Abstract Pinsapo fir (Abies pinsapo Boiss.) is an endangered Mediterranean conifer that has raised strong conservation interest as a paradigmatic example of species characterized by small and fragmented populations. We studied an old reforestation stand composed of A. pinsapo, Pinus nigra and Pinus sylvestris established in the 1910s in central-eastern Spain (about 500 km north of the species native distribution range), with the aim of evaluating the stand’s suitability as an ex situ conservation unit for the fir. To this end, we investigated the long-term performance of the stand and assessed genetic diversity of A. pinsapo. Tree-ring width (TRW) and carbon isotope discrimination (Δ13C) were used to characterise growth dynamics and intrinsic water-use efficiency (WUEi), respectively. Furthermore, 42 pinsapo firs were genotyped at five microsatellite loci to compare their genetic variation with published data on natural populations. A. pinsapo showed ca. two-fold higher radial growth than pines in the last 80 years; however, a growth decrease was observed for all species from the 1990s onwards. Indexed TRW was positively associated with Δ13C at the species level, denoting inter-annual growth dependence on water availability. Overall, Δ13C was higher for A. pinsapo compared to pines, indicating lower WUEi, but Δ13C significantly decreased over the last 50 years for all species, likely as the result of tighter stomatal regulation of water loss, resulting in WUEi increases of about 25 %. Recently, however, A. pinsapo showed reduced WUEi increase in concord with growth slowdown, suggesting a threshold response for stomatal regulation. Although genetic diversity of A. pinsapo was about half of natural populations, the old-planted stand could be important for the conservation of this endemic species considering its good long-term growth and physiology. The latest decrease in performance of A. pinsapo, however, asks for urgent management measures aimed at reducing the competition for water and promoting growth and natural regeneration. This study illustrates the potential of combining tree-ring-based long-term physiological information with genetic data to ascertain the prospects of artificial stands for conservation purposes.

中文翻译：

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对濒临灭绝的地中海冷杉 Abies pinsapo 的古老种植林的未来管理的树木生态学和遗传学见解

摘要 Pinsapo fir (Abies pinsapo Boiss.) 是一种濒临灭绝的地中海针叶树，作为以小而分散的种群为特征的物种的典型例子，已经引起了强烈的保护兴趣。我们研究了 1910 年代在西班牙中东部（物种原生分布范围以北约 500 公里）建立的由 A. pinsapo、Pinus nigra 和 Pinus sylvestris 组成的旧造林林分，目的是评估林分作为前冷杉原地保护单位。为此，我们调查了林分的长期表现并评估了 A. pinsapo 的遗传多样性。年轮宽度 (TRW) 和碳同位素鉴别 (Δ13C) 分别用于表征生长动态和内在用水效率 (WUEi)。此外，在 5 个微卫星位点对 42 棵松柏冷杉进行基因分型，以将它们的遗传变异与已发表的自然种群数据进行比较。A. pinsapo 显示约。在过去的 80 年中，径向增长比松树高两倍；然而，从 1990 年代开始，所有物种的生长都出现下降。指数 TRW 与物种水平的 Δ13C 呈正相关，表明年际增长对可用水量的依赖性。总体而言，与松树相比，A. pinsapo 的 Δ13C 更高，表明 WUEi 较低，但所有物种的 Δ13C 在过去 50 年中均显着下降，这可能是由于对水分流失的气孔调节更严格，导致 WUEi 增加了约 25% . 然而，最近，A. pinsapo 显示 WUEi 增加减少与生长放缓一致，表明气孔调节的阈值响应。尽管 A. pinsapo 的遗传多样性约为自然种群的一半，但考虑到其良好的长期生长和生理状况，旧种植的林分对于保护这种特有物种可能很重要。然而，最近 A. pinapo 的性能下降要求采取紧急管理措施，以减少对水的竞争并促进生长和自然再生。这项研究说明了将基于树木年轮的长期生理信息与遗传数据相结合以确定人工林分用于保护目的的前景的潜力。然而，pinsapo 要求采取紧急管理措施，以减少对水的竞争并促进生长和自然再生。这项研究说明了将基于树木年轮的长期生理信息与遗传数据相结合以确定人工林分用于保护目的的前景的潜力。然而，pinsapo 要求采取紧急管理措施，以减少对水的竞争并促进生长和自然再生。这项研究说明了将基于树木年轮的长期生理信息与遗传数据相结合以确定人工林分用于保护目的的前景的潜力。