Multi-scale characteristics and scale selection in landscape ecological studies

Landscape ecology is generally classified into the realm of macroecology and placed in a relatively high hierarchical level in ecological studies, which is above molecular ecology, individual ecology, population ecology, community ecology, and ecosystem ecology, yet below regional ecology and global ecology. In practice, however, landscape ecological research is not confined to macroscopic spatial scales but presents multi-scale characteristics. We systematically elaborated the multi-scale attributes and characteristics involved in landscape ecological studies from landscape pattern analyses, the coupling relationships between landscape patterns and processes. We further analyzed the fundamental principles to be followed in scale selection for landscape ecology research, as well as the associated issues and challenges faced. When selecting a scale, it is essential to consider the alignment with research objectives, the sensitivity of the research subject, the suitability of research units, and the compatibility of research data. Due to the knowledge limitation on scale multidimensionality and its spatiotemporal complexity in landscape ecological research, choosing an appropriate scale has significant challenges. For example, how to balance the relationship between grain size and extent, temporal and spatial scale, scale and data availability, has become key issues and challenges in scale selection for landscape ecological studies. We discussed the practical issues concerned in typical landscape pattern and process studies, which would provide references for making scientifically sound and rational scale selections in related research endeavors.