Instead of Eucalyptus
Eucalyptus plantations are common in northeastern Thailand as a source of cheap low quality wood and fiber for paper pulp. Adjacent farmlands have had problems with a lowered water table and angry farmers have occasionally burnt down such monocultures of exotic trees. The eucalypt leaf litter and water consumption have wiped out most understorey plants creating a biodiversity desert.
The Thai government and researchers have taken this problem seriously. As a result of screening hundreds of tree species (there are 1100 wild tree species just here in northern Thailand) for their fiber qualities and impact on the environment, the government now promotes Anthocephalus chinensis (Rubiaceae):
The tree grows wild in the nearby Opkhan national park, and this specimen can be seen at the Dokmai Garden parking. It can be acquired from many Thai nurseries. Since this has become a commonly planted tree also in gardens there is a need for an English name. How about ‘flash of wood’? The scientific name means ‘Chinese flowerhead’.
It is common in the lowlands of India and Southeast Asia, being a pioneer species after deforestation. It does not stunt other vegetation like eucalypts and is not as water consuming either. Its leaves are appreciated by the edible red ants. Although evergreen it does not provide a deep shade, and the speed of growth may imply this is not a long-lived tree nor a strong wood, so be careful not to plant it too close to buildings.