 In 1905 he served as general secretary of the International Botanical Congress, held in Vienna.Zahlbruckner is known for publication of "Catalogus lichenum universalis", a catalog of all published names of lichens, issued in ten volumes from 1922 up until 1940.He also published regional works on lichen-forming fungi of central Africa, South America, China, Easter Island, Juan Fernández Islands, Dalmatia, Formosa, Japan, Java and Samoa.