Failure to manage invasive species carries a possible price-tag of $423billion each year. What does this mean for the eight countries of the Hindu Kush Himalaya? 

Last week, the Intergovernmental Platform on Biodiversity and Ecosystem Services published a major Thematic Assessment Report on Invasive Alien Species and Their Control (IPBES invasive report), after its Global Assessment identified invasives as one of the five major drivers of biodiversity loss.

Biological invasions are responsible for substantial biodiversity declines as well as high economic losses associated with the management of these invasions. One recent global study estimates that the total costs of biological invasions was at least $ 1.288 trillion between 1970 and 2017.

The IPBES Invasive report now estimates the cost per annum at a staggering $423 billion as invasives drive plant and animal extinctions, threaten food security, impact human health, and exacerbate environmental losses across the globe.

A study from India estimated the cost to India alone to be between US$ 127.3 billion to 182.6 billion over 2016 to 2020, and showed that these costs have increased with time.

Worldwide, of 37,000 alien species that have been introduced, some 3,500 species are considered to be harmful invasive species that can have irreversible impacts on biodiversity and ecosystem services, with proven implications for human health and wellbeing. Some 1,500 invasives are found in the Hindu Kush Himalaya, including species such as mile-a- minute (Mikania micrantha), Lantana (Lantana camara), Parthenium (Parthenium hysterophorus) and Siam weed (Chromolaena odorata) among the world’s worst invasive species.

The fragile and remote areas of the high mountains and tundra are profoundly vulnerable to these species. Already we are seeing Lantana camara and Ageratina adenophora reducing the density and diversity, seedling growth and seed germination of native plants, and Parthenium hysterophorus and Conyza sumatrensis invasions altering the soil microbial community and nutrient content resulting to change in plant species composition. In Chitwan National Park, Nepal, Mikania micrantha invasion has not only occupied  44% of the habitat sampled but also showed high invasion rate threatening the thriving population of one-horned rhinoceros. 

As temperatures rise, studies suggest such invasives will shift northward and to higher elevations. However, being generally understudied and research on invasive species geographically scattered, the current and potential future impacts are not well understood in the region.

The IPBES invasive report highlights important data gaps in the mountains with comparatively few scientific studies on increasing infestations of some of the most vulnerable ecosystems such as high-altitude wetlands and rangelands, protected areas, and even agricultural fields.

It is crucial that conservationists and policymakers realise the potential impacts of invasive species and take a precautionary approach to minimise the impacts on fragile ecosystems of the Hindu Kush Himalaya. The IPBES invasive report outlines key responses and policy options for prevention, early detection and effective control and mitigation of their impacts to safeguard nature and nature’s contributions to people.