"Doncs" is a conjunction which express the conclusion of a deduction or express the consequence. In this context, the translation English it would be "SO". For expample, "Tot A és B, tot B és C, doncs, tot A és C" - "All A is B, All B is C, so all A is C". Expressing consequence: "Vols que visqui la teva planta doncs hauries de regar-la" - "You want your plant survive then/so you should water it." Another meaning is expressing the opposite or the antithesis. "No vols venir?? Doncs t'haurem d'obligar a venir" - "You don't want to come? So we'll obliged you to come." As I see you speak Spanish, I give you the translation in this language "pues o entonces".