Influence of fire severity on stand development of Araucaria araucana-Nothofagus pumilio stands in the Andean cordillera of south-central Chile
Influence of fire severity on stand development of Araucaria araucana-Nothofagus pumilio stands in the Andean cordillera of south-central Chile
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DOI：
10.1111/j.1442-9993.2009.02064.x
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发表时间：
2010-09
期刊：
影响因子：
1.5
通讯作者：
Mauro E. González;T. Veblen;Jason S. Sibold
中科院分区：
文献类型：
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作者：
Mauro E. González;T. Veblen;Jason S. Sibold
火灾是智利中南部南洋杉-Nothofagus森林景观中普遍存在的干扰。虽然地表和林分替代火灾是已知的这些生态系统的特点，在塑造森林结构的火灾严重程度的变化以前没有调查南洋杉，Nothofagus森林。年龄结构的16个立场，其中约650棵树的年龄进行了测定，表明火灾的严重程度和频率的变化是关键，以解释镶嵌在南洋杉，Nothofagus景观的森林斑块。高水平的树木死亡率在中度至高度严重的火灾，其次是新成立的Nothofagus pumilio通常会导致在看台上的特点是一个或两个队列的这个物种。大型南洋杉对火灾有很强的抵抗力，这种物种通常以分散的个体或多年龄树木的小群体的形式在中度到高度严重的火灾中幸存下来。火灾后的南洋杉小群体可能会建立，这取决于种子的可用性和随后的火灾的影响。南洋杉的长寿（通常>700年）和对火的抵抗力使一些个体能够在导致死亡并引发新的假法格斯种群的火灾中幸存下来。即使是在相对温和的栖息地，火灾不太频繁，最古老的南洋杉-Nothofagus pumilio站起源于高严重性火灾后。总体而言，亚高山南洋杉-N. pumilio森林在很大程度上是由中度至高度严重的火灾控制，因此树木再生动力学强烈主导的灾难性再生模式。
Fire is the prevalent disturbance in the Araucaria-Nothofagus forested landscape in south-central Chile. Although both surface and stand-replacing fires are known to characterize these ecosystems, the variability of fire severity in shaping forest structure has not previously been investigated in Araucaria-Nothofagus forests. Age structures of 16 stands, in which the ages of approximately 650 trees were determined, indicate that variability in fire severity and frequency is key to explaining the mosaic of forest patches across the Araucaria-Nothofagus landscape. High levels of tree mortality in moderate- to high-severity fires followed by new establishment of Nothofagus pumilio typically result in stands characterized by one or two cohorts of this species. Large Araucaria trees are highly resistant to fire,and this species typically survives moderate- to high-severity fires either as dispersed individuals or as small groups of multi-aged trees. Small post-fire cohorts of Araucaria may establish, depending on seed availability and the effects of subsequent fires. Araucaria's great longevity (often >700 years) and resistance to fire allow some individuals to survive fires that kill and then trigger new Nothofagus cohorts. Even in relatively mesic habitats, where fires are less frequent, the oldest Araucaria-Nothofagus pumilio stands originated after high-severity fires. Overall, stand development patterns of subalpine Araucaria-N. pumilio forests are largely controlled by moderate- to high-severity fires, and therefore tree regeneration dynamics is strongly dominated by a catastrophic regeneration mode.