Woodlands and forests are complex, fascinating and magnificent – and the Ecospheres collaborators are grateful to have enjoyed longstanding associations with these environments.

Ecologists continue to explore their immense biodiversity, the intricate inter-relationships between the plants, animals and micro organisms which they host, and the biogeochemical cycles in which they participate. At the same time, palaeontologists continue to pull back the veil on the history of forest biomes, which first appeared on Earth some 370 million years ago.

Simply to stand in the shade of a forest, however, and to  witness its life at first hand is an enthralling experience.

A major focus of the Ecospheres collaboration is to assess habitability in terms of the capability of planetary bodies to support Earth-type forest biomes, and equivalent high biomass and biodiversity (with speculation also about non-Earth-like options.)

Beech woodland on West Wycombe Hill, Buckinghamshire, England.

This forest-orientated approach to planetary habitability studies was launched by Martin Heath, and it featured prominently at a conference “Life & Death of the Earth” which he called in London in 1990. At this meeting, experts from across a wide range of disciplines looked at the processes which enable the Earth to support complex life, and the most extensive presentation was from a rain forest explorer, who discussed theses forests’ geographic context and biodiversity, looking also at ongoing threats to forests and projects to safeguard forest reserves. Heath examined the evidence from the geological record for planetary-scale changes that opened an environmental window for complex life late in the Earth’s history. He presented the latter, stressing the ecophysiological tolerances of Earth-type forests, to the 1994 First International Conference on Circumstellar Habitable Zones, in a session chaired by the late Carl E. Sagan (1934-1996), a valued friend and supporter of Laurance Doyle.

Best known as the ebullient presenter of the “Cosmos” TV series, Sagan himself had once pointed out that we have already sent a message into space which might convey our debt to the trees – where our primate ancestors evolved – to any other life form able to read it and to understand its implications.

Discussing the pictorial message engraved onto an aluminium plate aboard Pioneer 10, a 1970s giant planet probe which would be the first space craft whose velocity meant that it must escape from the Solar System after its mission, Sagan et al. wondered, (Science 175: p. 883): “It is not clear how much evolutionary or anthropological information can be deduced from such a sketch drawing. Ten fingers and ten toes may provide a clue to man’s arboreal ancestry, and the fact that the distance of Mercury from the sun is given as 10 units may be a clue to the development of counting.” Following the Conference, Heath, Doyle and associates, hiked through California’s redwood groves and discussed how collaborative research goals might be pursued. The setting was appropriate and inspiring.

A giant sequoia (Sequoiadendron giganteum) in the Sierra Nevada, California.

For both collaborators, an interest in discovering forest-type biomes on planets of other stars emerged from their appreciation of the forest biomes of their own planet. They share not only a love of woods and forests, but also a long-standing practical involvement with these biomes.

Laurance Doyle grew up in the rural district of Cambria, on the coast of California. He fought forest fires as a high school volunteer, which was rewarding work, helping to prevent loss of lives as well as restricting damage to habitats. It would, of course, be impossible for an environmentally-conscious Californian to be unaware of the classic campaigns fought to preserve the majestic redwoods, and Doyle deplores continuing inroads into forests world-wide.

The Kakum rain-forest reserve in Ghana.

Martin Heath also has a close  association with woodlands. Working with groups in the voluntary sector, he  facilitates consultations and  organises campaigns to encourage the  preservation and enhancement of urban woods, hedgerows and wildlife corridors in London. He is also keen to take a practical hand in the creation of new habitats. At Belair Park, London Borough of Southwark, he has introduced a broad hedgerow – narrow woodland-type habitat, running beside a lake, with ditches, wetland areas, vegetated lake margins and islands. Naturalists have monitored substantial improvements in local biodiversity, with a burgeoning catalogue of plant life, invertebrates, birds and bats.

Perching robin (Erithacus rubecula), a bird widespread in mainland Britain and Ireland.

Heath: “At the same time as my colleagues and I are exploring the possibilities for other habitable worlds, we must never forget that the planet beneath our feet remains the first and most urgent priority of the human species.”

Internal path through section of ecology area that mimics woodland habitat.

The speckled wood butterfly (Pararge aegeria) is typically seen in woodland in clearings in S. England. In this ecology area, it is most commonly seen around the hedgerow and within the woodland area.

Images: M.J.Heath.