4. Conclusion and future prospects
As a barometer of grassland health, the wide distribution of toxic weeds worldwide indicates that land degradation is a serious issue that threatens the sustainable developmental goal of “no poverty, zero hunger” of the Food and Agriculture Organization of the United Nations. This review provides an understanding of the adaptive abilities of toxic weeds and presents a new interpretation of their role in degenerated grassland ecosystems. Here, we argue that toxic weeds can provide self-protective mechanisms of degraded pastures and promote their resilience. In some cases, taking no action might be superior to taking actions that end up doing more harm than good. The blind removal of toxic weeds through the promotion of increased grazing will likely expose pastures to excessive damage, jeopardizing ecosystem balance. Thus, robust grassland management requires policy makers, managers and other personnel to continuously monitor and evaluate the long-term trade-offs between the development of livestock farming and the maintenance of multiple ecological services. An improved understanding of toxic weeds is valuable for the sustainable management of grasslands and for meeting the 2030 Global Land Degradation Neutrality Target set by the United Nations Convention to Combat Desertification (Tothet al. 2018).