Some area has introduced European and American black poplar for papermaking since the 1970 s. These European and American black poplars adapt to the local climate, grow fast and expand their planting area rapidly. However, in recent years, the local eco-environmental problems are becoming more and more serious. Therefore, some people think that the ecological environment of the region can be repaired by cutting off these European and American black poplars.
The statement 'It is acquiesced that there is a causal relationship between the expansion of planting area and eco-environmental problems in Europe and America' can best point out the shortcomings of the above discussion.