9-second gridded continental Australia novel ecological environments for Amphibians 1990:2050 CanESM2 RCP 8.5 (CMIP5) (GDM: AMP_r2_PTS1)

Novel ecological environments for Amphibians 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.

This 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.

This 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.

Data are provided in two forms:
1. 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.
2. ArcGIS layer package (*.lpk): These packages contain can be unpacked by ArcGIS as a raster with associated legend.

Additionally a short methods summary is provided in the file 9sMethodsSummary.pdf for further information.

Layers in this 9s series use a consistent naming convention:
BIOLOGICAL GROUP _ FROM BASE_ TO SCENARIO_ ANALYSIS
e.g. A_90_CAN85_S or R_90_MIR85_L
where BIOLOGICAL GROUP is A: amphibians, M: mammals, R: reptiles and V: vascular plants

本数据集基于物种组成更替的广义相异性建模（Generalised Dissimilarity Modelling, GDM），以CanESM2模式（典型浓度路径RCP 8.5）下，以1990年为基准的当前气候与以2050年为基准的预测未来气候之间的长期（30年平均值）气候变化为驱动变量，生成两栖类的新型生态环境数据集。

该指标用于描述每个9弧秒网格单元对应的以2050年为基准的未来环境特征。借助物种组成更替的广义相异性模型（即环境变化对物种变化的影响机制），将每个未来区位与当前澳大利亚大陆的所有区位进行比对。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，记录该单元未来生态状态与当前最相似网格单元的生态相似程度。当指标值为1时，表明该未来环境与当前某一区位的环境高度相似，且在澳大利亚境内可找到完全匹配的现代类似生态环境；当指标值为0时，表明当前现存环境中与该未来环境最相似的二者生态差异极大，几乎无共有物种，即该未来环境无现存类似生态环境，属于新型生态环境。介于0和1之间的数值则反映了该未来环境与当前最相似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，即便二者相隔数千公里，只要生态环境相似就会被计入。

该指标与其他同类指标一同开发，用于在大陆及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成效，相关成果曾在2014年世界自然保护联盟（IUCN）世界公园大会上展示。该指标的详细说明载于AdaptNRM指南《气候变化对生物多样性的影响：群落级建模方法》，可通过网址www.adaptnrm.org在线获取。

本数据集提供两种存储格式：
1. 压缩版ESRI浮点栅格数据：包含二进制浮点栅格文件（*.flt）、配套的ESRI头文件（*.hdr）与投影文件（*.prj）。从压缩包中解压后，这些文件可导入绝大多数地理信息系统（GIS）软件，也可通过替换对应头文件的方式，作为其他二进制栅格格式文件使用。
2. ArcGIS图层包（*.lpk）：此类文件可通过ArcGIS软件解压为带有配套图例的栅格图层。

此外，文件9sMethodsSummary.pdf中包含方法学概述，可供用户获取更多细节信息。

本9s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
其中生物类群的对应关系为：A=两栖类，M=哺乳类，R=爬行类，V=维管植物。