of the country. The elevation thus varies between 500 and 1000 metres above sea level except for lower-lying plains of 200 to 500 metres in the extreme southeast centered on the Dja, Boumba, Sangha, and Ngoko Rivers. The land consists largely of monotonous, gently undulating hills known as "half-oranges" due to their resemblance to that fruit. Climate The East has a Type A wet equatorial climate (also known as a Guinea type climate), meaning that it experiences high temperatures (24˚ C on average) and a lack of traditional seasons. Instead, there is a long dry season from December to May, a light wet season from May to June, a short dry season from July to October, and a heavy wet season from October to November. Humidity and cloud cover are relatively high, and precipitation averages 1500–2000 mm per year except in the extreme eastern and northern portions, where it is slightly less. Plant and animal life Approximately the lower two thirds of the region is covered in rain forest, which grows progressively thicker as one travels south. The forests are composed of hardwood evergreens of species such as dibetu, ebony, iroko, mahogany, obeche, and sapelli, some of which grow to heights of 70 metres or more. There are also numerous ferns and orchids. This forest is stratified into several levels. The first is composed of straight, thick-rooted trees averaging about 40-metres tall. After this grow shorter, thinner trees with highly placed clusters of leaves. Sparse grasses and other plants make up the ground layer. In areas closer to settlements and roads, human groups have harvested the larger trees, thus exposing the forest floor to more direct sunlight and allowing thick vegetation to thrive. The upper third of the province (beginning at about the latitude of Bertoua and Batouri) is dominated by humid, wooded savanna. Trees here are sparser, but still may grow to be as tall as 20 metres. The government of Cameroon has established four forest and game reserves in the East: the Dja Reserve (Réserve du Biosphère de Dja) in the southwest of the province and extending into the South Province, Lobéké Park (Parc National de la Lobéké), the Boumba-Bek Reserve (Réserve de Boumba-Bek) and the Nki Reserve (Réserve de Nki) in the southeast. The Pangar Djérem Reserve (Réserve Pangar Djerem) protects one of the more heavily wooded parts of the Guinean savanna in the region's northwest and