Advances in remote-sensing applications in silvo-pastoral systems

Abstract

Detailed studies of silvo-pastoral systems (SPS), including studies of changes in degradation patterns, as well as the causes and impacts of degradation, for example, on biogeophysical mechanisms, productivity, and resilience, are crucial for building a broad understanding of the overall process of SPS land-use change and to support policymakers in making informed decisions. Timely and accurate data on the main SPS components, such as tree and herbaceous layer cover fraction, and on the spatio-temporal patterns of SPS are therefore critical for such studies. Free access to remote-sensing data sets obtained from spaceborne sensors, along with imagery from airborne sensors and unmanned aerial vehicles (UAVs), supplemented by data from ground-based instruments, allows researchers to ask new scientific questions and address relevant issues, including monitoring and assessing the spatio-temporal trends of SPS land-use changes. Given the presence of a markedly dry season in SPS systems, and also the spatial fuzziness caused by its tree density variability, the spectral characteristics of these landscapes constitute one of the most challenging aspects for remote sensing. Despite the great progress, especially in recent years, the remote sensing of SPS is still evolving due to the growing availability of high-quality remote-sensing-based products able to effectively address the complexity, diversity, and dynamics of these ecosystems. This special issue addresses these and other challenges, as well as focusing on recent advances in remote sensing of SPS. The special issue includes manuscripts originally presented at the ‘World Congress Silvo-Pastoral Systems 2016: SilvoPastoral Systems in a changing world: functions, management and people’, held 27–30 September 2016 at Évora, Portugal. The articles can be divided into four groups according to the type of platform used to produce remote and proximal sensing data and derived products, namely spaceborne (satellite), airborne, UAVs, ground instruments, and multi-platform (multi-source applications).