呼伦贝尔沙地樟子松空间格局对地表火干扰的响应

利用全林木定位方法，对地表火干扰后樟子松林的残桩、倒木、枯立木和活立木等各林木组分进行了调查。Ripley’s K函数分析表明，地表火干扰后12年内樟子松的空间格局均表现为显著的均匀分布，且不同阶段樟子松均匀分布显著的尺度范围的变化幅度较小。地表火驱动的林分稀疏过程中，残桩和枯立木均表现出显著的聚集分布，而倒木的空间分布格局则是随机的。双变量分析也表明，活立木与残桩、全部死亡林木之间相互排斥显著，而活立木与倒木、枯立木间则是相互独立的。短期内，地表火成为樟子松空间格局变化的主要驱动力；随着时间的推移，这种作用会逐渐衰减并为其他因素所代替。因此，地表火改善了林分结构，使樟子松的空间格局更趋于均匀，有利于存活林木的生长发育，并加快林分向成熟林演变的进程。 

Responses of spatial pattern to surface fire in Mongolian pine forests,Hulun Buir Sand Region,Inner Mongolia of northern China

Here the authors investigated the variations of spatial pattern in the fire-mediated Mongolian pine forests using the scale-depended point pattern analysis of Ripley's K function.Stumps,fallen logs and standing dead trees were also quantified and added up to the stand to reconstruct the chronosequence of stem distribution within 12 years after surface fire attacking.The results showed that stem distributions were significantly regular over time,stumps and standing dead trees were all significantly aggregate...