Data for Zombie leaves: novel repurposing of senescent fronds in the tree fern Cyathea rojasiana for nutrient uptake in a tropical montane forest

This file contains the delta 15N values for leaf material collected from Cyathea rojasiana tree ferns before and after fertilization using ammonium -15N chloride solution to determine whether 15N update is possible from senescent leaves. Details of the experiment are provided in the online supplement to the published paper. Briefly, In February 2022 we selected three mature C. rojasiana individuals 1-1.5m in height that had leaves rooted in the soil and one new developing (but unexpanded) leaf. For each fern, two plastic pots (10 x 10 x 12 cm) were filled with a 50:50 mixture of washed river sand and soil from the Chorro watershed. For each pot, one senescent leaf that was rooted in the soil was carefully excavated and its roots transplanted into the pot. Pots were then fertilized by adding 30 ml of a 0.02 M 15N solution of ammonium-15N chloride (98% 15N; Sigma-Aldrich 299251; St Louis, MO) to yield a target concentration of 2 µg15N cm-3 of soil. After fertilization pots were carefully enclosed within thick plastic bags, and sealed around the senescent leaf rachis to prevent leaching any of 15N from the pot to the surrounding soil. At the time of N fertilization, pinnae of the youngest fully expanded leaf were collected from each fern. One pinna was collected from the base of the leaf and one from the distal end of the leaf. In March 2022, after 28 days the roots were removed from pots and two additional leaf pinnae sampled from each fern: one from the base and one from the distal end of the youngest (now fully expanded) leaf. Leaf samples were dried for 72 hours at 60 C and then leaf lamina tissue finely ground with a bead beater. The delta 15N for each leaf sample determined at the University of Illinois, Urbana-Champaign using a Thermo Delta V Advantage IRMS run in combination with a Costech 4010 Elemental Analyzer. Samples were run in continuous flow relative to laboratory standards that were calibrated with USGS 40, 41, and NBS 19 reference materials.

本文件包含了从Cyathea rojasiana树蕨采集的叶片材料在施用铵-15N氯化物溶液前后所测得的δ15N值，以确定是否可以从衰老叶片中实现15N的更新。实验的详细信息可在已发表论文的在线补充材料中找到。概而言之，2022年2月，我们选择了三株成熟的高度为1-1.5米的C. rojasiana个体，其叶片根植于土壤中，并选取了一片新发育但未展开的叶片。对于每株蕨类植物，我们使用含有河沙和来自Chorro流域土壤的50:50混合物填充了两个塑料盆（10 x 10 x 12厘米）。对于每个盆，我们小心地从土壤中挖掘出一片根植于土壤中的衰老叶片，并将其根系移植到盆中。然后，向每个盆中添加30毫升0.02 M的铵-15N氯化物溶液（98% 15N；Sigma-Aldrich 299251；密苏里州圣路易斯），以达到土壤中2 µg15N cm-3的目标浓度。施肥后，将盆小心地封装在厚塑料袋中，并在衰老叶片的中脉周围密封，以防止盆中的任何15N渗漏到周围土壤中。在施用氮肥时，从每株蕨类植物的最年轻完全展开的叶片中收集了羽片。一个羽片从叶片的基部收集，另一个从叶片的远端收集。2022年3月，经过28天后，从盆中移除根系，并从每株蕨类植物中各采集了两个额外的羽片样本：一个从最年轻的（现在已完全展开）叶片的基部收集，另一个从远端收集。叶片样本在60°C下干燥72小时，然后使用珠磨机将叶片组织细磨。使用伊利诺伊大学香槟分校的Thermo Delta V Advantage IRMS与Costech 4010元素分析仪联合运行，对每个叶片样本的δ15N值进行测定。样品以相对于实验室标准的连续流动方式进行运行，实验室标准已用USGS 40、41和NBS 19参考材料进行校准。