Complex sentence: When the park was officially completed in 1873, more than ten million cartloads of material had been transported out of the park, including soil and rocks, and more than four million trees, shrubs, and plants representing approximately 1,500 species were transplanted to the park.
Split into simpler sentences: When the park was officially completed in 1873, more than ten million cartloads of material had been transported out of the park, including soil and rocks. More than four million trees, shrubs and plants representing approximately 1,500 species were transplanted to the park.