The United States ecology is megadiverse: about 17,000 species of vascular plants occur in the contiguous United States and Alaska, and over 1,800 species of flowering plants are found in Hawaii, few of which occur on the mainland. 

Forests cover around 40% of Georgia's territory while the alpine/subalpine zone accounts for roughly around 10% of the land. Much of the natural habitat in the low-lying areas of western Georgia has disappeared during the past 100 years because of the agricultural development of the land and urbanization.

Cameroon's natural resources are well suited to agriculture and arboriculture, with 70% of the population engaged in farming, and agriculture made up an estimated 19.8% of GDP in 2009. Most agriculture is done at the subsistence scale by local farmers using simple tools.