We are working to determine the possible effect (if any) that different environmental parameters might have on seed germination and behaviour? I would like to know how I can go about doing this in an ex situ system.
The experiment carried out ex situ with controlled environmental parameters (temperature, humidity, hours day/night, pH substrate, soil salinity, ...) certainly will confirm the effect on seed germination and seedling development.
You can be inspired by this experiment, for example: Sera et al. 2011: Response of the digitaria sanguinalis (L.) Scop. To the soil salinity - A greenhouse experiment. Ecological Questions.