Spatiotemporal dynamics of encroaching tall vegetation in timberline ecotone of the Polar Urals Region, Russia
Spatiotemporal dynamics of encroaching tall vegetation in timberline ecotone of the Polar Urals Region, Russia
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DOI：
10.1088/1748-9326/ac3694
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发表时间：
2021-11
影响因子：
6.7
通讯作者：
Wenbo Zhou;V. Mazepa;S. Shiyatov;Yulia V. Shalaumova;Tianqi Zhang;Desheng Liu;A. Sheshukov;
中科院分区：
文献类型：
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作者：
Wenbo Zhou;V. Mazepa;S. Shiyatov;Yulia V. Shalaumova;Tianqi Zhang;Desheng Liu;A. Sheshukov;
先前的研究发现西伯利亚落叶松在空间上异质扩张到极地乌拉尔（俄罗斯）的苔原。这项研究表明，林分侵占的空间格局与地形和积雪等环境因素有关。沿 860 m 长、80 m 宽的横断面收集树木的结构和异速生长特征，以及地形海拔和积雪深度。地形曲率指数作为代表性属性，是在一系列尺度上得出的，以表征微地形。这里使用基于密度的聚类方法来分析树干分布的空间和时间模式。地形分析的结果表明，树木倾向于聚集在具有凸面的区域。聚类分析还表明，树木位置的模式与雪的分布有关。 1960年最早的活动记录显示，树木主要生活在高雪深地区样带的中部和底部。近几十年来，随着气候变暖，树木向山上扩展，高积雪深度区域也向上移动，为以前被大雪覆盖的地区最近的树木生长创造了有利条件。已确定的高植被增加的景观特征以及微地形和积雪的影响可能有助于了解更大尺度的林线动态。
Previous studies discovered a spatially heterogeneous expansion of Siberian larch into the tundra of the Polar Urals (Russia). This study reveals that the spatial pattern of encroachment of tree stands is related to environmental factors including topography and snow cover. Structural and allometric characteristics of trees, along with terrain elevation and snow depth were collected along a transect 860 m long and 80 m wide. Terrain curvature indices, as representative properties, were derived across a range of scales in order to characterize microtopography. A density-based clustering method was used here to analyze the spatial and temporal patterns of tree stems distribution. Results of the topographic analysis suggest that trees tend to cluster in areas with convex surfaces. The clustering analysis also indicates that the patterns of tree locations are linked to snow distribution. Records from the earliest campaign in 1960 show that trees lived mainly at the middle and bottom of the transect across the areas of high snow depth. As trees expanded uphill following a warming climate trend in recent decades, the high snow depth areas also shifted upward creating favorable conditions for recent tree growth at locations that were previously covered with heavy snow. The identified landscape signatures of increasing tall vegetation, and the effects of microtopography and snow may facilitate the understanding of treeline dynamics at larger scales.