College of Life Sciences, Beijing Normal University, Beijing, China.
Department of Botany, University of British Columbia, Vancouver, BC, Canada.
Glob Chang Biol. 2018 Jun;24(6):2463-2475. doi: 10.1111/gcb.14104. Epub 2018 Apr 10.
Nonanalogous climates (NACs), climates without modern analogs on Earth, challenge our understanding of eco-evolutionary processes that shape global biodiversity, particularly because of their propensity to promote novel ecosystems. However, NAC studies are generally inadequate and partial. Specifically, systematic comparisons between the future and the past are generally lacking, and hydraulic NACs tend to be underemphasized. In the present study, by adopting a frequency distribution-based method that facilitates the procedures of contributions parsing and conducting multiple comparisons, we provide a global overview of multidimensional NACs for both the past and the future within a unified framework. We show that NACs are globally prevalent, covering roughly half of the land area across the time-periods under investigation, and have a high degree of spatial structure. Patterns of NACs differ dramatically between the past and the future. Hydraulic NACs are more complex both in spatial patterns and in major contributions of variables than are thermal NACs. However, hydraulic NACs are more predictable than originally thought. Generally, hydraulic NACs in the future (2100 AD) exhibit comparable predictability to thermal NACs in the last glacial maximum (LGM) (21k BP). Identifying these NAC patterns has potential implications on climate-adaptive managements and preparing in advance to possibly frequent novel ecosystems. However, a learning-from-the-past strategy might be of limited utility for management under present circumstances.
非相似气候（NACs）是指地球上没有现代类似物的气候，它们挑战了我们对塑造全球生物多样性的生态进化过程的理解，尤其是因为它们倾向于促进新型生态系统的形成。然而，NAC 研究通常是不充分和片面的。具体来说，未来与过去之间的系统比较通常缺乏，并且水力 NAC 往往被低估。在本研究中，我们采用了一种基于频率分布的方法，该方法便于进行贡献解析和进行多次比较的程序，在统一的框架内为过去和未来的多维 NAC 提供了全球概述。我们表明，NAC 在全球范围内普遍存在，覆盖了研究时间段内大约一半的陆地面积，并且具有高度的空间结构。过去和未来的 NAC 模式差异很大。水力 NAC 在空间模式和主要变量贡献方面比热 NAC 更为复杂。然而，水力 NAC 的可预测性比最初想象的要高。一般来说，未来（2100 年）的水力 NAC 与末次冰期最大值（21k BP）的热 NAC 具有相当的可预测性。识别这些 NAC 模式对气候适应性管理具有潜在意义，并提前准备可能频繁出现的新型生态系统。然而，在当前情况下，从过去学习的策略可能对管理的实用性有限。
