Departamento de Ciencias Ecológicas, Facultad de Ciencias, Instituto de Ecología y Biodiversidad, Universidad de Chile, Santiago, Chile.
Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
Sci Rep. 2023 Jun 8;13(1):9340. doi: 10.1038/s41598-023-35658-8.
Based on the niche conservatism hypothesis, i.e. the idea that niches remain unchanged over space and time, climatic niche modelling (CNM) is a useful tool for predicting the spread of introduced taxa. Recent advances have extended such predictions deeper in time for plant species dispersed by humans before the modern era. The latest CNMs successfully evaluate niche differentiation and estimate potential source areas for intriguing taxa such as archaeophytes (i.e., species introduced before 1492 AD). Here, we performed CNMs for Acacia caven, a common Fabaceae tree in South America, considered an archaeophyte west of the Andes, in Central Chile. Accounting for the infraspecific delimitation of the species, our results showed that even when climates are different, climatic spaces used by the species overlap largely between the eastern and western ranges. Despite slight variation, results were consistent when considering one, two, or even three-environmental dimensions, and in accordance with the niche conservatism hypothesis. Specific distribution models calibrated for each region (east vs west) and projected to the past, indicate a common area of occupancy available in southern Bolivia-northwest Argentina since the late Pleistocene, which could have acted as a source-area, and this signal becomes stronger through the Holocene. Then, in accordance with a taxon introduced in the past, and comparing regional vs continental distribution models calibrated at the infraspecific or species level, the western populations showed their spread status to be mostly in equilibrium with the environment. Our study thus indicates how niche and species distribution models are useful to improve our knowledge related to taxa introduced before the modern era.
基于生态位保守假说，即生态位在空间和时间上保持不变的观点，气候生态位模型（CNM）是预测引入分类群扩散的有用工具。最近的进展已经将此类预测扩展到了人类在现代之前传播的植物物种的更深时间。最新的 CNM 成功地评估了生态位分化，并估计了有趣分类群（如古植物，即 1492 年以前引入的物种）的潜在源区。在这里，我们对南美洲常见的豆科树金合欢（Acacia caven）进行了 CNM 分析，该物种被认为是安第斯山脉以西的古植物。考虑到该物种的种下划分，我们的结果表明，即使气候不同，该物种在东部和西部范围之间的气候空间也有很大的重叠。尽管存在细微差异，但当考虑一个、两个甚至三个环境维度时，结果是一致的，并且与生态位保守假说一致。为每个区域（东部与西部）校准的特定分布模型，并投影到过去，表明自更新世晚期以来，玻利维亚南部-阿根廷西北部就有一个共同的可用栖息地，这可能是一个源区，并且这种信号在全新世变得更强。然后，根据过去引入的分类群，并比较在种下或种水平校准的区域与大陆分布模型，西部种群的扩散状态与环境基本处于平衡状态。因此，我们的研究表明，生态位和物种分布模型如何有助于提高我们对现代以前引入的分类群的相关知识。
