Since 2007, YEL staff have been monitoring the monthly phenology (flowering, fruiting, leaf production) of more than 1500 trees to determine the productivity of the Batang Toru forests.
Because the Batang Toru forests are mostly between 900 and 1100 m above sea level, or even higher, relatively few species of the Dipterocarpaceae are encountered, but some of those that do occur are in the IUCN red-list.
|1.||Dipterocarpus crinitus||EN (IUCN)|
|2.||Shorea platyclados||EN (IUCN)|
|3.||Shorea acuminata||CR (IUCN)|
|4.||Nepenthes spp||PP nomor 7/1999|
|5.||Gonystylus macrophyllus||Appendix II (CITES)|
Many orchid species have been found on the steep mountainous slopes, and several other interesting groups have been encountered such as parasitic plants from the Balanophoraceae family. The very rare giant rafflesia flower, Rafflesia cf micrpylora-gadutensis, has been encountered by only in the low area of the foothills facing the Indian Ocean, and this area has already been cleared by a gold mine. Various species of pitcher plants (Nepenthes spp.) can also be found in the Batang Toru forests.