i'v e i've looked nearly one in three of the world's tree species are facing extinction in the wild. according to a report published by conservationists, oaks, maples and magnolias are among those at risk. 0ur correspondent sanchia berg has been at kew gardens in south west london finding out just how serious the threat is. i have been looking at some of these species identified as being at risk down here at kew gardens, including some extraordinary trees from madagascar from what is called the dry forest which have been particularly affected by logging and some are close to extinction. of course, they are here being conserved at kew gardens as part of a huge programme in this area, but the authors of the report are concerned about the number of trees in their own native environment because a whole ecosystem can depend on them. so the lemurs of madagascar for example depend on those trees just as many other plants and animals do and as you said it's not just the exotic trees but also much more familiar british trees and european trees that this report identifies as being at risk in their home areas. so they are hoping that the report will alert people to what is actually happening in the fact that many species of trees are at risk particularly in the countries where they evolved.