Wingfield Jenna L, Ruane Lauren G, Patterson Joshua D
Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, Virginia 23606 USA.
Department of Organismal and Environmental Biology, Christopher Newport University, Newport News, Virginia 23606 USA.
Appl Plant Sci. 2017 Nov 16;5(11). doi: 10.3732/apps.1700056. eCollection 2017 Nov.
The three-dimensional structure of tree canopies creates environmental heterogeneity, which can differentially influence the chemistry, morphology, physiology, and/or phenology of leaves. Previous studies that subdivide canopy leaves into broad categories (i.e., "upper/lower") fail to capture the differences in microenvironments experienced by leaves throughout the three-dimensional space of a canopy.
We use a three-dimensional spatial mapping approach based on spherical polar coordinates to examine the fine-scale spatial distributions of photosynthetically active radiation (PAR) and the concentration of ultraviolet (UV)-absorbing compounds () among leaves within the canopies of black mangroves ().
Linear regressions revealed that interior leaves received less PAR and produced fewer UV-absorbing compounds than leaves on the exterior of the canopy. By allocating more UV-absorbing compounds to the leaves on the exterior of the canopy, black mangroves may be maximizing UV-protection while minimizing biosynthesis of UV-absorbing compounds.
Three-dimensional spatial mapping provides an inexpensive and portable method to detect fine-scale differences in environmental and biological traits within canopies. We used it to understand the relationship between PAR and , but the same approach can also be used to identify traits associated with the spatial distribution of herbivores, pollinators, and pathogens.
树冠层的三维结构造成了环境异质性，这可能会对叶片的化学组成、形态、生理和/或物候产生不同影响。以往将树冠层叶片大致分为几大类（即“上部/下部”）的研究，未能捕捉到树冠层三维空间中叶片所经历的微环境差异。
我们采用基于球极坐标的三维空间映射方法，研究了黑 mangroves（此处原文 mangroves 前应有具体名称，暂按“黑红树”处理）树冠层内叶片光合有效辐射（PAR）和紫外线（UV）吸收化合物浓度的精细尺度空间分布。
线性回归显示，树冠层内部叶片比外部叶片接收的PAR更少，产生的紫外线吸收化合物也更少。通过向树冠层外部的叶片分配更多紫外线吸收化合物，黑红树可能在最大限度地保护免受紫外线伤害的同时，将紫外线吸收化合物的生物合成降至最低。
三维空间映射提供了一种廉价且便携的方法，用于检测树冠层内环境和生物特征的精细尺度差异。我们用它来理解PAR与（此处原文缺失具体指标，暂按前文推测为紫外线吸收化合物浓度）之间的关系，但同样的方法也可用于识别与食草动物、传粉者和病原体空间分布相关的特征。
