A multifaceted ecological assessment reveals the invasion of the freshwater red macroalga Montagnia macrospora (Batrachospermales, Rhodophyta) in Taiwan

Invasive freshwater macroalgae are rarely described. Montagnia macrospora is a freshwater red alga introduced from South America to East Asia via the global aquarium trade. The earliest occurrence record of this alga in Taiwan is dated 2005. To determine whether M. macrospora has become invasive in Taiwan and to understand the traits that facilitated its invasion, we took a multifaceted approach that combines examination of ecological background and population genetic analysis. Our island-wide survey showed that M. macrospora is widespread in the field across Taiwan, where the climate greatly differs from that of South America, and can self-sustain for nearly a decade. Our population genetic analysis revealed a lack of genetic diversity of M. macrospora in Taiwan, consistent with the hypothesis that the alga expanded through asexual reproduction. Moreover, during our long-term ecological assessments and field surveys, we observed thatM. macrospora is an ecological generalist that can su..., Nutrient_levels_location_Mmacrospora_presence
For nutrient measurements, water samples of 1,000 mL were collected and stored in an ice box during transportation. Then, measurements of four nutrients (ammonia, nitrate, nitrite, and phosphate, in mg L-1) were taken in our laboratory using a SMARTSpectro spectrophotometer (LaMotte, Maryland, USA).
Taoyuan_stream_survey_data
Field surveys between August 2012 and October 2013 were carried out at four sites along a small spring-fed stream in Longtang District, Taoyuan City, Taiwan (24°53'09.3\"N, 121°13'54.1\"E), once a month. The four sites were 10 m apart from each other, going from downstream (site 1) to upstream (site 4). 
The percent cover of M. macrospora at each site was calculated as the average of the percent cover of five quadrats of the site positioned along a transect perpendicular to the streamflow at each site.
Water temperature, light intensity (µmol photons m-2 s-1), pH, conductivity (µS cm-1), turbidity (mg L-1), water velocity..., , # Data from: A multifaceted ecological assessment reveals the invasion of the freshwater red macroalga Montagnia macrospora (Batrachospermales, Rhodophyta) in Taiwan

[https://doi.org/10.5061/dryad.8cz8w9gt3](https://doi.org/10.5061/dryad.8cz8w9gt3)

## Description of the data and file structure

#### **Nutrient\_levels\_location\_Mmacrospora\_presence**

Nutrient levels (ammonia, nitrate, nitrite, and phosphate, in mg L-1) at the eight locations in Taiwan where *M. macrospora* was found, and in the artificial reservoir pond in Okinawa (Japan), where the presence of *M. macrospora* was first reported in East Asia (Kato et al., 2009). 

#### **Taoyuan\_stream\_survey\_data**

*M. macrospora* percent cover and environmental parameters measured during the field survey between August 2012 and October 2013 were carried out at four sites along a small spring-fed stream in Longtang District, Taoyuan City, Taiwan (24°53'09.3\"N, 121°13'54.1\"E).

#### **Taoyuan\_stream\_survey\_stats\_Rcodes**

R...

入侵性淡水大型藻类的相关研究报道较为匮乏。大孢蒙氏藻（Montagnia macrospora）是一种淡水红藻，通过全球水族贸易从南美洲传入东亚。该藻在台湾地区的最早出现记录可追溯至2005年。为明确大孢蒙氏藻是否已在台湾形成入侵种群，并解析其成功入侵的关键适应性性状，本研究采用结合生态背景调查与种群遗传分析的多维度研究方法。全岛调查结果显示，尽管台湾地区气候与南美洲差异显著，但大孢蒙氏藻已在台湾野外广泛分布，且可自主存续近十年。种群遗传分析结果表明，台湾地区的大孢蒙氏藻遗传多样性匮乏，与该藻通过无性繁殖实现种群扩张的假说一致。此外，在长期生态评估与野外调查中，我们观察到大孢蒙氏藻属于生态泛化种，可适应……Nutrient_levels_location_Mmacrospora_presence
营养盐检测方法：采集1000 mL水样，运输过程中置于冰盒中保存。随后在本实验室使用SMARTSpectro分光光度计（LaMotte，美国马里兰州）对四种营养盐（氨氮、硝酸盐氮、亚硝酸盐氮、磷酸盐，单位：mg L⁻¹）进行检测。

### 桃园溪流调查数据（Taoyuan_stream_survey_data）
2012年8月至2013年10月期间，我们在台湾桃园市龙塘区一处泉水补给的小型溪流的4个监测点位开展了每月一次的野外调查。该溪流点位坐标为24°53'09.3"N, 121°13'54.1"E，4个点位沿溪流从下游（点位1）到上游（点位4）依次排布，相邻点位间距为10米。
每个点位的大孢蒙氏藻盖度通过沿垂直于水流方向的样带设置的5个样方的盖度平均值计算得到。同时记录了该点位的水温、光照强度（单位：µmol photons m⁻² s⁻¹）、pH值、电导率（单位：µS cm⁻¹）、浊度（单位：mg L⁻¹）以及水流速度……

# 数据来源：《多维度生态评估揭示淡水大型红藻大孢蒙氏藻（串珠藻目 Batrachospermales，红藻门 Rhodophyta）在台湾的入侵过程》
[https://doi.org/10.5061/dryad.8cz8w9gt3](https://doi.org/10.5061/dryad.8cz8w9gt3)

## 数据与文件结构说明

#### **Nutrient_levels_location_Mmacrospora_presence**
本数据集收录了台湾地区8处发现大孢蒙氏藻的采样点位，以及日本冲绳人工水库池塘（东亚地区首次报道该藻分布的区域，Kato等，2009）的营养盐检测数据。所测指标包括氨氮、硝酸盐氮、亚硝酸盐氮与磷酸盐，单位：mg L⁻¹。

#### **Taoyuan_stream_survey_data**
本数据集包含2012年8月至2013年10月间，台湾桃园市龙塘区泉水补给小型溪流4个监测点位的大孢蒙氏藻盖度与环境参数实测数据。该溪流监测点位坐标为24°53'09.3"N, 121°13'54.1"E。

#### **Taoyuan_stream_survey_stats_Rcodes**
（原文未提供该数据集详细说明）