Biodiversity plays a crucial role in producing and maintaining ecosystem functions and services, so biodiversity conservation and preservation are prerequisites for the sustainability of regional landscape ecosystems. The mechanisms determining spatial patterns of plant communities in non-agricultural habitats are the basis for the construction of sustainable agro-landscapes. To understand the composition of plant communities in non-agricultural habitats, 54 plots were established in Fengqiu County, Henan Province. Plant communities in non-agricultural habitats (planted forests, treelines, field roads, and ditches) were investigated using the Braun-Blanquet method, and the spatial pattern of plant species diversity was analyzed by additive partitioning. We found that species richness and diversity were significantly higher in planted forests and treelines than in field roads and ditches, and field roads had the lowest plant diversity. A comparative analysis of common and rare species showed that rare species were the main component of species richness in non-agricultural habitats, whereas common species were dominant in agricultural habitats. Additive partitioning of species richness showed that β diversity made an important contribution to total regional species richness across multiple spatial scales. At the quadrat scale, α diversity contributed about 50% of the total species richness of common species, and the contribution of α+β₁ was more than 75% of the total common species richness. For rare species, the contribution of α was less than 6% of total species richness in each habitat. In contrast, β₂ contributed up to 97% of total rare species richness, especially in field roads. At the regional scale, the contribution of α was only 1.86%, while β₂+β₃ contributed more than 95% of total rare species richness. According to the results, the emergence of non-agricultural habitat could play an important role in improving total species richness in agro-landscapes. In addition, changes in landscape composition and configuration could have a profound impact on plant diversity, and the effects would be stronger for rare species. In future, more attention should be paid to the tradeoffs between agricultural production and sustainability of ecosystem services on landscape and regional scales, and improvement of the ecological processes and ecosystem services controlled by biodiversity should be emphasized.