Cary foliar nitrogen concentration data 1994 to 2003

The Forest Response to Stress and Damage (frequently referred to as FORSTAD) and long term forest monitoring project began in 1992 to study how mixed-oak forests respond to multiple forms of environmental change. The research took place at Cary Institute of Ecosystem Studies in the Hudson Valley of New York. FORSTAD included several sub-projects including (1) air pollution and nutrient cycling, (2) spongy moth dynamics, (3) small mammal dynamics and (4) vegetation dynamics. This dataset is a contribution to the Cary Institute of Ecosystem Studies, and is part of the Long term monitoring of forest ecosystems: air pollution and nutrient cycling archive.
To understand the effects of air pollution on forests, the chemistry of the precipitation as it fell onto and through the forest was measured. In addition, the chemistry of the soil where tree roots grew as well as the chemistry of leaves were measured. Lastly, to understand how the microbes in soil were affected by pollution, the breakdown of plant material into nitrogen that could be taken up by tree roots was measured. This latter process is called nitrogen cycling or nitrogen mineralization. The measurements included throughfall amount and chemistry, soil solution amount and chemistry, foliar chemistry, litterfall and frassfall amount and carbon (C) and nitrogen (N) concentration, potential N mineralization and nitrification. Datasets include, soil water, throughfall, leaf litter and nitrogen cycling.
The data presented here are percentages of nitrogen and carbon, obtained using the dry combustion method. Yearly site-wide means for each species are presented.
File list:
pj_ltm_data_foliar_metadata.pdf - contains complete project metadata, personnel, methodology, and definitions for data variables in data file.
pj_ltm_data_foliar_1994-2003.csv

森林胁迫与损伤响应（Forest Response to Stress and Damage，常简称FORSTAD）长期森林监测项目于1992年启动，旨在研究杂栎林对多种环境变化的响应机制。本研究开展于纽约哈德逊河谷的卡里生态系统研究所（Cary Institute of Ecosystem Studies）。FORSTAD包含四个子项目：(1) 空气污染与养分循环；(2) 舞毒蛾种群动态；(3) 小型哺乳动物种群动态；(4) 植被动态。本数据集为卡里生态系统研究所的研究成果之一，隶属于"森林生态系统长期监测：空气污染与养分循环"档案库。

为探明空气污染对森林的影响，研究人员对林外降水及林内穿透降水的化学组成进行了测定；此外，还测定了林木根系生长区的土壤化学组成以及叶片化学组成。最后，为明确土壤微生物受污染的影响机制，研究人员测定了植物残体分解为林木根系可吸收氮素的过程——该过程被称为氮循环（nitrogen cycling）或氮矿化作用（nitrogen mineralization）。本次测定涵盖穿透雨量与化学组成、土壤溶液量与化学组成、叶片化学组成、枯落物与虫粪沉降量及其碳（C）、氮（N）浓度，以及潜在氮矿化与硝化速率。本数据集包含土壤水、穿透雨、叶片枯落物及氮循环相关数据。

本次展示的氮、碳占比数据均采用干烧法（dry combustion method）测定，同时提供了各物种每年的样地整体均值。

文件列表：
pj_ltm_data_foliar_metadata.pdf：包含完整的项目元数据、研究人员信息、研究方法及数据文件中各变量的定义说明。
pj_ltm_data_foliar_1994-2003.csv