The role of remote sensing and geospatial modelling in mapping ecosystem condition und functioning

Abstract

The main scope of this habilitation thesis is to present a broad range of approaches on how remote sensing and geospatial modelling can be applied to map condition and degradation of different types of ecosystems. Data from both active and passive remote sensing instruments acquired by aircraft and satellite platforms at single dates or in multitemporal mode were used in the presented studies. Main drivers of ecosystem degradation such as Land Use/Land Cover changes, climate change and invasive alien species are addressed, and different types of ecosystems such as urban areas, temperate forests, Central European agricultural landscapes, tropical high-mountain grassland and dryland rangelands are examined. Beyond technical remote sensing aspects, the studies give insights on the importance of spatial modeling approaches in ecological applications, e.g. to account for the spatial heterogeneity of ecosystem properties. However, the increasing availability of remote sensing data poses both new opportunities and challenges in ecological or ecosystem studies, which are addressed in the conceptual and review paper of this thesis, e.g., dealing with large data volumes during processing and analysis. Future progress can be expected in fast evolving fields such as the use of drones, sensor-networks and crowd-sourced data together with interpretable artificial intelligence to study ecosystems. Further, very high resolution multispectral, thermal and radar satellite data is becoming more and more available, adding to the already filled toolbox from a data point of view. Nevertheless, a profound understanding of the ecological processes or mechanisms to be studied remains a fundamental requirement, as technological progress does not per se imply progress in using sensor-based approaches to study ecological phenomena. The increasing amount of studies and initiatives joining knowledge from different disciplines demonstrate that if we succeed in integrating expertise from different backgrounds, then we can create an innovative atmosphere that can lead to progress in using novel technologies to tackle urgent challenges regarding the degradation of our ecosystems.