The researchers studied an undisturbed forest in Kumpang Langgir Sri Aman to learn about the tree species, diversity, and structure. They found a total of 199 different tree species, with Syzygium antisepticum being the most dominant. The forest had high species diversity and healthy community structure, with various emergent trees like Tristaniopsis whiteana and Shorea multiflora. The distribution of tree species was uneven and random throughout the forest. Overall, the undisturbed forest at Kumpang Langgir Sri Aman was found to be in good condition.