More than one fifth of plant species worldwide are threatened with extinction.[i] Overgrazing by livestock has substantially reduced some plant populations, while others are being crowded out by foreign weeds. Urbanization and the intensification of agriculture have also destroyed populations of many plant species, while also restricting their habitat. Today, CWR face such threats no less than other plants.
Some important crop wild relative species have extremely limited ranges. For example, the maize wild relative Zea nicaraguensis is restricted to a single protected area in Nicaragua, while the wild sunflower species Helianthus paradoxus is found in only six small populations in Texas, Utah and New Mexico in the USA.
Climate change is also a threat: around 16-22% of peanut, potato and cowpea CWR are predicted to go extinct by 2055,[ii] while changing environmental conditions are projected to severely reduce the potential habitat of many maize wild relatives.[iii]
