AN ASSESSMENT OF PRESENT PLANT DIVERSITY ON THE NATEWA PENINSULA, VANUA LEVU, FIJI

POWLING, A. 2018. An assessment of present plant diversity on the Natewa Peninsula, Vanua Levu, Fiji. Reinwardtia 17(2): 125‒132. ‒‒ The Natewa Peninsula, part of the Fijian island of Vanua Levu, is naturally afforested but the forests have been extensively logged in the last 50 years. It is now planned to protect some of the forests from further logging by incorporating them into a National Park. A survey of plant species in the regenerating forests and surrounding land on the Peninsula was performed to assess the taxonomic and ecological diversity of the trees and shrubs, including figs and palms, and also the orchids presently to be found on the Peninsula. The degree of invasion by introduced plant species was also assessed. Of 67 tree and shrub species it was found that 17 were endemic to the Fijian islands, 40 others were indigenous and ten were introduced. The normal habitats of these species included dense, open and secondary forest, showing that trees with a range of ecological characteristics were still present. Endemic and indigenous species of both figs and palms were found, and also terrestrial and epiphytic orchids. No severe infestations of introduced species were observed. It is concluded that the forests of the Peninsula are of sufficient conservation value to justify National Park status.

Weed Management with Urochloa ruziziensis in Three Sowing Methods

ABSTRACT: This research aimed at investigating which sowing method is more suitable for the deployment of Urochloa ruziziensis to suppress the weed community in no-tillage. The design was a randomized block ones, with a 3 x 2 factorial design, in which the first factor was composed of three sowing methods (broadcast, broadcast with incorporation or line sowing) and factor B consisted in the application and non-application of the herbicide 2,4-D. On day 30 and 60 after sowing (DAS), the relative importance of the present plant species was determined. On day 120 and 180 DAS, the accumulation of biomass and the plant cover percentage on the soil provided by the cover crop and weed species were determined. Moreover, on day 180 DAS, the density of the existing weeds was determined. The weed with the highest occurrence in the area was Conyza canadenses, and the lowest percentage of soil covering by signalgrass and the greates occurrence of weeds occurred with broadcast seeding. It is possible to conclude that the broadcast seeding with the incorporation of signalgrass seeds and line sowing methods provide enough plant cover to suppress weed species, avoiding the application of the herbicide 2,4-D in order to suppress the infesting community.