Ecosystems that Dr. Swartzman has studied span oceans, lakes, rivers, forests, grasslands, high mountain areas, and the tundra.
(Dr. Swartzman; has studied; span oceans, lakes, rivers, forests, grasslands, high mountain areas, and the tundra)
Dr. Swartzman
has studied
span oceans, lakes, rivers, forests, grasslands, high mountain areas, and the tundra