America needs millions of new trees each year for forests damaged by natural catastrophes, thinned by logging and developed to protect watersheds. But this year, many of the workers who do the planting are being barred from the U.S. by the Trump administration. Seasonal temporary workers mainly from Mexico and South America perform most of the reforestation work in the U.S., entering the country in October each year for a six-month planting season. But the White House last month suspended most seasonal temporary visas, known as H-2Bs, for the rest of the year in an effort to free up jobs for American workers as the country experiences record-high unemployment. Now an entire planting season could be lost, leaving the U.S. with millions of fewer trees, forestry industry representatives warn. …Typically, only a handful of U.S. workers respond to listings seeking forestry crews.