Sugar Maple Regeneration in New Hampshire, 2019-2023

Overview: These data sets are the culmination of a five-year community science project done in collaboration with the Society for Protection of NH Forests. Co-authors on the resulting paper were: Carrie Deegan, Sarah Thorne, Ana Suppé, Kimberly L. Colson and Wanda Rice. Funding was provided by: Engaged Research Grant from the Einhorn Center for Community Engagement at Cornell University 2019 - 2023; Public Engagement with Science Grant (NSF grant #1713204) subcontract from Hubbard Brook Research Foundation; USDA Climate Hub; NSF-REU supplement under the HBR LTER (NSF grant #1637685) in 2021 and 2022 and HBR LTER in 2023 (NSF grant #2224545 ). Undergraduate students who helped on the project: Katie Sims, Alex Ding, Esmée deCortie, Sage Wentzell-Brehme, Colin Craig, Linda Mahecha, Roxy Moore. Community volunteers who contributed to field data collection and project meetings: Paul Doscher, Dave Heuss, Kim Sharp, Chris Brown, Tim Kendrick, Dan Poor, Rickey Poor, and Blaine Kopp.
The study was conducted in four mature forest stands with a notable sugar maple component owned and managed by the Society for Protection of New Hampshire Forests (Forest Society) and spanning most of the latitudinal gradient in the state. Plots were established in autumn of 2018. In general, 12 plot locations were established for each of the four forest stands. Plots are spatially-uniform and placed as close to a 100 m grid system as possible with the restriction that the plot had to include three canopy sugar maple trees. The plots are 0.05 hectares or 500 m2 in size measured in a 12.62 m radius circular plot.
Marked_sdlg_site_EDI: This data set contains survival, leaf area and leaf damage for 1191 sugar maple seedlings at four sites in New Hampshire. The sugar maple seedlings were two years old at the time of marking in 2019 and were from the 2017 mast year. The study followed the seedlings on 12 plots per site for 5 years (2019-2023). The data file also contains plot and site variables for topography, soil chemistry and tree density and sugar maple dominance. Some of the main findings from the study were the importance of site, initial leaf area and leaf damage to seedling survival.
Litter_coll_ForestSoc_2yr: Leaves and seeds were collected from half of the plots (N=6) per site using three collectors. Count and dry weight were obtained for the leaves and counts for any seeds. This data set contains the main autumn collection data for 2019 and 2020. The were 20 tree species included over the four sites. There was a pattern of greater productivity in the southern site (greatest number of leaves) and decreased productivity in the northern site (lowest dry mass of leaves). Seed production for sugar maple was higher in 2019.
Sweep_ForestSoc: Sapling layers were generally open with only 281 saplings from all plots. Kauffmann had the densest and most diverse sapling layer. The saplings were only measured once in 2019.
Tagged_trees_ForestSoc: The data set includes growth (4 year) and vigor data (every other year) for 1335 trees in four study sites in New Hampshire. The data set includes data for 16 tree species tagged in 2019 and assessed in 2021 and 2023. At all sites, sugar maple growth was slower than average tree growth and mortality for sugar maple was higher than the average tree. This data set does not include data for trees that died during the study and therefore do not have growth data (96 trees).
Common_garden_sdlgs: This data set includes harvest data for 50 sugar maple seedlings grown in a common garden experiment with soil from the four study sites taken from two microsites: sugar maple dominated and dominated by other species. The experimental setup had two controls. One control was the live soil from the site where the seedlings were obtained (native soil control). A second control contained a mix of sugar maple soil from the four sites that had been sterilized (pathogen free control). The experiment did not demonstrate a microsite difference for seedling growth but rather sites differed with the most nutrient rich soil resulting in larger seedlings. Overall, the experiment did not support a significant role of soil pathogens in explaining seedling survival differences between sites.
ACSA_samaras_2019: This data table gives counts and condition of the samaras collected at the four study sites in autumn 2019, which represented the largest seed year during the study time. This data is useful for comparing differences in pre-dispersal damage to the seeds and seed production across sites.

2020_germinant_counts: This data table gives counts of newly germinated sugar maple seedlings at the plots with collectors (odd numbered plots). Sites were visited 14-18 May 2020. These data are used for comparing initial seedling densities across sites and the number of seedlings compared to the number of seeds for those plots, which gives an idea of post-dispersal survival.

概述：本数据集系列是与新罕布什尔州森林保护协会（Society for Protection of NH Forests）合作开展的一项为期五年的社区科学项目的成果。相关论文的共同作者包括：Carrie Deegan、Sarah Thorne、Ana Suppé、Kimberly L. Colson及Wanda Rice。资助方包括：康奈尔大学Einhorn社区参与中心2019-2023年的参与式研究基金；Hubbard Brook研究基金会的科学公众参与基金（NSF grant #1713204）分包合同；美国农业部气候中心（USDA Climate Hub）；2021-2022年HBR长期生态研究站（LTER）下的NSF-REU补充资金（NSF grant #1637685）及2023年HBR LTER资金（NSF grant #2224545）。参与项目的本科生包括：Katie Sims、Alex Ding、Esmée deCortie、Sage Wentzell-Brehme、Colin Craig、Linda Mahecha、Roxy Moore。参与野外数据采集及项目会议的社区志愿者包括：Paul Doscher、Dave Heuss、Kim Sharp、Chris Brown、Tim Kendrick、Dan Poor、Rickey Poor及Blaine Kopp。
本研究在新罕布什尔州森林保护协会（Forest Society）拥有并管理的四个成熟林分中开展，这些林分以糖枫为显著优势树种，且覆盖该州大部分纬度梯度。样地于2018年秋季设立，四个林分各设12个样地。样地空间分布均匀，尽可能接近100米网格系统，且每个样地必须包含三棵冠层糖枫。样地为半径12.62米的圆形区域，面积为0.05公顷（即500平方米）。
Marked_sdlg_site_EDI：本数据集包含新罕布什尔州四个站点1191株糖枫幼苗的存活率、叶面积及叶片损伤情况。这些糖枫幼苗在2019年标记时为两年生，源自2017年的种子丰收年（mast year）。研究对每个站点12个样地的幼苗进行了为期5年（2019-2023）的跟踪调查。数据文件还包含样地和站点的地形、土壤化学性质、树木密度及糖枫优势度等变量。研究的主要发现包括：站点、初始叶面积及叶片损伤对幼苗存活具有重要影响。
Litter_coll_ForestSoc_2yr：通过三个收集器从每个站点半数样地（N=6）中采集叶片和种子，测定了叶片的数量及干重，以及各类种子的数量。本数据集包含2019年和2020年秋季的主要采集数据，涵盖四个站点的20个树种。结果显示：南部站点生产力更高（叶片数量最多），北部站点生产力较低（叶片干重最小）；糖枫2019年的种子产量更高。
Sweep_ForestSoc：幼树层总体稀疏，所有样地共记录281株幼树。Kauffmann站点的幼树层最密集且多样性最高。幼树仅在2019年进行过一次测定。
Tagged_trees_ForestSoc：本数据集包含新罕布什尔州四个研究站点1335棵树木的4年生长数据及隔年活力数据，涵盖2019年标记、2021年和2023年评估的16个树种。所有站点中，糖枫的生长速度慢于树木平均生长速度，且死亡率高于树木平均死亡率。本数据集不包含研究期间死亡、无生长数据的树木（共96棵）。
Common_garden_sdlgs：本数据集包含50株糖枫幼苗的收获数据，这些幼苗种植于共同园实验（common garden experiment）中，所用土壤取自四个研究站点的两种微生境：糖枫优势微生境及其他物种优势微生境。实验设置了两个对照：一是幼苗原产地的活体土壤（原生土壤对照）；二是四个站点糖枫土壤混合后灭菌的土壤（无病原菌对照）。实验未发现幼苗生长存在微生境差异，但不同站点间存在差异：土壤养分最丰富的站点培育出的幼苗更大。总体而言，实验未发现土壤病原菌在解释站点间幼苗存活差异中具有显著作用。
ACSA_samaras_2019：本数据表记录了2019年秋季在四个研究站点采集的翅果（samaras）数量及状态，2019年是研究期间种子产量最高的年份。该数据可用于比较不同站点间种子扩散前的损伤情况及种子产量差异。
2020_germinant_counts：本数据表记录了设有收集器的样地（奇数编号样地）中新萌发的糖枫幼苗数量，站点调查时间为2020年5月14-18日。该数据可用于比较不同站点间的初始幼苗密度，以及这些样地中幼苗数量与种子数量的比值，从而反映种子扩散后的存活率。