Complex sentence: Mendoza is one of the Preservers who has been foisted upon him; ostensibly she is to gather plant species soon to become extinct in a years-long drought, but the Company fails to move her on once the drought hits.
Split into simpler sentences: Mendoza is one of the Preservers who has been foisted upon him. Ostensibly she is to gather plant species soon to become extinct in a years-long drought, but the Company fails to move her on once the drought hits.