Low tolerance of New Caledonian secondary forest species to savanna fires
Article first published online: 5 JUL 2012
© 2012 International Association for Vegetation Science
Journal of Vegetation Science
Volume 24, Issue 1, pages 177–188, January 2013
How to Cite
Ibanez, T., Curt, T., Hely, C. (2013), Low tolerance of New Caledonian secondary forest species to savanna fires. Journal of Vegetation Science, 24: 177–188. doi: 10.1111/j.1654-1103.2012.01448.x
- Issue published online: 4 DEC 2012
- Article first published online: 5 JUL 2012
- Manuscript Accepted: 18 MAY 2012
- Manuscript Received: 25 AUG 2011
- Allometric relationships;
- Bark thickness;
- Cambium damage;
- Crown damage;
- Escape size;
- Fire behaviour;
- Surface fires;
- Tree height
How do early secondary successional forest species that grow in savannas differ in their tolerance to surface fires? What are the consequences of these fire tolerances for savanna–forest dynamics and landscape management?
Anthropogenic savannas in the New Caledonian biodiversity hotspot (SW Pacific).
We estimated the range of fire intensity in New Caledonian savannas using field survey of fuels and the BehavePlus fire behaviour model. Within the predicted range of fire line intensity, we assessed theoretical fire injury to the cambium and crown for 11 species: the dominant tree of New Caledonian savannas (Melaleuca quinquenervia) and early secondary successional forest species. Using empirical models, for each species we estimated cambium damage from depth of necrosis (as a function of fire line intensity and fire residence time) and bark thickness, and crown damage from scorch height (as a function of fire line intensity) and tree height. We compared bark thickness and tree height increment patterns among species as well as species potential fire tolerance.
The 11 species had very contrasting capacity to avoid fire injury to the bole cambium due to differences in bark investment patterns, but were all very exposed to scorching and crown injury. Overall, most of sampled individuals are likely top-killed by low intensity fires (<1000 kW·m−1), which are frequent according to our simulations.
The early secondary successional forest species growing in New Caledonian savannas are poorly adapted to fire, in comparison with literature on worldwide trees in savannas. As a result, their juveniles are unlikely to reach adult size in fire-prone areas. Restoration using the most fire-tolerant species and fire prevention may be complementary strategies to manage such tropical landscapes in order to conserve biodiversity and ecosystem services.