Tree plantations often replace natural ecosystems, or lands that were in process of ecosystem restoration. The replacement of forests by tree plantations is one of the main threats to the world’s biodiversity. Monoculture tree plantations also have a negative impact on water sources, as they tend to require the use of agrochemicals, and often exist of species like Pine and Eucalyptus that require an excessive amount of water. Alien invasive species like Eucalyptus (if planted outside its country of origin, Australia) are the second most important cause of global biodiversity loss.
