When wildfires occur at sufficiently low frequencies, chaparral shrubland regenerates without the need for active restoration. However, shrubland with high fire frequency, particularly in conjunction with other stressors, can require active restoration. Here we present a Post-fire Restoration Prioritization (PReP) tool for chaparral shrublands which identifies priorities for post-fire restoration based on the regeneration potential of shrubs and accounts for fire history, drought tolerance, and competition from annual grasses. We demonstrate the tool on the Copper (2002) and Powerhouse (2013) fires on the Angeles National Forest and determine that 9% (665 ha) and 14% (1,532 ha) of the fire areas, respectively, have low regeneration capacity, and therefore represent priority areas for restoration. For more recent fires (≤2 years ago), an additional component of the tool integrates erosion risk data to identify locations where active restoration may enhance hillside stabilization. To ground-truth tool outputs for the Powerhouse Fire, we sampled 57 plots to assess if recovery was indeed impeded in low versus high regeneration capacity classes. Low regeneration plots exhibited significantly higher grass and herbaceous cover, with high abundance of non-native species. Furthermore, resprouting shrub species contributed proportionally more cover than obligate seeders in low regeneration plots, with fewer individuals regenerating from seed compared to resprouting. These findings underscore the potential of the PReP tool to provide credible spatial guidance for shrubland management, both in California and potentially in other Mediterranean-type climate regions, as to where active restoration is most likely to ensure long-term sustainability of chaparral and associated ecosystem services.

中文翻译：

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确定加州灌木丛林地火灾后恢复的优先事项

当野火以足够低的频率发生时，灌木丛无需积极恢复即可再生。然而，火灾频率高的灌木丛，特别是与其他压力源一起，可能需要积极恢复。在这里，我们提出了一种用于灌木丛的火灾后恢复优先级 (PReP) 工具，该工具根据灌木的再生潜力确定火灾后恢复的优先级，并考虑火灾历史、耐旱性和一年生草的竞争。我们在洛杉矶国家森林的 Copper (2002) 和 Powerhouse (2013) 火灾中演示了该工具，并确定分别有 9%（665 公顷）和 14%（1,532 公顷）的火灾区域具有低再生能力，并且因此是恢复的优先领域。对于最近的火灾（≤2 年前），该工具的一个附加组件集成了侵蚀风险数据，以确定积极恢复可以增强山坡稳定性的位置。对于 Powerhouse Fire 的真实工具输出，我们对 57 个地块进行了抽样，以评估在低再生能力与高再生能力类别中恢复是否确实受到阻碍。低更新地块表现出显着更高的草和草本覆盖，非本地物种的丰度很高。此外，在低再生地块中，重新发芽的灌木物种比专性播种机贡献更多的覆盖，与重新发芽相比，从种子中再生的个体更少。这些发现强调了 PReP 工具的潜力，可以为加利福尼亚和其他地中海型气候区域的灌木丛管理提供可靠的空间指导，