Photosynthetic induction and sunfleck responses of three shade-tolerant temperate saplings

Novel understory tree species composition has arisen throughout forests of the eastern U.S. as various, often human-caused, pressures have led to regeneration mismatch between trees in the forest canopy and understory.  Physiological attributes supporting the relative success of these novel understory tree communities are poorly characterized.  We sought to examine photosynthetic induction and sunfleck responses in three shade-tolerant understory tree species now common in the U.S.’s Mid-Atlantic region.  Focal species included the non-native Acer platanoides, as well as the natives Acer rubrum and Fagus grandifolia.  Three experiments were performed on three individuals of each species at three independent study sites in the broadleaf forests of southeastern Pennsylvania, USA.  The experiments were: (1) a photosynthetic induction experiment where uninduced leaves were first exposed to low light, followed by saturating light and measured until photosynthesis and..., A full description of the research methods is available in the associated published manuscript.  Three understory tree species, Acer platanoides (Norway maple), Acer rubrum (red maple), and Fagus grandifolia (American beech) were the focus of this study.  Three saplings per species at three southeastern Pennsylvania broadleaf forest study sites were measured.  Experiments were performed on different individual leaves per tree: (1) The first experiment was designed to measure the process of photosynthetic induction when leaves were uninduced (i.e., covered in light-blocking nylon bags), then exposed to low light (10 µmol m-2 s-1) followed by saturating light (1000 µmol m-2 s-1).  (2) Thirty second sunfleck experiments were also performed, in which uninduced leaves were exposed to low light followed by a series of five 30 second saturating sunflecks, with two minutes of low light provided between each sunfleck.  (3) Finally, a 60 second sunfleck experiments was ca..., , # Photosynthetic induction and sunfleck responses of three shade-tolerant temperate saplings

1. **Title of Dataset:** Photosynthetic induction and sunfleck responses of three shade-tolerant temperate saplings
2. **Author Information**
A. Principal Investigator Contact Information
Name: Jessica L. Schedlbauer
Institution: West Chester University of Pennsylvania
Address: Department of Biology, 730 S. Church St., West Chester, PA 19383, USA
Email: [[e-mail]](mailto:[e-mail])
3. **Date of data collection:** 2020-06-29 through 2020-07-28
4. **Geographic location of data collection:** Four sites in Chester County, PA, USA (Binky Lee Preserve (BLP): 40°05'42\" N, 75°36'00\" W; Gordon Natural Area (GNA): 39°56'08\" N, 75°35'55\" W; Mount Bradford Preserve (MBP): 39°56'33\" N, 75°37'26\" W, Miller Farm (MF): 40°01'54\" N, 75°43'29\" W)
5. **Information about funding sources that supported the collection of the data:** West Chester Univerisity's Department of B...,

美国东部全域森林均已出现全新的林下（understory）树木物种组成，多种（多为人为驱动）压力导致林冠层（forest canopy）与林下树木的更新出现错配。目前，支撑这类新型林下树木群落相对优势地位的生理特征仍未得到充分表征。本研究旨在探究美国中大西洋地区现今常见的三种耐荫林下树种的光合诱导（photosynthetic induction）与阳光光斑（sunfleck）响应。研究目标物种包括外来种挪威枫（Acer platanoides），以及本土种红花槭（Acer rubrum）与美洲山毛榉（Fagus grandifolia）。

研究团队在美国宾夕法尼亚州东南部的阔叶林中的三处独立研究样地，对每个物种的3株个体开展了三项实验。实验内容包括：(1) 光合诱导实验：将未诱导的叶片先置于弱光环境，随后转移至饱和光强下进行测量，直至光合速率及……完整的研究方法细节可参见已发表的相关研究论文。

本研究聚焦三种林下树种：挪威枫（Acer platanoides）、红花槭（Acer rubrum）与美洲山毛榉（Fagus grandifolia）。在宾夕法尼亚州东南部的三处阔叶森林研究样地中，对每个物种的3株幼树（saplings）进行了测量。实验针对每棵树的不同叶片开展：(1) 第一项实验旨在测量光合诱导过程：将未诱导的叶片（即先用遮光尼龙袋覆盖）先置于弱光（10 µmol·m⁻²·s⁻¹）环境，随后转移至饱和光强（1000 µmol·m⁻²·s⁻¹）环境下进行监测。(2) 开展了30秒阳光光斑实验：将未诱导的叶片先置于弱光环境，随后依次接受5次时长30秒的饱和光强光斑照射，每次光斑之间设置2分钟的弱光间隔。(3) 最后一项60秒阳光光斑实验……

# 三种耐荫温带幼树的光合诱导与阳光光斑响应
1. **数据集标题**：三种耐荫温带幼树的光合诱导与阳光光斑响应
2. **作者信息**
A. 项目负责人联系方式
姓名：Jessica L. Schedlbauer
所属机构：宾夕法尼亚州西切斯特大学
通讯地址：美国宾夕法尼亚州西切斯特市南教堂街730号，生物系，邮编19383
电子邮箱：[e-mail]
3. **数据采集日期**：2020年6月29日至2020年7月28日
4. **数据采集地理位置**：美国宾夕法尼亚州切斯特县的4处样地（宾基李保护区（Binky Lee Preserve, BLP）：40°05'42"N，75°36'00"W；戈登自然区（Gordon Natural Area, GNA）：39°56'08"N，75°35'55"W；布拉德福德山保护区（Mount Bradford Preserve, MBP）：39°56'33"N，75°37'26"W；米勒农场（Miller Farm, MF）：40°01'54"N，75°43'29"W）
5. **数据采集资助信息**：西切斯特大学（West Chester Univerisity）生物系……