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

与大多数自然灾害（如飓风或洪水）不同，火灾的特征和影响取决于存在的植物和它们产生的燃料，包括活的可燃叶子和释放到周围环境中的死组织。生活在经常发生火灾的地方的植物往往能够在火灾中幸存下来。其中一些植物产生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。土壤生物也会影响植物燃料，有些能够在火灾中幸存下来。它们是一种重要但未被认识到的驱动因素，能够改变燃料和未来的火灾，尤其是在火灾频发的栖息地。土壤真菌是这类土壤生物的一个重要例子，它们通过分解死去的植物组织直接影响燃料负荷，并通过对植物生长的影响间接影响燃料生产。由于真菌对火灾的易感性不同，反复的火灾可能会塑造真菌，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稀树草原和草原等自然火灾频发的栖息地以及预测大多数陆地栖息地未来火灾的特征（如可能性和强度）非常重要。本研究考察了火灾的变化（严重程度、频率、抑制）如何直接通过燃料分解和间接通过植物影响真菌及其对新燃料的影响，然后模拟了这些差异如何影响未来的火灾。该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教室将使用针对火、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，这是一个高度多样化的、受到威胁的东南部栖息地，依赖于频繁的火灾。最初的研究表明，火灾改变了土壤真菌，并导致微生物对新沉积在地面上的植物死亡叶片的分解速度减慢40%。较慢的分解导致燃料在环境中积累得更快，增加了未来火灾的几率和强度。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做出反应，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到的作用。由于这些影响是在火灾严重程度的范围内进行测试的，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。

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.