Rory

This is actually a project, but.. I have to make a small self contained ecosystem modeling the chaparral biome, and once I set it all up I leave it sealed for 3 days before adding organisms, then I can go ahead and add the organism but seal it once again for 2 weeks. I know chaparral is kinda an inbetween of grassland and desert and is generally the result of destroyed forest so it has poor soil, and during most of the year it is pretty dry. So what are some suggestions of autotrophs I can place and let grow and in these poor conditions? And would I need to add any insects(I want to avoid large animals) or bacteria to keep stable cycles like water/carbon/nitrogen/phosphorus/oxygen in check? The container will most likely be part of a two liter and maybe a plastic bag if that helps knowing the space.