Engineering Research Centre for Southwest Forest and Grassland Fire Ecological Prevention, College of Forestry, National Forestry and Grassland Administration, Sichuan Agricultural University, Chengdu, 611130, China.
Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Forestry Ecological Engineering in the Upper Reaches of the Yangtze River, Key Laboratory of Sichuan Province, National Forestry and Grassland Administration, Chengdu, 611130, China.
New Phytol. 2023 Oct;240(1):105-113. doi: 10.1111/nph.18905. Epub 2023 Apr 5.
Plant flammability is an important driver of wildfires, and flammability itself is determined by several plant functional traits. While many plant traits are influenced by climatic conditions, the interaction between climatic conditions and plant flammability has rarely been investigated. Here, we explored the relationships among climatic conditions, shoot-level flammability components, and flammability-related functional traits for 186 plant species from fire-prone and nonfire-prone habitats. For species originating from nonfire-prone habitats, those from warmer areas tended to have lower shoot moisture content and larger leaves, and had higher shoot flammability with higher ignitibility, combustibility, and sustainability. Plants in wetter areas tended to have lower shoot flammability with lower combustibility and sustainability due to higher shoot moisture contents. In fire-prone habitats, shoot flammability was not significantly related to any climatic factor. Our study suggests that for species originating in nonfire-prone habitats, climatic conditions have influenced plant flammability by shifting flammability-related functional traits, including leaf size and shoot moisture content. Climate does not predict shoot flammability in species from fire-prone habitats; here, fire regimes may have an important role in shaping plant flammability. Understanding these nuances in the determinants of plant flammability is important in an increasingly fire-prone world.
植物易燃性是野火的一个重要驱动因素，而易燃性本身由几个植物功能特征决定。虽然许多植物特征受气候条件影响，但气候条件与植物易燃性之间的相互作用很少被研究。在这里，我们探讨了 186 种来自易发生火灾和不易发生火灾生境的植物物种的气候条件、枝梢易燃性成分和易燃性相关功能特征之间的关系。对于来自不易发生火灾生境的物种，来自温暖地区的物种往往具有较低的枝梢水分含量和较大的叶片，并且具有较高的点火性、可燃性和持续性，从而具有较高的枝梢易燃性。由于枝梢水分含量较高，在较湿润地区的植物往往具有较低的可燃性和持续性，从而具有较低的可燃性。在易发生火灾的生境中，枝梢易燃性与任何气候因素都没有显著关系。我们的研究表明，对于来自不易发生火灾生境的物种，气候条件通过改变与易燃性相关的功能特征，包括叶片大小和枝梢水分含量，影响了植物的易燃性。气候并不能预测来自易发生火灾生境的物种的枝梢易燃性；在这里，火灾发生频率可能在塑造植物易燃性方面起着重要作用。了解植物易燃性决定因素中的这些细微差别，对于日益易发生火灾的世界非常重要。
