Institute for Conservation Biology, School of Biological Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia.
Glob Chang Biol. 2015 Jun;21(6):2454-64. doi: 10.1111/gcb.12848. Epub 2015 Feb 18.
Increased aridity is of global concern. Polar regions provide an opportunity to monitor changes in bioavailable water free of local anthropogenic influences. However, sophisticated proxy measures are needed. We explored the possibility of using stable carbon isotopes in segments of moss as a fine-scale proxy for past bioavailable water. Variation in δ(13) C with water availability was measured in three species across three peninsulas in the Windmill Islands, East Antarctica and verified using controlled chamber experiments. The δ(13) C from Antarctic mosses accurately recorded long-term variations in water availability in the field, regardless of location, but significant disparities in δ(13) C between species indicated some make more sensitive proxies. δ(13) CSUGAR derived from living tissues can change significantly within the span of an Antarctic season (5 weeks) in chambers, but under field conditions, slow growth means that this technique likely represents multiple seasons. δ(13) CCELLULOSE provides a precise and direct proxy for bioavailable water, allowing reconstructions for coastal Antarctica and potentially other cold regions over past centuries.
干旱加剧受到全球关注。极地为监测不受当地人为影响的可用生物水变化提供了机会。但是，需要复杂的替代指标。我们探讨了利用苔藓段中的稳定碳同位素作为过去可用生物水的精细替代指标的可能性。在东南极的风车群岛的三个半岛上，我们在三个物种中测量了 δ(13) C 与水分可用性的变化，并使用受控室实验进行了验证。南极苔藓中的 δ(13) C 准确地记录了野外水分可用性的长期变化，无论位置如何，但物种之间 δ(13) C 的显著差异表明某些物种具有更高的敏感性。来自活体组织的 δ(13) CSUGAR 在室内的一个南极季节（5 周）内可能会发生显著变化，但在野外条件下，缓慢的生长意味着这种技术可能代表了多个季节。 δ(13) CCELLULOSE 是可用生物水的精确和直接替代指标，允许对过去几个世纪的南极洲沿海地区和其他寒冷地区进行重建。
