Climbing chalk harmful to cliffside plants

Jake Buehler

For a firmer grip on unforgiving rock faces, rock climbers often dust their hands with climbing chalk. Composed of magnesium carbonate hydroxide, the powdery white substance leaves floury streaks behind on popular climbing routes. New research suggests that this influx of chemicals could be harmful to the vegetation that ekes out a precarious existence in this habitat.

Large boulders are often strewn about in valleys carved out by glaciers, deposited there by ancient ice flows. In the lowlands of southern Switzerland, these acidic, siliceous rock “erratics” contrast against the basic, calcareous valley floor. The islands of habitat harbor acid‐loving ferns and mosses, but in recent years, these huge rocks have also become popular with rock climbers, who use the rocks’ sheer surfaces for bouldering. “Climbing chalk has a rather high pH – it’s kind of calcareous – and those plants are adapted to very acidic environments”, explains Daniel Hepenstrick (Swiss Federal Institute of Technology; Zurich, Switzerland).

To determine whether the chalk adversely affected these plants, Hepenstrick and his team measured magnesium carbonate hydroxide levels on boulders used by climbers in the Swiss canton of Ticino, and brought four fern species and four mosses into the lab to see if various climbing chalk concentrations influenced their survival or how they germinated from spores.

Chalk levels were elevated in 65% of the areas that didn’t even have visible white marks, indicating the presence of climbing chalk in the ecosystem beyond fresh deposits. The team also found that the chalk impeded the germination and survival of all of the studied ferns and mosses (Ecol Evol 2020; doi.org/10.1002/ece3.6773).

Most research on the impacts of rock climbing to date has focused on the mechanical stress of hands and feet crushing sensitive plants, but the new findings identify an adverse chemical impact as well. This could be a conservation concern for rare rock‐dwelling plants like northern spleenwort (Asplenium septentrionale), for which only six populations remain in this part of Switzerland.

Going forward, Hepenstrick wants to test if the chalk exposure experiments can be replicated in the field. “Maybe this study will make people use climbing chalk more considerately”, he wonders. Climbers could also consider using grip‐enhancing alternatives, he says, like sticky colophony resin.

Northern spleenwort (Asplenium septentrionale), a rare fern that grows on erratic boulders, is potentially threatened by the use of climbing chalk. Credit: D Hepenstrick

中文翻译：

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派遣

攀爬对悬崖植物有害的白垩

杰克·布勒

为了更牢固地握住不宽容的岩壁，攀岩者经常用攀岩粉笔擦手。由氢氧化碳酸镁组成的粉状白色物质在流行的攀登路线上留下粉状条纹。新的研究表明，这种化学物质的流入可能会对在该生境中不稳定存在的植被有害。

大型巨石经常散落在冰川刻出的山谷中，并被古老的冰流沉积在山谷中。在瑞士南部的低地，这些酸性硅质岩“不稳定”与基本的钙质谷底形成对比。栖息地的岛屿上藏有嗜酸的蕨类植物和苔藓，但近年来，这些巨大的岩石也受到攀岩者的欢迎，他们使用岩石的纯粹表面进行抱石。“攀岩粉具有很高的pH值-它是钙质的-而且这些植物都适应于非常酸性的环境，”丹尼尔·赫本斯特里克（Daniel Hepenstrick）解释说（瑞士联邦理工学院，瑞士苏黎世）。

为了确定白垩是否对这些植物造成了不利影响，Hepenstrick和他的团队测量了瑞士提契诺州登山者使用的巨石上碳酸镁的氢氧化镁含量，并将4种蕨类和4种苔藓带入实验室，以查看各种攀岩粉笔浓度是否有影响它们的生存或如何从孢子发芽。

在甚至没有可见白色标记的区域中，有65％的地区的粉笔含量都升高了，这表明生态系统中除了新鲜沉积物之外还存在攀缘粉笔。研究小组还发现，粉笔阻碍了所有研究的蕨类植物和苔藓的发芽和存活（Ecol Evol 2020； doi.org/10.1002/ece3.6773）。

迄今为止，有关攀岩影响的大多数研究都集中在压碎敏感植物的手和脚的机械应力上，但新发现也发现了不利的化学影响。对于像北部脾草（Asplenium septentrionale）这样稀有的岩石植物，这可能是一个保护问题，在瑞士的这一地区，仅剩下六种种群。

展望未来，Hepenstrick希望测试是否可以在野外重复进行粉笔暴露实验。他想知道：“也许这项研究将使人们更加谨慎地使用攀岩粉笔。” 他说，登山者还可以考虑使用增强抓地力的替代品，例如粘性树脂树脂。

北方脾草（Asplenium septentrionale）是一种生长在不稳定的巨石上的稀有蕨类植物，可能会受到攀爬粉笔的威胁。 信用： D Hepenstrick