BOTANISTS AND THE CONSERVATION OF NATURAL RESOURCES 365 



western New Mexico, represents a span of about five thousand years. Yet 

 to the ordinary observer there is less evidence of selective improvement from 

 bottom to top than might have been possible in less than fifty growing sea- 

 sons. Incidentally, the great lake which once lay below Bat Cave has now 

 dried up, and the alluvial fans which were once maize fields now have a cover 

 of short and mid-grasses. Other cultures in the area, many of whose sites have 

 been studied by the Field Museum, postdate the Bat Cave people and are 

 at higher altitude where springs were available. A similar phenomenon oc- 

 curred within the Basin of Mexico, circa 500 b.c, when the lakes dried down 

 and human activity shifted to higher altitude at Teotihuacan. Whether 

 modern man can override the limitations of environment or not, their effects 

 upon simpler cultures whose demands were much more modest are clear. 



The course and consequences of domestication are too involved for more 

 than brief mention. Domestication of plants made possible leisure and urbani- 

 zation and placed in man's hands for the first time sufficient potential to 

 disrupt natural processes to a serious degree. The domestication of plants 

 and animals gave rise to competitive types of land use which are still with 

 us in aggravated form. The recent chapters by Weaver and Albertson (1956) 

 on The Mixed Prairie contains a mass of data pertinent to this problem. The 

 evidence indicates clearly that moderate grazing represents the most effective 

 economic use of our semi-arid grasslands, and indeed was a normal factor 

 in natural grasslands. It further shows that the varied composition of these 

 grasslands gives them a resilience to the vicissitudes of an extreme climate, to 

 fire, and to biotic episodes that is quite lacking in any kind of monoculture. 

 Only the plow is truly lethal. 



But the data also reveal the extent and degree of damage caused by over- 

 grazing of areas that have not been plowed. From this one may infer the loss 

 in moral and economic advantage that handicaps the grazing industry in its 

 efforts to arrest the spread of its destructive rival, agriculture. Granting all 

 the difficulties and hazards of the livestock industry — many of which are 

 familiar to the writer through firsthand experience — it is an interesting fact 

 that this phase of private enterprise often resents the suggestions of competent 

 scientists regarding proper treatment of its basic resource, the range. This 

 attitude at a time when industry is bidding against government and itself 

 for the services of scientists and engineers suggests that in conservation the 

 botanist has a considerable job of education to do. 



Conservation rests on a tripod — scientific knowledge, ethical commitment, 

 and action to produce social change. Any botanist who adds competently 

 to our understanding of plant life makes his contribution. To the degree that 

 he becomes aware of the context of his work in the broad perspective of 

 nature he is likely, in my observation, to become sensitive to the ethical 

 obligations of man toward environment. Beyond this, he is often a teacher, 

 and always a citizen. In both roles he encounters moral as well as technical 



