Floristics of forests across low nutrient soils in Sulawesi, Indonesia.

Abstract

• The island of Sulawesi formed from the joining of proto‐islands roughly three million years ago. Regions of zoological endemism, corresponding to the proto‐islands, have been reported. Sulawesi's tree communities, however, remain poorly documented. In better‐studied tropical regions, soil types similar to those found in Sulawesi often have distinctive tree communities. To gather data on Sulawesi's tree communities, we established ten (0.25 ha) plots on four soil types across three regions. We documented diversity, endemism, dominance, and species composition. Linear models of species composition showed greater influence of geographic distance rather than soil, and no relationship with climate. This suggests that the legacy of Sulawesi's formation may have influenced tree communities more so than the soil types we sampled. Most of our plots were on stressful soil types making it difficult to conclude on the importance of edaphic specialization in the Sulawesi tree flora. The lack of climatic effects reflects Sulawesi's position within the wet tropics where the small climatic differences are unlikely to have large influence on tree communities.