Complex sentence: The island is now uninhabited, with the exception of the wardens, and protected as a nature reserve and Site of Special Scientific Interest (SSSI) with a large bird population and plants including wild peonies.
Split into simpler sentences: The island is now uninhabited, with the exception of the wardens. It is protected as a nature reserve and Site of Special Scientific Interest (SSSI) with a large bird population and plants including wild peonies.