Abstract This study explores the effects of year and location on reproductive traits and flowering phenology in Retama raetam populations growing in a hyper-arid environment. Besides year, season, and location, variations in the soil seed bank were also evaluated. Germination percentage of seeds buried in soil at two different depths for one year was determined. I hypothesized that changes in water availability between years and locations would lead to variations in reproductive traits, flowering phenology, and the seed bank of R. raetam. The study was conducted at a midstream and an upstream location during 2013 and 2014 in Wadi Rishrash in the Eastern Desert of Egypt. Flower, fruit, and seed production were significantly higher in the midstream location than the upstream location and in 2014 than in 2013. Flowering onset and duration did not differ significantly between locations. Flowering occurred earlier in 2014 than in 2013 at both locations, and the flowering period was longer in 2014 than in 2013. The size of the seed bank was greater at the midstream than at the upstream location, and in summer than in spring season. Germination of seeds decreased with burial depth, but increased with burial duration. Larger individuals produced more seeds and flowered earlier than smaller plants. The size of plant was also positively correlated with flowering duration. The location and temporal variations in all these traits may be related to environmental differences between locations and differences in annual precipitation.

中文翻译：

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超干旱环境中 Retama raetam（豆科）的繁殖性状、开花物候和种子库动态

摘要 本研究探讨了年份和地点对生长在超干旱环境中的 Retama raetam 种群繁殖性状和开花物候的影响。除了年份、季节和地点之外，还评估了土壤种子库的变化。确定埋在土壤中两种不同深度一年的种子发芽率。我假设年份和地点之间可用水量的变化会导致繁殖性状、开花物候和 R. raetam 种子库的变化。该研究于 2013 年和 2014 年在埃及东部沙漠的 Wadi Rishrash 的中游和上游地点进行。中游地区的花卉、果实和种子产量显着高于上游地区，2014 年显着高于 2013 年。开花开始和持续时间在地点之间没有显着差异。两地2014年开花均早于2013年，2014年开花期长于2013年。中游种子库规模大于上游，夏季大于春季。种子发芽率随埋藏深度增加而减少，但随埋藏时间延长而增加。较大的个体比较小的植物产生更多的种子并且开花更早。植物的大小也与开花持续时间呈正相关。所有这些性状的位置和时间变化可能与位置之间的环境差异和年降水量的差异有关。2014年开花期长于2013年。种子库规模在中游大于上游，夏季大于春季。种子发芽率随埋藏深度增加而减少，但随埋藏时间延长而增加。较大的个体比较小的植物产生更多的种子并且开花更早。植物的大小也与开花持续时间呈正相关。所有这些性状的位置和时间变化可能与位置之间的环境差异和年降水量的差异有关。2014年开花期长于2013年。种子库规模在中游大于上游，夏季大于春季。种子发芽率随埋藏深度增加而减少，但随埋藏时间延长而增加。较大的个体比较小的植物产生更多的种子并且开花更早。植物的大小也与开花持续时间呈正相关。所有这些性状的位置和时间变化可能与位置之间的环境差异和年降水量的差异有关。较大的个体比较小的植物产生更多的种子并且开花更早。植物的大小也与开花持续时间呈正相关。所有这些性状的位置和时间变化可能与位置之间的环境差异和年降水量的差异有关。较大的个体比较小的植物产生更多的种子并且开花更早。植物的大小也与开花持续时间呈正相关。所有这些性状的位置和时间变化可能与位置之间的环境差异和年降水量的差异有关。