<p>Chicago is indeed a city in a garden just as our "Urbs in Horto" motto has been telling us in Latin since 1837.</p><p>We tend to get the urbs part right, with the buildings, infrastructure and all. But too often, the horto gets treated like garnish — mere green detailing surrounding the built environment — when in reality, the garden is a living thing just as complex, vital and in need of protection as the human-made structures we construct and admire.</p><p>"Flyway City: Architecture for a Flourishing Ecosystem", and "Chicago's Living Habitat", companion exhibitions that opened this week at the Chicago Architecture Center, 111 E. Wacker Drive, rightfully reminds us of the importance of balancing nature and architecture.</p><p>Designed and co-curated with the Chicago Architecture Center by the celebrated architect Jeanne Gang — who is a birdwatcher — and her firm, Studio Gang, Flyway City shows how glassy facades can be designed or reworked to help keep birds from running into buildings.