Data from: Genetic evidence for a Janzen-Connell recruitment pattern in reproductive offspring of Pinus halepensis trees.

Effective seed dispersal, combining both dispersal and post-dispersal (establishment) processes, determines population dynamics and colonization ability in plants. According to the Janzen-Connell (JC) model, high mortality near the mother plant shifts the offspring establishment distribution farther away from the mother plant relative to the seed dispersal distribution. Yet, extending this prediction to the distribution of mature (reproductive) offspring remains a challenge for long-living plants. To address this challenge we selected an isolated natural Aleppo pine (Pinus halepensis) population in Mt. Pithulim (Israel), expanded from five ancestor trees in the beginning of the 20th century into ~2000 trees today. Using nine microsatellite markers, we assigned parents to trees established during the early stages of population expansion. To elucidate the effect of the distance from mother plant on post-dispersal survival, we compared the effective seed dispersal kernel, constructed based on the distribution of mother-offspring distances, to the seed dispersal kernel, computed based on simulations of a mechanistic wind dispersal model. We found that the mode of the effective dispersal kernel is shifted farther away than the mode of the seed dispersal kernel, reflecting increased survival with increasing distance from the mother plant. The parentage analysis demonstrated a highly skewed reproductive success and a strong directionality in effective dispersal corresponding to the wind regime. We thus provide the first evidence that JC effects act also on offspring that become reproductive and persisted as adults for many decades, a key requirement in assessing the role of post-dispersal processes in shaping population and community dynamics.有效的种子扩散结合扩散过程与扩散后（建群）过程，共同决定植物的种群动态与定殖能力。根据詹森-康奈尔（Janzen-Connell, JC）模型，母株周边的高死亡率会使子代建群分布相较于种子扩散分布向远离母株的方向偏移。然而，将该预测推广至成熟（生殖）子代的分布格局，对于长寿植物而言仍是一项未解难题。为解决这一难题，我们选取了以色列皮图勒姆山（Mt. Pithulim）一处孤立的天然阿勒颇松（Pinus halepensis）种群：该种群于20世纪初由5株祖先个体发展而来，如今已增至约2000株。我们利用9个微卫星标记（microsatellite markers），对种群扩张早期阶段建立的实生个体进行了亲本归属鉴定。为阐明母株距离对扩散后存活的影响，我们将基于母子距离分布构建的有效种子扩散核（effective seed dispersal kernel），与基于机理型风扩散模型模拟得到的种子扩散核进行了对比。研究发现，有效扩散核的众数相较于种子扩散核的众数向更远位置偏移，这反映出随着与母株距离增加，子代存活率显著提升。亲权分析结果显示，种群内个体的繁殖成功存在极强的偏斜性，且有效扩散存在与区域风况对应的显著方向性。据此，我们首次证实詹森-康奈尔效应同样作用于能够完成繁殖并存活数十年的成熟子代，这是评估扩散后过程在塑造种群与群落动态中作用的核心前提。