Leaf Area Index Images, South East Queensland Peri-urban SuperSite, Karawatha, Core 1 ha, 2016

Leaf area index (LAI) can be defined as the total one sided area of leaf tissue per unit area of ground and is a key derived parameter that is associated with water and light interception, radiation transfer, water and carbon exchange. Canopy cover can be defined as the fraction of ground shaded by the vertical projection of tree crowns. These measures may be used as proxies for actual canopy leaf area. Leaf area index is the preferred measure of cover for vegetation and is a key variable used in total biomass estimation and in carbon cycling prediction models. Indirect measures of LAI include digital photographic methods using flat or hemispherical images, referred to respectively as Digital Cover Photography (DCP) and Digital Hemispheric Photography (DHP). LAI measurements are carried out at each SuperSite using the most appropriate method for the vegetation type present. Digital Cover Photography (DCP) was carried out at the South East Queensland Peri-urban SuperSite, Karawatha, Core 1 ha plot on 08 Feb 2016. Leaf Area Index images are available for viewing and download from the TERN SuperSites BioImage Portal http://bioimages.supersites.net.au/data/photopoint/seqp_karawatha/default

叶面积指数（Leaf Area Index, LAI）可定义为单位地面面积上的植物叶片单侧总表面积，是与水分与光照截获、辐射传输、水碳交换紧密关联的关键衍生参数。冠层盖度（canopy cover）可定义为树木树冠垂直投影所遮蔽的地面占比。上述两类指标均可作为实际冠层叶面积的替代表征指标。叶面积指数是植被盖度评估的优选指标，同时也是总生物量估算与碳循环预测模型中的核心变量。叶面积指数的间接测量方法包括基于平面影像与半球影像的数码摄影技术，二者分别称为数字覆盖摄影法（Digital Cover Photography, DCP）与数字半球摄影法（Digital Hemispheric Photography, DHP）。研究团队会针对每个超级站点（SuperSite）的植被类型，选用最适配的方法开展叶面积指数测量工作。2016年2月8日，研究团队于昆士兰州东南部城郊超级站点——卡拉沃莎（Karawatha）的1公顷核心样地开展了数字覆盖摄影（DCP）作业。叶面积指数影像可通过TERN超级站点生物影像门户（TERN SuperSites BioImage Portal）的链接http://bioimages.supersites.net.au/data/photopoint/seqp_karawatha/default 进行查看与下载。