In Trella Green Series™ Seeds and Trees, we take a broad approach to look at the interdependencies of life in our ecosystems. We start with the biome and large ecosystems and how they are classified. We look at how big systems like the water cycle are dependent on systems driven at the cellular level of plants – photosynthesis and respiration. The global water cycle system is dependent, at least in part, on healthy roots with access to water and we learn that roots just don’t take water up as needed. There is a whole biome in the rhizosphere bringing water to roots. Throughout the course we revisit this theme of the dependence of large systems on small relationships. Life is complex. We built up to looking at seeds and their germination and how the environment influences that. We are mentally healthier when we are near plants. Trees matter on a global scale, in our ecosystems and in our cities.