A new perspective on the ecological effects of toxic weeds in grassland
ecosystems
Abstract
The sharp rise in anthropogenic activities and climate change have
caused the extensive degradation of grasslands worldwide, jeopardising
ecosystem function and threatening human well-being. Toxic weeds have
been constantly spreading in recent decades; indeed, their occurrence is
considered to provide an early sign of land degeneration. Policy makers
and scientific researchers often focus on the negative effects of toxic
weeds, such as how they inhibit forage growth, kill livestock and cause
economic losses. However, toxic weeds can have several potentially
positive ecological impacts on grasslands, such as promoting soil and
water conservation, improving nutrient cycling and biodiversity
conservation, and protecting pastures from excessive damage by
livestock. We reviewed the literature to detail the adaptive mechanisms
underlying toxic weeds and to provide new insight into their roles in
degraded grassland ecosystems. The findings highlight that the
establishment of toxic weeds may provide a self-protective strategy of
degenerated pastures that does not require special interventions.
Consequently, policy makers, managers and other personnel responsible
for managing grasslands need to take appropriate actions to assess the
long-term trade-offs between the development of animal husbandry and the
maintenance of ecological services provided by grasslands.