Resilience and alternative equilibria in a mire plant community after experimental disturbance by volcanic ash.
Resilience and alternative equilibria in a mire plant community after experimental disturbance by volcanic ash.
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火山灰实验干扰后沼泽植物群落的恢复力和替代平衡。
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
P. Poschlod
中科院分区：
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作者：
S. Hotes;A. Grootjans;Hidenori Takahashi;K. Ekschmitt;P. Poschlod
干扰事件发生后，植被可以恢复并恢复到原来的状态，或者植被组成和丰度模式可能会发生变化，这可能表明替代平衡。我们进行了长期的实地实验，模拟影响空运火山喷出物（火山灰）在泥炭藓为主的植物群落，以测试这种类型的大规模干扰的影响。在日本北方北海道的Sarobetsu沼泽地建立了60个1.4 x 1.4 m的样地，并进行了7个处理（包括对照），其中包括粒度、层厚和施用季节不同的天然火山灰或毛玻璃碎片。水化学和植被进行了调查前火山灰应用程序和扰动后，分别在5年和8年。从细粒玻璃碎片的离子淋溶引起土壤水pH值和电导率的持续增加。在较粗的材料下，水质与对照组相差不大，但钾的短暂峰值表明，分解植物材料的营养释放等机制可能会影响火山干扰后的水化学。扰动最初减少了覆盖的优势功能组（泥炭藓藓）在所有的治疗，维管植物的影响较小。所有的物种都能够通过在火山灰中生长来恢复，开放的火山灰表面被无处不在的隐花植物所殖民，但不是种子植物。与植被的整体弹性行为相反，在一些地块，收到天然火山灰的替代状态与高覆盖的矮灌木杨梅大风开发。这些模式表明火山灰的物理和化学性质决定了对植物的初始影响，但随机过程有助于随后的演替。这些都可能对生态系统的功能产生影响，例如水文过程和碳固存。
Following disturbance events vegetation can either be resilient and return to its original state, or there can be shifts in vegetation composition and abundance patterns that may indicate alternative equilibiria. We conducted a long-term field experiment that simulated impact by aerially transported volcanic ejecta (tephra) in a Sphagnum-dominated plant community in order to test the effects of this type of large-scale disturbance. Sixty plots of 1.4 x 1.4 m were established at Sarobetsu mire in northern Hokkaido, Japan and subjected to seven treatments (including the control) with natural tephra or ground glass shards differing in grain size, layer thickness and season of application. Water chemistry and vegetation were surveyed before tephra application and during five and eight years after the perturbation, respectively. Leaching of ions from fine-grained glass shards caused a sustained increase of soil water pH and electric conductivity. Under coarser materials water quality differed little from the control, but a short-lived peak of potassium suggested that mechanisms like nutrient release from decomposing plant material may influence water chemistry after volcanic disturbance. The perturbation initially reduced the cover of the dominant functional group (Sphagnum mosses) in all treatments; vascular plants were less affected. All species were able to recover by growing through the tephra, and open tephra surfaces were colonized by ubiquitous cryptogams, but not by spermatophytes. In contrast to the overall resilient behaviour of the vegetation, in some plots that received natural tephra an alternative state with high cover of the dwarf shrub Myrica gale developed. The patterns indicated that physical and chemical properties of the tephra determined the initial effects on plants, but that stochastic processes contributed to subsequent succession. These are likely to have effects on ecosystem functioning, e.g. hydrological processes and carbon sequestration.