Dr Pablo González-Moreno, one of CABI’s senior researchers with expertise in invasive plant ecology, has joined a workshop of international scientists concerned with investigating the invasive non-native species that pose the greatest threat to Gibraltar’s terrestrial and marine environments.
Parthenium weed and annual ragweed are closely related members of the Asteraceae, known for their high allergenicity. The detrimental effects on human health of the more temperate annual ragweed are very well known. However, those of the more tropical parthenium weed are less well known and in fact much more severe, affecting many tens of millions of people each year.
Invasive species pose a serious threat to food security, biodiversity, water resources, human and animal health, and economic development. It is widely acknowledged that integrated control is the most effective strategy in managing invasive plants where it involves the use of herbicides, manual or mechanical control, and biological control agents in an integrated way. Last month, a short course on invasion biology and classical biological control of weeds was delivered at CABI in Pakistan.
Giant hogweed (Heracleum mantegazzianum) is a monocarpic perennial herb, native to the Caucasus region. Since the late 1800s, giant hogweed has spread extensively across Europe and in eastern and western parts of North America following its likely initial introduction to the continent as an ornamental curiosity as early as 1917. Hogweed is an extremely successful invader in part due to its prolific seed production and growth rate. These attributes coupled with its large size allow giant hogweed to significantly alter natural environments and plant community structures. In addition, the plant is hazardous to humans and leaves riparian banks susceptible to erosion as it dies off in autumn.
Himalayan balsam (Impatiens glandulifera) is a non-native annual plant that was introduced into parts of Europe during the mid-nineteenth century as an ornamental plant for parks and gardens.
This plant species was first recognised as an invasive species and a threat to ecological stability in the 1930’s. However, since then the problem has escalated and is now of international concern, due to its negative impact on ecosystem biodiversity. This is primarily due to its ability to out-compete and overcrowd native vegetation. Himalayan balsam has now naturalised in many countries, resulting in a shift in management strategies from attempting to remove the invasive plant, to limiting its territory and further spread.
According to new research, scientists found that a number of invasive alien plant species initially introduced as ornamental plants at tourism facilities are now spreading rapidly throughout the Serengeti-Mara ecosystem, posing a major threat to wildlife, including the annual wildebeest and zebra migration as well as a range of other plant and animal species. Continue reading →