A NATIONAL PLAN FOR AMERICAN FORESTRY 1647 



The Sierra de Luquillo, the most easterly of the three ranges making 

 up the central mountains, is nearly surrounded by low coastal plains 

 and is practically isolated. The remaining mountain mass forms an 

 uninterrupted expanse of broken uplands. The eastward portion is 

 known as the Sierra de Cayey ; that to the west, the Cordillera Central. 

 This region has an average elevation of about 2,500 feet, above which 

 the higher peaks project irregularly, a few to an elevation of more than 

 3,500 feet. 



As a result of the almost uninterrupted action of abundant precipi- 

 tation, a high relative humidity, and a warm temperature, rock 

 weathering at the higher elevations is more rapid than erosion, as 

 shown by a soil mantle of unusual depth and almost no bare rock. 

 The characteristic soils are deep, reddish clay loams and tenacious 

 red clays. So cohesive, unctuous, and compact are these soils that 

 they are able to maintain themselves in an almost vertical position. 

 Cultivation, in consequence, is in many places carried on to the very 

 tops of the ridges and on the steepest slopes, yet evidence of gullying 

 and landslides in the high country is surprisingly inconspicuous. 

 Sheet erosion, which removes the top layers of the soil, is common, 

 but ordinarily escapes notice. 



There can be little doubt that at one time Puerto Kico was com- 

 pletely forested. Following the Spanish settlement, early in the six- 

 teenth century, land passed rapidly into the hands of private owners. 

 Final clearings, severe burning, and the previous cutting of the more 

 desirable timber trees, all in preparation for the planting of coffee, 

 tobacco, cane, or other crops, continuing over a long period of time, 

 has resulted in the present naked state of the island 's hills and valleys. 

 The valleys and other topographically suited and fertile areas have 

 been justly devoted to tillage or coffee growing; but there remain 

 today approximately 1,100,000 acres of forest, brush, swamp, and 

 barren lands of which but an insignificant part contains forest growth 

 of economic value. According to statistics of the Department of 

 Agriculture and Labor of Puerto Rico, the land area of the island is 

 classified approximately as follows : 



The "conuco" system of farming, a shifting method of agriculture 

 employed by primitive people throughout the tropics, is responsible for 

 much of Puerto Rico's deplorable forest condition. Years of cutting, 

 burning, and clearing succeeded by the planting of some small food 

 crop, continuously cultivated until the surface soil is worn out 

 (usually in 3 to 4 seasons), followed by complete abandonment of 

 the plot to grass, weeds, and other volunteer growth, is the cycle of 

 operations which has caused the present barren and exposed state of 

 thousands of acres. Charcoaling, an adjunct of " conuco" farming, 

 is a further factor contributing to the deforested condition of the land. 



Of the once unbroken tropical forest there now remain only isolated 

 remnants scattered over the island in its most mountainous parts. 



