The Trump administration says the detention center for undocumented migrants will house the “worst of the worst.” Conservationists are concerned about its impact on the river of grass.By Amy GreenPresident Donald Trump landed this week on an airstrip in the Florida Everglades for a visit to a swiftly assembled detention facility that federal and state officials say will house 3,000 undocumented migrants, as the president aims to fulfill his plans for mass deportations.