A Framework for Dynamic Assessment of Terrestrial Ecosystem Condition

ABSTRACT Aim The condition of terrestrial ecosystems (i.e., structure, function and composition) has been altered by increasing human pressure globally, affecting biodiversity and the sustainability of services that ecosystems provide. Effective conservation and restoration decisions will be supported by a continuous global fine‐scale assessment of changes in ecosystem condition over time. Innovation We developed a framework to provide annual ecosystem condition assessment based on remotely sensed ecosystem condition variables. Our conceptually simple approach compares the ecosystem variables of a target site to training sites with known condition. The comparison yields an ecosystem condition score as the similarity to the training sites. This framework provides a way to identify the temporal change in ecosystem condition while accommodating the natural dynamics of ecosystems and the spatial change from alternative natural states of ecosystems. Main Conclusions As a case study, we mapped annual ecosystem condition across Australia from 2013 to 2022, using Landsat‐derived condition variables at 100 m resolution. Our approach estimated ecosystem condition with high accuracy (RMSE = 0.23), which remained consistent along large environmental gradients. When evaluated against independent field‐based observations and other condition maps, our approach showed high agreement and identified the trajectories of ecosystem condition over time for sites with known changes. The case study suggests our approach is a useful tool to assess and monitor annual changes in ecosystem condition at continental scales. Our maps provide the information needed for assessing long‐term anthropogenic impacts on ecosystem condition and to support policy, planning and management decisions.