Light and temperature conditions trigger germination in specific temporal windows and microhabitats, thus determining the germination niche of plant species. Manihot species grow in fire-prone ecosystems and their seeds show heat tolerance. Successful establishment in disturbed environments might be related to seed attributes that allow seeds to cope with or avoid stressful environments. We studied some characteristics of the germination niche of Manihot grahamii, a pioneer woody species present in dry subtropical forests of central Argentina, to understand its successful establishment in disturbed environments. We evaluated the germination ecology of the seeds of M. grahamii with the aims to (1) characterize seed traits (viability, mass and moisture content); (2) determine whether it has dormancy and if it is physical or physiological; (3) evaluate the effect of several pre-treatments (gibberellic acid, after ripening, dry prechilling and dry prechilling + warm) on seed dormancy; and (4) assess the effect of different environmental events of high temperatures on the germination process simulating two treatments: fire intensities (with three levels of heat shock) and a gap temperature. M. grahamii seeds have large mass (0.24 g), low moisture content (8%), physiological dormancy, negative photoblastic behaviour and high heat tolerance. Dormancy was alleviated and seeds became insensitive to light when they were exposed to pre-treatments of dry prechilling + warm and high-temperature treatments. This germination strategy promotes secure germination timing into the rainy season on undisturbed habitats as well as a cue for competition-released gaps which in turn favour recruitment in open, disturbed and dry habitats, respectively. In the context of global change, with an increasing habitat fragmentation and fire frequency, M. grahamii could become more abundant and extend its geographic distributional range in central Argentina.

光照和温度条件触发特定时间窗口和微生境的发芽，从而决定植物物种的发芽生态位。木薯物种生长在易发生火灾的生态系统中，其种子表现出耐热性。在受干扰的环境中成功建立可能与种子属性有关，这些属性使种子能够应对或避免压力环境。我们研究了木薯（Manihot grahamii）发芽生态位的一些特征，木薯是阿根廷中部干燥亚热带森林中的先锋木本物种，以了解其在受干扰环境中的成功建立。我们评估了M. grahamii种子的发芽生态学，目的是（1）表征种子性状（活力、质量和水分含量）；(2)判断是否有休眠，是否是物理休眠或生理休眠；(3)评价几种预处理(赤霉酸、后熟、干预冷和干预冷+温)对种子休眠的影响；(4) 模拟两种处理：火灾强度（具有三个级别的热冲击）和间隙温度，评估不同的高温环境事件对发芽过程的影响。M. grahamii种子质量大（0.24 g），含水量低（8%），具有生理休眠性、负光母细胞行为和高耐热性。经过干预冷+温高温处理的预处理后，种子的休眠状态得到缓解，对光变得不敏感。这种发芽策略促进了在未受干扰的栖息地进入雨季的安全发芽时间，并为竞争释放的间隙提供了线索，从而分别有利于在开放、受干扰和干燥的栖息地进行补充。在全球变化的背景下，随着栖息地破碎化和火灾频率的增加，M. grahamii可能会变得更加丰富，并扩大其在阿根廷中部的地理分布范围。