and interference of various weeds; in the early stage of lawn construction, the ecosystem was unstable, and the frequency and intensity of management measures such as MRW should be increased; entering the mid- to late-stage, as the species composition and structural function of the lawn ecosystem tended to stabilize with the increase of construction years, the degree of manual intervention could be appropriately reduced, and the mutual constraint between the various components of the ecosystem could be fully utilized to manage the lawn for improving the quality of the lawn and reducing the amount of manual labor.