Data from: Unraveling conflicting density- and distance-dependent effects on plant reproduction using a spatially-explicit approach

1. Density- and distance-dependent (DDD) mechanisms are important determinants of plant reproductive success (PRS). Different components of sequential PRS can operate either in the same or in different directions and thus reinforce or neutralize each other, and they may also operate at different spatial scales. Thus, spatially-explicit approaches are needed to detect such complex DDD effects across multiple PRS components and spatial scales. 2. To reveal DDD effects of different components of early PRS of the Iberian pear (Pyrus bourgaeana) sampled over three consecutive years, we used marked point pattern analysis. Our special interest is to identify conflicting processes that regulate populations at different spatial scales, e.g. whether DDD on fruit initiation and on fruit development acted in opposite directions. To evaluate the significance of observed mark correlation functions based on empirical data (e.g. fruiting success) we compared them to expectations given by spatially-explicit null models. 3. Diverse DDD processes affected several aspects of PRS in a variable extent over the three seasons. First, early fruit set was higher for individuals with more neighbors at small distances (i.e. up to 40m). However, late P. bourgaeana fruit set decreased with increasing number of nearby neighbors, but these effects canceled for overall fruit set that did not show DDD effects. Second, the absolute number of fruits produced (crop sizes) by trees showed positive density dependence in 2011 and 2012 but not in 2013. Finally, the total number of seeds produced did not show DDD effects, indicating that conflicting demographic processes can disrupt the initial spatial pattern of tree investment in reproduction. 4. Synthesis: Understanding complex spatial effects of density- and distance-dependent (DDD) processes requires dissection of component processes to attain the complete picture since contrasting DDD processes may be hidden behind a single cumulative measure of reproductive success. The combination of novel and classic mark correlation functions used here constitute a powerful spatially-explicit tool that can be broadly applied to unravel conflicting mechanisms of DDD regulating the persistence of sessile organisms at a range of spatial scales. Our findings help to explain why some authors failed to find expected DDD of PRS and highlight the importance of detailed multi-year field studies on plant reproductive success.

1. 密度与距离依赖（Density- and distance-dependent, DDD）机制是调控植物繁殖成功（plant reproductive success, PRS）的关键驱动因子。植物序列式繁殖成功的不同组分既可同向发挥作用，亦可异向作用，进而彼此强化或相互抵消，且可能在不同空间尺度上运作。因此，亟需采用空间显式方法，以检测跨多个繁殖成功组分与空间尺度的复杂DDD效应。
2. 为揭示连续三年采样的伊比利亚梨（*Pyrus bourgaeana*）早期繁殖成功不同组分的DDD效应，本研究采用标记点格局分析（marked point pattern analysis）方法。本研究的核心目标是识别调控不同空间尺度种群的冲突过程，例如调控坐果起始与坐果发育的DDD效应是否方向相反。为评估基于经验数据（如坐果成功率）得到的标记相关函数的显著性，我们将其与空间显式零模型给出的理论预期值进行了对比。
3. 在三个连续生长季中，多样的DDD过程以不同程度影响了植物繁殖成功的多个维度。首先，在小尺度（即40米以内）邻株数量更多的个体，其早期坐果率更高。然而，伊比利亚梨的后期坐果率随邻近邻株数量增加而降低，但该效应在总体坐果率中被抵消，总体坐果率未表现出DDD效应。其次，树木的绝对结实量（座果总数）在2011年与2012年呈现正密度依赖效应，但2013年未出现该现象。最后，总种子产量未表现出DDD效应，这表明相互冲突的种群统计过程可能会破坏树木繁殖投入的初始空间格局。
4. 综合讨论：要理解密度与距离依赖过程的复杂空间效应，需拆解各组分过程以完整呈现全貌，因为对立的DDD过程可能隐匿于单一的繁殖成功累积指标之后。本研究结合使用的新型与经典标记相关函数，构成了一套强大的空间显式分析工具，可广泛应用于解析调控固着生物在多个空间尺度上存续的DDD冲突机制。本研究结果有助于解释为何部分学者未能发现预期的植物繁殖成功DDD效应，并凸显了针对植物繁殖成功开展多年度详细野外研究的重要性。