By 1527 there were 18 mills and 2 trapiches functioning in Hispaniola, with another 12 under construction. By 1545 Gonzalo Fernandez de Oviedo offers a more believable amount of 20 sugar mills and 4 trapiches in production. Most of the sugar mills belonged to the colonial functionaries or their sons, since Charles I had dictated protective laws establishing that these productive units were properties which could not be impounded nor mortgaged by their heirs, and that their transfer to their descendants must be done in the Spanish tradition of primogeniture (inherited only by the eldest son).
By the end of the 1520 decade, various settlements founded by Ovando had been abandoned. The villages of Santiago, La Vega, San Juan de la Maguana and Higuey, didn't reach 20 or 30 families. The Spanish exodus was very large but didn't impact those with considerable interests in the island. Only Santo Domingo, due to its administrative and commercial position, continued a stable growth as principal city. Later, the Crown would try to re-populate some zones sending Spanish farming families, specially Galician and Canarian who settled in villages like Monte Cristi and Bayaja.
The majority of sugar mills and trapiches operated between Santo Domingo and Azua de Compostela, located there due to the proximity to shipping ports and as security measures upon the possibility of pirate attacks or of runaway blacks and Indians called "cimarrons".
The great plantations included lands dedicated to the sugar cane cultivation around an acre for every ton of sugar produced; diverse parcels were destined for gracing and the cultivation of tubbers for feeding the slaves, foremen and Sirs. Other areas of land were used in the cut and collection of wood for fuel. There were also estates or principal houses, usually a small church, as well as the dwellings of the employees and the slave barracks. Markets were organized in these estates where merchants from Santo Domingo and neighboring areas attended with their diverse produce, as well as small farmers who sold their surplus to the large mills. Little by little the population of the island began developing around the sugar mill zones in order to make a living by trading indirectly with them.
The mill itself could be one of two kinds: the trapiche, propelled by animal traction and of limited yield, or the mills propelled by hydraulic energy, using water mills in rivers of canals, which produced a larger yield. The establishment of a sugar mill required the original investment of around 10,000 Castilians or currency of the time, which was spent in slaves, foremen, experienced technicians, and the machinery which, although it could be brought in tax free, were regularly imported from Holland or Italy which resulted in higher costs.
The cultivation of sugar cane was done by slave labor and plowed with the use of oxen. The cut cane was transported by wagon to the mill. The sugar juice was then boiled in boilers to a specific heat in order to obtain the molasses which was transferred to other receptacles or pools for its first cooling. The molasses was later poured into urns or clay vessels and moved to the purging rooms where they would be put through the crystallization process, achieved by extreme changes in temperature. Once the sweet crystallized, the urns would be cracked and the blocks or sugar bread were transferred to wooden boxes, which were then transported in wagons to the shipping port destined for Europe.
The amount of slaves needed to achieve this huge process was anywhere between 60 and 400 slaves, depending on the size of the mill. These were supervised by Spanish foremen or trusted blacks. The technical direction of the sugar production was done by the sugar masters, brought specially from the Canary Islands or Portugal.
Even with a considerable risk margin and high costs, the sugar business yielded great earnings, with an arroba (same as a bushel) being sold for two ducats in Seville and production from the large mills reaching some 10,000 arrobas (125 tons) a year.
In this manner, large expansions of the island were planted with a new plant in its earth, within a different crop and production schematic. From the arrival of the conquistadors, the local ecology had begun to change drastically with the introduction of new species and plants that ensured the displacement and destruction of many of the indigenous species, situation made worse by the felling of great areas of forests that were designated for the Spanish method of intensive single crop farming, done with plows, which provokes the erosion of the top soil with rains much faster than with the previous method of mounds and small farms. Through the years, many rivers, ponds and other natural water estuaries disappeared invaded by the abundance of sediment. With the systematic cutting of dense wood forests in the southeast of the island,also caused a weather change in this zone, lowering the amount of rain and eventually, causing the raise in temperatures.
Cattle and hog production had also reached levels so high that Santo Domingo exported livestock for raising and consuming to the rest of the colonies. Also, the leather market grew without interruption becoming another very important facet of the economy. Livestock invaded the countryside and abandoned villas, depleting many native herbal species and stripping the vegetable blanket covering the earth and preventing erosion. Many farms had a large number of livestock, but the majority of cattle and hogs grew wild or cimarrons, being attacked by great wild dog packs which also roamed the countryside.
It is worth pointing out the cold disassociation of the colonists of the epoch that, "with the obvious and spectacular bio geographic phenomenon that was happening right under their noses"4 many simply didn't take it in. Fernandez de Oviedo and Joseph de Acosta offer us marvelous descriptions of the American flora and fauna, without mentioning the disappearance of some species. With the elimination of a large part of native population, the introduction of great quantities of foreign humans, plants and mammals, the old world changed the biological and ecological characteristics of the Antilles forever.