Journal of Tropical Ecology



The effects of Cyclone Waka on the structure of lowland tropical rain forest in Vava'u, Tonga


Janet Franklin a1c1, Donald R. Drake a2, Kim R. McConkey a3, Filipe Tonga a4 and Leslie B. Smith a1
a1 Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego CA 92182-4614, USA
a2 Botany Department, University of Hawaii at Manoa, 3190 Maile Way, Honolulu, HI 96822, USA
a3 Wildlife Research Group, Department of Anatomy, Cambridge University, Cambridge CB2 3DY, UK
a4 International Fund for Animal Welfare, and Whales Alive, Box 17, Neiafu, Tonga

Article author query
franklin j   [PubMed][Google Scholar] 
drake dr   [PubMed][Google Scholar] 
mcconkey kr   [PubMed][Google Scholar] 
tonga f   [PubMed][Google Scholar] 
smith lb   [PubMed][Google Scholar] 

Abstract

On 31 December 2001, Tropical Cyclone Waka passed directly over the Vava'u island group, Kingdom of Tonga, with sustained and maximum wind speeds of 185 km h−1 and 230 km h−1 respectively. During a prior study of forest secondary succession, 44 forest plots on 13 islands had been surveyed in 1995 and their locations marked. Nineteen of the plots were resurveyed and two additional transects established in May–June 2002, 6 mo following the cyclone. Cyclone-related tree mortality averaged 6%, varied from 0–7% for lowland late-successional species, and tended to be higher for early successional plots (8–16%) and species (4–19%). Severe damage (uprooting, snapped stems) affected 25% of the 2030 stems measured. The proportion of snapped stems was disproportionately high in the 10–15-cm stem diameter class. Uprooting was more prevalent than expected by chance among larger trees (>20 cm diameter). The greatest mortality and severe damage (combined,>35% of stems) occurred in plots that were early successional. Over the 6 y prior to the storm, background recruitment and mortality averaged 1.4% and 3.3% respectively. Mortality was greater than recruitment, while basal area was increasing, in most plots that had not experienced additional anthropogenic disturbance.

(Accepted July 19 2003)


Key Words: cyclone; disturbance; forest dynamics; hurricane; mortality; Pacific Islands; recovery; recruitment; tropical cyclone; tropical rain forest; West Polynesia.

Correspondence:
c1 Corresponding author.