Complex sentence: He is a scientist, educator, administrator and one of the world's leading ecologist who is internationally known for his groundbreaking work on nitrogen cycling, sustainable ecosystem management, climate change, and effects of acid rain on forests.
Split into simpler sentences: He is a scientist, educator, administrator and one of the world's leading ecologists. Aber is internationaly known for his groundbreaking work on nitrogen cycling, sustainable ecosystem management, climate change, and the effects of acid rain on forests.