Cultural Pyroscapes at the Centre of the Global Heat Engine – Fire Histories in the Montane Tropics of Papua New Guinea.

Papua New Guinea is situated at the heart of the Indo-Pacific Warm Pool—the planet's largest reservoir of warm surface waters and a primary driver of global atmospheric circulation—making its palaeoecological records uniquely valuable for understanding how tropical convection, monsoon dynamics, and teleconnections such as the El Niño-Southern Oscillation have shaped climate variability across hemispheres throughout the Quaternary. Fire has played a fundamental role in shaping the forests and grasslands of Papua New Guinea over millennia, serving as both a natural ecological process and a powerful tool of human landscape management that has influenced vegetation composition, maintained forest-grassland boundaries, and created diverse habitat mosaics. These cultural pyroscapes encompass extensive agricultural, horticultural and forest/grassland systems that are integral to the livelihoods of Indigenous communities, holding biocultural and spiritual significance while embodying traditional knowledge of sustainable management practices. Montane peatlands are also important agricultural centres since at least the last 7000 years, though the introduction of new dryland crops in the last 300 years has resulted in a shift of emphasis away from peat-based agriculture towards the drylands systems.Here I review the current state of scientific research on the role of fire in creating, transforming and managing the biodiverse ecosystems of montane Papua New Guinea using new case studies from the southern and northern foothills of the central highlands, where the impact of climate change on plants and people are being felt at an increasing rate. Despite several decades of research, detailed knowledge of the hyper-diverse lower montane environments is poor and highlights the need for greater understanding of these systems for future management in a world of rapidly changing climate.