Terrestrial Condition Assessment (TCA) Vegetation Departure

Direct Download (Raster Data Gateway) Objective: Identify locations where vegetation composition and successional stage are departed from the natural range of variation. Data: Vegetation departure within a TCA landscape ecosystem describes the degree to which the observed proportion (percent, 0-100%) of successional classes (i.e., A through E) derived from Landfire Succession Classes (SClass) dataset, is departed from the proportions one would expect based on the reference condition contained in the Landfire Biophysical Settings (BpS) dataset at each cell location. Departure is calculated as: Departure = 100 – Similarity where Similarity = ∑ (min(Ai,Bi)) over all classes i,…n Departure is determined for each BPS within an LTA, and then weighted average for departure is calculated for the LTA based on the areal extent of the BPS. After being added to the assessment in 2022, the update timeline of the input source data from LANDFIRE did not align with the timing of TCA assessment in 2023, so data from 2022 was reused. The 2024 TCA Assessment used updated source data to create new vegetation departure indicator data. Units: Percent Format: Raster data are continuous Resolution: 30m Source: Landfire Succession Class and Biophysical Setting, methods from Swaty et al. 2022 Additional Resources: Details on Method Changes and Source Data Versions Overview of the Terrestrial Condition Assessment: TCA Hubsite or Landfire Office Hour Presentation Explore the results of the most recent assessment: TCA Interactive Data Viewer Learn more about the TCA KPI: TCA Dashboard *if you have trouble viewing the Dashboard, please submit a Tableau Viewer Access Request直接下载（栅格数据网关） 研究目标：识别植被组成与演替阶段偏离自然变化范围的区域。 数据：陆地状况评估（Terrestrial Condition Assessment, TCA）景观生态系统内的植被偏离度，指由Landfire演替类别（Succession Classes, SClass）数据集推导得到的各演替等级（即A至E类）的观测占比（百分比，取值范围0-100%），在每个栅格单元位置上，与基于Landfire生物物理背景（Biophysical Settings, BpS）数据集参考条件得出的预期占比之间的偏离程度。 偏离度计算公式为：偏离度 = 100 – 相似度，其中相似度 = ∑(min(Ai, Bi))，遍历所有类别i,…n。 先针对每个BPS（生物物理背景，Biophysical Settings）计算植被偏离度，随后基于各BPS的面积占比对LTA内的植被偏离度计算加权平均值。 该数据集于2022年被纳入评估体系后，Landfire输入源数据的更新周期与2023年TCA评估的时间节点不匹配，因此复用了2022年的数据集。2024年TCA评估采用更新后的源数据，生成了全新的植被偏离度指标数据。 单位：百分比 格式：栅格数据为连续型数据 分辨率：30米 数据源：Landfire演替类别与生物物理背景数据集，方法源自Swaty等人2022年的研究成果。 附加资源： 1. 方法变更与源数据版本详情 2. 陆地状况评估（TCA）概述：TCA枢纽站点或Landfire线上办公研讨展示 3. 查看最新评估结果：TCA交互式数据查看器 4. 了解更多TCA关键绩效指标（KPI）：TCA控制面板 *若无法正常查看控制面板，请提交Tableau查看器访问申请