Physical and chemical properties of the foliage of 10 live wildland fuels

This data package contains data from over 3000 individual fuel elements collected as part of Joint Fire Science Program (JFSP) project 11-1-4-19 "Determination of the effects of heating mechanisms and moisture content on ignition of live fuels." Data were collected each month during one of two one-year periods. Species collected from the chaparral ecosystem near Riverside, California were manzanita (2013-2014), ceanothus (2013-2014), and chamise (2012-2013). Interior western species collected in Montana included Douglas-fir (2013-2014) and lodgepole pine (2012-2013); sagebrush (2012-2013) and Gambel oak (2013-2014) were collected in Utah. Southern species collected in Florida in 2013-2014 were fetterbush, gallberry and sand pine. Species were characterized as broadleaf (manzanita, ceanothus, Gambel oak, fetterbush, gallberry) and needle (chamise, sagebrush, Douglas-fir, sand pine, lodgepole pine). Broadleaf samples consisted of whole leaves; needle samples consisted of a small length of branch with the foliage attached. Although sagebrush foliage is comprised of leaves rather than needles, the sagebrush samples were characterized as needle samples because the leaves are so small. Measurements include moisture content, relative moisture content, apparent density, length, width, needle length, stem diameter, leaf thickness, leaf surface area, fresh mass, volatiles content, fixed carbon content, ash content and lipid content.The data presented here describe physical and chemical characteristics of the 10 species used in JFSP project 11-1-4-9. There were five objectives for this project. The first was to determine how heat fluxes produced by convection and thermal radiation, individually and together, influence mass loss in moist live fuels prior to ignition. Secondly, to determine experimentally if thermal radiation alone is sufficient for ignition of live fuels or if an additional source of heat (coil, hot convection gases) is necessary to ignite the pyrolyzates. Thirdly, to determine through computer simulation of ignition if thermal radiation alone is sufficient or if an additional source of heat (hot convection gases from a flame) is necessary to ignite the pyrolyzates. The fourth objective was to expand species tested in JFSP project 10-1-08-6 “Linking photosynthesis and combustion characteristics in live fuels: The role of soluble carbohydrates in fuel preheating” to include important shrub species. Lastly, to determine if results of the tests vary over the year as fuel moisture changes within living plants.Original metadata date was 07/21/2016. Minor metadata updates on 12/16/2016.本数据包包含来自联合火灾科学计划（Joint Fire Science Program, JFSP）项目11-1-4-19“加热机制与含水率对活体可燃物点燃影响的测定”中收集的3000余根独立可燃物试样数据。数据采集于两个为期一年的采样周期之一，每月开展一次采样。在加利福尼亚州里弗赛德附近的查帕拉尔灌丛生态系统中采集的物种包括熊果（2013-2014年）、美洲茶（2013-2014年）与查帕拉尔灌木（2012-2013年）；蒙大拿州采集的西部内陆物种包括花旗松（2013-2014年）与扭叶松（2012-2013年）；犹他州采集的物种包括山艾树（2012-2013年）与甘贝尔栎（2013-2014年）；2013-2014年在佛罗里达州采集的南部物种为绊足木、加仑莓与沙松。按物种叶片类型可将其分为阔叶类（熊果、美洲茶、甘贝尔栎、绊足木、加仑莓）与针叶类（查帕拉尔灌木、山艾树、花旗松、沙松、扭叶松）。其中阔叶类试样采用完整叶片，针叶类试样为带有叶片的小段枝条。尽管山艾树的叶器官为叶片而非典型针叶，但因其叶片尺寸极小，故将山艾树试样归类为针叶类。本次测量涵盖的参数包括含水率、相对含水率、表观密度、试样长度、试样宽度、针叶长度、茎直径、叶片厚度、叶表面积、鲜重、挥发分含量、固定碳含量、灰分含量及脂质含量。本数据集呈现了JFSP项目11-1-4-9所使用的10个物种的物理与化学特性。本项目共设定五项研究目标：其一，探究对流与热辐射单独及联合作用产生的热通量，对点燃前湿润活体可燃物的质量损失的影响规律；其二，通过实验验证仅依靠热辐射是否足以点燃活体可燃物，抑或需要额外热源（如加热线圈、热对流气体）来引燃热解产物；其三，通过点火过程的计算机模拟，验证仅依靠热辐射是否足以引燃热解产物，或是需要额外热源（如火焰产生的热对流气体）；其四，将JFSP项目10-1-08-6“活体可燃物的光合作用与燃烧特性关联：可溶性碳水化合物在燃料预热中的作用”中测试的物种范围扩展至重要灌木物种；其五，探究随着全年活体植物内含水率的变化，测试结果是否会随之发生改变。原始元数据日期为2016年7月21日，2016年12月16日进行了少量元数据更新。