Fifteen years of canopy dynamics analyzed by aerial photographs in a temperate deciduous forest, Japan
Fifteen years of canopy dynamics analyzed by aerial photographs in a temperate deciduous forest, Japan
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通过航空照片分析日本温带落叶林十五年的树冠动态
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
T. Nakashizuka
中科院分区：
文献类型：
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作者：
Hiroshi Tanaka;T. Nakashizuka
航空照片被用来分析超过15年的长期冠层动态在一个大面积（25.25公顷）的混合落叶林小川森林保护区，日本中部。利用1976 ~ 1991年4个夏季每隔5年的航空摄影资料，建立了林冠表面的数字高程模型。根据1991年冬季的航空摄影资料，建立了地面数字高程模型。在每个位置的冠层高度计算从冠层和地面之间的海拔差，和“植被剖面技术”被应用到量化冠层动态。在每个观测时间的间隙和观测时间之间创建的间隙的大小分布遵循幂函数模型。虽然在整个期间的差距形成和关闭的速度几乎是平衡的，他们之间的观测期间表现出很大的时间变化。新形成的林隙的空间分布明显偏向于老林隙的边缘。重复间隙产生的可能性也显著高。应用转移概率矩阵分析林窗高度剖面的变化，结果表明林窗面积的分布基本上处于稳定状态。
Aerial photographs were used to analyze long-term canopy dynamics over 15 yr in a large area (25.25 ha) for a mixed deciduous forest in the Ogawa Forest Reserve, central Japan. Digital elevation models of canopy surface were made from aerial photo- graphs taken in four summers at 5-yr intervals from 1976 to 1991. A digital elevation model of ground surface was also made from the aerial photograph taken in winter 1991. The canopy height at each location was calculated from the elevational difference between the canopy and the ground, and the "vegetation profile technique" was applied to quantify canopy dynamics. The size distributions of gaps at each observation time and of gaps that were created between observation times followed a power function model. While the rates of gap formation and closure throughout the whole period were nearly balanced, they showed large temporal variations among the observation periods. Spatial distribution of newly created gaps was significantly biased toward the edges of old gaps. Probability of repeated gap creation was also significantly high. Analysis of changes in the canopy height profile by a transition probability matrix showed that gap area distribution of this forest may be nearly in a steady state.