Mohamed bin Zayed Species project number 202523743

Habitat characteristic, population assessment and predicting potential distribution of endangered titan arum (Amorphophallus titanum) in Sumatra

Amorphophallus titanum is the most charismatic giant flower endemic to Sumatra. It has been categorised as endangered based on the IUCN Red List. Recently, this species has been facing a serious threat because of overharvesting of its tuber. Furthermore, land use change also threatens its habitat in the wild. The proposed project tries to provide a comprehensive conservation picture of the endangered giant flower Amorphophallus titanum in Sumatra. This project has been successfully granted by the Mohamed bin Zayed Species Conservation Fund in 2020.

The overall objectives of the project are:

1. Understand the habitat preferences of endangered giant flower Amorphophallus titanum in the wild.

2. Assess the current population and renew conservation status of Amorphophallus titanum.

3. Predict potential current and future distribution of Amorphophallus titanum under climate change and land cover change.

4. Determine the hot spots distribution of Amorphophallus titanum.

5. Assess the habitat risk from any potential threats.

Our results showed that 

1. slope and distance to the nearest river are the two most important variables associated with the occurrence of Amorphophallus titanum in Sumatera. The plant species associations of Amorphophallus titanum are very diverse. Soil aeration and good drainage are key factors for the species, both in natural environments and in cultivation.

2. Very few mature individuals were found in this study with local populations dominated by seedlings and juveniles. Based on the IUCN criteria, the conservation status of the endemic Amorphophallus titanum in Sumatera is endangered with criteria EN A2cd+3 C, C2a(i).

3. Land cover change and climate change scenarios predicted significantly reduced suitable geographic distribution by 2070. Most of the predicted suitable habitat areas of this species are located outside of conservation areas.

4. Population hot spots were identified in Sumatera Utara (North Sumatera) and the Southern part of Aceh.

5. Potential threats at occurrence points were evaluated using the Analytic Hierarchy Process (AHP) method. Human pressures, particularly harvesting and land conversion, are the main threats to the Amorphophallus titanum populations.