Lantana camara, an evergreen perennial, erect, and aromatic shrub originates from tropical America. It is invasive in Africa. In Bwindi Impenetrable National Park (BINP), it has invaded the Northern sector of the park where it has replaced much of the native vegetation. It is preferred by farmers for its brightly colored flowers (pink and yellow on opening, changing to red and orange and on rare occasions purple and blue) and is widely planted in the community lands surrounding BINP. L. camara is believed to inhibit and/or suppress the growth of native plant species. Its spreading also has a shading effect that inhibits the growth of native seedlings. Propagation of L. camara is both vegetative and by seed.

The main objective of this study was to determine the impact of L. camara on the growth of native tree species, its ability to spread and its possible control. The study was conducted in the Northern part of BINP. The research used paired nested quadrats in both invaded and non- invaded areas. The data was analyzed using SYSTAT 8.0. Shannon Weiner indices were used in the comparison of diversity; while species richness, stem density and tree regeneration comparisons were made using Mann-Whitney U test. The Mann-Whitney U test was also used to compare regeneration of native plant species in permanently established quadrats in order to find appropriate means of L. camara control. The relationships between L. camara stem density and other tree species stem density were tested using Spearman’s rank correlation.

L. camara was found in open forest gaps and disturbed areas where it formed thickets. It was also seen to grow under tree cover where it would grow vertically towards the canopy. The native tree species' regeneration potential, species richness, diversity and stem density were significantly higher in non-invaded areas.

Herbs and seedlings showed more diversity in invaded areas. This can be attributed to low evenness in non-invaded area.

L. camara percentage cover and number of thickets were negatively related to plant densities and species which could be because less diverse areas are more susceptible to invasion. L. camara's vegetative regeneration was significantly higher than that by seed. Its expansion was observed to be mainly through terminal branching. A large L. camara seed bank was found once the thickets were eliminated, which could be attributed to the need for light during germination.

The tree species which tolerate L. camara include: Xymalos monospora, Markhamia lutea and Clausena anisata. However, the weight of L. camara thickets made them produce poor and unhealthy lateral branches. In permanently established quadrats of cut and uprooted L. camara, native vegetative regeneration was significantly higher in cut quadrats than in uprooted quadrats (U= 400.00; p= 0.001; x²= 29.459). Reseeders did not show any significant difference in both areas (U= 179.50; p= 0.58; x²= 0.308). Areas where L. camara was uprooted were more diverse than where it was cut (H^/= 0.684 and 0.596 respectively).

Since L. camara inhibits the growth of native plants, it should be eradicated. Repeated uprooting and burning of L. camara thickets is recommended as the best method of control in BINP.