AN early scene in The Green Planet (BBC1, Sunday, 7pm), Sir David Attenborough’s new series, finds the naturalist standing next to the biggest living thing in the world. It is not a picture of a whale, a swathe of territory, or, indeed, some physical representation of his own towering reputation. It is a plant; a giant sequoia in California to be precise.

Plants, Sir David reminds us, are the basis of all our lives. Without them to give us food and air, life on Earth as we know it would cease to be. Yet for the most part, he says, the secrets of their world have been hidden, adding teasingly, “until now”.

Note that caveat, “for the most part”. There have of course been centuries of study into plants. Most recently, Sir David made his own contribution to the sum of knowledge about them in his 1995 series, The Private Life of Plants.

What he means is that advances in camera technology now allow us to see as never before how plants live and die. In short, to get down in the dirt, up in the air, and in among the leaves and the creatures who depend on them. Using the latest in time lapse photography, we can watch years of growth unfold in seconds.

One segment tracks the sequence of events that follow an old tree dying and crashing to the ground in the rainforests of Costa Rica. A battle begins to fill the space and soak up the precious light, vines vying with balsa trees to see who can climb higher, faster. Animals including sloths and kinkajous come and go, feeding and helping to propagate the plants, while below ground leafcutter ants allow the fungi to thrive. The photography yields astonishing sights, particularly when Sir David looks at plants that eat animals rather than the other way around.

Yes, it is a jungle out there and, as ever, it is humans who are not pulling their weight in preserving it. Some 70% of rainforest plants, says Sir David, grow within a mile of clearings that we have cut into the forest. But even here, in the strips between the clearings, there is hope.

Another landmark series from the 95-year-old. While there are no fluffy baby animals or scenes of hunting – thankfully – it is astonishing viewing.

Life on the Bay (BBC Scotland, Sunday, 9.30pm, repeated Wednesday, 7.30pm) sounds like it might be another slice of wildlife documentary, but the subject here is a caravan park on the Fife coast. Owned and run by three generations of the Wallace family, it is one of Scotland’s biggest caravan parks, a second home from home for the many residents who occupy the 600-plus spots on a hill overlooking the sea.

Made in the same style as Inside Central Station, and with Edith Bowman on narrating duty, Life on the Bay focuses as much on the staff as the residents, showing what goes into maintaining the place, from strimming the grass to anchoring the caravans so they can cope with the high winds that sweep in during the cooler months.

Caravans can cost anything up to £85,000 new, but in this, the first of eight episodes, we meet a family who have bought their dream of coastal holidays for just £7000.

Netflix viewers are used to the “coming soon” emails the streaming platform issues regularly, trumpeting this or that as the next show or film not to be missed. Not all live up to the hype. There is a genuine sense of anticipation, though, over the return of Ricky Gervais’s comedy drama, After Life (Netflix, Friday, from 8am).

The creator of The Office plays Tony, a widower. Since he lost his beloved Lisa (Kerry Godliman), curmudgeonly Tony has been alternately raging at and despairing of the world. Though he carries on putting one foot in front of the other, the local newspaper reporter rarely seems to make much progress through his grief.

With the help of friends and colleagues, and despite many a set-back along the way, Tony slowly finds he has carved a new life for himself, one that will never be as good as the old, but which might just be worth sticking around for.

It takes a rare talent to turn such a story into comedy that is as moving as it is funny. Gervais makes it look easy, through his writing, performance, and a superb cast of regulars that includes Ashley Jensen (his co-star in Extras) and Penelope Wilton.

If you can, do catch up on series one and two before the third drops. As with The Office, this is comedy taken to a higher level.

Get ready for a changing of the guard on Sunday mornings as the BBC learns to live without The Andrew Marr Show. Sunday Morning (BBC1, Sunday, 9am) finds Sophie Raworth taking over, temporarily we are told, till a new anchorman or anchorwoman is found.