Invasion of Norway spruce (Picea abies) and the rise of the boreal ecosystem in Fennoscandia
Invasion of Norway spruce (Picea abies) and the rise of the boreal ecosystem in Fennoscandia
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挪威云杉（Picea abies）的入侵和 Fennoscandia 北方生态系统的兴起
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发表时间：
2009
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影响因子：
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通讯作者：
P. Muukkonen
中科院分区：
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作者：
H. Seppä;T. Alenius;R. Bradshaw;T. Giesecke;Maija Heikkilä;P. Muukkonen
1.挪威云杉（Picea abies）是欧亚大陆的主要树种之一，在欧洲北方缓慢向西扩展，大约在6500 calibrated years BP前入侵芬兰东部，大约在2700 calibrated years BP前入侵瑞典东部中部，大约在1000 calibrated years BP前入侵挪威南部。它的传播是最近和最好的限制入侵的主要树种在北方欧洲，并允许评估殖民模式和相关的竞争性替代过程。2我们分析了沿700公里长的样带的五个选定的高分辨率花粉积累率（PAR）记录，该样带从芬兰东部到瑞典中部，沿着冷杉入侵的方向，穿过目前的冷杉和樟子松为主的南部寒带。3我们的结果表明，从最初的扩张到与现代相当的水平，在100-550年内，欧洲冷杉种群的规模有所增加。在每一个站点，冷杉入侵了密集的，完整的松桦赤杨林，混合温带落叶类群，特别是紫椴和榛。留居混交林对冷杉种群的定殖没有抵抗力或抵抗力很弱，因此，种群增长率的变化不是由留居混交林的组成差异引起的，而是由其他可能是当地土壤因素引起的。4在形成常驻森林的分类群中，T.心叶类植物对冷杉入侵的反应最强烈。这表明中全新世T. cordata种群的下降不是直接由气候引起的，而是由于与P. abies（一个更强大的竞争对手）重叠的生态位而引起的竞争性替代。5合成。冷杉的优势地位不仅是由于其快速的人口增长，而且是由于其他类群的竞争性抑制，导致生态系统发生重大变化，从针叶林-落叶林混合林到现代冷杉-和樟子松-占主导地位的北方针叶林。这种竞争性抑制仍然反映在T. abies的分散出现和普遍较弱的性能。在预测的未来气候情景下，欧洲北部地区的cordata可能会影响其分布和丰度模式。
1 Norway spruce (Picea abies), one of the dominant tree species in Eurasia, has spread slowly westward in northern Europe, invading eastern Finland about 6500 calibrated years ago (cal. years BP), eastern central Sweden about 2700 cal. years BP and southern Norway about 1000 cal. years BP. Its spread is the most recent and best constrained invasion of a main tree species in northern Europe and allows an assessment of colonization patterns and associated competitive replacement processes. 2 We analysed five selected high‐resolution pollen accumulation rate (PAR) ‐records along a 700‐km long transect in the direction of P. abies invasion from eastern Finland to central Sweden across the present P. abies‐ and Pinus sylvestris‐dominated southern boreal zone. 3 Our results show that the P. abies population increased in size from the time of the initial expansion to levels comparable with the modern in 100–550 years. At each site P. abies invaded a dense, intact Pinus–Betula–Alnus forest, mixed with temperate deciduous taxa, particularly Tilia cordata and Corylus avellana. The resident mixed forest provided no or weak resistance to the colonization of P. abies, and the variable population growth rate was therefore not caused by compositional differences in the resident forest but by other, possibly local edaphic factors. 4 Of the taxa that formed the resident forest, T. cordata responded most strongly to the invasion of P. abies. This suggests that the mid‐Holocene T. cordata population decline was not directly climate‐induced but resulted from competitive replacement due to overlapping ecological niches with P. abies, a stronger competitor. 5 Synthesis. The rise to dominance of P. abies was caused not only by its rapid population growth but by associated competitive suppression of other taxa, leading to a major ecosystem change from a mixed conifer‐deciduous forest to the modern P. abies‐ and P. sylvestris‐dominated boreal conifer forest in central Fennoscandia. This competitive suppression by P. abies is still reflected in the scattered occurrence and generally weak performance of T. cordata in the boreal zone of Europe and may influence its distribution and abundance patterns under predicted future climate scenarios.