An investigation of the hydrological requirements of River Red Gum (Eucalyptus camaldulensis) Forest, using Classification and Regression Tree modelling

River Red Gum (Eucalyptus camaldulensis) is widely distributed throughout many water Courses and floodplains within inland Australia. Ill recent years. accelerated decline of River Red GUM condition has been observed ill many locations. and field observations of the degradation are consistent with the reduction of flooding. However, there are few publications that quantitatively investigate the relationships between River Red Gum condition and flooding history. We applied Classification and Regression Tree (CART) to model the minimum flooding requirement of River Red Gum forest/woodland ill Yanga National Park, located oil the Lower Murrumbidgee Floodplain, Southeast Australia. using crown conditions derived from historical aerial photographs spanning more than 40 years. The Model produced has a moderate reliability with all overall accuracy of 64.1% and a Kappa index of 0.543. The model brings ill important insights, about the relationship between River Red GUM community type, flood frequency and flood duration. Our results demonstrated that ( I) CART analysis is a simple yet powerful technique with significant potential for application ill river mid environmental flow management (2) River Red Gum communities on the Lower Murrumbidgee Floodplain require periodic inundation (3-5 years) for a duration of up to 64 days to be ill moderate to good conditions (3) Although the crown conditions, Of different community types displayed similar degradation trends. they have distinct flooding requirements: and (4) The River Red Gum community ill Yanga National Park may be managed is hydrological units given limited environmental water allocations. Copyright (C) 2009 John Wiley & Sons, Ltd.