Impacts of logging on primary forests of Siboma Village in the Morobe Province, Papua New Guinea

M.S. University of Hawaii at Manoa 2013.Includes bibliographical references.In a world of changing climate, the relationship between species richness, community composition, and anthropogenic landscape change has become an increasingly critical concern for conservation and management. In tropical regions, species diversity is very high with pressure for development being equally as high due to a growing human population. Papua New Guinea (PNG) is an area of critical concern for conservation because of its high rates of endemism and biodiversity, geologic history, proximity to the equator, and assortment of ecosystem types. However, lowland forests of PNG are becoming more and more threatened by logging operations. Few studies have examined the long-term impacts of logging in the tropics, especially in the primary forests of PNG, which is considered "one of the last great unknowns". The goal of this project was to assess the long-term impacts of logging on plant diversity. We assessed generic diversity, richness, basal area, and canopy cover of trees in a forest that had been logged about 60 years ago compared to a primary old-growth forest in the coastal lowland rainforests of the Siboma Village, Morobe Province, PNG. In each forest type, we surveyed ten 10m x 50m plots. Student's t-tests, non-parametric Wilcoxon rank sum tests, and non-metric multidimensional scaling ordinations were used to compare the two sites for the vegetative characters listed. Generic diversity, dbh, basal area, and canopy cover were significantly greater in the primary forest than the previously logged forest. The practical implications of these results: 1) A longer interval than 60 years is required for a more complete recovery of the forest. 2) More selective harvesting techniques for future logging operations in these forest types might better preserve long-term diversity