Estimating leaf inclination and G-function from leveled digital camera photography in broadleaf canopies
Estimating leaf inclination and G-function from leveled digital camera photography in broadleaf canopies
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DOI：
10.1007/s00468-011-0566-6
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发表时间：
2011-04
期刊：
影响因子：
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通讯作者：
J. Pisek;Y. Ryu;K. Alikas
中科院分区：
文献类型：
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作者：
J. Pisek;Y. Ryu;K. Alikas
本研究探讨了用水平数码相机测量叶片倾斜角的有效性，作为现有方法的一种廉价和方便的替代方法。通过对爱沙尼亚半北部地区和夏威夷群岛热带森林常见的各种阔叶树种的人工叶角测量，验证了新方法的有效性。所获得的叶角分布表明，在模拟(半)北方阔叶林冠层的辐射传输时，食虫性情况可能比通常假设的球状情况更适合作为叶片方向的一般近似。然而，应尽可能获得直接的叶片倾斜度测量，因为无论是在不同物种之间还是在单一物种内的时空域中，叶片取向总是存在着很大的变化。在这项研究中测试的相机方法提供了一种新的健壮和负担得起的工具来获取这些信息。
The effectiveness of using leveled digital camera for measuring leaf inclination angles was investigated in this study as an inexpensive and convenient alternative to existing approaches. The new method is validated with manual leaf angle measurements for various broadleaf tree species common to hemi-boreal region of Estonia and the tropical forests of Hawai’i Islands. The acquired leaf angle distributions suggest that planophile case might be more appropriate than the commonly assumed spherical as the general approximation of leaf orientation while modeling the radiation transmission through the canopies of (hemi)-boreal broadleaf stands. However, direct leaf inclination measurements should be obtained whenever possible, as there will always exist a large variety of leaf orientation, both among different species and in the space–time domain within a single species. The camera method tested in this study provides a new robust and affordable tool to obtain this information.