IAPS targeted: Lantana camara and Eupatorium odoratum
The Lunugamvehera National Park is inhabited by a wide variety of fauna, including elephants, leopards, sloth bears, and several ungulate species. The park is connected to other protected areas (PAs), creating a critically valuable habitat cluster for Dry Zone fauna and flora. Poor land management practices, coupled with water scarcity, has enabled many an invasive plant species (IAPS) to establish and spread extensively within the national park.
In February 2021, the FEO and the Department of Wildlife Conservation (DWC) estimated that approximately 900 Ha in LNP were covered with the IAPS Lantana camara (Gandapana) and Eupatroium odoratum (Podi Singho Maran). Both plant species have specific adaptations that give them advantages over the native flora:
- The Lantana species has the ability to grow in a diverse range of habitats. It can grow in clumps or as dense thickets and so can crowd out other, more desirable species for the park. In disturbed native forests, Lantana can become the dominant understory species, disrupting forest succession, decreasing native biodiversity. This species produces thousands of berries every year, which are consumed by a large variety of birds and animals, meaning its seeds can be dispersed far and wide.
- The Eupatorium species is one of the fastest spreading IAPS in Sri Lanka. It is a rapidly growing perennial herb that can produce up to 90,000 seeds per plant which are dispersed quite effectively by the wind. While the seeds need light to germinate, it can also regenerate from its roots.
As these IAPS can grow rapidly and outcompete the native flora, they also deprive grazing animals, such as elephants and deer, of fodder. This is because the leaves of both the Lantana and Eupatorium species are toxic and are avoided by herbivores, so they do not provide alternative fodder for these animals. Additionally, their presence prevents the growth of plants that can provide cover for their safety, resting, and reproduction.
After carrying out pilot studies, we determined that the best method by which to remove these IAPS was manual removal before the flowering phase of each plant species, to minimise seed dispersal. Additionally, we would have to perform up to four rounds of clearing to maintain culled areas and to minimise the seed bank of these IAPS.
To date, we have cleared almost 800 Ha from LNP, and have recently been asked by the DWC to tackle one of the park’s most infested areas – another 400 Ha of land.