Interesting article over at HAARETZ.com about the invasion of the blue acacia (most likely the blue leaf wattle, Acacia saligna) in Israel. Seems that the tree, native to Australia, was once planted across the country to stabilize sand dunes and create forests across the landscape. Once established, it began to spread on its own, helped in part by the proliferation of fires caused by wartime activities. An effort is now underway to manage down populations of this species by injecting them with the herbicide glyphosate. A second research project is testing controlled burns as a way of destroying seed banks...I assume that would go hand in hand with restoration/native plantings to avoid repopulation from acacias adjacent to the burned areas. Blue leaf wattle was also once widely planted in South Africa, which also considers it an invasive species.