Simultaneous growth releases and reductions among Populus alba as an indicator for floods in dry mountains (Morocco)

作者：Ireneusz Malik, Maciej Dłużewski, Joanna Rotnicka, Małgorzata Wistuba, Kazimierz Krzemień, Andrzej Muszyński, Elżbieta Rojan, Albert Ślęzak · 发表于：Ecological Indicators · 年份：2021 · DOI：10.1016/j.ecolind.2021.107874 · 被引用次数：10 · 研究领域：Tree-ring climate responses、Plant Water Relations and Carbon Dynamics、Soil erosion and sediment transport

We studied the growth reaction of silver poplar trees (Populus alba) to a large flood in November 2014 in the semi-arid High Atlas Mountains, Morocco. The flood resulted in half of the studied trees developing wider tree rings in 2015 and the other half developing narrower rings in 2015, next year after the flood. For 57.1% of trees which released growth in 2015, this was the most significant increase of ring width during their whole lives (in whole tree-ring chronologies), and for 23.8% of trees which reduced growth in 2015, this was the most significant decrease of ring width. Tree-ring reductions in next year after the 2014 flood resulted from environmental stress related to burying stems with alluvia deposited during the flood. Fresh sediments cut off air access from the root system, and for some of the sampled trees, this stress was strong enough to control their radial growth. Growth releases that follow the 2014 flood are a record of trees benefitting from a sudden supply of water, a rare opportunity in dry study area, where water is usually scarce. The study demonstrates that floods in high mountains of arid zone can cause dual, opposite growth reaction of affected trees. Such dual record is characteristic for environmental impulses, which exert stress on trees, but, at the same time, improve other conditions of tree growth. Environmental events that cause simultaneous positive and negative reactions among a population of trees, like studied flood, can easily be overl...