Ligia Herrera in Panama indicates that tropical rainforest transformed into pastures from 1950 to 1990 exceeded the total amount lost from 1500-1950. Spanish crown and conservation The Spanish crown was concerned with conservation of resources it deemed vital, asserting right of eminent domain over territory it conquered On the island of Cuba, the crown attempted to regulate the cutting of trees needed for ship building and repairs, especially masts. Although sugar was a valuable and expanding agro-export crop, the crown kept its expansion in check for much of the colonial era because of deforestation. In colonial Mexico, the crown set up an official body, the Council of Forests, to conserve them from destruction from unregulated cutting. The main fuel in the colonial era was wood, often transformed to charcoal. There was an increasing demand from mining regions as well as cities and towns, so that as trees were cut down entirely rather than cut allowing them to regrow, forest resources further from these sites were vulnerable to deforestation. The crown saw deforestation as a threat to silver mining, the motor of the empire's economy, so that establishing regulations was a matter for the state. Commodity boom and environmental impact, 1825-present With Spanish American and Brazilian independence from Spain and Portugal in the early nineteenth century, independent nation-states initiated a new era of resource utilization, which transformed Latin America, a "second conquest." The Spanish Empire and the Portuguese Empire had kept other powers at bay, but now many new sovereign states sought financial benefit from private enterprise, foreign and domestic, in exploiting the environment. Nitrates For Peru, huge deposits of bird guano on the Chincha islands off its coast provided revenue for the Peruvian state, facilitating its post-independence consolidation. Guano was a valuable commodity, which prompted Peruvian government monopoly control. Rich in nitrates for fertilizer and saltpeter for gunpowder, guano was mined and shipped directly from the mine sites. The deposits were huge, accumulated from bird droppings over a long time period. The local environmental impact is difficult to assess, since the islands were not occupied by humans. To exploit this valuable resource was easy, since it only required shovels and conscript labor. Once humans started mining the guano, the birds could not produce enough guano to replenish it, so it was not a sustainable export industry. Spain sought to regain control over this valuable commodity in their former empire, fomenting