Impact of herbicides on wild plant diversity in agro-ecosystems: a review

Abstract

Plant diversity in agro-ecosystems is an important component of global biodiversity. However, wild plant diversity in agro-ecosystems is influenced by herbicide use. We reviewed recent studies on the impacts of herbicides on wild plant diversity in agro-ecosystems and the underlying mechanisms. It is found that herbicide application (i) decreases the number of plants that are sensitive to herbicides; (ii) increases the number of plants that are resistant to herbicides; (iii) changes species composition; and (iv) decreases genetic diversity and species diversity of wild plants in agro-ecosystems. Herbicide impacts simplify plant functional groups and hence add instability to communities. The underlying mechanism is that herbicides kill plants or change plant metabolism, resistance, reproduction and the habitat of plants. Furthermore, herbicides, human activities, and environmental factors have interactions. The impacts of herbicides on plants are plant-specific and the responses of various species or communities to the herbicides are also different. At present, the use of herbicides is increasing rapidly in agricultural production in China. We therefore suggest that more studies are needed on the impact of herbicides on wild plants and the underlying mechanisms, and the historical performances of herbicides use should be studied using long-term monitoring of wild plant changes carried out in China’s agro-ecosystems. Studies on policies and laws related to the use of herbicides also need to be strengthened, whicn can help to improve conservation of biodiversity in agro-ecosystem of China.