Causes of secondary sexual dimorphism (SSD) in dioecious plants are very poorly understood, especially in woody plants. SSD is shown mainly in mature plants, but little is known about whether secondary sexual dimorphism can occur in juveniles. It is also assumed that stress conditions intensify differences between the sexes due to the uneven reproductive effort. Therefore, the following research hypotheses were tested: (1) secondary sexual dimorphism will be visible in juveniles; (2) unfavourable soil conditions are the cause of more pronounced differences between the sexes. Rooted shoots of the common yew (Taxus baccata L.) and common juniper (Juniperus communis L.), previously harvested from parental individuals of known sex were used in the study. During two growing seasons vegetation periods and four times a year, comprehensive morphological features of whole plants were measured. Some SSD traits were visible in the analysed juveniles. Contrary to expectations, differences were more pronounced in the fertilized treatment. Both species reacted to fertilization in different ways. Female yew had a clearly higher total plant mass, root mass, and mean root area when fertilized, whereas male juniper had a higher root mass when fertilized. Differences between the sexes independent of the fertilization treatment were seen, which can be interpreted as sexual adaptations to a continued reproduction. Female yews and male junipers made better use of fertile habitats. Our study showed that SSD may be innate, and sexual compensatory mechanisms could generate uneven growth and development of both sexes. Because the SSD pattern was rather different in both species, it was confirmed that SSD is connected with the specific life histories of specific species rather than a universal strategy of dioecious species.

对雌雄异株植物中第二性二态性 (SSD) 的原因知之甚少，尤其是在木本植物中。SSD主要出现在成熟植物中，但关于幼体是否会发生第二性二态性知之甚少。还假设由于不均匀的生殖努力，压力条件会加剧两性之间的差异。因此，测试了以下研究假设：（1）在青少年中会出现第二性二态性；(2) 不利的土壤条件是导致两性差异更加明显的原因。红豆杉 ( Taxus baccata L.) 和杜松 ( Juniperus Communis ) 的生根芽L.)，之前从已知性别的父母个体中采集，用于研究。在两个生长季节的植被期和一年四次中，对整株植物的综合形态特征进行了测量。在分析的青少年中可以看到一些 SSD 特征。与预期相反，受精处理的差异更为明显。这两个物种对受精的反应不同。雌性红豆杉在受精时具有明显更高的总植物质量、根质量和平均根面积，而雄性杜松在受精时具有更高的根质量。观察到独立于受精处理的性别差异，这可以解释为对持续繁殖的性适应。雌性红豆杉和雄性杜松更好地利用了肥沃的栖息地。我们的研究表明 SSD 可能是与生俱来的，性补偿机制可能导致两性的不平衡生长和发育。由于两个物种的SSD模式差异很大，因此证实SSD与特定物种的特定生活史有关，而不是雌雄同体物种的普遍策略。