Vegetation of zonal patterned‐ground ecosystems along the North America Arctic bioclimate gradient
Vegetation of zonal patterned‐ground ecosystems along the North America Arctic bioclimate gradient
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DOI：
10.1111/j.1654-109x.2011.01149.x
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发表时间：
2011-10
影响因子：
2.8
通讯作者：
D. Walker;P. Kuss;H. Epstein;A. Kade;C. Vonlanthen;M. Raynolds;F. Daniëls
中科院分区：
文献类型：
--
作者：
D. Walker;P. Kuss;H. Epstein;A. Kade;C. Vonlanthen;M. Raynolds;F. Daniëls
问题：自然环境和植被的生物特性之间的相互作用如何影响北极生物气候梯度上小图案地面特征的形成？地点：北纬68°至78°：阿拉斯加北极道尔顿高速公路沿线的6个地点和加拿大的3个地点（班克斯岛、帕特里克王子岛和埃尔夫林内斯岛）。方法：分析147个地带性微生境的区系和结构植被、生物量和非生物数据（土壤化学和物理参数、n因子[a土壤热指数]和光谱信息[NDVI， LAI]）。使用映射、表分析（JUICE）和协调技术（NMDS）。结果：利用JUICE表分析和ph系数对诊断种进行鉴定，在5个地带性植被复区中有4个诊断植物类群具有明确的类群。在NMDS排序中，植物群落和地带性复合体总体上分离较好。由于不同的冰川历史和不同的地理位置，阿拉斯加和加拿大的群落在空间上是分离的，但没有单一的环境梯度控制。植被结构，特别是苔藓植物和总生物量的结构，对土壤的热性质有强烈的影响。地形图与周围植被的热差异最大，地形图形态最清晰。结论：研究在格局地复合体内不同微生境上生长的小型植物群落的组成和结构，对于了解植被对格局地形态的生物和物理控制是必要的。更大尺度的植被单位，在这里被称为“地带性带状地面植被复合体”（地带性景观中的带状地面植物群落群），对于景观和区域层面的比较以及将在样地尺度上收集的信息外推到更大的区域是有用的。外推需要各分区代表性景观的植被图。南北缘植物生长特征的不同，对稳定高霜活性土壤有重要作用。一个概念图总结了沿北极气候梯度的植被和地形形态之间的相互作用。
Question: How do interactions between the physical environment and biotic properties of vegetation influence the formation of small patterned-ground features along the Arctic bioclimate gradient? Location: At 68° to 78°N: six locations along the Dalton Highway in arctic Alaska and three in Canada (Banks Island, Prince Patrick Island and Ellef Ringnes Island). Methods: We analysed floristic and structural vegetation, biomass and abiotic data (soil chemical and physical parameters, the n-factor [a soil thermal index] and spectral information [NDVI, LAI]) on 147 microhabitat releves of zonal-patterned-ground features. Using mapping, table analysis (JUICE) and ordination techniques (NMDS). Results: Table analysis using JUICE and the phi-coefficient to identify diagnostic species revealed clear groups of diagnostic plant taxa in four of the five zonal vegetation complexes. Plant communities and zonal complexes were generally well separated in the NMDS ordination. The Alaska and Canada communities were spatially separated in the ordination because of different glacial histories and location in separate floristic provinces, but there was no single controlling environmental gradient. Vegetation structure, particularly that of bryophytes and total biomass, strongly affected thermal properties of the soils. Patterned-ground complexes with the largest thermal differential between the patterned-ground features and the surrounding vegetation exhibited the clearest patterned-ground morphologies. Conclusions: Characterizing the composition and structure of small-scale plant communities growing on distinctive microhabitats within patterned-ground complexes was necessary to understand the biological and physical controls of vegetation on patterned-ground morphology. Coarser-scale vegetation units, referred to here as ‘zonal patterned-ground vegetation complexes’ (groups of patterned-ground plant communities within zonal landscapes), were useful for landscape and regional-level comparisons and for extrapolation of information collected at plot scales to larger regions. Vegetation maps of the representative landscapes in each subzone were needed for extrapolation. Different growth characteristics of plants growing in northern and southern parts of the gradient have an important effect in stabilizing highly frost-active soils. A conceptual diagram summarizes the interactions between vegetation and patterned-ground morphology along the Arctic climate gradient.