The Encyclopedia Americana (1920)/Carnegie Desert Laboratory

CARNEGIE DESERT LABORATORY, one of the most important of all the many research departments allied with the Carnegie Institution at Washington, situated near Tucson, Ariz. In connection with the department of botanical research, this laboratory was established in 1903 and almost at once took its place among the great institutions of the world. It concerns itself chiefly with the plant life of the desert, seeing how the impoverished plants which grow there can be made to thrive and improve and become of benefit to mankind, and is a movement of great agricultural import.

The equipment of the Carnegie Desert Laboratory is in proportion to the elaborate work undertaken there. The area of ground embraced for experimental work comprises 860 acres, situated just west of Tucson. Within this tract Tunamoc Hill rises to a height of 800 feet above the lower mesas. These topographical features present a wide range of varied conditions for plant growth. The laboratory proper is located half-way up the hill, and the entire grounds are fenced in. The laboratory forms three sides of a quadrangle 126 feet long with a short axis of 85 feet. Besides this is a small glass house for experimental purposes along special lines, and also a workroom.

The laboratory is conducting interesting work on Alpine and Austral plantations, located on the mountains, for the furtherance of which work it is provided with a complete pack equipment, including two pairs of heavy rawhide kyacks suitable for transporting instruments without damage. Although the greater part of the departmental work is carried on here, it is essential to a comprehensive study of desert plant life to explore distant as well as adjacent arid regions and much important work has also been carried on in the Salton Basin, where it has been established that the highly specialized flora is of comparatively recent origin. This basin and its accompanying vegetation have suggested experiments relative to the influence of altitude and climatic factors upon vegetation. To carry on these, plantations have been established on the Santa Catalina Mountain at various altitudes, ranging from 2,300 feet to 8,000 feet in height. Thermometric observations are made at each of these plantations. Culture has also been carried on at the tropical station at Cinchona, island of Jamaica, for comparisons. In order to obtain more complete comparisons the establishment of a station is now being contemplated in the San Francisco Mountain in northern Arizona, having an elevation of about 12,000 feet. Notable experiments have also been made in demonstrating the movements of vegetation over desert areas, and the distribution of native and alien plants. This study has been greatly facilitated by a topographical survey and a geological survey, both of which were conducted under the direction of the University of Arizona. Twelve well-defined plants were considered by the staff in this field of science, and various stations established, to demonstrate correlate plant

with known factors of environment, with special attention to water supply, conditions of soil, exposure and drainage.

Other notable work of the laboratory has been the measurements of bodies of certain succulents in which the storing of water has been developed; experiments in the physiology of stomata, covering research in relation to the colors in flowers. In this, convincing data have been collected through the agency of the dark room, starvation and feeding. Similar investigation has been made in regard to the topography of chlorophyll masses, one of the distinct characteristics here noted bring the depth to which the chlorophyll has been deposited in some desert plants, primarily, it is believed, because of the highly intensified light of the desert regions. Experiments have also been carried on in regard to the habits of roots in the desert regions, with comparative results obtained in the New York Botanical Gardens and data from the Jamaica institution. A great deal of highly interesting work has also been done in studying the water storage capacity of certain desert plants. Many specimens which grow in the desert have developed this capacity to a remarkable extent in order to tide them over through the long droughts which often occur there. The work of the Carnegie Desert Laboratory is thorough and exhaustive. It is not spectacular, since years are often required before even a single fact can be absolutely assured, but the work is cumulative in its nature, and in the future its importance will be adequately realized by the nation at large, and particularity by that portion of the population which is interested in the deserts of the West and other cultivation.