SUCCESSION OF GROUND VASCULAR PLANT COMMUNITIES ON PYROCLASTIC DEPOSITS SEVEN YEARS AFTER A VOLCANIC ERUPTION ON MOUNT MERAPI
Keywords:Merapi’s eruption, succession, patch, vegetation
Seven years after the eruption of Mount Merapi, there were substantial differences in the degree of recolonisation on barren landscape formed by pyroclastic flow. This study aimed to quantify the ground vascular plant communities represented through an investigation of plant cover, rock cover, species richness, diversity, and frequency in three different habitats, bare ground, herbaceous and tree patches. Tree patches were characterized by the presence of trees and shrubs ≥ 1 m height. Plant cover was less (P < 0.001) and rock cover more (P < 0.001) on bare ground than the two patches. Although tree patches had the highest plant and lowest rock cover, these were not significantly different to those in the herbaceous patches. Species richness and diversity were not different among habitats and species composition had a commonality of 55%. Pytirogramma calomelanos, Imperata cylindrica and Eupatorium riparium accounted for half the plant cover in all habitats. Parasponia parviflora was the most frequent tree species but Acacia decurrens had the greatest mean stand basal area in the tree patches. The earlier formation of tree canopies and more ground space for colonisation due to low rock cover is anticipated to promote the further development of vegetation cover and primary succession on Mount Merapi.