Collaborative Research: Fire-fungal-plant feedbacks in pyrogenic ecosystems

合作研究：热解生态系统中的火真菌植物反馈

• 批准号: 1556837
• 负责人: William Platt
• 金额: $ 41万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-15 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1556837&HistoricalAwards=false
• 关键词: Collaborative; Research; Fire; fungal; plant

Unlike most natural disturbances, such as hurricanes or floods, characteristics and effects of fires depend on the plants present and the fuels they produce, both live flammable leaves and dead tissues that are released into the surrounding environment. Plants that live where fire occurs frequently are often capable of surviving fires. Some of these plants produce fuels that change the likelihood and characteristics of future fires, producing conditions favorable to them and/or their offspring. Soil organisms also affect plant fuels, and some are capable of surviving fires. They represent an important but unrecognized driver capable of altering fuels and future fires, especially in habitats with frequent fires. Soil fungi are a key example of such soil organisms, directly affecting fuel loads by decomposing dead plant tissues and indirectly affecting fuel production through their effects on plant growth. Because fungi differ in fire susceptibility, repeated fires may shape the fungi present, altering direct and indirect effects on fuels (and thus future fires). Knowledge of these fungal effects is important for managing natural fire-frequented habitats such as savannas and grasslands and forecasting the characteristics (such as the likelihood and intensity) of future fires in most terrestrial habitats. This research examines how changes in fires (severity, frequency, suppression) influence fungi and their effects on new fuels, both directly through fuel breakdown and indirectly through plants, then models how these differences may affect future fires. This research will also develop two educational modules on fire, fungi and plants: 1) undergraduate students will test different fire traits of cultured fungi and 2) K-5 classrooms will use inquiry-based learning kits that are developed on fire, fungi and plants, and that directly address next generation science standards. The research will be conducted in pine savannas, highly diverse and threatened southeastern habitats dependent on frequent fire. Initial research showed that fire alters soil fungi and results in 40% slower decomposition by microbes of dead plant leaves newly deposited on the ground. Slower decomposition causes fuels to accumulate more quickly in the environment, increasing chances and intensities of future fires. This research uses large-scale field experiments with fire, next generation DNA sequencing, and computer modeling to determine how soil microbes like fungi respond to fire, and if they play an unrecognized role by influencing likelihoods and characteristics of future fires. Because these effects are tested over a spectrum of fire severities, the model based on experimental results can be used in other pyrogenic habitats and can be used to forecast likelihoods and effects of future fires.

与大多数自然干扰（如飓风或洪水）不同，火灾的特征和影响取决于存在的植物及其产生的燃料，包括释放到周围环境中的活的易燃树叶和死亡组织。生活在经常发生火灾的地方的植物通常能够在火灾中幸存下来。其中一些工厂生产的燃料改变了未来火灾的可能性和特征，为它们和/或它们的后代创造了有利的条件。土壤生物也影响植物燃料，有些能够在火灾中幸存下来。它们是一种重要但未被认识的驱动因素，能够改变燃料和未来的火灾，特别是在经常发生火灾的栖息地。土壤真菌是这类土壤生物的一个重要例子，通过分解死亡植物组织直接影响燃料负荷，并通过影响植物生长间接影响燃料生产。由于真菌对火灾的敏感性不同，重复的火灾可能会改变现有的真菌，改变对燃料的直接和间接影响（从而改变未来的火灾）。了解这些真菌的影响对于管理热带稀树草原和草原等经常发生火灾的自然生境以及预测大多数陆地生境未来火灾的特征（如可能性和强度）非常重要。这项研究探讨了火灾的变化（严重程度，频率，抑制）如何影响真菌及其对新燃料的影响，直接通过燃料分解和间接通过植物，然后模型这些差异如何影响未来的火灾。这项研究还将开发两个关于火，真菌和植物的教育模块：1）本科生将测试培养真菌的不同火特性，2）K-5教室将使用基于火，真菌和植物开发的探究式学习工具包，并直接解决下一代科学标准。 这项研究将在松树稀树草原进行，这是一种高度多样化和受威胁的东南部栖息地，依赖于频繁的火灾。最初的研究表明，火改变了土壤真菌，导致新沉积在地面上的植物枯叶的微生物分解速度减慢了40%。缓慢的分解会导致燃料在环境中更快地积累，增加未来火灾的机会和强度。这项研究使用大规模的火灾现场实验，下一代DNA测序和计算机建模来确定真菌等土壤微生物如何对火灾作出反应，以及它们是否通过影响未来火灾的可能性和特征而发挥未被认识的作用。由于这些影响是在一系列火灾严重程度上进行测试的，因此基于实验结果的模型可用于其他热原栖息地，并可用于预测未来火灾的可能性和影响。