A biogeochemical cycle is a pathway by which a chemical substance moves through biotic (living world) and abiotic (lithosphere, atmosphere, and hydrosphere – non-living) components of Earth. Such cyclic flow involves the transfer of matter and energy between the different components of the biosphere.
First level of classification among plants depends on whether the plant body possesses well-differentiated distinct cellular components or not. Next level is based on the presence or absence of special vascular tissues for the transport of water and other substances. Further classification takes into account the ability to bear seeds and whether seeds are enclosed within the fruits or not.
Depending on these characteristics, kingdom-Plantae is divided as of Thallophyta, Bryophyta, Pteridophyta, Gymnosperms and Angiosperms.
From the components to ecosystem, the a comprehensive blog post on ‘Our Environment’. Its a time saver.