华南陡山沱期晚期宏体生物生态系统的出现及其意义

Emergence of marco-organismal ecosystem of the Late Doushantuoian in South China and its significance

生态系统的演化是生物起源与演化的主要驱动动力之一。在生命演化早期,生态系统的演化大体经历了"微生物席生态系统"、"浮游真核生物生态系统"、"宏体藻类生态系统"、"宏体生物生态系统"和寒武纪及其后较为完善生态系统的演化历程。早期生态系统的演化主要表现为:生物生境从沉积物表层到水体之中再到沉积物内部的扩展,生物种群之间的关系从被动地接受到对环境因子需求的相互竞争,能量传递方式从生物体外摄取或体外同化到体外摄食体内同化,生态金字塔结构由简单到多层次化和复杂化,生物参与对环境的改造能力逐渐增强。随着华南伊迪卡拉纪陡山沱期晚期"宏体生物生态系统"的出现,生物对环境因子需求的竞争性和改造能力大幅度增强,实现了生物体内能量的传递方式,生态金字塔多层次化和复杂化,成为生物迅速演化和其后"寒武纪生命大爆发"的重要转折。

The evolution of ecosystem is a major force on the origin and evolution of life. In the early evolution of life, the process of ecosystematic evolution was from the Mat-dominated Ecosystem, through the Plankton-eukaryotic Ecosystem and Marcoalgal Ecosystem, to the Macro-organismal Ecosystem, then to a relatively mature ecosystem in the Cambrian. The evolution of the early ecosystem mainly exhibited the developments ： （ I ） what the habitats expanded from the surface layer of deposits to the water column and then to the inner of deposits in habitat ; （2） what the relation of different species was from passive accept- ers to active competitors in life demands for environment factors; （3） what the energy transformation changed from the extra-intussuscepting or extra-assimilating to the endo-assimilating after extra-feeding;（4） the ecological pyramid changed complication and multilevel; and （5） what the organisms gradually enhanced the ability improving environment. In the macro-organismal ecosystem which emerged in the Late Doushantuoian of the Ediacaran in South China, organisms drastically enhanced the competition and reform for environment factors demanded by them, and began to actualize the energy transformation in the inner body of organism. The multilevel and complication of the ecological pyramid show that the macro-organis- mal ecosystem in the Late Doushantuoian is a key transition in the evolutional speed of life and a prelude of the Cambrian explosion.