Planeta Tierra es una aclamada serie de documentales creada por la BBC que nos muestra, en 11 episodios escritos por el prestigioso naturalista David Attenborough, la belleza de nuestro enorme planeta con imágenes nunca antes vistas. 10. "Seasonal Forests" UK broadcast 3 December 2006, 7.42 million viewers (29% audience share);[25] US broadcast 22 April 2007 The penultimate episode surveys the coniferous and deciduous seasonal woodland habitats — the most extensive forests on Earth. Conifers begin sparsely in the subarctic but soon dominate the land, and the taiga circles the globe, containing a third of all the Earth's trees. Few creatures can survive the Arctic climate all year round, but the moose and wolverine are exceptions. 1,600 kilometres (990 mi) to the south, on the Pacific coast of North America, conifers have reached their full potential. These include some of the world's tallest trees: the redwoods. Here, a pine marten is shown stalking a squirrel, and great grey owl chicks take their first flight. Further south still, in the Valdivian forests of Chile, a population of smaller animals exist, including the pudú and the kodkod. During spring in a European broad-leafed forest, a mandarin duck leads its day-old family to leap from its tree trunk nest to the leaf litter below. Bialowieza Forest typifies the habitat that characterised Europe around 6000 years ago: only a fragment remains in Poland and Belarus. On a summer night on North America's east coast, periodical cicadas emerge en masse to mate — an event that occurs every seventeen years. After revisiting Russia's Amur leopards in winter, a timelapse sequence illustrates the effect of the ensuing spring on the deciduous forest floor. In India's teak forests, a langur monkey strays too far from the chital that act as its sentinels and falls prey to a tiger. In Madagascar, mouse lemurs feed on the nectar of flowering baobab trees. Planet Earth Diaries explains how aerial shots of the baobab were achieved by the use of a cinebulle, an adapted hot air balloon.