This event looks at two sides of the delicate and sometimes deadly interplay between native and non-native species. At 4 p.m., we'll visit Merry Lea?s chestnut research plot and see some of the first American chestnut trees resistant to the Asian blight that wiped out this species. After dinner, we?ll take the discussion to our own backyards as Merry Lea?s Dale Hess, a plant pathologist, explains why native plantings are critical to local fauna. Free to Friends of Merry Lea; $15 per person or $25 per couple for others. Advance registration required.