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Juan Cruz-Barrios





Human life occurs in the context of a particular time in a particular space. As such, it is necessary not only to look at a specific time of human activity proposed for study, but also take into consideration the place where the activity is realized. Therefore, geography can be utilized as the setting for historical analysis. Geography may then be conceptualized as the stage where people act.
In line with this principle, this chapter presents the relationship of Puerto Ricans with their environment during different periods of time historically. Factors such as geological evolution and the shape and location of the Island of Puerto Rico in the Archipelago Antilles and the American continent are essential for understanding the actions of the Puerto Rican community. Themes such as topography, climate, hydrography, precipitation and hurricanes, natural resources and the soil, will also be presented.
Notwithstanding that physical geography will point out a few relatively stable characteristics for a particular area, they have different significance for the persons living in those environments at distinct times. The human-environment relationship varies across time. For example, a mountain range does not always have the same significance for those who dwell in its slopes. For the indigenous villages of Puerto Rico, the mountains were symbols of the mystery of nature and constituted a natural barrier between the political groups which existed. The Spaniards of the XVII Century continually saw the mountains as obstacles to free communication between north and south. While at the same time their land served as an indispensable source of subsistence. In the XX century we have shorten the physical distance with technological improvements in communication.
An individual transforms their means of coping with their environment at the same time that the environment significantly influences their way of life. Neither geography nor the social environment will determine exactly how an individual may act, since members of the human race have the capability of making decisions. However, although the environment does not dictate the steps to any action, it does establish limits accordingly. For example, the fact that Puerto Rico is situated in the tropical cyclone zone influences the manner in which houses are built and the agriculture is organized; nevertheless, the geographic location and the condition of the island, which appear to be very determining conditions, have been understood in different ways throughout time. These conditions may appear to be advantageous for some individuals, while for others to be the opposite.

Individuals, for their part, continuously modify their environment creating different conditions with the passage of time. It is known that with the arrival of the Spaniards to Boriquen (Puerto Rico), a good part of the land was covered with forest. The rainfalls, vegetation, humidity and landscape were different. With the passing of years, a good part of this forest has been destroyed with the consequence of changes in the precipitation, flora and wildlife. Urban expansion, the intensive commercial use of agriculture, mineral exploitation and the channeling of rivers are some examples of drastic changes in the environment. The construction of living complexes, the excavation of the land and the disposition of waste are other means of altering the environment.
The human-environment interaction process is continual. It may change its rhythm, but cannot disappear. We must always understand that as human beings, we take action and make decisions in a physical and social setting. The environment, without the individual, would be empty, as it would not have its main ingredient. Therefore, in this chapter we will consider how at different times in history, Puerto Ricans have related to the world surrounding them.


In order to understand the origin and geological evolution of Puerto Rico, it is important to know the existing classes of rocks on the island, their placement and age of formation. Three great groups of rock are found in the earth's crust: the igneous, which have been formed from magma, as they erupt volcanically in the form of lava and cool into rock; the sedimentary, formed by sediment or matter deposited by water, wind or ice, and the metamorphic, which are formed by pressure and heat on existing matter changing it into a hard crystalline rock.
The volcanic rocks, forming the dorsal spine of the island of Puerto Rico, constitute the island's central mountain chain. This chain is comprised of the Cordillera Central, which rises almost directly out of the sea on the west coast of the island and extends eastward finally terminating in the Sierra de Luquillo in the northeast and the Sierra de Cayey in the southeast. This rugged terrain covers about 70% of the island's land mass.
The more abundant sedimentary rocks in Puerto Rico are calcareous. These are comprised of calcium carbonate deposited by sea water in the precipitation or, more frequently, extracted from the water by animals and plants. The principle calcareous belt extends from Loiza to Aguadilla in the north and from Juana Diaz to Yauco in the south.
The metamorphic rocks are not very abundant in Puerto Rico. The more common type is marble.

The geological history of Puerto Rico dates back to the Cretaceous period of the Mesozoic era, characterized by the following stages:

First: Volcanic and Cretaceous Sedimentation Stage. - In the beginning of the Cretaceous period crevices opened in the bottom of the Atlantic Ocean and great amounts of lava, powder, ash and gases poured through. These deposits grew into submersed mountains forming volcanic islands.

Second: Antilles revolution. - The terrestrial crust deformed at the end of the Cretaceous period, resulting in an arch shape mountainous chain, direct predecessor to the actual Greater Antilles.
Third: Calcareous sedimentary stage. - During the first period of the third stage the mountains in Puerto Rico suffered extensive erosion, until they were reduced to a peneplain. During the last period of this stage the erosion culminated in the formation of what is known as the Saint John Peneplain.

Fourth: Stage of elevation, erosion and formation of an additional peneplain. - Following the Miocene Epoch of the Tertiary period in the Cenozoic era, orogenic forces elevated Puerto Rico to a height of 800 feet, followed by a new period of erosion resulting in the destruction of the borders of the Caguaian peneplains.

Fifth stage: Stage of faulting, elevation and glaciations. - During the end of the Pliocene Epoch, the Island was elevated further, forming faults at its borders and remaining close to its present day contour. This last elevation dates back only one million years and continues at an extremely decelerated pace.
The geological development of Puerto Rico demonstrates the process in which the Island developed into the form and location it enjoys today. It has been a slow and gradual process which still has not ended.


In relationship to the map of America, Puerto Rico is located in the group of islands known as the Antilles, separating the Greater Antilles - consisting of Cuba, la Espanola (Haiti and Santo Domingo) and Jamaica - with the Lesser Antilles. Its position in the Caribbean Sea has been very important, as much for its relationship with the other areas in the same region, as for its relationship with the world surrounding it. Puerto Rico has occasionally been referred to as “the gateway to the Caribbean", due to its central position and its dominance of the northeastern Caribbean boundary and setting as a place of union for diverse cultures. The island facilitated the interchange between Taino and Caribe Indians since pre-Columbian times. Additionally, the Island served as a point of defense and harbor for Spanish ships and passengers, as they traveled through their empire in the Americas, and served as treasure bounty for foreign corsairs and pirates. Furthermore, the Island became a prosperous market of foreign products and a place of encounter, not always free of tension, between diverse cultures.
The Puerto Rican territory is formed by a group of islands, of which Puerto Rico is the principal one. To the north of Puerto Rico you'll find the Islet of San Juan; to the west, the islands of Mona, Monito and Desecheo; to the south, the island of Caja de Muertos; and to the east, Vieques and Culebra. Its limit to the west is the Dominican Republic, which is separated by the Canal de Mona (Mona Passage); to the east is the Virgin Islands; while to the north and south, respectively, are the Atlantic Ocean and the Caribbean Sea.

Puerto Rico is nearly triangular with a length from east to west of 113 miles and a width of 40 miles. Its area is 3,315 square miles (3,435 including adjacent islands). Puerto Rico may be divided into three geographical regions, using as the principal criteria the contrasting altitudes.

1. Lowlands and Coastal Plains. - Geographers have calculated that 27% of the island's land can be classified as flat or gently rolling lowlands. With one or two minor exceptions offered by small inland valleys, one near Caguas and the other near Cayey, this region is comprised primarily of land along the coastal fringe of the island. Depending upon the availability of water, the flat or rolling coastal lands are the most fertile areas in Puerto Rico. The abundant rainfall on the north coast assures production, but on the south coast and particularly in the southwest corner, in the Lajas valley sector, the flat rolling land needs irrigation. In the Lajas valley the insular government built an extensive and costly irrigation project which collects in artificial lakes the heavy rain that falls on the nearby highlands, brings the water down over hydroelectric dams and channels the distribution into the previously arid valley.
For the most part the coastal plains produce the bulk of the islands sugar crop. About 30 sugar mills, or centrales, located in this region produce more than 90% of the island's sugar. More than 20% of this sugar is produced on the north coast and about 30% is produced on the irrigated plains of the south coast. Some coastal land lacking in rainfall or fertility is used as pasture. Prior to the completion of the irrigation project, the Lajas valley was used primarily in this way. On the north coast about 50 miles west of San Juan, near the port of Arecibo, pineapple production has been expanding. The coastal area has some unproductive land in mangrove swamps and in limited areas where sand dunes have moved inland. By far the best of the island's beaches can be found on the sheltered west coast. The north coast also has excellent beaches wherever offshore reefs serve to break the heavy Atlantic serf. The Luquillo beach east of San Juan is perhaps the most popular and widely known.

2. Highlands. - In contrast to the coastal plains is the markedly mountainous terrain of the central part of the island, which accounts for about 36% of the land area. This extensive area is marked by high local relief with little flat land. Most of the slopes range from 30% to over 60% grade. This region, comprised of the Cordillera Central, the Sierra de Cayey and the Sierra de Luquillo, includes the highest peaks of the island’s drainage divide.
Heavy rainfall and fertile soil permit extensive cultivation of this region in spite of the sharp slopes. Coffee is the main crop in the area which extends from near the west coast to the centre of the island. The shrub which produces the coffee bean is very sensitive to temperature variations and grows best in the shaded areas between 1,000-ft. and 3,000-ft. altitude; orange and grapefruit trees and the broad-leaf banana plants are utilized for shade. As a result of the cultivation of coffee in the western mountain area, the impression is given of a cleared, well-gardened forest. Two insular forest reserves, Maricao and Toro Negro, with picnic facilities and lookout towers, can be found in the western and central mountain areas.
The eastern mountainous section, with the exception of the Sierra de Luquillo, receives less rain than the western highlands and the vegetation is less thick, with the land unprotected by a lack of covering forest. Tobacco is the principal commercial crop. Small farms produce subsistence crops, and extensive pasture areas can be found. The Sierra de Luquillo, where the tropical rain forest (El Yunque) is located, has a recreation park with trails, swimming pools and lookout towers.

3. Rolling Hill Land. - The area of the island which lies between the two extremes of the flat coastal plains and the markedly mountain terrain can be described as rolling hill land; it comprises the remaining 37% of the land surface. Foothills adjacent to the central core of the mountains are included in this area. Unique limestone belts of the North eastern and north central sections of Puerto Rico are found in this region. This area is of less geological age than the rest of the island, having been formed during the Tertiary period. The limestone plateau, at one time under the sea, once lifted and exposed to rain and wind erosion, was slowly converted into striking karstic topography. The area is characterized by precipitous cliffs, caves and large caverns, deep depressions or sinkholes and solidified limestone remnants, which resemble conical haystacks. In this area rivers such as the Tanama or Camuy disappear suddenly and, running underground, appear just as unexpectedly miles away. In spite of the rugged terrain, the irregular valleys among the limestone remnants and precipices are cultivated with the same success by the small farmer. Subsistence crops, vegetables and fruits are the main products.


TEMPERATURE: While Puerto Rico lies just within the tropics, its climate is usually agreeable. The average annual temperature is 76.3 F. and the island is without sunshine, on the average, for only five days a year. On the coast the winter monthly average is 75; for the summer months it is 80. In the interior at an altitude of 1,500 ft. the average winter temperature is 70; during the summer it is 75. The absolute minimum temperature recorded in Puerto Rico was 39 at an altitude of 3,000 ft. Frost may occur at higher altitudes but has never been officially recorded. The maximum recorded temperature in San Juan is 94. Cool, invigorating sea breezes, constantly brought by the trade winds which bathe the islands of the West Indies, help to soften the effect of the hot sun. During the summer months these winds come directly from the east, or slightly southeast. During the winter they shift and come from the northeast. At night, gentle land breezes coming down from the mountainous interior bring cool and refreshing air to the coastal areas, causing a drop of 6 or 7 from the day temperature.

RAINFALL: The trade winds also bring abundant rainfall, which for the island averages 74.4 in. annually. It rarely rains for more than a few hours at a time, even during the rainy season, which lasts from May to November. The coastal areas are cooled in the late morning or afternoon by light showers during the warmer months of the year. The variation in rainfall recorded in different parts of the island is much greater than the temperature variation. The rain forest of the Sierra de Luquillo (El Yunque) which receives the trade wind first, has recorded an average annual rainfall of 184 in. over a ten year period. In the southwest corner of Puerto Rico annual rainfall drops to about 30 in. The island is subject to occasional tropical storms. The winds, which reach a velocity of 150-200 mph, are usually accompanied by torrential rains. The storms, which rarely last more than a day, occur from July to October.

HUMIDITY: The amount of humidity or water vapor in the air, combined with the temperature, has a direct effect on individuals. In the event that both temperature and humidity are high, the effect is a feeling of personal discomfort which at times makes physical activity difficult. In the summer the humidity is slightly higher, as the result of the east winds, loaded with water vapor.


VEGETATION: The erosive effect of a heavy rainfall on the precipitous slopes of the central mountain range of the island is counteracted by a particularly tenacious soil bound together by clinging and abundant vegetation. The wide variation of rainfall, a fairly rich soil and different altitudes produce a great variety of plant life. Because of the extensive cultivation of the land, the vegetation in a relatively natural state is limited to the insular and national forest reserves located at higher altitudes in the western, central and eastern sections of the island. The tropical rain forest El Yunque, located at the eastern end of the island, is composed of a great variety of trees, clinging and hanging vines and a thick undergrowth of shrubs, ferns and thickets. The jungle like density is almost impenetrable without the aid of a machete, a sharp, long broad-bladed knife. In this area wild orchids can be found. Trees include bamboo, palm, cedar, ebony, calabash, whitewood, lancewood, boxwood and logwood.
Along the coastal plains, which probably were covered once with a thick forest growth, sugar cane and pineapples are grown. In the northwest corner of the island and in the mountain areas tropical fruit of all varieties are produced. Together with the coffee bush, a great variety of citrus fruits can be found in the western highlands. In addition to the common fruits such as bananas and oranges, the island produces papayas, pomegranates, avocados, guavas, mangoes, breadfruit, passion fruit and guanabana. Spices such as ginger, pepper, vanilla and chicory are also grown, in addition to roots and tubers such as yuca, yautia and batata (sweet potatoe).

WILDLIFE: Physically isolated at an early geological age and densely populated, Puerto Rico has very little wild animal life. Bats, birds, a scarce and harmless species of snake and several varieties of harmless lizards, together with the mongoose and rat, comprise most of Puerto Rican wildlife. For the patient bird watcher the island offers a wide variety of species of birds, nesting or in transit. About 190 species have been identified, and of these 89 are known to nest. Some 36 birds are endemic to Puerto Rico. Thrushes, tanagers, bullfinches, flycatchers, warblers, plovers, terns and sandpipers are the birds most commonly seen.
The waters around the island are excellent for sport fishing. Yellow-fin tuna, white marlin, sailfish, dolphins, kingfish and wahoo are only a few of the commoner varieties which can be found 2 to 5 mi. from the coast. There are also fine black bass in the fresh-water reservoirs of the island.

MINERALS: Since the times of Spanish rule there have been attempts to evaluate, with some degree of certainty, the types and quantities of minerals found in Puerto Rico. The result of prior efforts were based on studies lacking a system of precision and failed to cover the entire island. In 1970 Professor of geography, Jose F. Cadilla completed a comprehensive inventory of the existing minerals to date, in which he indicated in great detail, the location and availability of the minerals. Although the long list compiled by Pofessor Cadilla cannot be presented here, those minerals which had or have more commercial or industrial value will be discussed.

1. Non-metallic. In terms of products utilized locally, non metallic minerals are of extreme importance. Some are found in abundance, such as calcium, marble, silica and argil sands, and others which are very limited and difficult to extract, such as gypsum, guano and natural oil. Water, sand and gravel are also of great value to the construction industry. Although these resources exist in abundance, they should be carefully conserved, being that they have a generalized effect on the balance of the ecology. For example, the destruction of sand dunes along the beach to extract sand, removes the natural barrier which protects the interior against the liberal entry of the sea.
Water resources, such as rivers, lagoons and artificial lakes (rain pools), should serve to be sufficient if used adequately. Nevertheless, the unequal distribution of water across the island and its poor use, frequently results in the determination that in some areas there is an insufficient amount. Due to a growing population and the increased number of industries, satisfying the necessity for this resource is becoming more difficult.
There is an abundance of calcium in Puerto Rico. As much of this mineral's vast reserves is found in the south, as is in the north, which in the form of stone is used by the construction industry. There is also a variety of marble concentrated in the southern part of the island. Although it is exploited in a limited manner, there is still a need to explore its industrial possibilities further.
Puerto Rico relies on a variety of argils (clay) which are frequently classified by color. Although the red variety is found along the length of the entire island, it is predominantly found in the regions of Mayaguez-Maricao-San German, Barranquitas-Orocovis, Naranjito-Corozal, Caguas-Cayey and Rio Piedras-Trujillo Alto. The red argil is used in ceramics and for the production of bricks, blocks and tubing. The yellow toned type is commonly found in the mid-eastern region, where it is utilized for the production of cardboard, paper and soap or as a filling.

2. Metallic. In contrast to the non-metallic minerals, metallic minerals have to be extracted from rocks or mined. Puerto Rico has magnesium, tin, mercury, manganese, silver, zinc, lead, cobalt, gold, copper, iron, nickel, molybdenum, chromium and titanium, however, not all are found in sufficient quantities for commercial use.
As of the XVI century, when the Spaniards conquered Puerto Rico, the search for metals has been an important element in the life of Puerto Ricans. In that epoch, since the control of the metals served as the basis for the acquisition of power, the Spaniards immersed themselves in the struggle of extracting gold out of the sands of the rivers, to the point of exhausting those reserves.

Iron, copper and nickel are the metals with the greatest possibility of commercial extraction. Nevertheless, the best manner in which the exploitation of these metals benefits the Puerto Rican community should be cautiously studied. Perhaps, together with its exploitation, an industry of locally manufactured products may be established, which would prevent the exporting of these materials without elaboration.
Copper is the most abundant metal, with the greatest probabilities of exploitation. Although deposits are found in Ciales, San German, Aguada and the Sierra de Luquillo, the deposits of greatest importance are found in the Utuado-Jayuya-Adjuntas-Lares zone, where approximately 300 tons of 70% copper mineral exist.
In addition, iron can be found in the east (Juncos-Las Piedras), in the west (Mayaguez) and in the central region (Adjuntas-Jayuya). However, not all of it can be utilized commercially, since for example, in the Cerro las Mesas in Mayaguez, the deposits are too close to urban areas.

MEAT AND POULTRY PRODUCTS: Another activity related to the land is the production of meat, milk, eggs and fowls. From 1940 to 1980 these agricultural trades grew slowly in Puerto Rico during this period. The milk industry has been the one with the quickest growth, which due to the best technology, has been able to triple its productivity. Statistics demonstrate that for the year 1978-79 the increment in the production of milk reached 8.3 million dollars. Although at a lesser pace, the production of meat increased for the same year (1978-79), registering an increment equivalent to 7.7 million dollars. The poultry industry has also grown. Although it suffers from competition due to the poultry and eggs brought in by the United States, it has been able to almost triple its production since 1951. In this trade, for the year 1978-79, the registered increment was 8.4 million dollars.