Climate has changed sufficiently over the last 150 years and forced out upper treeline advance at the most studied sites around the world. The rate of advance has been extremely variable – from tens to hundreds meters in altitude. This is because the degree at which tree frontal populations respond to climate change depends on the complex interaction of biological and physical factors. The resulting stand pattern is the consequence of the interaction between dispersal and survival functions. A few publications have addressed the question of how this pattern is generated. In order to understand how the spatial structure of tree stands was formed at the upper limit of their distribution in the Ural Mountains, we assessed the distance and direction of dispersal of offspring from maternal individuals. We found that in frontal Larix sibirica Ledeb. populations, ‘effective’ dispersal of offspring ranges from 3 to 758 ​m (with a median of 20–33 ​m in open forest and 219 ​m in single-tree tundra in the Polar Urals and 107 ​m in open forest in the Northern Urals). We revealed that most of the offspring effectively dispersed not only in the direction of the prevailing winds, but also in the opposite direction up the slope, and the distance can reach 500–760 ​m. The data obtained can be used to develop an individual-based model which is capable of simulating in detail the dynamics of tree stands at the upper limit of their growth and reliably predicting the future position and pattern of treeline ecotone as growth conditions continue to improve in the face of observed climate change.

中文翻译：

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俄罗斯北方和极乌拉尔地区落叶松后代在上部林线扩散的主导方向及有效距离


在过去的 150 年里，气候已经发生了足够的变化，并迫使世界上研究最多的地点的上部林线向前推进。前进的速度变化极大 – 从几十米到几百米不等。这是因为树木正面种群对气候变化的反应程度取决于生物和物理因素的复杂相互作用。由此产生的林分模式是分散函数和生存函数之间相互作用的结果。一些出版物已经解决了这种模式是如何产生的问题。为了了解树林的空间结构是如何在乌拉尔山脉分布的上限形成的，我们评估了后代从母系个体扩散的距离和方向。我们发现，在额叶 Larix sibirica Ledeb.种群中，后代的“有效”传播范围为 3 至 758 m（极地乌拉尔开阔森林的中位数为 20-33 m，单木苔原的中位数为 219 m，北乌拉尔的开阔森林中位数为 107 m）。我们发现，大多数后代不仅有效地向盛行风的方向分散，而且向斜坡上的相反方向分散，距离可达 500-760 m。获得的数据可用于开发基于个体的模型，该模型能够详细模拟处于其生长上限的树木的动态，并可靠地预测林线生态交错带的未来位置和模式，因为面对观察到的气候变化，生长条件不断改善。