118 MAN ON THE LANDSCAPE 



shore of a prehistoric ocean, on stratified silt washed off old moun- 

 tains, on glacial drift bulldozed down from the north by mile-thick 

 ice? From a high point in your locality, view the drainage pattern 

 developed by thousands (more likely millions) of years of climate. If 

 you live in a region of deciduous trees, be sure to do much of your 

 observing when Nature has her makeup off, when every wrinkle, sag, 

 or bulge is starkly revealed. It is probable that a major part of the 

 relief you see was fashioned before plants exerted any great influence 

 in stabilizing the soil. Would you recommend that the hydraulic 

 power so obviously employed in rearranging the earth's surface be 

 again released, now that man occupies the landscape? If you so 

 recommend, then the next step is to get rid of the vegetation, and the 

 power of climate will be unhindered. If you do not so recommend, 

 what course would you advise concerning vegetation? 



(3) The physicist reports that the transporting ability of running 

 water varies as the sixth power of the velocity, that is, T - V 6 . If 

 water is moving down a more or less bare slope at a velocity or rate of 

 1 inch per second, then Tr=lxlxlxlxlxl, or T = 1. Let us 

 assume that at this rate some soil will be moved. 



If the water were moving twice as fast, 2 inches per second, what 

 would its transporting ability be ? How many times as much soil could 

 it move? 



Suppose, after a cloudburst, the water were flowing at 100 inches 

 per second (less than 6 miles per hour). What would its transporting 

 power be, compared to the first case? Does this figure explain the 

 dissection or cutting up of the Piedmont, Appalachian, Colorado, 

 Ozark and other plateaus? Water alone could hardly have cut the 

 Grand Canyon. What does the river use for abrasive tools? Would 

 the same principles apply to small gullies in a field? What methods 

 can you suggest to prevent both rapid runoff and abrasive cutting ? 



(4) If there is opportunity, observe abandoned fields and note the 

 species which occupy them. Are any species invading the area ? What 

 evidence can you find that conditions of soil organic matter, soil mois- 

 ture, soil temperature, and light are changing? As the invaders 

 increase, what changes will they bring about ? 



CHAPTER VII 



(1) On a field trip, observe how plants grow in colonies. Note 

 parent trees and families of youngsters. See how the forms of some 

 tree crowns are misshappen because of shading by taller neighbors. 

 Find thickets of fiercely competing saplings. Estimate the amount of 

 thinning which would be beneficial. Select crooked, low-grade, sun- 

 hogging "weed" or "wolf" trees which you would remove. Have 

 they any value as wildlife food or den trees ? Do they provide needed 

 shade for livestock? Would these questions modify your decision? 



(2) On a field trip, observe the four-storied forest: herbs, shrubs, 

 saplings, and mature trees. Note the vines, mosses, ferns, fungi. Where 

 is the greater fraction (on a weight basis) of animal life located. Do 

 not overlook the insects. Where do woody plants concentrate their 



