The impact of ebony wood harvesting on Diospyros samoensis (Ebenaceae) on Vangunu Island, Western Solomon Islands

Abstract

Ebony wood, the black heartwood of trees in the genus Diospyros, is a high-value commodity of many Pacific Islands. The revenue earned from the sale of ebony carvings is important for many low-income rural communities, resulting in high harvesting pressure and reported declines of ebony-producing species. This study investigates the impact of ebony wood harvesting on species of Diospyros on Vangunu Island, Western Solomon Islands. Diospyros samoensis, locally known as ‘rihe’, was the main source of ebony wood, with D. vera occasionally harvested but producing poorer quality wood. For D. samoensis, we investigated the existing ethnobotanical knowledge and harvesting dynamics using questionnaires and surveyed 11 populations using five 15×15m plots. Although D. samoensis was common throughout the study area, trees with harvestable ebony heartwood were considered rare. The sale of ebony carvings contributed substantially to the livelihood of carvers. Harvesting practices cause considerable damage to the stem and appeared to alter population structure, with fewer seedlings found in stands with higher harvesting intensities (r=−0.704, P=0.008). Therefore, populations of D. samoensis appear to be negatively impacted by current harvesting practices, which should be modified to (1) cause less damage to individual trees and populations, and (2) protect larger and older trees to help regeneration. Therefore, the increasing rarity of ebony heartwood in the Pacific may not equate to dangerous declines in Diospyros species and implementing low-impact harvesting practices could help improve the health and long-term persistence of Diospyros populations.