Films about the environment are not exactly a threatened species. This selection of more than 100 features and shorts includes many that were made for mass-market TV channels or governmental institutions—yet a sampling of the films is full of surprises. Chernobyl Heart (at 7 p.m. Monday, March 14) reveals that more than 13,000 have died from the aftereffects of a nuclear catastrophe that’s nearly forgotten in this country, that medical consequences continue to beleaguer the region’s young, and that the complex is not yet stabilized: “The next Chernobyl will be Chernobyl itself,” warns one local expert. Another environmental threat is shown as both universal and quite local in We Are All Smith Islanders (pictured; at noon Thursday, March 17), an account of the Chesapeake Bay isles that are vanishing as sea levels rise. For balmy adventure, there’s Alone Across Australia (at 6:30 p.m. Tuesday, March 15), the tale of a 1,600-mile march across the outback by one obsessive hiker and his indefatigable Jack Russell terrier. Other local or even world premieres include Remembered Earth: New Mexico’s High Desert (at 1 p.m. Saturday, March 19), which mixes lyrical imagery with clips from old cowboy flicks; Roar: Lions of the Kalahari (at 7 p.m. Monday, March 14); and Silent Killer: The Unfinished Campaign Against Hunger (at noon & 3:30 p.m. Monday, March 14). The fest opens Thursday, March 10, and runs through Sunday, March 20, at venues around the city (see Showtimes for a weekly schedule, or visit for a complete schedule of events and locations). Most screenings are free, but others range in price from $5 to $13. In some cases, reservations are required. (202) 342-2564. (Mark Jenkins)