chapter  3
20 Pages

Disturbance and Climatic Drivers of Carbon Dynamics of a North Australian Tropical Savanna

ByLindsay B. Hutley, Jason Beringer

Australian tropical savannas occur at annual rainfalls greater than 600 mm and extend from the Gulf of Carpentaria in north Queensland, across the northern half of the Northern Territory (NT), to the Kimberly region of northwest Western Australia. This is a savanna biome of almost 2 million km2 and one of the world’s most ecologically intact savanna regions (Mackey et al., 2007). Australian savanna ecosystems experience one of the most seasonal of the world’s savanna climates (Prior and Bowman, 2005) with 90-95% of rainfall between November and April (Figure 3.1). This seasonality is driven by the annual movement of the Intertropical Convergence Zone, which drives the Australian summer monsoon. Soils of the region are ancient, highly weathered, and leached and are dominated by low-nutrient Kandosol (equivalent to Palexeralf using U.S. Taxonomy) and affiliated types. Soil and climate characteristics are generally unsuitable for broad-acre cropping, and grazing is the dominant land use with some horticulture. In the Northern Territory and Kimberly region, indigenous lands and conservation

CONTENTS

Introduction ........................................................................................................... 57 Carbon Dynamics at the Howard Springs Flux Site ........................................60