High in the hills of the Snowdonia National Park in Wales, can be found a rare and fascinating habitat. We all know of the importance of the Tropical Rainforests, however these Celtic Rainforests are in a way even rarer, with Britain being home to most of the best preserved examples in the World. The Valley is changing and time could possibly be running out for these remarkable and sensitive habitats, which have been suffering from pollution and climate change since the dawn of the Industrial Age.

Brett Westwood relives programmes from The Living World archives, this episode from 2011. Wales is home to a remarkable and rare forest. Paul Evans joins Ray Woods from Plantlife Cymru in Snowdonia.

In an area where 200 days of rain each year is normal, Paul and Ray don their waterproofs and venture up the valley of the Rhaeadr Ddu, the Black Waterfall. The landscape in this valley is dominated by water, not only from the exceptional rainfall this area is known for, but from the river thundering along many rapids and waterfalls providing a constant mist of high humidity within the Atlantic wood enveloping the valley. Linked to a mild climate in this part of Wales, everything in the woodland is a carpeted in a magical sea of emerald green moss, fungi and lichen.

This valley is home to some rare and exotic plants, the filmy ferns are however special in this landscape. Ray and Paul eventually make it to the side of the huge Rhaeadr Ddu waterfall itself, where, as the roar of the water almost drowns their voices, there on a single rocky outcrop, bathed in constant spray they discover the rare, minute and exotically beautiful Tunbridge Filmy-fern. Nearby a Wilson's Filmy-fern is found on a single boulder of an ancient moss encrusted dry stone wall. How did this Filmy-fern get here is a point of discussion.

Around 100,000 dark bellied brent geese head to Britain every winter to escape the extreme cold weather of their arctic breeding grounds in Russia. Britain is therefore an important wintering ground for these geese with many thousands heading to the Essex Marshes. But what brings them here and what are the management needs of this populated area of the South East coastal?

To find out for himself, as Brett Westwood introduces in this Living World episode first broadcast in 2005, Peter France heads over to the Essex coastline in the company of ecologist Graeme Underwood from Essex University and Chris Tyas from the RSPB. Overlooking the wide marginal landscape wedged between the sea and the land they discuss mudflats and difference between marine and freshwater marshes. An ever changing landscape that requires specific management with all the challenges of creating the best habitat for all plants and animals here, including the thousands of dark bellied brent geese, in front of them.

Around 100,000 dark bellied brent geese head to Britain every winter to escape the extreme cold weather of their arctic breeding grounds in Russia. Britain is therefore an important wintering ground for these geese with many thousands heading to the Essex Marshes. But what brings them here and what are the management needs of this populated area of the South East coastal?

To find out for himself, as Brett Westwood introduces in this Living World episode first broadcast in 2005, Peter France heads over to the Essex coastline in the company of ecologist Graeme Underwood from Essex University and Chris Tyas from the RSPB. Overlooking the wide marginal landscape wedged between the sea and the land they discuss mudflats and difference between marine and freshwater marshes. An ever changing landscape that requires specific management with all the challenges of creating the best habitat for all plants and animals here, including the thousands of dark bellied brent geese, in front of them.

The famous evening murmuration, fantastic formations of huge flocks of starlings coming in to roost, brings hundreds of visitors to the levels each winter. But far fewer people see the spectacle of the dawn eruption when the starlings take off en masse to start their day foraging in the surrounding fields.

Brett Westwood relives programmes from The Living World archives. This episode from 2014 sees Trai Anfield immerses herself in a starling spectacle many people have never seen. Each year the reedbeds of the Somerset Levels become the winter home for hundreds of thousands of starlings. Making their way from across the UK and Europe these birds have found a safe haven to roost with plenty of food nearby. Simon Clarke of Natural England talks Trai Anfield through the spectacle on Shapwick Heath. When it is all over and three quarters of a million starlings have departed for the day, thoughts turn to the reedbed and the effect the presence of so many birds has on their winter roost site and the animals they share it with.

The famous evening murmuration, fantastic formations of huge flocks of starlings coming in to roost, brings hundreds of visitors to the levels each winter. But far fewer people see the spectacle of the dawn eruption when the starlings take off en masse to start their day foraging in the surrounding fields.

Brett Westwood relives programmes from The Living World archives. This episode from 2014 sees Trai Anfield immerses herself in a starling spectacle many people have never seen. Each year the reedbeds of the Somerset Levels become the winter home for hundreds of thousands of starlings. Making their way from across the UK and Europe these birds have found a safe haven to roost with plenty of food nearby. Simon Clarke of Natural England talks Trai Anfield through the spectacle on Shapwick Heath. When it is all over and three quarters of a million starlings have departed for the day, thoughts turn to the reedbed and the effect the presence of so many birds has on their winter roost site and the animals they share it with.

There are 19 species of the wild snowdrop in the world, all in the genus Galanthus. Wild snowdrops are found across much of Europe from Spain to the Caucasus , with Turkey being a hot spot for these 'milk flowers', but they are not found in Britain. What we think of as British wild snowdrops which herald the beginning of spring, are an introduced species or escapees from garden collections. Over the centuries gardeners have selected over 1000 distinct cultivars and that number is increasing every year. And so it takes a certain special kind of person to become a galanthophile, or a lover of snowdrops.

Brett Westwood relives programmes from the Living World archives and in this episode from 2004 Brett himself travels to Somerset to explore the fascinating world of snowdrops with one such galanthophile Christine Skelmesdale. They start by discussing the snowdrop cultivars in Christine's garden before moving on to 'Snowdrop Valley' (or the more correctly called Avill Valley) on Exmoor. Christine explains the origins of UK snowdrops as imports from abroad, and that far from being native, snowdrops are a naturalised alien, though wonderful, plant.

The Mountain Hare, sometimes called the Arctic or Blue Hare, is a native of Scotland but to most people's surprise a colony also live in England.

Brett Westwood relives programmes from The Living World archives. This episode from 2005 Sarah Pitt heads into a wintry Peak District with the late Derek Yaldon in search of mountain hares, one of the great relics of the ice age. Nestled into the hills and as white as white during the winter these animals are very at home straddling the Pennine Way. But how did they get here? To discover this Sarah Pitt is led by zoologist Derek Yalden deep into wintry moors to find these animals, and much to his surprise is given a special device by Sarah to enable him to see the hares at night, something he's never done before. So a double surprise. Hares by day and hares by night. It certainly seems from Sarah and Derek's encounter that the night time is the right time for Mountain Hares.

Brett Westwood relives programmes from the Living World archives. This episode from 2012 sees Miranda Krestovnikoff with Jeremy Biggs then from Pond Conservation (now known as Freshwater Habitats Trust) for a special Living world devoted to the ponds of the New Forest.

Jeremy has chosen these as some of the finest of their type because they are keep open by grazing ponies and deer, don't suffer from pollution from roads or agricultural run-off , and are some of the cleanest ponds in the United Kingdom. When they go pond-dipping , kneeling in muddy water in chest-waders, he proves it by finding some of our rarest plants and animals including the mud snail which thrives in shallow pools whose margins dry out in summer . Damselfly larvae prowl among the plants and there are even newts active in January , animals which have grown too slowly in the previous summer and are spending the winter as youngsters. Best of all, in the shallows of the pond are clumps of the year's first frogspawn, in mid -January.

This pond contains water all year round, but temporary ponds are a speciality of the New Forest. At Burley, Jeremy shows Miranda a roadside pool which fills with water in winter but is a grassy hollow in summer. Here they dip for one of Britain's rarest animals , the delicate fairy shrimp which can only survive in pools which dry out. These beautiful creatures are some of the oldest living animals on the planet, virtually unchanged in appearance from their ancestors 400 million years ago. Their eggs can survive in soil until the rains fill their ponds again in autumn and a new generation hatches to swim safe from fishes in the New Forest's temporary ponds.

Brett Westwood relives programmes from the Living World archives. In this episode from 2011 Joanna Pinnock travels up to the Stiperstone Hills of Shropshire where she meets up with Sara Bellis and Carl Pickup from the Shropshire Wildlife Trust at a remarkable site, The Hollies.

Here high up on the windswept hills, Joanna encounters ancient holly trees, which could be as old as 400 years. Holly, naturally an understory tree of more developed woodland, is not suited to grow up here in the cold windy conditions. But how and why these trees came to be here is something of a mystery. It is thought these holly trees are a living link to a past age in this landscape, where lead mining was once common and over 2 centuries ago there were thousands of people eking a subsistence living up here. Possibly the hollies we seen now, gnarled and twisted though they are, are all that remains of a woodland which at one time covered all the hills around here. That woodland was subsequently cleared for whatever reason, leaving the holly trees as a valuable source of winter fodder. With the altitude and animal grazing on the hills these days, young holly cannot regenerate, so this landscape is one of preservation not conservation.

But the story ends with a surprise, the cuckoo trees up here. Sometimes known as bonded trees, here Joanna witnesses the growing of full height rowan trees, inside the trunks of older holly trees. How did the rowan trees get there, well, it all has something to do with winter thrushes, as is revealed in the programme.

Black-tailed godwits are an elegant long legged bird about the size of a pigeon. In the summer they are found in the arctic where the Icelandic race of this species then migrates to Britain to spend the winter in relatively warmer weather. For this week's Living World Brett Westwood relives programmes from the Living World archives with an episode from 2013 which sees Chris Sperring visit a private estate in Hampshire where 2000 black tailed godwit visit their flooded water meadows along the River Avon in winter. Here Chris is guided by Pete Potts from Operation Godwit.