Root productivity of riverine and scrub mangroves from the Shark River Slough and Taylor Slough, Everglades National Park (FCE LTER), Florida, USA, March 2024 - ongoing

Root productivity of riverine and scrub mangroves in the Florida Everglades: Mangrove root productivity in the shallow root zone (0-45 cm depth) was estimated at all Shark River (SRS-4, SRS-5, SRS-6, SRS-7) and Taylor River (TS/Ph-6, TS/Ph-7) sites in March-April 2024. Root productivity was estimated with the ingrowth core technique using the same sampling protocol previously published for the study area (Castañeda-Moya et al. 2011). Ingrowth cores (10.2 cm diameter x 45 cm length) were made of synthetic material (3 mm mesh) and filled with root-free commercial sphagnum peat moss. This material has similar soil properties (i.e., bulk density, organic matter content, total C and N) as mangrove peat in our study sites as previously reported by Castañeda-Moya et al. (2011). Ingrowth cores were installed in holes made out with a PVC coring device (10.2 cm diameter x 45 cm length). At each site, 8 ingrowth cores were deployed vertically into the soil to a depth of 45 cm and retrieved one year later (March-April 2024). After collection, ingrowth cores were processed individually and initially rinsed with water through a 1-mm screen mesh to remove soil particles and peat moss material. Live roots were separated manually based on their buoyancy, turgor, and color (Castañeda-Moya et al. 2011; Cormier et al. 2015; Medina-Calderon et al. 2021). Live roots were further sorted into three size diameter classes including fine (<2 mm), small (2-5 mm), and coarse (5-20 mm). Roots greater than 20 mm in diameter were not included in this study due to sampling limitations (i.e., core area). All root samples were oven-dried at 60°C to a constant mass and weighed. Root growth within each ingrowth core following one year of incubation was used to estimate annual root productivity (g m⁻² yr⁻¹) in the shallow root zone across all mangrove sites. This is an ongoing project with data collection occurring every 2-3 years after 2024. All data collection and processing were funded by FCE-LTER. References: Castañeda-Moya, E., R.R. Twilley, V.H. Rivera-Monroy, B.D. Marx, C. Coronado-Molina, and S.M.L. Ewe. 2011. Patterns of root dynamics in mangrove forests along environmental gradients in the Florida Coastal Everglades, USA. Ecosystems 14: 1178-1195. https://doi.org/10.1007/s10021-011-9473-3. Cormier, N., R.R. Twilley, C.K. Ewel, and K.W. Krauss. 2015. Fine root productivity varies along nitrogen and phosphorus gradients in high-rainfall mangrove forests of Micronesia. Hydrobiologia 750, 69-87. Medina-Calderon, J.H., J.E. Mancera-Pineda, E. Castañeda-Moya, and V.H. Rivera-Monroy. 2021. Hydroperiod and salinity interactions control mangrove root dynamics in a karstic oceanic island in the Caribbean Sea (San Andres, Colombia). Frontiers in Marine Science 7: 598132. https://doi.org/10.3389/fmars.2020.598132.

佛罗里达大沼泽地河流型与灌丛型红树林的根系生产力数据集
本数据集针对佛罗里达大沼泽地的红树林浅根区（0~45 cm深度）根系生产力展开测定。2024年3—4月，研究团队于夏克河（Shark River）的SRS-4、SRS-5、SRS-6、SRS-7位点，以及泰勒河（Taylor River）的TS/Ph-6、TS/Ph-7位点开展采样。
根系生产力测定采用内生长芯法（ingrowth core technique），并沿用此前针对该研究区域发布的标准化采样规程（Castañeda-Moya等，2011）。内生长芯采用孔径3 mm的合成材料制成，规格为直径10.2 cm×长度45 cm，内部填充无根系的商用泥炭藓泥炭。该填充材料的土壤性质（容重、有机质含量、总碳与总氮含量）与本研究位点的红树林泥炭基质特征一致，相关结果已由Castañeda-Moya等（2011）先期报道。
内生长芯通过PVC取芯器（直径10.2 cm×长度45 cm）钻出的孔洞植入土壤。每个采样位点垂直布设8个内生长芯至45 cm深度，并于一年后（2024年3—4月）回收。
样品回收后逐一进行预处理：先用1 mm孔径筛网水洗以去除土壤颗粒与泥炭基质。随后依据浮力、膨压及颜色特征人工分选活根（Castañeda-Moya等，2011；Cormier等，2015；Medina-Calderon等，2021）。将分选得到的活根按直径划分为三个等级：细根（<2 mm）、小根（2~5 mm）与粗根（5~20 mm）。受限于芯样采样面积，直径大于20 mm的根系未纳入本研究。
所有根系样品于60 ℃下烘干至恒重后称重。以一年培育期内每个内生长芯中的根系生长量为基础，估算所有红树林采样位点浅根区的年根系生产力（单位：g m⁻² yr⁻¹）。
本项目为长期持续研究，2024年后将每2~3年开展一轮数据采集。全部数据采集与处理工作由FCE-LTER资助。

## 参考文献
1. Castañeda-Moya, E., R.R. Twilley, V.H. Rivera-Monroy, B.D. Marx, C. Coronado-Molina, S.M.L. Ewe. 2011. 美国佛罗里达海岸大沼泽地环境梯度下红树林森林根系动态格局. 《生态系统》（Ecosystems）14: 1178-1195. https://doi.org/10.1007/s10021-011-9473-3
2. Cormier, N., R.R. Twilley, C.K. Ewel, K.W. Krauss. 2015. 密克罗尼西亚高降雨红树林森林中沿氮磷梯度分布的细根生产力变化. 《水生生物学》（Hydrobiologia）750: 69-87
3. Medina-Calderon, J.H., J.E. Mancera-Pineda, E. Castañeda-Moya, V.H. Rivera-Monroy. 2021. 水文周期与盐度交互作用控制加勒比海喀斯特海洋岛屿（哥伦比亚圣安德烈斯岛）的红树林根系动态. 《海洋科学前沿》（Frontiers in Marine Science）7: 598132. https://doi.org/10.3389/fmars.2020.598132