Few studies have examined post-fire vegetation recovery in temperate forest ecosystems with Landsat time series analysis. We analyzed time series of Normalized Burn Ratio (NBR) derived from LandTrendr spectral-temporal segmentation fitting to examine post-fire NBR recovery for several wildfires that occurred in three different coniferous forest types in western North America during the years 2000 to 2007. We summarized NBR recovery trends, and investigated the influence of burn severity, post-fire climate, and topography on post-fire vegetation recovery via random forest (RF) analysis. NBR recovery across forest types averaged 30 to 44% five years post fire, 47 to 72% ten years post fire, and 54 to 77% 13 years post fire, and varied by time since fire, severity, and forest type. Recovery rates were generally greatest for several years following fire. Recovery in terms of percent NBR was often greater for higher-severity patches. Recovery rates varied between forest types, with conifer−oak−chaparral showing the greatest NBR recovery rates, mixed conifer showing intermediate rates, and ponderosa pine showing slowest rates. Between 1 and 28% of patches had recovered to pre-fire NBR levels 9 to 16 years after fire, with greater percentages of low-severity patches showing full NBR recovery. Precipitation decreased and temperatures generally remained the same or increased post fire. Pre-fire NBR and burn severity were important predictors of NBR recovery for all forest types, and explained 2 to 6% of the variation in post-fire NBR recovery. Post-fire climate anomalies were also important predictors of NBR recovery and explained an additional 30 to 41% of the variation in post-fire NBR recovery. Landsat time series analysis was a useful means of describing and analyzing post-fire vegetation recovery across mixed-severity wildfire extents. We demonstrated that a relationship exists between post-fire vegetation recovery and climate in temperate ecosystems of western North America. Our methods could be applied to other burned landscapes for which spatially explicit measurements of post-fire vegetation recovery are needed.

中文翻译：

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利用Landsat时间序列分析检查北美西部三种森林类型的火后植被恢复

很少有研究使用Landsat时间序列分析研究温带森林生态系统中火后植被的恢复。我们分析了从LandTrendr光谱-时间分段拟合得出的归一化燃烧比（NBR）的时间序列，以研究2000年至2007年间在北美西部三种不同针叶林类型中发生的几种野火的火后NBR恢复。我们总结了NBR恢复趋势，并通过随机森林（RF）分析调查了烧伤严重程度，火灾后气候和地形对火灾后植被恢复的影响。火灾后五年，各种森林类型的NBR回收率平均分别为30-44％，火灾后十年平均为47-72％，火灾后13年平均为54-77％，并且自火灾，严重性和森林类型以来的时间而异。火灾后的几年中恢复率通常最高。对于较高级别的补丁程序，以NBR百分比表示的恢复通常更大。不同森林类型的恢复率各不相同，其中针叶树-橡木-针叶林显示出最大的丁苯橡胶恢复率，混合针叶树显示出中等的恢复率，而美国黄松显示出最慢的恢复率。火灾后9至16年，有1％至28％的补丁已恢复到着火前的NBR水平，而低严重程度补丁中有更大百分比的NBR完全恢复。着火后降水减少，温度通常保持不变或增加。火灾前NBR和烧伤严重程度是所有森林类型NBR恢复的重要预测指标，并解释了火灾后NBR恢复变化的2％至6％。火灾后的气候异常也是NBR恢复的重要预测指标，并解释了火灾后NBR恢复的另外30％至41％的变化。Landsat时间序列分析是描述和分析混合严重程度野火范围内火后植被恢复的有用手段。我们证明了北美西部温带生态系统中火后植被恢复与气候之间存在关系。我们的方法可以应用于需要空间明确测量火后植被恢复情况的其他燃烧景观。我们证明了北美西部温带生态系统中火后植被恢复与气候之间存在关系。我们的方法可以应用于需要在空间上明确测量火后植被恢复情况的其他燃烧景观。我们证明了北美西部温带生态系统中火后植被恢复与气候之间存在关系。我们的方法可以应用于需要空间明确测量火后植被恢复情况的其他燃烧景观。