Mark Mortenson will take over as president and CEO of the Buffalo and Erie County Botanical Gardens in March. Photo courtesy Buffalo and Erie County Botanical Gardens Mark Mortenson will take over as the new president and CEO of the Buffalo and Erie County Botanical Gardens in March when David Swarts retires from the role after 12 years. Mortenson led the transformation efforts at the Buffalo Museum of Science and Tifft Nature Preserve. Most recently he played a dual role…