Dissertation Research: Light Interception and Growth in Four Pioneer Tree Species with Contrasting Canopy Architecture

研究将集中在冠层结构的意义上 对四个速生树种幼苗的光截获和生长有明显的影响。 生长的新热带树种与对比建筑 模式. 四种，Cecropia obtusifolia，Heliocarpus apparentulatus，Piper auriculatus和Trema micrantha，提出了一种 林冠结构的光谱，从几个大叶子出生在一个 单枝到生于分枝树冠的许多小叶。 在田间生长的幼苗的光截获将 估计与计算机模拟结合联合收割机测量 叶片显示与冠层光半球形照片 环境 光截获能力将与 在18个月的时间内增长。 该分析将 辅之以在受控环境中研究幼苗生长， 环境，其中相对增长率被分解为 三个因素，环境光水平，光量 拦截，以及光利用效率。 最后， 每个物种的个体将在空间上生长 异质环境，以评估可塑性 叶展的结构和形态成分。 这 研究将提供功能的定量分析 冠层结构与光照关系 拦截和碳增益。

The research will focus on the significance of canopy structure for light interception and growth in seedlings of four fast- growing neotropical tree species with contrasting architectural patterns. The four species, Cecropia obtusifolia, Heliocarpus appendiculatus, Piper auritum, and Trema micrantha, present a spectrum of canopy architectures, from few large leaves born on a single shoot to many small leaves born in a branched crown. Light interception of seedlings growing in the field will be estimated with computer simulations which combine measurements of leaf display with hemispherical photographs of the canopy light environment. The light interception capacity will be correlated with growth over an 18 month period. This analysis will be complemented by a study of seedling growth in a controlled environment, in which relative growth rate is decomposed into three factors, the ambient light level, the amount of light intercepted, and the efficiency of light utilization. Finally, individuals of each species will be grown in spatially heterogeneous environments to evaluate the plasticity of architectural and morphological components of leaf display. This research will provide a quantitative analysis of the functional significance of canopy architecture in relation to light interception and carbon gain.