Complex sentence: The terrain of the upper Chagres watershed is rugged, with its mountain slopes exceeding 45 degrees in 90 percent of its territory, and 98 percent of the park consists of old-growth tropical forest.
Split into simpler sentences: The terrain of the upper Chagres watershed is rugged, with its mountain slopes exceeding 45 degrees in 90 percent of its territory. Some 98 percent of the park consists of old-growth tropical forest.