Weak effect of urbanisation on bdelloid rotifers living in lichens

Human activities have an overwhelming impact on the natural environment, leading to a deep biodiversity crisis whose effects range from genes to ecosystems. We here analysed the effect of such anthropogenic impacts on bdelloid rotifers (Rotifera: Bdelloidea), for whom these effects are poorly understood. We targeted bdelloid rotifers living in lichen patches across urbanisation gradients in Flanders and Brussels (Belgium). Urbanisation was measured as the percentage of built-up area across different spatial scales, at circles from 50 m to 3,200 m of radius around the lichen. Urbanisation effects on biodiversity were assessed on abundance, species richness, and community-weighted mean body size of bdelloid rotifers, as well as on genetic diversity of one of the most common and widespread bdelloid species, Adineta vaga. Overall, no negative effect of urbanisation was found at any diversity level and at any spatial scale. Counterintuitively, built-up area quantified at the largest spatial ..., Communities of bdelloid rotifers were sampled by collecting one lichen patch in each subplot. We selected lichens of the genus Xanthoria, for which bdelloid rotifer communities have been previously studied in Europe (Fontaneto et al. 2011). Lichens of the genus Xanthoria are among the most abundant in urban and rural areas, apparently unaffected by urbanisation levels (Nekrošienė 2012). Sampling was performed in June and July 2013. Suitable Xanthoria patches could be found in all but two subplots: total sample size is thus 79 lichens and not 81. 
The selection of the lichen was haphazard: the first suitable lichen patch encountered in each subplot was collected. Dry lichen thalli between 5 and 10 cm2 were cut from the substrate with a knife and kept in zip lock bags. For each lichen sample, an area of 2.5 cm2 was hydrated with distilled water in a plastic petri dish. 
All active bdelloid rotifers that recovered from dormancy within the four hours following hydration in the lab were sort..., , # Weak effect of urbanisation on bdelloid rotifers living in lichens

Here we report all the datasets and R scripts that we used to test our hypotheses about rotifer community abundance and assemblage in a context of increasing urbanisation.

## Description of the data and file structure

1. The main dataset, contained in the file “ESM_04-speedy_bdello.csv” describes each of the 79 samples collected for this study.

* Column 1, “lichen.patch”, uniquely defines the sampled lichen patch. It coincides with column 28, “sampleID”.
* Columns 2-22 report individual quantity of each bdelloid rotifer species. For example: in the lichen sample Gg8 only 2 individuals of *Macrotrachela ehrenbergii* were identified.
* Column 23, “abundance”, reports the total abundance of rotifers found in the lichen patch. For example, in the sample Gg8 only 2 rotifers were found, hence quantity is 2.
* Column 24, “richness”, informs on how many different species were found in the patch of lichen collect...

人类活动对自然环境具有压倒性影响，引发了严重的生物多样性危机，其影响范围涵盖从基因到生态系统的各个层级。本研究针对人为活动对蛭形轮虫（bdelloid rotifers，轮虫动物门：蛭形轮亚纲）的影响展开分析，目前学界对这类影响的认知仍较为匮乏。我们选取了比利时佛兰德斯与布鲁塞尔地区沿城市化梯度分布的地衣斑块中的蛭形轮虫作为研究对象。城市化水平以地衣周边半径50米至3200米的圆形区域内的建成区占比来衡量，涵盖多种空间尺度。我们从蛭形轮虫的丰度、物种丰富度、群落加权平均体型，以及最常见且分布最广的蛭形轮虫物种——阿氏旋轮虫（Adineta vaga）的遗传多样性这几个维度，评估了城市化对生物多样性的影响。整体而言，在任何多样性层级与空间尺度下，均未发现城市化产生显著负面影响。出乎意料的是，在最大空间尺度下量化的建成区面积……，蛭形轮虫群落通过在每个样方小区（subplot）中采集一块地衣斑块进行采样。我们选取了黄枝衣属（Xanthoria）的地衣，该属的蛭形轮虫群落此前已在欧洲地区得到研究（Fontaneto等，2011）。黄枝衣属地衣是城市与农村地区分布最广泛的地衣类群之一，且似乎不受城市化水平的影响（Nekrošienė，2012）。采样工作于2013年6月至7月开展。除两个样方小区外，其余所有样方小区均采集到了合格的黄枝衣属地衣斑块，因此最终有效样本量为79份地衣样品，而非计划的81份。
地衣样品的选取采用随机方式：采集每个样方小区中遇到的第一块合格地衣斑块。使用小刀从基质上切取面积为5至10平方厘米的干燥地衣体，装入自封袋中保存。对于每份地衣样品，取2.5平方厘米的地衣碎片置于塑料培养皿中，用蒸馏水进行水化处理。
所有在实验室水化后4小时内从休眠状态恢复活动的活跃蛭形轮虫将被分选……，
# 城市化对地衣生境中蛭形轮虫的微弱影响
本研究公开了用于验证我们关于城市化程度提升背景下轮虫群落丰度与组成的假说的全部数据集与R脚本。

## 数据与文件结构说明
1. 主数据集存储于文件"ESM_04-speedy_bdello.csv"中，记录了本研究采集的全部79份样品的相关信息。
* 第1列"lichen.patch"为采样地衣斑块的唯一标识符，与第28列"sampleID"完全一致。
* 第2至22列记录了每种蛭形轮虫的个体数量。例如：在Gg8号地衣样品中，仅鉴定出2个*Macrotrachela ehrenbergii*个体。
* 第23列"abundance"记录了该份地衣样品中轮虫的总丰度。例如：Gg8号样品仅发现2只轮虫，因此该列数值为2。
* 第24列"richness"记录了该份地衣斑块中发现的不同物种数量……