Plantations are generally long-rotation perennial woody crops established and maintained for a variety of food and materials. The harvested products include wood, various fruits, tea, coffee, palm oil and other food additives, materials such as rubber, ornamental materials (cut flowers), etc. The vegetation of most plantations comprises at least two vertical strata (the managed woody species and a ruderal ground layer), although mixed plantings may be more complex and host a relatively diverse flora and fauna if managed to promote habitat features. Fertilisers and water subsidies are applied, and harvesting occurs at intervals depending on the crop.