干旱区生态环境知识资源中心

In extreme deserts with precipitation of less than 10-20 mm/yr, biocoenoses occur which are void of producers but show ecosystem functions such as food chains and energy flow. Since they are fed by the importation of allochthonous organic material the term ’allochthonous ecosystems’ is proposed to designate these systems. The application of this term to other incomplete ecosystems without producers is discussed.