2021 ESA Annual Meeting (August 2 - 6)

Tree species diversity and conservation priorities of the tropical dry forest of Ankarafantsika National Park, NW Madagascar

On Demand
Kaoru Kitajima, Kyoto University;
Background/Question/Methods

Ankarafantsika National Park (135,000 ha), located in NW Madagascar, is one of the oldest and most significant protected areas in Madagascar. The large part of this area is occupied by a primary tropical dry forest, with a high diversity of mammals (including 8 species of lemurs), reptiles, birds, and insects, as well as plants. As the largest remnant of the pristine dry forests that used to distribute widely in NW Madagascar, its conservation values are unparalleled. What is the composition, structure, and dynamics of the tree community that supports this rich biodiversity? To answer this question, we set up a 15 ha forest dynamics plot in the primary dry forest on a quartz-rich white-sand hill in 2019 and completed mapping and identification of all woody stems with the diameter at breast height (DBH) > 5 cm in 2020.

Results/Conclusions

We mapped and identified a total of ca. 42,400 stems (2427 ± 144 per ha), encompassing 147 tree species belonging to 44 families. The majority of trees had DBH < 20 cm. This forest consists of many small-diameter trees, the majority of which are 10-15 m in height. The top 20 tree species account for > 70% of the relative basal area. The species list includes species with valuable properties of wood and chemical extracts, and those serving as the critical food source for many frugivorous animals. In conclusion, these results provide scientific evidence for the high conservation of the dry forest in Ankarafantsika National Park, which is acutely threatened by fire and destructive land exploitation in the surrounding area. Our team will continue to uncover further details of forest dynamics, especially regeneration characteristics of tree species, to provide a scientific basis for effective conservation of dry forests in the region.