PART IX — TERRESTRIAL ECOSYSTEMS 



processes that he does not fully 

 comprehend. 



There are two reasons for the prob- 

 lems of environmental design. First, 

 man cannot, with any certainty, now 

 foretell the consequences of the trans- 

 formations in which he is engaged. 

 Second, he cannot yet design alter- 

 nate processes for his own ecosystem 

 that will assure his survival. 



Some Specifics 



In his design of the environment, 

 man seems to have locked himself 

 into a course that will bring him to 

 the climax visualized before he has 

 developed the knowledge and skills 

 for managing such a human ecosys- 

 tem. This is the essence of the prob- 

 lem. We shall examine briefly a 

 few aspects in order to gain a per- 

 spective on the decisions about en- 

 vironmental design that man must 

 make in the decades ahead. 



Urban Growth — From the view- 

 point of environmental design, the 

 city may be conceptualized as an 

 empirical allocation of the landscape 

 to accommodate high population den- 

 sities in functionally effective con- 

 figurations of structures, spaces, in- 

 stitutions, and processes. Although 

 the city gives the appearance of in- 

 dependent existence, it is inexorably 

 bound to its surround, for the city is 

 a specialized consumer of resources. 

 It is entirely dependent on a continu- 

 ing inflow of biological and physical- 

 chemical resources for its very ex- 

 istence. These resources include 

 foodstuffs, fuels, and a variety of 

 raw materials. Its productivity can 

 be measured in terms of diverse 

 fabrications. 



The city has become the scene of 

 some intriguing shifts of population. 

 There is at once an outward migration 

 of people from the central city to the 

 suburbs and an inward migration of 

 people from the country to the city. 

 To accommodate these flows, urban 



sprawl has developed; the central 

 city, which began to deteriorate, is 

 being rebuilt to house greater popu- 

 lation densities; and vast transporta- 

 tion links have been constructed to 

 carry workers between residence and 

 place of work and to relate the city 

 to its surround. The spread of the 

 city has consumed large areas of pro- 

 ductive agricultural land. The shift 

 of population into high-density areas 

 has sharpened the dependence of the 

 city on the remaining agricultural 

 lands and on the efficiency and effec- 

 tiveness of the communication links 

 with that managed landscape. 



Monoculture and the Shrinking 

 Gene Pool — For relatively fewer and 

 fewer persons to support the growing 

 dependent populations residing in 

 high-density areas, the productivity 

 of agricultural lands must be con- 

 tinually intensified. High produc- 

 tivity demands that an increasing 

 amount of the landscape be trans- 

 formed from low-producing climax 

 associations of a diversity of plants 

 and animals to high-producing mono- 

 cultures of domesticated plants and 

 animals bred to provide for human 

 needs and requirements and for re- 

 sistance to pathogens and adverse 

 weather conditions, particularly cold 

 and drought. To assure that these 

 managed lands are maintained as 

 monocultures, they are protected from 

 invaders by a variety of biocides toxic 

 to the invaders but not toxic to the 

 domesticated organisms or the con- 

 sumers of the produce. Because the 

 nutrients extracted from the soil by 

 the domesticates are not recycled but 

 diverted to the human consumers, the 

 nutrients must be restored as chemi- 

 cal fertilizers. To maintain the vigor 

 and the resistance of the domesti- 

 cates, they must be continually inbred 

 with material from appropriate wild 

 genes. 



As the demands upon the land- 

 scape intensify, its transformation to 

 managed agricultural systems spreads 

 and the space that can be allocated to 

 pools of wild plant and animal genes 

 shrinks. As the stocks of wild genes 



diminish, the opportunity for invigo- 

 rating the domesticates and for pro- 

 viding new domesticates is reduced. 

 Because man's food base is already 

 rather narrow, an important decision 

 in environmental design will be how 

 to provide adequate space for reser- 

 voirs of wild plant and animal genes. 



Conservation and Recycling of Re- 

 sources — Reservoirs of wild genes 

 represent only one decision in envi- 

 ronmental design to conserve natural 

 resources essential for the human eco- 

 system. Because of their vital role in 

 subsistence, steps must be taken to 

 preserve the quality of lakes, rivers, 

 estuaries, and zones of oceanic up- 

 welling so that their biological pro- 

 ductivity is maintained. Man also 

 extracts other natural resources from 

 the landscape. These resources pro- 

 vide fuel to support his activities and 

 materials for his fabrications. Be- 

 cause the supply of these resources 

 is finite, environmental designers 

 must plan for their conservation, allo- 

 cation among competing needs, and 

 processes whereby essential materials 

 may be recycled. 



Managing feedback in the emerg- 

 ing human ecosystem is one of the 

 most complex problems in environ- 

 mental design. In the natural eco- 

 system, organic detritus is fed back 

 into the environment and recycled 

 into new organic forms. Relatively 

 little detritus accumulates in the en- 

 vironment. Man adapted his methods 

 of managing wastes to the processes 

 of the natural ecosystem, but the scale 

 and tempo of waste production have 

 exceeded the capacity of natural feed- 

 backs and the toxic nature of the 

 human detritus has disrupted the 

 orderly functioning of the organisms 

 in the ecosystem. Man must now de- 

 vise innovative processes to manage 

 the rapidly accumulating detritus of 

 the human ecosystem. 



Because the resources of the land- 

 scape are limited, the decisions of 

 environmental design for the alloca- 

 tion of these resources among com- 

 peting demands must include the 



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