中国西南四种常见松树火适应性状比较

野火对松属植物的进化和分布有重要的影响。在与野火长期抗争中，松属植物形成了一系列性状提高在易火生境中的适合度，维持种群生存与繁衍。西南地区是中国野火高发区，作为这一地区特有松树，云南松、思茅松和高山松具有一些典型的火适应性状，如厚树皮。以这3种松树和东部常见的马尾松为研究对象，比较4种松树的火适应对策。结果表明：4种松树的火适应性状存在一定的差异。与火适应相关的13项性状主成分分析显示，4个种在空间上总体是分离的，也表现出一些重叠。其中云南松火适应生活史对策是火耐受型和火依赖型的中间类型，适应会发生林冠火的生境。高山松、思茅松和马尾松都是火耐受型，通过快速高生长、厚树皮等性状适应生境不同频度的地表火。四种松树火适应对策与分布区火险基本相符。表明野火在这一区域广泛存在，并对植物进化和森林格局有重要影响。野火在西南地区松属分布和种群维持中的生态作用应被给予足够重视。

Fire-adapted traits of four pine trees in the southwestern China

Fire plays an important role in the evolution and distribution of pine species. Pines developed a series of traits to improve their fitness in the fire-prone ecosystems to maintain the populations. The Southwest China is a hot spot of wildfire. There are three endemic pine species in this region, Pinus yunnanensis, Pinus kesiya var. langbianensis and Pinus densata, which have been reported to have some fire-adapted traits, like thick bark. In this study, we compared the fire-adapted traits among the three pines and another pine wildly distributed in eastern China (Pinus massoniana). The results showed that the fire-adapted traits of the four pines had some differences. Principal component analysis of 13 fire-adapted traits suggested that the four pines were separated spatially, with partially overlapped. The fire-adapted syndromes of P. yunnanensis was an intermedius type between fire-tolerator and fire-embracer, which adapted to the environment where crown fires occurred. The other three pines were fire-tolerators, they adapted to surface fires of different frequencies in their habitat through traits like fast growth, thick bark, and so on. Overall, the fire-adapted syndromes of the four pines were consistent with the fire risk of their distribution area. Our results suggested that fire in this region was a widespread disturbance, and had an important impact on plant evolution and vegetation pattern. More attention should be paid to the ecological role of fires in the distribution and maintenance of pine species.