Details

Autor(en) / Beteiligte

• Potts, Ebony
• Tng, David
• Apgaua, Deborah
• Curran, Timothy J.
• Engert, Jayden
• G. W. Laurance, Susan

Titel

Growth form and functional traits influence the shoot flammability of tropical rainforest species

Ist Teil von

• Forest ecology and management, 2022-10, Vol.522, p.120485, Article 120485

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The image on the left-hand side shows a shoot sample burning on the flammability testing device. The right-hand side graph shows the post-hoc plot burnt biomass results for growth form (top) and family (bottom) with leaf dry matter content. The green squares represent low flammability groups and red squares represent high flammability groups. [Display omitted] •Rainforest trees are higher in flammability compared to shrubs and vines.•Plant families Sapindaceae, Proteaceae, Fabaceae, and Lauraceae are especially high in flammability while Moraceae is very low.•Plant functional trait leaf dry matter content is significantly positively associated with flammability.•Restoration plantings in the Wet Tropics of Australia include large proportions of highly flammable plant species. Canopy fires are increasing globally with anthropogenic climate and land-use changes, even in fire-sensitive rainforest ecosystems. Identifying the ecological drivers that may be aiding canopy fires, such as species or growth form flammability, is crucial to recognising and mitigating fire risks. To address this, we quantified the shoot-flammability of 124 rainforest plant species using an experimental approach. We compared three flammability measures (burnt biomass, total burn time and maximum temperature reached) with plant functional traits across seven different growth forms (i.e., canopy, pioneer, and understory trees; pioneer, understory and invasive shrubs, and vines) and nine common plant families and other higher-level clades, such as conifers, hereafter abbreviated to families. From burning > 600 sun-exposed shoots, we found trees were higher in flammability than shrubs and vines, and the plant families: Sapindaceae, Proteaceae, Fabaceae, and Lauraceae, had especially high flammability, whereas Moraceae was very low. Of the functional traits examined, leaf dry matter content was consistently and significantly positively associated with species flammability. Invasive shrubs as a group were not particularly flammable, although there were exceptions, e.g., wild tobacco (Solanum mauritianum) was highly flammable. This study has two important implications for the management of fire in rainforests. First, we have demonstrated that many tropical rainforest trees may readily burn under severe fire conditions if fire were to reach the rainforest canopy. Second, a large proportion of the > 1 million rainforest trees planted in the Wet Tropics under restoration planting schemes are from our most flammable rainforest plant families, as these families are often recommended for their carbon sequestration potential. Hence, these plantings may be highly vulnerable to fire and if planted along the borders of primary forest they may carry fire into their canopies. Therefore, where fire risk is high, we recommend planting species with low flammability along borders of plantings and forests to act as ‘green firebreaks’ to reduce the risk of fire incursions.