i'm frank gardner and i am heading into what remains of the virgin tropical rainforest.wheelchair for a packhorse and am tested to my limits. i think this is too dangerous. i don't think i can do this. i am joining a crack team of scientists from the royal botanic gardens, kew. they are on a mission to discover and save unique plant species before they vanish forever. i am going to bear witness on the frontline of rainforest conservation. this is where the journey begins — not in colombia, but in the royal botanic gardens, kew, london. kew is the world leader in developing plant science. the botanists are preparing for their mission to discover new species. and it is from here that this expedition will be launched. i have come here to see the expedition leader, doctor mauricio de bernardos. he works in a library for lab specimens. this is where we identify new plants. we believe we have more than 200,000 different species here. you are a botanist and a biologist. and a scientist and an explorer in some sense. what are you expecting to get from this mission? the most remo

more now from our security correspondent frank gardner.services are under. security services have a database of thousands of persons of interest, people known to have links with suspected terrorist organisations overseas, extremist. but in addition to that there is another list of around 40,000 people not thought to be an immediate risk but have had former links, some of them deceased, some of them contact that had been passed from overseas agencies but what happens inside m15 is that every week they hold a formal meeting called the grid, they sit down with counterterrorism police and they go through the prioritisation list and decide who should be moved up, moved down, what is the priority. the challenge here is the priority. the challenge here is trying to see inside people's heads, where you've got somebody who is possibly mentally unstable, has got other, various stimuli that are driving him or her towards extreme action, you often don't spot that. the person doesn't necessarily give that away on social media or in their communications

i'm frank gardner, and i am heading into what remains of the virgin tropical rainforest.aded in my wheelchair for a packhorse a the royal botanic gardens, kew.