粤北山地常绿阔叶林自然干扰后冠层结构空间异质性动态

以受2008年冰灾破坏的广东始兴车八岭山地常绿阔叶林为研究对象,采用半球面影像技术、地统计学的空间异质性和空间自相关分析方法,连续3年(2008-2010年)对林冠结构空间异质性动态进行了检测研究.结果表明:(1)从2008到2010年,林冠开度的平均值、标准差、变异系数、最大值、最大值和最小值的差值以及林冠结构的空间异质性均在逐渐减小,且后两年较为接近；(2)受灾当年冠层结构由随机因素造成,其半方差拟合函数属纯块金模型,后两年冠层结构则由结构性因素引起,其半方差拟合函数属球状模型；(3)受灾当年冠层结构不存在空间自相关；随着时间推移其空间自相关越来越强.说明冰灾后常绿阔叶林冠层结构在没有人为干预的情况下会逐渐恢复到灾前水平,体现出天然的空间分布状况.

Spatial Heterogeneity Dynamics of Canopy Structure in a Montane Evergreen Broadleaved Forest Following a Natural Disturbance in North Guangdong

The spatial heterogeneity dynamics of canopy structure were successively investigated（from 2008 to 2010） in Chebaling montane evergreen broadleaved forest following an ice storm in 2008.We used hemispherical photography to acquire canopy pictures and geostatistics to analyze the spatial heterogeneity and spatial autocorrelation of canopy structure.The mean,standard deviation,variation coefficient,minimum and maximum of canopy openness,and spatial heterogeneity of canopy structure decreased from 2008 to 2010,and the values were more similar to each other in 2009 and 2010.Geostatistical analysis indicated that semivariance function of the 2008 canopy structure fitted with the pure nugget model and demonstrated stochastic factors in interpreting canopy structure,while 2009 and 2010 fitted with the spherical model and demonstrated structural factors,especially in 2010.No spatial autocorrelation was found in the canopy structure of 2008,while spatial autocorrelation became stronger with time.Our results indicated that canopy structure could recover to its pre-disaster level gradually without human intervention and reflect spatial distribution in natural state conditions.