9-second gridded continental Australia revegetation benefit (cleared natural areas) for Amphibians 1990:1990 (GDM: AMP_r2_PTS1)

Benefits of revegetation index for Amphibians as a function of land clearing within the present long term (30 year average) climate (1990 centred) based on Generalised Dissimilarity Modelling (GDM) of compositional turnover. This 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.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 “Helping Biodiversity Adapt: Supporting climate adaptation planning using 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 BiodiversityModellingMethodsSummary.pdf for further information.Layers in this 9s series use a consistent naming convention:BIOLOGICAL GROUP _ FROM BASE_ TO SCENARIO_ ANALYSISe.g. A_90_CAN85_S or R_90_MIR85_Lwhere BIOLOGICAL GROUP is A: amphibians, M: mammals, R: reptiles and V: vascular plantsLineage: 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. GDM Model: Generalised dissimilarity model of compositional turnover in amphibian species for continental Australia at 9 second resolution using ALA data extracted 27 February 2014 (GDM: AMP_r2_PTS1)Climate data. Models were built and projected using:a) 9-second gridded climatology for continental Australia 1976-2005: Summary variables with elevation and radiative adjustmentb) 9-second gridded climatology for continental Australia 1990: Summary variables with elevation and radiative adjustmentNatural Areas Layer (intact to degraded land)Australian 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.

基于物种周转的广义相异模型（Generalised Dissimilarity Modelling, GDM），在以1990年为中心的长期（30年平均）气候背景下，两栖类植被恢复收益指数随土地开垦程度的变化规律。
该指标表征研究样地内植被每单位增加所带来的边际收益，其直接取决于样地测试状态下物种-面积曲线的斜率。实际操作中，由于研究单元内已开垦土地的可获取性限制，以及土地权属、植被恢复成本等现实约束，对整个研究单元开展全面植被恢复往往不具备可行性。因此本指标在分析中剔除了上述因素，以便直接对比不同研究单元间同等面积植被恢复的相对收益。根据上述公式生成的指数数值普遍偏低（因为支撑新增物种需要较大的植被面积），因此通过乘以1000对指数进行重缩放，使其大致处于0-1区间内。
该指标与其他指标一同开发，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的生物多样性保护效能，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。其详细说明见于AdaptNRM指南"Helping Biodiversity Adapt: Supporting climate adaptation planning using a community-level modelling approach"，可通过网址www.adaptnrm.org在线获取。
本数据集提供两种格式：
1. 压缩的ESRI浮点栅格：二进制浮点栅格文件（*.flt），附带关联的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，作为其他二进制栅格格式使用。
2. ArcGIS图层包（*.lpk）：此类文件可通过ArcGIS软件解压为带关联图例的栅格图层。
此外，数据集中附带的《BiodiversityModellingMethodsSummary.pdf》文件提供了简短的方法学概述，可供读者获取更多细节。
本9秒分辨率系列栅格图层采用统一命名规范：
BIOLOGICAL_GROUP_BASE_SCENARIO_ANALYSIS
示例：A_90_CAN85_S 或 R_90_MIR85_L
其中生物类群的缩写含义为：A为两栖类，M为哺乳类，R为爬行类，V为维管植物。
数据溯源：本植被恢复收益指数通过运行于Linux高性能计算集群的定制化并行CSIRO Muru软件计算得到，输入数据为经GDM模型转换的环境栅格。该植被恢复指数被定义为：在已开垦区域开展植被恢复行动所带来的边际增益，其为相似生态环境面积的函数。更多计算细节与方法说明详见数据下载包中附带的《BiodiversityModellingMethodsSummary.pdf》文件。
GDM模型：
基于2014年2月27日提取的澳大利亚生命图谱（Atlas of Living Australia, ALA）数据，针对澳大利亚大陆9秒分辨率的两栖类物种周转构建的广义相异模型（GDM: AMP_r2_PTS1）。
气候数据：本模型的构建与投影基于以下数据集：
a) 1976-2005年澳大利亚大陆9秒分辨率格点气候数据集：包含经高程与辐射校正的汇总变量
b) 1990年澳大利亚大陆9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
自然区域图层（原生至退化土地）：
澳大利亚环境部（2014）《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。其中西澳大利亚州的最新数据采用25米阿尔伯斯（Albers）投影坐标系，随后被重投影至GDA94坐标系，经合并与聚合后，得到9秒分辨率下每个栅格单元的原生区域占比连续度量值。