Account-ready data: ecosystem condition in the Western Australian Wheatbelt. A data collection from the Regional Ecosystem Accounting Pilot projects

This collection comprises ecosystem condition account-ready data for the Western Australia Wheatbelt, which is one of two case studies of the Ecosystem Accounting Pilots for Agricultural and Mixed-Use Landscapes project, delivering ecosystem accounts at sub-national scales. Dataset values (index) vary continuously from a theoretical minimum of 0.0 (ecosystem integrity extinguished) to a maximum of 1.0 (ecosystem integrity in reference condition). The index represents the contribution that a given site (grid cell) makes to the effective area of ecosystem integrity remaining within any given spatial reporting unit, expressed as a proportion of the contribution made by a site in reference condition. Ecosystem condition data are provided for 18 annual epochs (between 2001 and 2018) derived by combining data developed through applications of the Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing-based Habitat Condition Assessment System (HCAS) and the expert opinion-based Australian Ecosystem Models (AusEcoModels) Framework. The HCAS application version 2.3 (v2.3) is a modification of the original HCAS version 2.1 and further incorporates landscape context effects through inferred local pressures, resulting in the ecosystem site condition subindex. The AusEcoModels application uses expert elicitation to derive conceptual models of ecosystem reference and modified condition states and associated condition scores. Rule sets relate these condition states to remote sensing variables representing ecosystem characteristics to map the ecosystem state condition subindex. These subindex datasets are included in this collection. The supplementary metadata report summarises how the ecosystem condition index was derived, and describes the datasets in this collection. Supplementary data are provided in this collection to support interpretation and use. These include the overall HCAS v2.3 best estimate of ecosystem condition for the 2001 to 2018 long-term remote sensing epoch and associated subindex datasets; the significant trend in ecosystem condition from the 18 annual epochs; an analysis of how ‘nearby’ and relevant the 20 reference sites used as benchmarks were to the estimate of HCAS habitat condition for each site of interest; and a spatial mask for use when aggregating ecosystem condition data into accounts and tables for reporting to exclude areas identified as potentially erroneous. All raster data in this collection are provided as 100 m spatially-registered GeoTiff files, mostly in floating point format (Spatial extent in GDA2020, Australian Albers, EPSG:9473: xmin: -1532000, xmax: -1060000, ymin: -3858000, ymax: -3319000). These were used as a basis for developing a set of ecosystem condition stock accounts and supplementary data tables for the Western Australia Wheatbelt (see companion data collection - Experimental ecosystem accounts and supplementary data for the Western Australia Wheatbelt, accessed at https://data.csiro.au/collection/csiro:57811).

本数据集集合包含可用于生态系统核算的西澳大利亚小麦带（Western Australia Wheatbelt）生态系统状况就绪数据。该区域是农业与混合用地景观生态系统核算试点项目的两个案例研究区域之一，该项目旨在实现次国家级尺度的生态系统核算。数据集的索引值连续变化，理论最小值为0.0（代表生态系统完整性完全丧失），最大值为1.0（代表生态系统完整性处于参照状态）。该索引代表某一给定位点（网格单元）对任意指定空间报告单元内尚存的有效生态系统完整性面积的贡献占比，该占比以处于参照状态的位点的贡献值为基准进行计算。本数据集提供了2001年至2018年间共18个年度时段的生态系统状况数据，其整合了基于中分辨率成像光谱仪（Moderate Resolution Imaging Spectroradiometer, MODIS）遥感的生境状况评估系统（Habitat Condition Assessment System, HCAS）开发的数据，以及基于专家意见的澳大利亚生态系统模型（Australian Ecosystem Models, AusEcoModels）框架的成果。HCAS 2.3版（v2.3）是对原始HCAS 2.1版的改进版本，通过引入推断得到的局部压力因子纳入了景观背景效应，进而生成生态系统位点状况子索引。AusEcoModels工具通过专家征询构建生态系统参照状态与改良状态的概念模型，并生成对应的状况评分。规则集将这些状态与表征生态系统特征的遥感变量相关联，从而制图生成生态系统状态状况子索引。本数据集集合包含上述两类子索引数据集。

补充元数据报告总结了生态系统状况索引的构建流程，并对本集合中的数据集进行了说明。本集合还提供了辅助数据以支持数据的解读与使用，具体包括：2001至2018年长期遥感时段内HCAS v2.3对生态系统状况的最优估算结果及其配套子索引数据集；基于18个年度时段得到的生态系统状况显著变化趋势；针对各目标位点，对作为基准的20个参照位点与HCAS生境状况估算值的相关性与关联性进行的分析；以及在将生态系统状况数据汇总为核算报表与报告表格时，用于排除疑似错误区域的空间掩膜文件。

本集合中的所有栅格数据均采用100米空间分辨率且经空间配准的GeoTiff格式存储，多数为浮点型数据（空间参考采用GDA2020澳大利亚阿尔伯斯投影，EPSG:9473，空间范围：xmin: -1532000, xmax: -1060000, ymin: -3858000, ymax: -3319000）。上述数据被用于开发西澳大利亚小麦带的生态系统状况存量核算数据集及配套数据表（详见配套数据集集合：西澳大利亚小麦带实验性生态系统核算与辅助数据，访问链接：https://data.csiro.au/collection/csiro:57811）。