Short-term effects of cyclone impact and long-term recovery of tropical rain forest on Kolombangara, Solomon Islands

Citation
Dfrp. Burslem et al., Short-term effects of cyclone impact and long-term recovery of tropical rain forest on Kolombangara, Solomon Islands, J ECOLOGY, 88(6), 2000, pp. 1063-1078
Citations number
70
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
JOURNAL OF ECOLOGY
ISSN journal
0022-0477 → ACNP
Volume
88
Issue
6
Year of publication
2000
Pages
1063 - 1078
Database
ISI
SICI code
0022-0477(200012)88:6<1063:SEOCIA>2.0.ZU;2-B
Abstract
1 We evaluate the effects of large-scale disturbance on tropical tree commu nities by examining the population dynamics of all individuals > 4.9 cm in diameter at breast height (d.b.h.) of 12 tree species over 30 years (1964-9 4) in lowland tropical rain forest on Kolombangara, Solomon Islands. 2 During the study period Kolombangara was struck by four cyclones between 1967 and 1970. The last cyclone caused most damage to canopy structure. Mor tality in the 6-month interval spanning the first cyclone was 7.0% of all t rees, while mean annual mortality for all other intervals (including those spanning other cyclones) was 1.4-2.2% year(-1). Mortality varied between sp ecies but was independent of topography and geographical location. 3 Recruitment increased from very low rates (median 0.0% year(-1)) before t he first cyclone to median values of 1.6-3.2% year(-1) during 1971-79, i.e. following a lag period of 3.5-8 years after the first cyclone. Recruitment rates were higher on plots showing greater mortality rates during this cyc lone. Recruitment and mortality rates were still higher in 1994 than they h ad been before the 1967-70 cyclones. 4 Mean annual mortality rates were positively correlated with mean annual r ecruitment rates across species. This relationship reflects a continuum of life-history characteristics and contributes to constancy in the relative a bundance of the 12 species when the same sets of plots are compared over al l measurement intervals up to 30 years. 5 We conclude that cyclone impacts have only short-term effects on the rela tive abundance of common tree species on Kolombangara, and do not therefore prevent the establishment of an equilibrium rank abundance hierarchy or cr eate spatial variation in tree species composition. Differences in forest c omposition across Kolombangara are more likely to have been caused by diffe rential anthropogenic disturbance linked to settlement patterns.