2022-2023 Palmer Station terrestrial carbon fluxes - field warming experiment

This data set contains the raw data for measurements of carbon fluxes at four field sites along a successional gradient near Palmer Station, Antarctica. At the beginning of the experiment, field site 1 (youngest site, closest to the glacier) was approximately 2 years since deglaciation, field site 2 about 30 years since deglaciation, field site 3 about 60 years since deglaciation, and Litchfield Island: hundreds of years since deglaciation. These sites have each: 5 control plots and 5 warmed plots (warmed via open-top chambers, OTC). Carbon flux measurements were taken weekly at most sites (40 plots total). A custom chamber connected to a LI-COR 6800 was placed on a stainless steel ring. Then measurements were taken over a 90 second or 120 second interval. Measurements were taken with a transparent chamber to obtain net ecosystem exchange (NEE; micromols CO2/m2/s), and then covered with dark cloth to obtain ecosystem respiration (ER) measurements. The incoming carbon fluxes was then obtained based on the NEE and ER.

本数据集涵盖南极帕尔默站（Palmer Station）附近沿演替梯度分布的4处野外站点的碳通量实测原始数据。实验初始阶段，站点1（最年轻、距冰川最近）自冰川消退至今约2年，站点2约30年，站点3约60年，利奇菲尔德岛（Litchfield Island）则已有数百年未受冰川覆盖。各站点均设置5个对照样地与5个增温样地，增温采用开顶箱（open-top chambers, OTC）实现。多数站点每周开展碳通量测定，总计覆盖40个样地。测定时将定制呼吸箱连接至LI-COR 6800分析仪，放置于不锈钢环之上，随后在90秒或120秒的时长内完成数据采集。先使用透明呼吸箱测定净生态系统交换量（net ecosystem exchange, NEE；单位为微摩尔CO₂/平方米/秒），再用黑布覆盖呼吸箱以获取生态系统呼吸速率（ecosystem respiration, ER）的测定数据，最终基于NEE与ER得到入射碳通量。