Broadcast 2 February 1995, the fifth programme explores the alliances formed between the animal and plant worlds. Attenborough dives into Australia's Great Barrier Reef and contrasts the nocturnal feeding of coral, on microscopic creatures, with its daytime diet of algae. Some acacias are protected by ants, which will defend their refuge from any predator. Besides accommodation, the guards are rewarded with nectar and, from certain species, protein for their larvae as well. Fungi feed on plants but also provide essential nutriment to saplings. The connection is never broken throughout a tree's life and a quarter of the sugars and starches produced in its leaves is channelled back to its fungal partners. Meanwhile, fungi that feed on dead wood leave a hollow trunk, which also benefits the tree. Orchids enjoy a similar affiliation. Lichens are the product of a relationship between fungi and a photosynthetic associate, usually algae. They are extremely slow-growing, and a graveyard is the perfect location to discover their exact longevity. Mistletoe is a parasite that obtains its moisture from a host tree, while its seeds are deposited on another by the mistletoe tyrannulet, following digestion of the fruit. The dodder is also parasitic, generally favouring nettles, and siphons its nourishment through periodic 'plugs' along its stem. The rafflesia has no stem or leaves and only emerges from its host in order to bloom — and it produces the largest single flower: one metre across. (source: wikipedia.org)
The series utilizes time-lapse sequences extensively in order to grant insights that would otherwise be almost impossible. Plants live on a different time scale, and even though their life is highly complex and often surprising, most of it is invisible to humans unless events that happen over months or even years are shown within seconds.
Like many traditional wildlife documentaries, it makes use of almost no computer animation. The series also discusses fungi, although as it is pointed out, these do not belong to the kingdom of plants. The mechanisms of evolution are taught transparently by showing the advantages of various types of plant behavior in action.
The adaptations are often complex, as it becomes clear that the environment to which plants must adapt comprises not just soil, water and weather, but also other plants, fungi, insects and other animals, and even humans. The series shows that co-operative strategies are often much more effective than predatory ones, as these often lead to the prey developing methods of self-defense – from plants growing spikes to insects learning to recognise mimicry.
Yet humans can work around all these rules of nature, so Attenborough concludes with a plea to preserve plants, in the interest of self-preservation. (source: en.wikipedia.org)