9-second gridded continental Australia potential degree of ecological change for Amphibians 1990:2050 CanESM2 RCP 8.5 (CMIP5) (GDM: AMP_r2_PTS1)

Potential degree of ecological change in 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. \n\nThis metric describes the change in long term average environmental conditions at a single location (9s grid square) from the present (1990 centred) to a 2050 centred future, scaled in terms of its expected effects on the turnover of species. Compositional turnover patterns in amphibian species across continental Australia were derived using Generalised Dissimilarity Modelling (GDM). These models use best-available biological data extracted from the Atlas of Living Australia (ALA) in 2013, and spatial environmental predictor data compiled at 9 second resolution. GDM-scaled environmental grids were used as the basis for pairwise cell comparisons across space and time using the highly parallel CSIRO Muru software to derive the potential degree of ecological change. Each location is compared with its future state. The difference in environment is presented as an expected ecological similarity, ranging from 1 (completely similar) to 0, for which we would expect no species in common. If this environmental difference was observed in a different spatial location within the present, we would expect to observe such a difference if we visited both sites. \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.Tom HA\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: amphibians, M: mammals, R: reptiles and V: vascular plants\n\nLineage: Potential degree of ecological change 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 ecological similarity of each cell in the present to its future state was calculated. More detail of the calculations and methods are given in the document “9sMethodsSummary.pdf” provided with the data download. \nGDM Model: \nGeneralised 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)\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

基于群落更替广义相异性建模（Generalised Dissimilarity Modelling, GDM），本数据集分析了以1990年为中心的当前气候与CanESM2模式（RCP 8.5）下2050年为中心的预估未来气候的长期（30年平均）变化对两栖类生态变化的潜在影响程度。

该指标描述单个位点（9秒栅格）的长期平均环境条件从当前（以1990年为中心）到以2050年为中心的未来的变化，并以其对物种类群更替的预期效应进行标度。澳大利亚大陆两栖物种类群的群落更替模式通过广义相异性建模（GDM）推导得出。此类模型采用2013年从澳大利亚生物多样性图谱（Atlas of Living Australia, ALA）获取的最优可用生物数据，以及分辨率为9秒的空间环境预测因子数据集。研究借助高度并行化的CSIRO Muru软件，以经GDM标度的环境栅格为基础，开展跨空间与跨时间的栅格对比较，进而推导生态变化潜在程度。每个位点与其未来状态进行比对，环境差异以预期生态相似性表示，取值范围为1（完全相似）至0（此时预期两处位点无共有物种）。若在当前的另一空间位点观测到该环境差异，则在两处位点开展采样时可观测到此类差异。

该指标与其他指标一同开发，用于评估大陆及全球尺度下保护区系统应对气候变化的生物多样性保护效力，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。相关描述见于《AdaptNRM指南：气候变化对生物多样性的影响：群落水平建模方法》，可通过以下网址在线获取：www.adaptnrm.org。

数据以两种形式提供：
1. 压缩的ESRI浮点栅格：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）。从压缩包解压后，此类文件可导入绝大多数地理信息系统（Geographic Information System, GIS）软件，也可通过替换对应头文件的方式用作其他二进制文件格式。
2. ArcGIS图层包（*.lpk）：此类包可通过ArcGIS解压为带配套图例的栅格图层。

此外，数据下载包中附带了9sMethodsSummary.pdf文件，提供了简要的方法概述以供进一步查阅。Tom HA

本9秒栅格系列的图层采用统一命名格式：生物类群_基准时段_情景_分析类型
例如：A_90_CAN85_S 或 R_90_MIR85_L
其中生物类群的缩写对应为：A=两栖类，M=哺乳类，R=爬行类，V=维管植物

谱系说明：生态变化潜在程度通过运行于LINUX高性能计算集群的高度并行化定制CSIRO Muru软件计算得出，输入数据为经GDM模型转换的环境栅格。研究计算了当前每个栅格位点与其未来状态的生态相似性。更详细的计算与方法说明见于数据下载包中的9sMethodsSummary.pdf文件。

GDM模型：
针对澳大利亚大陆9秒分辨率下的两栖类群落更替，采用2014年2月27日获取的ALA数据构建广义相异性模型（GDM: AMP_r2_PTS1）。

气候数据：模型构建与预估采用以下数据集：
a) 1976-2005年澳大利亚大陆9秒格点气候数据集：包含经高程与辐射校正的摘要变量
b) CanESM2模式RCP 8.5（CMIP5）下2036-2065年澳大利亚大陆9秒格点气候数据集：包含经高程与辐射校正的摘要变量