in Sri Lanka - Ministry of Environment

(a) Fire in a P. maximum dominated grassland atMawuara, Udawalawe(b) Prosopis juliflora invaded land in Bundala forest.Figure 8Figure 10. Die-back of M. hexandra inBundala National Park (Photograph by courtesy ofMr. Udaya Gunarathne)Figure 9. The dreadful invader: Bambusa bambosin Minneriaya Forestvary from region to region. Thus, Prosopis juliflora is found in coastal dry forests at Hambanthotaand Mannar districts (Figure 8b) while Bambusa bambos is a common invader in Minneriya andGirithale forests in Polonnaruwa district (Figure 9). In contrast, Lantana camara is universallydistributed across the whole dry land of the country.Heavy grazing and trampling by feral cattle and buffaloes are serious threats in occasionallyflooded dry land grasslands and seasonally flooded damp grasslands. Frequent grazing andtrampling expose the soil and facilitate the seeds of invasive species to grow. These ungulatesact as the seed dispersal agents of invasive species as well. Thus, L. camara invades ingrasslands at Udawalawe National Park while P. juliflora has invaded the areas closer tolagoons in Hambanthota District.Forest die-back is commonly seen in tropical semi-deciduous forests where the canopydominant M. hexandra trees are dying back (Figure 10). As the canopy of these forests consistsof only M. hexandra, its die-back would affect the forest structure and the micro-climate and172