英语一句话,Sparsely populated by the descendants of its original

英语一句话,
Sparsely populated by the descendants of its original inhabitants,Arnhem Land is accessible through specialized operators (some of them Aboriginal owned) which give travellers rare and unforgettable insights into indigenous Australian art and culture.
译文头半句为：Arnhem Land 人烟稀少,只有一些原始居民.
为什么不能理解为Arnhem Land 人口中只有很少一部分是原著民的后裔.