Thinning forests can affect the diversity and biomass of herbaceous plants. A study in Changbai Mountain found that different levels of thinning changed the types of herb species present, but seasonal changes had a bigger impact. Thinning didn't increase species diversity, but it did boost total herb biomass. The number of plants and coverage were linked to biomass levels. Thinning altered the light in the forest, leading to short-term improvements in plant diversity and biomass. The findings help guide forest management practices in mixed coniferous and broad-leaved forests.