Department of Pest-management and Conservation, Lincoln University, Lincoln, New Zealand.
Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.
Nat Plants. 2020 Apr;6(4):355-359. doi: 10.1038/s41477-020-0635-1. Epub 2020 Apr 13.
Terrestrial plants and fire have interacted for at least 420 million years. Whether recurrent fire drives plants to evolve higher flammability and what the evolutionary pattern of plant flammability is remain unclear. Here, we show that phylogeny, the susceptibility of a habitat to have recurrent fires (that is, fire-proneness) and growth form are important predictors of the shoot flammability of 194 indigenous and introduced vascular plant species (Tracheophyta) from New Zealand. The phylogenetic signal of the flammability components and the variation in flammability among phylogenetic groups (families and higher taxonomic level clades) demonstrate that shoot flammability is phylogenetically conserved. Some closely related species, such as in Dracophyllum (Ericaceae), vary in flammability, indicating that flammability exhibits evolutionary flexibility. Species in fire-prone ecosystems tend to be more flammable than species from non-fire-prone ecosystems, suggesting that fire may have an important role in the evolution of plant flammability. Growth form also influenced flammability-forbs were less flammable than grasses, trees and shrubs; by contrast, grasses had higher biomass consumption by fire than other groups. The results show that shoot flammability of plants is largely correlated with phylogenetic relatedness, and high flammability may result in parallel evolution driven by environmental factors, such as fire regime.
陆生植物与火已经相互作用了至少 42000 万年。反复发生的火灾是否会促使植物进化出更高的可燃性，以及植物可燃性的进化模式是什么，这些问题仍不清楚。在这里，我们表明，系统发育、生境对反复发生火灾的易感性（即火灾倾向性）和生长形式是新西兰 194 种本地和引进的维管植物（Tracheophyta）的芽部可燃性的重要预测因子。可燃性成分的系统发育信号以及不同系统发育群（科和更高的分类群分支）之间的可燃性变化表明，芽部可燃性在系统发育上是保守的。一些密切相关的物种，如 Dracophyllum（杜鹃花科）中的物种，在可燃性上存在差异，这表明可燃性表现出进化的灵活性。在火灾多发的生态系统中的物种往往比非火灾多发的生态系统中的物种更易燃，这表明火可能在植物可燃性的进化中起着重要作用。生长形式也影响可燃性——草本植物比草、树木和灌木的可燃性低；相比之下，草类的生物量被火消耗的比例高于其他类群。研究结果表明，植物的芽部可燃性在很大程度上与系统发育的亲缘关系相关，高可燃性可能导致由环境因素（如火灾发生模式）驱动的平行进化。
