Ecological resilience is the capacity of a system to maintain function following disturbance. With the frequency and severity of wildfire activity increasing due to warmer and drier global climate conditions, there are increasing reports of declines in ecological resilience and ecosystems at risk of collapse due to post-fire recovery failure. Observational monitoring of post-fire recovery at the landscape scale is important to understand drivers, identify vulnerable ecosystems and prioritize management intervention to support resilience. Defining a suitably representative baseline condition to compare post-fire recovery states against can be challenging, particularly in broad-scale remote sensing approaches. Here, we introduce a new approach to monitoring post-fire recovery by satellite imagery, the post-fire stability index. The method is based on the concept that a disturbed system state will be reflected by increasing or decreasing rates of system change, while undisturbed or recovered system states are characterised by near-zero rates of change. This reflects the typical pattern of diminishing rate of change in post-fire recovery trajectories. We demonstrate strong performance and suitability of the post-fire stability index in comparison to alternative approaches through time series analyses, and independent validation from post-fire vegetation surveys taken at one-year post-fire. The post-fire stability index was consistently the best performing model across all field measures of vegetative response following the fire event. In ecosystems which exhibit post-fire resprouting, higher values in the post-fire stability index were associated with higher levels of field-based measures of foliage projective cover and canopy cover (+/− resprouting), and with lower levels of basal and no resprouting. The post-fire stability index provides a relatively simple and practical solution for consistent broad-scale monitoring post-fire recovery with satellite imagery, which together with standardised fire severity mapping, provide extensive opportunities for further fire and landscape ecology research.

生态复原力是系统在受到干扰后维持功能的能力。由于全球气候条件变暖和干燥，野火活动的频率和严重程度增加，越来越多的报道称，生态恢复力下降，生态系统因火灾后恢复失败而面临崩溃风险。在景观尺度上对火灾后恢复进行观测监测对于了解驱动因素、识别脆弱的生态系统和优先管理干预以支持恢复力非常重要。定义一个具有适当代表性的基线条件来比较火灾后恢复状态可能具有挑战性，尤其是在大范围遥感方法中。在这里，我们介绍了一种通过卫星图像监测火灾后恢复的新方法，即火灾后稳定性指数。该方法基于这样的概念，即受干扰的系统状态将通过增加或减少的系统变化率来反映，而未受干扰或恢复的系统状态的特征在于接近于零的变化率。这反映了火灾后恢复轨迹变化率递减的典型模式。与通过时间序列分析的替代方法相比，我们展示了火灾后稳定性指数的强大性能和适用性，以及火灾后一年后进行的火灾后植被调查的独立验证。火灾后稳定性指数始终是火灾事件后植物响应的所有现场测量中表现最好的模型。在表现出火灾后重新萌芽的生态系统中，火灾后稳定性指数的较高值与较高水平的树叶投影覆盖和冠层覆盖（+/- 重新萌芽）的基于现场的测量水平相关，并且与较低水平的基础和无重新萌芽相关。火灾后稳定性指数提供了一个相对简单和实用的解决方案，用于通过卫星图像进行一致的大范围火灾后恢复监测，与标准化的火灾严重性绘图一起，为进一步的火灾和景观生态学研究提供了广泛的机会。