Abstract Through microclimate modifications, coffee agroforestry systems have both facilitative and inhibitory effects on the persistence of Hemileia vastatrix, a major fungal pathogen. Wind, a key element in the dispersal of H. vastatrix uredospores, is affected by shade tree presence, especially at the edge of agroforestry systems. However, little is known on how shade tree leaf functional and canopy-level architectural traits impact wind dynamics and subsequent airborne uredospore dispersal in this transition zone. In this study, we determine the contribution of shade tree leaf functional and canopy traits to changes in throughflow wind speeds and H. vastatrix uredospore dispersal at the edge of coffee agroforests across three size classes of the shade tree Erythrina poeppigiana (sparse (pruned shade trees), medium (conventional management) and dense (mature, larger, unpruned shade trees)). As expected, dense shade trees reduced throughflow speeds into the farm more frequently than the other size classes. Shade tree leaf functional traits (e.g. specific leaf area, leaf thickness, leaf angle) expressed high variability (coefficient of variations: 13.67%–89.48%) across the size classes and significantly predicted throughflow speed reductions (r2 = 0.891, P = 0.002). Emerging mature uredospore counts were significantly lower (P

中文翻译：

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遮荫树对咖啡农林业系统边缘的风动力学和病原体传播的贡献：功能性状方法

摘要 通过微气候的改变，咖啡农林业系统对主要真菌病原体 Hemileiavasatrix 的持久性具有促进和抑制作用。风是 H.vastatrix uredospores 传播的一个关键因素，它受到遮荫树存在的影响，尤其是在农林业系统的边缘。然而，关于遮荫树叶功能和冠层建筑特征如何影响该过渡区中的风动力学和随后的空气中孢子散布，我们知之甚少。在这项研究中，我们确定了遮荫树叶功能和树冠特征对通流风速变化的贡献，以及咖啡农林边缘三个大小等级的遮荫树 Erythrina poepppigiana（稀疏（修剪过的遮荫树） ), 中等（常规管理）和密集（成熟、较大、未修剪的遮荫树））。正如预期的那样，茂密的遮荫树比其他大小级别的树更频繁地降低进入农场的通流速度。遮荫树叶功能性状（例如特定叶面积、叶厚度、叶角）在不同大小级别中表现出高度可变性（变异系数：13.67%–89.48%），并显着预测通流速度降低（r2 = 0.891，P = 0.002） . 新兴成熟葡萄孢子数显着降低（P 48%) 跨尺寸等级并显着预测通流速度降低 (r2 = 0.891, P = 0.002)。新兴成熟葡萄孢子数显着降低（P 48%) 跨尺寸等级并显着预测通流速度降低 (r2 = 0.891, P = 0.002)。新兴成熟葡萄孢子数显着降低（P