Broadcast 9 February 1995, the final episode deals with plants that live in hostile environments. Attenborough visits Ellesmere Island, north of the Arctic Circle, to demonstrate that even in a place that is unconducive to life, it can be found. Algae and lichens grow in or on rock, and during summer, when the ice melts, flowers are much more apparent. However, they must remain close to the ground to stay out of the chilling wind. In the Tasmanian mountains, plants conserve heat by growing into 'cushions' that act as solar panels, with as many as a million individual shoots grouped together as one. Others, such as the lobelia in Mount Kenya, have a 'fur coat' of dense hairs on their leaves. The saguaro cactus in the Sonoran Desert flourishes because of its ability to retain vast amounts of water, which can't be lost through leaves because it has none. Many desert dwellers benefit from an accelerated life cycle, blooming rapidly within weeks after rainfall. Conversely, Mount Roraima is one of the wettest places on Earth. It is a huge sandstone plateau with high waterfalls and nutrients are continuously washed away, so plants have to adapt their diet if they are to survive. A bladderwort is shown invading a bromeliad. Inhabitants of lakes have other problems to contend with: those that dominate the surface will proliferate, and the Amazon water lily provides an apt illustration. Attenborough ends the series with an entreaty for the conservation of plant species. (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)