Many efforts have been made in recent years to better understand the economic impacts of the invasive shot-hole borer Fusarium dieback pest complex. In their 2017 article, Dr. Gregory McPherson (USDA Forest Service) and collaborators studied the forest structure in urban areas throughout California. They estimated that out of the 70.8 million urban trees present in Southern California, 32.8% (23.2 million trees) are susceptible to the ISHB-FD complex1. Should just 50% of these 23.2 million trees at risk die, the approximate cost for removing and replacing the trees with similar species and size would be $15.9 billion. On top of that, the loss of ecosystem services provided by those trees —including energy conservation, air quality improvement and carbon storage— would generate a cost of $616.8 million annually over the next 10 years1 and these costs would be even bigger if we also consider the effects of urban forests on local economies, wildlife, biodiversity, and human health and well-being.
Source: Boland, JM. 2016
California’s urban forests are being threatened by emerging pests like ISHB. By protecting them, we are not only preventing economic losses, but we are also investing on our future quality of life.
1 G. McPherson, Q. Xiao, N.S. van Doorn, L. de Goede, J. Bjorkman, A. Hollander, R.M. Boynton, J.F. Quinn, and J.H. Thorne (2017) The structure, function and value of urban forests in California communities. Urban Forestry & Urban Gardening 28: 43-53.