well, that made me remind of a link I saw a while ago, but it´s in german.
http://www.uni-saarland.de/fa...bionik.htm
basically it tries to copy the praerie dog cynomys way to build his burrow which uses the bernoulli principle for ventilation. using this in a human building could reduce energy costs for cooling by 80% in summer and for heating by 40-60% in winter.
a termite´s mound can do the same with 20 different openings in different directions, by blocking some of those leading to the sun, to get a lambda in air temperature of 4° celsius.
another species I´m thinking of is spirulina, cyanobacteria or blue algae. they have the highest efficiency to produce oxygen and are used as a dietary supplement because of the high amount of proteine. just think about all the light energy that gets wasted by walls and roofs. now imagine using those solar thermal energy panels to create warm water filled with spirulina and the result is a below zero carbon city ..
