Economic Cost Assessment of Global Forest Alien Invasive Species from 1970 to 2017

To identify the economic costs of global forests due to biological invasions, the InvaCost database was used to analyze the economic cost of forest biological invasions reported globally from 1970 to 2017, and the screening data were processed through R language to adjust each cost value to 2017 equivalent dollars, and summed separately to calculate the average economic cost per decade, loss and management costs, expenditure costs by country and total costs by species. Based on this, five models were constructed to predict the cost components from 2010 to 2017, and the possible costs of global forest biological invasion in the 21^st decade were analyzed by comparing the accuracy of each prediction model through root mean square error(RSME). The results showed that the economic cost of global forest ecosystems due to the invasion of alien organisms was 181.532 billion USD(about 1.23 trillion CNY) from 1970 to 2017, and the 1980s was the fastest growing period of cost; the management cost accounted for a low proportion of the total cost, and the highest expenditure was only 496 million USD/year(about 3.35 billion CNY) in the early 21^st century, which was much lower than the damage loss caused by forest biological invasion in the same period. Among the 36 countries included in the study, China spent 54.05% of the economic costs, totaling 98.12 billion USD(about 662.771 billion CNY), ranking first, 60.603 billion USD in the United States and 11.459 billion USD in Canada, ranking second and third respectively. The 10 invasive species with the highest economic cost included 3 diseases, 3 insects, 2 pest animals and 2 invasive plants. The economic losses caused by pine wilt disease amounted to 97.717 billion USD, representing the highest economic costs compared to other invasive organisms. The generalized additive model and multivariate adaptive sample regression show good prediction results, and the root mean square error is the lowest. The global total cost calculated by the model will further increase in 2010-2017, up to 252.11 billion USD(about 1.7 trillion CNY), and the average annual cost from 2010 to 2017 is 8.802–9.704 billion USD(about 59.455–65.548 billion CNY).