Easter Island has suffered from heavy soil erosion in recent centuries, perhaps aggravated by agriculture and massive deforestation. This process seems to have been gradual and may have been aggravated by sheep farming throughout most of the 20th century. Jakob Roggeveen reported that Easter Island was exceptionally fertile. "Fowls are the only animals they keep. They cultivate bananas, sugar cane, and above all sweet potatoes." In 1786 Jean-François de La Pérouse visited Easter Island and his gardener declared that "three days' work a year" would be enough to support the population. Rollin, a major in the Pérouse expedition, wrote, "Instead of meeting with men exhausted by famine... I found, on the contrary, a considerable population, with more beauty and grace than I afterwards met in any other island; and a soil, which, with very little labor, furnished excellent provisions, and in an abundance more than sufficient for the consumption of the inhabitants."