Abundance, richness and composition of lianas in forest communities along an elevation gradient in New Caledonia

Abstract

Background: Lianas are an abundantand dynamic component of tropical forests, and their abundance ispredicted to increase with global change. A better understandingof factors that explain their distribution is required, especially onoceanic islands for which few data are available.

Aims: Identifythe environmental factors that shape liana communities in NewCaledonian forests

Methods: We studied liana abundance,basal area, richness and climbing modes in 27 forest plots (20m × 20 m) along an elevation gradient (sea level to ca. 1000 ma.s.l.) that covers different forest types and precipitation regimes.

Results: We inventoried 992 lianas belonging to 71 species. The abundance and basal area decreased logarithmically withincreasing elevation while species richness tended to peak at midelevations.Twining lianas were the most abundant and species-richfunctional group. We found no clear relationship between climbingmodes and forest structure.

Conclusions: Our results show thatliana abundance decreases with increasing elevation in responseto lower precipitation in seasonal dry forest. At high elevation (600–1000 m a.s.l.), climbing secondary hemi-epiphytes replace lianasprobably as a result of climate-based niche differentiation. Variationof species richness along the gradient could not be explained byprecipitation or by forest structural parameters.

Keywords:

• climbers
• climbing secondary hemi-epiphytes
• climbing modes
• diversity
• forest structure
• oceanic island
• twining

Acknowledgements

We are very grateful to the Province Sud of New Caledonia (Vivaldi program) and the Grand Observatoire du Pacifique Sud (GOPS) for funding. We are grateful to W. Nigote, J. Girardi and M. Magat for help on the field and to J. Fambart for help at the NOU herbarium. Thank you to Nick Rowe for revise the wording of the manuscript. We also thank to all the staff of UMR AMAP of Nouméa for help and support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Grand Observatoire du Pacifique Sud (Clivenc Project); Province Sud of New Caledonia (Vivaldi program); UMR AMAP.

Notes on contributors

David Bruy

David Bruy is a Ph.D. student in plant systematic and evolution. He is interested in processes responsive for plant diversity patternsand use the New Caledonian flora as a model system.

Thomas Ibanez

Thomas Ibanez is a postdoctoral researcher. He is interested in the assembly and dynamics of forest communities as well as their distribution and diversity in tropical rainforests.

Jérôme Munzinger

Jérôme Munzinger is a researcher. His research is focused on the systematics, origin and conservation of the New Caledonian flora.

Sandrine Isnard

Sandrine Isnard is a functional biologist whose research focuses on tropical ecosystem diversity and plant structure and function.