Current status and management options for invasive plants at the Mihintale Wildlife Sanctuary

 The present study describes the current spread of plant invaders and management efforts at Mihintale, Sri Lanka’s first recorded Wildlife Sanctuary. Among the five land use zones identified, roadside (RS), village (VA) and reservoir associated (RA) zones were subjected to a detailed analysis of diversity and abundance of Invasive Alien Plants (IAP) using stratified random sampling plots of 20 m x 20 m (n=09). Encroachment of IAP into the forested (FO) zone was studied using three 50 m transects established from edge to interior of the forest. The above ground diversity of IAP was assessed via Margalef’s, Shannon –Weiner, Shannon evenness, abundance and important value indices. Aquatic IAP were also identified. Below ground diversity of IAP was estimated by enumerating soil seed banks via seedling establishment method. A questionnaire (n=60) was used to ascertain the invasion history, awareness on IAP, their interference on human activities, uses and control measures adopted by the villagers. Nearly half of the IAP reported for Sri Lanka were present in the Mihintale Sanctuary. Richness of  IAP was high in RA but the abundance was high at RS zone. Lantana camara and Chromolaena odorata had the highest spread, extending even >25 m into the forests. Salvinia was the most abundant aquatic IAP. Top soil layer contained the highest number of germinable IAP seeds. The villagers were well aware of the impacts of IAP and indicated their attempts and potential in IAP management. The study revealed that spread of IAP at the Mihintale Sanctuary currently lies at a manageable level. Better awareness among villagers on “do’s and dont’s with IAP” would assist in opening up more opportunities for community participation in effective IAP management.

Keywords: Chromolaena odorata, invasive plants, Lantana camara, Mihintale, Salvinia.

DOI: http://dx.doi.org/10.4038/jnsfsr.v40i1.4170

J.Natn.Sci.Foundation Sri Lanka 2012 40 (1):67-76