Temporal-spatial change research on pure masson pine forest with decision-tree's help

Ecological deterioration caused by pure masson pine forest in red soil region in South China has severely endangered local ecosystem and sustainable development of social economy. To understand temporal-spatial distribution and succession rule of pure masson pine forest is an important basic study to control pure masson pine forest. Current research mainly relies on traditional interpretation by remote sensing image, which has lower accuracy in identification of specific tree species. This study, taking Changting County in Fujian Province as study area, in the view of soil erosion and on the base of man-land relationship, analyzes emergence driving force of pure masson pine forest from aspects of tree species, habitat condition, ecological environment and human activities; from the remote sensing images of Changting County in 1975, 1990, 1999 and 2006, it also analyzes distribution of pure masson pine forest in different periods based on relatively complete system of knowledge rules and by means of decision-tree algorithm; meanwhile, it distinguishes non-erosion area and vegetation restoration area in different periods. The result shows that since 1975 spatial succession of pure masson pine forest in Changting County has a downward tendency, which is most evident during 1975 and 1990, but slowed down after 1990.Comparison between the result of decision classification and data from monitoring actual sample shows that identification result from decision-tree is more accurate and dependable, which provides a theoretical base to control regional pure masson pine forest and soil and water loss.