Monitoring Agricultural Land Use Intensity with Remote Sensing and Traits

The intensification of agricultural land use (A-LUI) has significant environmental and economic impacts worldwide, including soil degradation, water quality problems, loss of biodiversity and increased greenhouse gas emissions. Monitoring agricultural land use intensity is a major challenge due to the complexity of the underlying processes and the spatio-temporal variability. This review summarises and compares definitions and standards of A-LUI at national and international levels (FAO, OECD, World Bank, EUROSTAT). It also discusses both in-situ methods, which provide high local accuracy, and remote sensing (RS) approaches for deriving A-LUI indicators, which allow for area-wide, temporally dense and standardised coverage. The use of RS offers significant advantages for large-scale and continuous assessment of A-LUI, while specific challenges remain, such as the assessment of small-scale structures, seasonal dynamics and management practices. The paper proposes a novel definition and structuring of RS-based LUI indicators, which includes five main features: Trait LUI indicators, Genesis LUI indicators, Structure LUI indicators, Taxonomic LUI indicators and Functional LUI indicators. These characteristics allow better access to and understanding of agricultural indicators derived from RS data. Examples of indicators for these five main characteristics are discussed. Finally, innovative technologies and approaches, including hyperspectral RS, artificial intelligence and semantic data integration, are highlighted that may be instrumental in improving the monitoring, derivation and assessment of A-LUI in the future. Finally, a comprehensive compilation of A-LUI indicators that can be derived from RS data is provided. In order to successfully establish biodiversity credits in the future, a standardised and globally comparable assessment of A-LUI using efficient indicators is required. These financial instruments could make sustainable agriculture economically attractive and thus contribute significantly to the protection and restoration of biodiversity.