9-second gridded continental Australia revegetation benefit (cleared natural areas) for Mammals 1990:2050 MIROC5 RCP 8.5 (CMIP5) (GDM: MAM_r2)

Benefits of revegetation index for Mammals as a function of land clearing and changing climate based on Generalised Dissimilarity Modelling (GDM) of compositional turnover. \nThis metric represents the marginal benefit from a unit increase of vegetation at the site, which is a direct function of the slope of the species area curve at the test state of the site. In practice, revegetation of the whole cell is likely to be impractical due to the availability of cleared land within the cell, and practical limitations such as land ownership and revegetation cost. The metric therefore excludes these factors from the analysis, allowing direct comparison of the relative benefit of a given area of revegetation between cells. The values of the index generated according to the above formula are generally low (since a significant area is required to support additional species) and the index is rescaled by multiplying by 1000 to bring it into an approximate 0-1 range.\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 “Helping Biodiversity Adapt: Supporting climate adaptation planning using a community-level modelling approach”, available online at: www.adaptnrm.org. \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.\nAdditionally a short methods summary is provided in the file BiodiversityModellingMethodsSummary.pdf for further information.\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: amphibians, M: mammals, R: reptiles and V: vascular plants\nLineage: Benefits of revegetation index was 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 index of revegetation was calculated as the marginal gain from revegetation actions at a cleared location as a function of the area of similar ecological environments More detail of the calculations and methods are given in the document “BiodiversityModellingMethodsSummary.pdf” provided with the data download. \nGDM Model: \nGeneralised dissimilarity model of compositional turnover in Mammal species for continental Australia at 9 second resolution using ALA data extracted 27 February 2014 (GDM: MAM_r2)\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 MIROC5 RCP 8.5 (CMIP5): Summary variables with elevation and radiative adjustment\nNatural Areas Layer (intact to degraded land)\nAustralian Government Department of the Environment (2014) Natural areas of Australia - 100 metre (digital dataset and metadata). Available at http://www.environment.gov.au/metadataexplorer/explorer.jsp and up to date information for Western Australia were provided at 25m Albers projection were reprojected to GDA94, merged and aggregated to a continuous measure of proportion of intact area per grid cell at 9s.\n

基于物种组成更替的广义相异性建模（Generalised Dissimilarity Modelling，GDM），开展土地清理与气候变化背景下哺乳动物植被恢复指数效益的研究。
该指标表征样地植被每单位增加所带来的边际效益，其直接由样地测试状态下的物种-面积曲线斜率决定。实际应用中，由于样地内已清理土地的可获得性、土地权属与植被恢复成本等现实限制，对整个网格单元开展全面植被恢复往往不具备可行性。因此，该指标未纳入上述因素，可实现不同网格单元间特定面积植被恢复相对效益的直接对比。依据上述公式生成的指数数值普遍偏低（因支撑额外物种需占用较大面积），故通过乘以1000对指数进行重新标度，使其大致处于0-1区间。
该指标与其他指标一同开发，用于评估气候变化背景下大陆及全球尺度保护区系统对生物多样性的保护效能，相关成果已在2014年世界自然保护联盟（IUCN）世界公园大会上展示。其详细说明见于《AdaptNRM指南："Helping Biodiversity Adapt: Supporting climate adaptation planning using a community-level modelling approach"》，可通过在线网址www.adaptnrm.org获取。
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）、关联的ESRI头文件（*.hdr）与投影文件（*.prj）。从压缩包解压后，这些文件可导入绝大多数GIS软件，也可通过替换对应头文件的方式作为其他二进制文件格式使用。
2. ArcGIS图层包（*.lpk）：此类包可通过ArcGIS解压为带有关联图例的栅格图层。
此外，数据集中附带了《BiodiversityModellingMethodsSummary.pdf》文件，其中提供了简要的方法学概述以供参考。
该9秒分辨率系列栅格采用统一命名规则：
生物类群_基准情景_分析情景
示例：A_90_CAN85_S 或 R_90_MIR85_L
其中，生物类群对应关系为：A代表两栖动物，M代表哺乳动物，R代表爬行动物，V代表维管植物。
谱系说明：本植被恢复指数通过运行于LINUX高性能计算集群的高度并行化定制化CSIRO Muru软件计算得到，输入数据为经GDM模型转换的环境栅格。该植被恢复指数表征清理区域开展植被恢复行动所带来的边际增益，其函数为相似生态环境的面积。相关计算细节与方法可参阅数据下载包中附带的《BiodiversityModellingMethodsSummary.pdf》文件。
GDM模型：
针对澳大利亚大陆9秒分辨率的哺乳动物物种组成更替广义相异性模型，所用数据为2014年2月27日提取的澳大利亚生物图集（Atlas of Living Australia, ALA）数据（模型标识：GDM: MAM_r2）。
气候数据：模型构建与投影采用以下数据集：
a) 1976-2005年澳大利亚大陆9秒分辨率格点气候数据集：经海拔与辐射校正的摘要变量数据集
b) 2036-2065年澳大利亚大陆9秒分辨率格点气候数据集（MIROC5模式RCP 8.5情景，CMIP5框架）：经海拔与辐射校正的摘要变量数据集
自然区域图层（原生至退化土地）
澳大利亚环境部（2014）发布的《澳大利亚自然区域——100米分辨率数字数据集与元数据》，可通过http://www.environment.gov.au/metadataexplorer/explorer.jsp获取。西澳大利亚州的最新数据以25米Albers投影格式提供，经重投影至GDA94坐标系后，被合并并聚合为9秒分辨率下各网格单元的原生区域占比连续度量值。