The dispersal services of frugivores affect plant community assembly, persistence, and gene flow in the short-term, and in the long-term are critical to ensuring that tropical trees and palms can regenerate in disturbed areas and can migrate amidst climate change. Halmahera is the largest Moluccan island within the Wallacea biodiversity hotspot, yet data on its plant and animal distributions and interactions are almost null. I studied the tropical trees and palms of Halmahera and their seed dispersal dynamics. Chapter I explores the palms of the Moluccan islands through field-, herbarium-, and literature- based studies. The results of herbarium specimen collections are presented within a preliminary list of palms for Halmahera’s Aketajawe-Lolobata National Park, and contextualized in a review of regional palm biogeography. Expanding beyond the study of one plant family, Chapter II compiles and examines all the tree and palm taxa of the Moluccan islands in order to infer seed dispersal syndromes for each taxon, resulting in an analysis of over 900 taxa. Zoochory was found in 93% of plant families, and nearly 30% of endemic taxa rely primarily on dispersal by large-bodied frugivores. The role of a hypothesized keystone disperser (the Papuan hornbill, Rhyticeros plicatus ruficollis) is confirmed experimentally to disperse about 10% of Halmahera’s tropical tree and palm taxa. The final chapter encompasses an ex-situ germination trial and a year-long in-situ experimental study that examines the germination and recruitment of three palm species post-ingestion by Papuan hornbills, in four different habitat types representative of Halmahera’s landscape. Palms dispersed by hornbills into disturbed habitats and primary forests resulted in enhanced recruitment, although results varied by habitat and species. Hornbills aid both in forest conservation and recovery/assembly after disturbance. The results of this dissertation provide a foundation for further ecological studies and for enhanced conservation of Halmahera island.

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Despite an abundance of archaeological material recovered from sites in Island Southeast Asia, the timing and route by which cultigens first arrived in Wallacea remains unclear. Many of the staple crops now grown on these islands were domesticated in mainland Asia, and were deliberately introduced by humans at an unknown point during the Holocene, through several possible routes. In this study, the δ 13C, δ15N and δ18O values of subfossil bones and teeth attributed to Sus celebensis and Sus scrofa are analyzed. These materials, which span the last 5160 years at Liang Bua, Flores, Indonesia are used to determine if and when there was a shift towards agricultural intensification, and whether this intensification included the integration of domesticated C4 crops. The δ13C and δ15N values of the bone and dentin collagen samples indicate an abrupt shift towards enrichment in 13C and depletion in 15N at some time between 5160 and 2750 yBP. This hints at changes in human subsistence patterns that may have included the clearing of forests, and the integration of nonendemic C4 cultigens such as foxtail millet (Setaria italica) onto the island. No statistically significant variation in the δ 18O values of the enamel carbonate samples over time is observed, suggesting that once they appeared on Flores, semidomesticated pigs became an important part of the island ecosystem, and were bred and raised on Flores instead of being continuously imported from elsewhere.