Eucalyptus and eucalyptus issue:
(Eucalyptus is key to the paper manufacturing and rubber industry.)
Eucalyptus is not a type of species but a general term for all the kinds of Eucalyptus. Within 945 species over 100 have economic uses. The formation period of it is around 5-7 years, so it is listed by FAO as one of the fast-growing tree species.
Eucalyptus wood has an obvious economic value compared with other local plants. It is widely used in pulp manufacturing, housing construction, furniture manufacturing and landscaping and was introduced in China 100 years ago.
It is argued that eucalyptus issue is not caused by the species itself but human activities, such as how people plant eucalyptus, manage forests and the related laws and regulations. Therefore, the discussion about it should be expanded to botany, biology, ecology and sociology etc.
(It is reported that eucalyptus affects the local reservoir and land is drier and drier.)
Eucalyptus is known as “water pump” because transpiration volume of it is so high that underground water declined fast, causing drought and lack of water. But the study shows that the water utilizing efficiency of eucalyptus is comparatively high so it can conserve water and soil and adjust climate. Scientist Bailly has learned from the data in 8 years that most of the water absorbed by eucalyptus infiltrates into the soil so that it can conserve water and soil effectively instead of causing drought.
According to the farmers who plant eucalyptus, the species requires a large amount of fertilizer and nutrients and the lands after planting eucalyptus face the problem of fertility decline and even drain up so other plants cannot survive any more. In fact, the negative affects happens at the beginning period of planting (the first 8-10 years ) but after the fast-growing period it gradually shows the positive effect of conservation.
Eucalyptus as an introduced species may severely affect the local species and harm the local ecological environment. It is reported that all the harmful species come from foreign herbaceous plants while the ecological harm of eucalyptus as a species of trees has yet to be confirmed.
(large area of eucalyptus planted in Luliang County, Qujing City,Yunnan Province)
Researcher from Institute of botany, Chinese academy of sciences holds that the application of techniques rather than planting of the eucalyptus may produce negative effects. The heated debate of “Whether eucalyptus is harmful or not” was aroused across the country. The research was initiated by an NGO and later drew attention of the public. The status and results collected by social organizations were cited and spread among people and most popular version claims that eucalyptus is related to the severe drought in southwest China in 2010. Under the pressure of pubic and media, government officials and experts held press conference to clarify that there is no scientific basis that eucalyptus leads to the drought.
On the one hand, the environmental protection organizations and media lack professional knowledge and field trip. On the other hand, the authority are little trusted by the public. The appearance and expansion of the argument that ”eucalyptus is harmful” is to some extent similar to the discussion of genetically modified crops and climate warming. Most importantly, the lack of discussion platform and mechanism can easily make the most sensational version stand out.