More realistic approaches are needed to understand the complexity of ecological systems. Emergent properties of real systems can be used as a basis for a new, neither reductionist nor holistic, approach. Three systems, termed here BUBBLEs, WAVEs and CRYSTALs, have been identified as exhibiting emergent properties. They are non-hierarchical assemblages of individual components, with amplification and connectedness being two main principles that govern their build-up, maintenance and mutual relationships. Examples from various fields of biological and ecological science are referred to, ranging from individual organisms to landscapes.