With the climate changing, many species are marching towards cooler climes – but trees are being outpaced. Some ecologists say assisted movement is the answer
In some cases, it's local plants making a return after the invasive ones got killed by climate change. For example, pine trees getting decimated by a pine borer bug all across Europe. In most of those places, they were planted in the 1950s to produce lumber which in turn was used to rebuild all of those destroyed European cities.