Forest management, especially restoration, is informed by understanding the dominant natural disturbance regime. In many western North American forests, the keystone disturbance is fire, and a plethora of research exists characterizing various fire regime parameters, although often only one or two parameters are addressed in individual studies. I performed a systematic review of the literature and meta-analysis of the derived data from 26 publications to characterize five parameters of the historical fire regime of ponderosa pine (Pinus ponderosa Lawson & C. Lawson) ecosystems in Colorado, USA: fire frequency, severity, extent, seasonality, and climate. The collection of evidence indicates a fire regime predominantly characterized by moderate to high frequency, low- and mixed-severity fires that occurred in late summer to fall, with fires occurring in drier than average years that were often preceded by two to three years of wetter than average conditions. The overall average mean fire return interval (MFI) was 21 years (SD = 1.4 years, n = 78 sites) and increased with site elevation (r = 0.33, P < 0.05). Low- and mixed-severity fires accounted for 83% of all observations, and 69% of fires occurred in late summer to fall with no relationship found between latitude and seasonality. Geographic region (Front Range and southwestern Colorado) was associated with variability in fire regime parameter values, with southwestern Colorado sites having a stronger association with wetter than average conditions in the three years preceding fire years and a shorter mean MFI (18 years) relative to Front Range sites (23 years). Data were insufficient to evaluate changes in fire severity and extent due to a lack of historical information, as well as differences in sampling methods and reporting. This meta-analytic approach identified variation within and among fire regime parameter values that occurred along elevational and geographic axes, and this information should be useful to managers engaging in forest restoration aimed at enhancing resilience of fire-adapted forests to disturbance and climate change.

中文翻译：

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美国科罗拉多州的美国黄松（Pinus tankerosa）生态系统火情研究的系统综述和荟萃分析

通过了解主要的自然干扰制度，可以进行森林管理，特别是恢复。在北美西部许多森林中，主要的扰动是火灾，尽管存在大量研究来表征各种火灾状况参数，但在个别研究中通常只涉及一两个参数。我对来自26个出版物的文献进行了系统的综述并对衍生数据进行了荟萃分析，以表征美国科罗拉多州黄松（Pinus tankerosa Lawson＆C. Lawson）生态系统历史火灾状况的五个参数：火灾频率，严重性，程度，季节性和气候。证据收集表明，着火情况主要是夏末至秋季发生中度到高频，低度和混合严重度的火灾，发生的火灾比正常年份干燥，通常比正常情况湿润两到三年。总体平均平均回火间隔（MFI）为21年（SD = 1.4年，n = 78个站点），并随站点海拔的升高而增加（r = 0.33，P <0.05）。低度和混合严重度火灾占所有观测值的83％，69％的火灾发生在夏末至秋季，没有发现纬度与季节之间的关系。地理区域（前锋和科罗拉多州西南部）与火势参数值的变化相关，西南科罗拉多州站点在火灾前三年的湿润关联性高于平均状况，相对于火灾发生前三年的平均MFI较短（18年）前沿靶场（23年）。由于缺乏历史信息以及采样方法和报告的差异，数据不足以评估火灾严重性和程度的变化。这种荟萃分析方法可以识别出沿海拔和地理轴发生的火灾状况参数值之内和之间的变化，该信息对于从事森林恢复工作的管理者应该是有用的，旨在增强适应火灾的森林对干扰和气候变化的适应能力。