Impacts of bark beetles and termites on wood decomposer communities in Honduras

Wood decomposition impacts forest ecology and is driven primarily by termites and fungi. Bark beetles attack and kill trees, inoculating them with blue stain fungi, which attracts termites. Termites are ecosystem engineers that can impact other decomposer’s colonization of wood. We predicted that wood with termites would have higher species abundance. To test this, bark beetle attacked trees and healthy trees were examined in Honduras, which in 2015 lost 25% of its pine forests to bark beetles. In 2016, a bark beetle attacked tree and a healthy tree were felled and cut into 8cm thick slices and placed in a pine forest with one of three fine mesh covering treatments: 1) wood slices fully covered to prevent exposure to macro-decomposers, 2) wood slices covered from above to prevent additional bark beetle attacks and other above-ground invertebrates, 3) wood slices with no covering. We predicted that uncovered and half-covered wood would have the highest species abundance because of termite presence. After one year, 10 replicates of each treatment were collected and placed in Berlese funnels to extract invertebrates, which were identified to at least order or finer taxonomic resolution where applicable. Contrary to our prediction, species abundance did not increase with the presence of termites and the fully covered wood had the highest species abundance. This pattern was largely driven by oribatid mites. These results suggest that termites do not facilitate species abundance at this stage of decomposition and that decomposer fungi may play a larger role in supporting wood decomposers.