"Only three of the 20 national parks that SANP manages are large enough to contain completely viable biomes and ecosystems.
(SANP manages; are; large enough to contain completely viable biomes and ecosystems) (SANP manages; to contain; completely viable biomes and ecosystems)
SANP manages SANP manages
are to contain
large enough to contain completely viable biomes and ecosystems
completely viable biomes and ecosystems