我们都在暴风雨后的消息中看到了图像。树枝，有时是整棵树，躺在地面上的碎片中。但是，尽管该消息侧重于这些事件的人类影响，但也需要考虑的生态影响，正如发表在BMC Ecologyearlier this year investigated.

‘A tree that refuses to dance will be made to do so by the wind’ – so the African saying goes, but the wind can be a fearsome force that won’t be satisfied with mere swaying of branches.

风，有时在炎热的天气里微风拂面，而在其他人则是一个全能的暴君吹滚滚的大风。至少大多数动物可以避开它，但是树木无处可隐藏。暴风雨过后，有些人可能会毫发无损地生存，而邻居则躺在地上，树干分裂，两分之一，甚至是抬起的根源，它们的牙冠扔进了泥土中。

These casualities have suffered a case of ‘windthrow’, a natural phenomenon where strong winds break or uproot trees. Windthrow can have a dynamic influence on tree community structure, allowing an entire new species of trees to seize the area or causing regeneration by increasing the availability of resources.

The most susceptible individuals to windthrow mortality are large, tall trees with a wide crown and shallow anchorage, such as a Beech tree. Reduced stem flexibility too makes them more prone to breaking.

And it’s not just the strong gusts of wind that are a threat to trees, but the fact that they are typically accompanied by heavy downpours. The soil becomes waterlogged and malleable, loosening the trees secure rooting. Trees rapidly absorb the excess water and store it in their canopies of branches and leaves, making them top heavy. Loose anchorage and a heavy crown is a recipe for disaster, as another blow results in a fallen tree.

Although a well-established cause of tree mortality in forested regions, windthrow is poorly documented in Southern Africa and little is known about its effects in open arid regions. With the threat of extreme weather events seemingly increasing,a team of researcherssought to identify how common the phenomenon is and what impact it may have on the African ecosystem.

他们学习了Aloe dichotoma，通常称为Quiver Tree或Kokerboom，一种南非土著物种。标志性的标本和气候变化指标，其特征性的刚性结构及其宽阔的牙冠和浅根深度，将其处于风流的高风险。

根据这项研究，Winthrow是死亡率的更大原因A.dichotomathan previously thought. It accounts for 49% of species mortality. Most trees can mitigate against the wind’s drag forces through flexing in its stems and branches, butA.dichotomahas no defence strategy. Its inflexibility renders it helpless against greater drag forces, especially adults with denser canopies compared to their smaller unbranched juveniles.

There is concern for important adult populations of these trees, as they tend to bear the weight of reproductive responsibility, and were found to be more vulnerable than juveniles. Small isolated adult populations are more likely to suffer localised extinction due to windthrow events.

Usually more than a dozen individuals in a given tree community are blown over during a single storm event. This is worrying given the slow recruitment, as saplings only establish themselves every 10 to 15 years or more.

Windthrow could affect the long term persistence ofA.dichotoma和other tree populations, given the fact that lack of water and limited access to nutrients slows the recovery rate in arid environments.

Prolonged recovery and increased frequency of storms predicted to hit southern Africa could have a huge impact on these ecosystems in the future. These findings could serve as important guidelines for conservation management, helping tree populations to stand fast in the face of the forthcoming storms.