Cause Effect Chart . . . Chinese Exploration and Isolation. CauseEffect. Ming emperors disallowed foreign trade.. . The reason why they disallowed trade was because China became very isolated.. . . Chinese citizens who made goods for trade lost income.. Ming emperors desire to show the greatness of their rule and to collect tribute.. . . . . . Chinese require payment in gold and silver.. Ming leaders ban ships with more than two masts. There will be no further construction of ships.. . . . . . . . The Chinese keep close control over contact with Europeans..