Data from: Foraging impacts of Asian megafauna on tropical rainforest structure and biodiversity

Megaherbivores are known to influence the structure, composition, and
diversity of vegetation. In Central Africa, forest elephants act as
ecological filters by breaking tree saplings and stripping them of
foliage. Much less is known about impacts of megafauna on Southeast Asian
rain forests. Here, we ask whether herbivory by Asian megafauna has
impacts analogous to those of African forest elephants. To answer this, we
studied forest (1) structure, (2) composition, (3) diversity, and (4) tree
scars in Belum and Krau, two protected areas of Peninsular Malaysia, and
compared the results with those obtained in African forests. Elephants are
abundant in Belum but have been absent in Krau since 1993. We found that
stem density and diversity, especially of tree saplings, were higher in
Krau than in Belum. Palms and other monocots were also more abundant in
Krau. In Belum, however, small monocots (<1 m tall) were very
abundant but larger ones (>1 m tall) were virtually absent,
suggesting size-selective removal. The frequency of stem-break scars was
equal at Belum and Krau but less than in Central Africa and greater than
in the Peruvian Amazon where tapirs are the only megafauna. Pigs and
tapirs could also contribute to the high frequency of tree scars recorded
in Malaysian forests. Forest-dwelling elephants in Asia seem to have a
reduced impact on tree saplings compared to African forest elephants, but
a very strong impact on monocots.