【摘要】 利用全林木定位的方法,对地表火干扰1年后的樟子松(Pinus sylvestris L.var.mongolica Litv.)林进行调查,并通过假设检验和成对相关函数对其林火及林分结构特征和空间格局进行分析。结果表明,林火强度相似的同一场地表火干扰下,不同林分的密度均大大降低,胸高断面积仅略有下降,林分结构特征则有趋同的态势。不同林分的空间格局也有相似的变化趋势,烧死木均表现为显著的双尺度聚集分布及显著的正相关,活立木也表现出显著的正相关;地表火干扰前后,樟子松林的空间格局均为显著的聚集分布,但地表火干扰后其聚集分布的尺度范围变小;存活林木中,大树和幼树则呈现出相互独立或略微排斥的关系。显然,地表火驱动下,不同樟子松林的空间格局呈现出相似的变化趋势,并推动其向着成熟林方向演替,这对天然樟子松林的资源保护和经营管理有着重要意义。更多还原

【Abstract】 Aims Our objectives were to 1) explore variations of stand structure and spatial pattern after surface fire in Mongolian pine forest of the Hulun Buir sand region and 2) elucidate surface fire as a dynamic driving force in stand thinning and succession. Methods Fire-killed and live trees were mapped in two 1-hm2 plots one year postfire. Differences of fire intensities and stand structures were tested by the Kruskal-Wallis procedure, and spatial patterns were explored using the pair correlation function g(r). Important findings Tree densities decreased greatly and basal areas were decreased slightly by surface fire with similar intensities. Fire-killed trees showed a nested, double-cluster, positively correlated pattern. Stems were aggregated spatially preand postfire; however, the ranges of significant scales were narrower postfire. Adults and saplings were independent or slightly negatively associated at small scales. We conclude that surface fire is an important driving force of stand thinning and variations in spatial pattern that influence succession to mature forest.更多还原