Evaluating the impact of historical climate and early human groups in the Araucaria Forest of Eastern South America

It has been hypothesized that the Araucaria Forest in Southern Brazil underwent expansions in the past, driven either by human groups or by climate fluctuations of the Holocene and Pleistocene. Fossil pollen records of the Paraná Pine (Araucaria angustifolia), a dominant tree in that forest, provide some insights into when those may have occurred. Still, the timing of those expansions has never been estimated. To infer past range shifts and shed light on their main drivers, we employed next-generation DNA sequencing (ddRADseq), machine learning, and a comprehensive database of fossil pollen records in a study of historical demographic inference and paleo-distribution modeling of the Paraná Pine. We found that A. angustifolia comprises two populations expanding at different times: one in the Mantiqueira mountain chain, and the other in the southern Brazilian plateau. The Southern population began to expand during the Last Glacial Period ~70kya, long before human arrival in South America...., , , # Evaluating the impact of historical climate and early human groups in the *Araucaria* Forest of Eastern South America

[https://doi.org/10.5061/dryad.9ghx3ffr8](https://doi.org/10.5061/dryad.9ghx3ffr8)

## Description of the data and file structure

* Fossil_pollen_reference_list.pdf – complete list of references from which fossil pollen data were retrieved and used in the multitemporal species distribution models of *Araucaria angustifolia*.
* Fossil_pollen_data_Araucaria.xlsx – spreadsheet containing two tabs: [data] with the data retrieved from the reference list above, and [colunm_description] with explanations of the column names. Each row of data refers to a sediment layer covering a period described in the 'sedim_young' and 'sedim_old' columns, which might portray a discontinuous distribution of *Araucaria* pollen in the core over time (if more than one row). Columns named in gray describe data directly retrieved from each reference and columns named in yellow contain our c...

已有假说提出，巴西南部的南洋杉林曾在历史上发生过范围扩张，其驱动因素可能为人类活动，或是全新世与更新世的气候波动。作为该林分优势树种的巴拉那松（Araucaria angustifolia），其化石花粉记录为这类扩张事件的发生时间提供了一定线索，但此前从未有研究对这些扩张的时间节点进行过估算。为推断该树种过去的分布范围变化，并阐明其扩张的主要驱动因素，本研究针对巴拉那松开展了历史种群推断与古分布建模工作，采用了下一代DNA测序（ddRADseq）、机器学习方法，以及一套完整的化石花粉记录数据库。研究发现，巴拉那松存在两个扩张时间各异的种群：一个分布于曼蒂凯拉山脉链，另一个分布于巴西南部高原。南部种群于末次冰期开始扩张，距今约7万年前（~70kya），这一时间远早于人类抵达南美洲的时间……

# 评估历史气候与早期人类活动对南美洲东部南洋杉林的影响

https://doi.org/10.5061/dryad.9ghx3ffr8

## 数据与文件结构说明

* Fossil_pollen_reference_list.pdf —— 完整参考文献列表，本研究从中提取并使用了巴拉那松（Araucaria angustifolia）多时间尺度物种分布模型所需的化石花粉数据。
* Fossil_pollen_data_Araucaria.xlsx —— 包含两个工作表的电子表格：[data]工作表存放从上述参考文献列表中提取的原始数据，[colunm_description]工作表用于阐释各列名称的含义。每一行数据对应一个沉积层，其覆盖的时间范围由"sedim_young"与"sedim_old"两列标注；若存在多行数据，则可反映出岩芯中南洋杉花粉分布随时间呈现的不连续性特征。以灰色标注的列对应直接从各参考文献中提取的原始数据，以黄色标注的列则包含我们的……