“The macrotermitine termites build some of the most spectacular animal-built structures on the planet. Some, like the mound of Macrotermes michaelseni…are dominant landscape features over much of southern Africa. These termites control a significant portion of the flows of carbon and water through arid savanna ecosystems. These remarkable structures are not the residence for the colony–very few termites actually are found in them. Rather, they are accessory organs of gas exchange, which serve the respiratory needs of the subterranean colony, located about a meter or two below the mound…Functionally, these mounds are devices for capturing wind energy to power active ventilation of the nest. They are adaptive structures, continually molded by the termites to maintain the nest atmosphere. This ability confers on the colony emergent homeostasis, the regulation of the nest environment by the collective activities of the inhabitants.” (Turner 2000)
“As it is in lungs, the colony’s respiratory function is dominated by a mixed-phase regime that is sandwiched between the subterranean structures (where natural convection dominates), and the upper parts and peripheral air spaces of the mound (where wind-driven forced convection dominates). By our best estimates, this mixed natural/forced convection regime occupies the lower parts of the chimney and the deeper parts of the mound reticulum .” (Turner and Soar 2008:222)
“…so-called pendelluft ventilation (literally, air pendulum) enhances gas exchange across the mixed-regime region of lungs through weakly-driven bulk flows of air between alveolar ducts and between the fine bronchi (Figure 7, [17, 18]). We believe there is a pendelluft in termite mounds as well, driven by an interaction between buoyant forces generated by the colony, slow transients in turbulent wind energy that penetrate to the lower chimney and subterranean tunnels and the rapid transients that drive flows in the superficial tunnels…The end result of these complicated interactions is a pendelluft that drives slow quasi-tidal air movements in the chimney and lower parts of the mound interior, enhancing exchange between the nest and mound .” (Turner and Soar 2008:222-223)
“In most building designs, walls are erected as barriers to isolate spaces: internal spaces from the outside world,internal spaces from one another and so forth. Yet spaces, if they are to be occupied and used, cannot be isolated. Resolving this paradox is what forces building designs to include infrastructure—windows, fans, ducts, air conditioning, heating etc—all essentially to undo what the erection of the walls did in the first place. In short, the paradox forces building design toward what we call the “building-as-machine” paradigm (BAM).
Living systems, which also are avid space-creators, resolve the paradox in a different way: by erecting walls that are not barriers but adaptive interfaces, where fluxes of matter and energy across the wall are not blocked but are managed by the wall itself [28, 29]. This is illustrated dramatically in the complex architecture of the interface that termites build—the mound—to manage the environment in their collectively constructed space—the nest .” (Turner and Soar 2008:225)