Human-driven ecosystem simplification has highlighted questions about how the number of species in an ecosystem influences its functioning. Biodiversity is now known to affect ecosystem productivity and stability of the ecosystem. In this study, different vegetation types in Ruyang County, Henan Province, China, were examined to evaluate the impact of large-scale planting of Eucommia ulmoides on local species diversity. The species diversity was analyzed using Shannon-Wiener diversity (H), Simpson diversity (D), and evenness (J_H') indices in three different vegetation types: Eucommia ulmoides plantation, temperate fallen broad-leaved forest (referred to as secondary forest), and abandoned land (old field). The results indicated that there were 82 species belonging to 39 families and 63 genera in the Eucommia ulmoides forest, in which the herbaceous layer was the most developed. The secondary forest contained 70 species belonging to 32 families and 62 genera, and the tree layer was more developed than more developed than the herbaceous and shrub layers. The old field included 84 species of 35 families and 69 genera but lacked a tree layer. The richness and abundance of species in the Eucommia ulmoides forest were similar to those in the secondary forest and old field, whereas the richness and abundance of species in the herbaceous layer of the Eucommia ulmoides forest were higher than those in the secondary forest. Our results showed that the H, D, and J_H indices of the three layers of the Eucommia ulmoides forest were not significantly different from those of the secondary forest and old field (P> 0.05). Collectively, these results illustrate that, with a reasonable planting density and proper management, Eucommia ulmoides forests can not only provide us with leaves and fruit but can also enrich the amount and diversity of herbaceous plants, thereby increasing biological diversity.