This paper proposes The Ecology of Understanding, a phenomenological framework reconceiving knowledge as an ecology of awareness in motion. It identifies 100 modes of engaged awareness grouped into five phenomenological families: Emergent (receptive-exploratory), Structuring (analytical-constructive), Transformative (creative-generative), Reflective (evaluative-meta-cognitive), and Integrative (applied-embodied). The framework synthesizes Husserlian phenomenology, Heideggerian existentialism, Jamesian pragmatism, systems theory, and contemplative science. Central is the distinction between engaged awareness (active cognition through specific modes) and open awareness (the receptive ground from which engagement arises). Moving beyond hierarchical taxonomies (Bloom, SOLO, Marzano), it proposes "Learning 3.0"—where education shifts from knowledge acquisition to cultivating awareness of understanding itself. The paper includes complete taxonomy with operational definitions, empirical validation methodology (micro-phenomenological interviews, EEG studies, longitudinal interventions), and applications to education, clinical psychology, and human-AI collaboration. Contributions: ecological model of cognition, operationalized phenomenology, Learning 3.0 paradigm, and bridge between Continental philosophy and empirical psychology. Includes transparent AI-assistance disclosure (ChatGPT-4, Claude Sonnet 4.5 for editing/formatting; all core theory and phenomenology are original author contributions).