9-second gridded continental Australia novel ecological environments for Vascular Plants 1990:2050 CanESM2 RCP 8.5 (CMIP5) (GDM: VAS_v5_r11)

Novel ecological environments for Vascular Plants as a function of change in long term (30 year average) climates between the present (1990 centred) and projected future (2050 centred) under the CanESM2 model (RCP 8.5) based on Generalised Dissimilarity Modelling (GDM) of compositional turnover. \n\nThis metric describes the nature of the projected 2050 centred future environmental conditions for each 9s grid square. Using a Generalised Dissimilarity Model of compositional turnover (the effects of changing environment on changing species), each future location is compared with the continent in the present. For each cell, the metric looks out to all other cells in the continent, and records the ecological similarity of the future state of the cell to the most similar cell in the present. A value of 1 indicates that the future environment is similar to a current location in the present, and perfect analogue can found somewhere in Australia. A value of 0 indicates that the most similar environment to be found in the present is ecologically so different that we would expect no species in common, i.e. there are no current analogues for this environment; it is novel. Intermediate values show how ecologically similar the most similar cell is. However, no weight is given to the proximity of the most similar cell. The environment may be similar, but the cells thousands of kilometres apart.\n\n\nThis metric was developed along with others for use in an assessment of the efficacy of the protected area system for biodiversity under climate change at continental and global scales, presented at the IUCN World Parks Congress 2014. It is described in the AdaptNRM Guide “Implications of Climate Change for Biodiversity: a community-level modelling approach”, available online at: www.adaptnrm.org. \n\nData are provided in two forms:\n1. Zipped ESRI float grids: Binary float grids (*.flt) with associated ESRI header files (*.hdr) and projection files (*.prj). After extracting from the zip archive, these files can be imported into most GIS software packages, and can be used as other binary file formats by substituting the appropriate header file.\n2. ArcGIS layer package (*.lpk): These packages contain can be unpacked by ArcGIS as a raster with associated legend.\n\nAdditionally a short methods summary is provided in the file 9sMethodsSummary.pdf for further information.\n\nLayers in this 9s series use a consistent naming convention:\nBIOLOGICAL GROUP _ FROM BASE_ TO SCENARIO_ ANALYSIS\ne.g. A_90_CAN85_S or R_90_MIR85_L\nwhere BIOLOGICAL GROUP is A: Vascular Plants, M: Vascular Plants, R: Vascular Plants and V: vascular plants\n\nLineage: Novel ecological environments were calculated using the highly parallel bespoke CSIRO Muru software running on a LINUX high-performance-computing cluster, taking GDM model transformed environmental grids as inputs. The ecological similarity of the most similar present cell to the future environment of each cell was calculated. More detail of the calculations and methods are given in the document “9sMethodsSummary.pdf” provided with the data download. \nGDM Model: \t\nGeneralised dissimilarity model of compositional turnover in vascular plant species for continental Australia at 9 second resolution using ANHAT data extracted 4 April 2013 (GDM: VAS_v5_r11)\nClimate data. Models were built and projected using:\na) 9-second gridded climatology for continental Australia 1976-2005: Summary variables with elevation and radiative adjustment\nb) 9-second gridded climatology for continental Australia 2036-2065 CanESM2 RCP 8.5 (CMIP5): Summary variables with elevation and radiative adjustment\n

本数据集针对维管植物（Vascular Plants），基于物种组成更替的广义相异模型（Generalised Dissimilarity Modelling, GDM），刻画了以1990年为中心的当前气候与CanESM2模式（RCP 8.5）下以2050年为中心的预估未来气候之间的长期（30年平均）气候变化所对应的新型生态环境。

本指标描述了每个9秒（经纬度）网格单元（9s grid square）以2050年为中心的预估未来环境特征。借助刻画环境变化对物种组成变化影响的物种组成更替广义相异模型，将每个未来样点与当前大陆的环境进行比对。针对每个网格单元，该指标会遍历大陆内所有其他网格单元，记录该单元未来环境状态与当前最相似网格单元的生态相似性。当指标值为1时，表明该未来环境与当前某一地点的环境高度相似，且在澳大利亚境内可找到完美匹配的现存生境；当指标值为0时，说明当前所能找到的最相似环境在生态上差异极大，预计二者无共有物种，即该环境无现存相似生境，属于新型生态环境。中间值则反映了最相似网格单元的生态相似程度。但该指标未考虑最相似单元的空间邻近性，即便环境相似，两个网格单元可能相距数千公里。

本指标与其他指标一同开发，用于在大陆和全球尺度下评估气候变化背景下保护区系统对生物多样性的保护效能，相关成果发表于2014年世界自然保护联盟（International Union for Conservation of Nature, IUCN）世界公园大会。该指标的详细说明载于AdaptNRM指南"Implications of Climate Change for Biodiversity: a community-level modelling approach"，可通过网址www.adaptnrm.org在线获取。

本数据集以两种形式提供：
1. 压缩的ESRI浮点栅格文件：包含二进制浮点栅格（*.flt）、配套的ESRI头文件（*.hdr）与投影文件（*.prj）。从压缩包解压后，这些文件可导入多数地理信息系统（Geographic Information System, GIS）软件，也可通过替换对应头文件的方式作为其他二进制格式文件使用。
2. ArcGIS图层包（*.lpk）：该类文件可通过ArcGIS解压为带配套图例的栅格数据。

此外，数据附带的9sMethodsSummary.pdf文件中提供了方法学摘要，以供获取更多细节。

本9秒系列栅格图层采用统一命名规则：
生物类群_基准时段_情景_分析类型
示例：A_90_CAN85_S 或 R_90_MIR85_L
其中生物类群的取值为：A：维管植物（Vascular Plants）、M：维管植物、R：维管植物、V：维管植物

数据集溯源：新型生态环境的计算借助运行于Linux高性能计算集群的高度并行化定制化澳大利亚联邦科学与工业研究组织（Commonwealth Scientific and Industrial Research Organisation, CSIRO）Muru软件完成，输入数据为经广义相异模型（GDM）转换的环境栅格。本研究计算了每个网格单元的未来环境与当前最相似网格单元的生态相似性。计算细节与方法学说明详见数据下载包附带的9sMethodsSummary.pdf文件。

广义相异模型（GDM）：
本模型针对澳大利亚大陆9秒分辨率的维管植物物种组成更替构建，采用2013年4月4日提取的ANHAT数据，模型版本为VAS_v5_r11（GDM: VAS_v5_r11）。
气候数据：模型构建与预估采用以下数据集：
a) 澳大利亚大陆1976-2005年9秒分辨率格点气候数据集：包含经高程与辐射校正的汇总变量
b) 澳大利亚大陆2036-2065年9秒分辨率格点气候数据集（CanESM2模式RCP 8.5情景，耦合模式比较计划第五阶段（Coupled Model Intercomparison Project Phase 5, CMIP5））：包含经高程与辐射校正的汇总变量