HABITAT UTILIZATION PATTERN OF Lantana camara IN UDAWAlAWA NATIONAL PARK

Abstract

Time to time, many plant species has been introduced to Sri Lanka either intentionally oraccidentally. However, with the present interest on biodiversity it was realized that some of thesespecies are posing a threat to the existence of many other native species. These species areknown as invasive species.

Lantana camara an invasive plant is introduced to Sri Lanka in 1926 through the Royal BotanicGardens of Sri Lanka and currently has spread across the island to a significant extent. Now ithas become invasive and a threat to the Udawalawe National Park.

Further more, growth of this species in Udawalawe NP at an alarming rate would eliminate thenatural vegetation in this area, causing loss of habitat for many animal and plant speciesendangering their survival. To effective manage and control L. camara in Udawalawa NP, it isnecessary to have knowledge of the distribution within this park and asses the invasivebehaviour of this species.

Main objectives of this research study were to find the extent and distribution. This study wasconducted in purposely-selected vegetation types such as degraded open secondary forest, scrubgrasslands, medium high scrub vegetation, scrub forest transitional vegetation and teakplantation. The percentage coverage was assessed using 2mx2m quadrats. In each quadrate %cover of reproductives and non-renroductives of L. camara were measured. Seed samples weregerminated in the lab using soil collected from the natural habitat. The study had shown thatwithin the Udawalawa NP, the L. camara cover affects some vegetation types such as degradedopen secondary forest, scrub grass lands, medium high scrub vegetation, scrub forest transitionalvegetation and teak plantation. The plant is capable of producing a large number of seeds and itis spreading fast. The seeds showed high capability of direct germination. Total area ofUdawalawa NP is 30821 hectares and the area, which consists of L. camara, is 20%, spread intoabove vegetation types covering Udawalawa NP. The distribution pattern of the species showedthat the area around the main road the main road and VeheragoIla, Seenuggala, Mauara,Thimbiriyamankada and 5th milepost are the most densely and continuously distributed areas.Except this, there are few isolated patches on either side of the road and some vegetation types.It was interesting to note that the density of the L. camara is high in open areas than naturalforest areas.

As for control methods, uprooting and burning was tested for plants with different cover.Uprooting of small plants was effective than mature plants. Mature plants regenerated even fromsmall pieces of rootlets. Cutting drring drought season, showed more effectiveness.

This alien invasive plant, which reduce land productivity and value is a threat specially to thispark. Present investigation highlights the necessity of proper control method for L. camara inUdawalawa NP