In The Secret Network of Nature by Peter Wohlleben the close connections that exist between flora and fauna are explored and several unexpected relationships reveal the delicate balance which maintains vulnerable ecosystems. Wohlleben stresses that nature works on cause and effect, however the earths ecosystems are too complex for us to ever easily map out simple rules to ensure the balance is never interrupted. It is therefore difficult for us to imagine today some of the long-term effects and disruption being created through the anthropocentric control of nature.
One of the most interesting chapters in the book is entitled ‘Salmon in the Trees’ and here Wohlleben explains the relationship between salmon, bears and trees. He states that along the Pacific Coast of North America black and brown bears catch salmon as they journey back upstream in preparation to spawn. The bears catch the salmon but will discard the carcass if they are no longer carrying much body fat, ensuring a tasty meal for other animals in the area. The head and bones of the salmon often get left to rot amongst the vegetation and this subsequently fertilises the soil. This results in extremely high levels of nitrogen being distributed which has the effect of speeding up the growth of the Sitka spruce in particular which grows nearby. It has been reported that more than 80 per cent of the nitrogen that is found in the trees can be traced back to fish.
In Europe, where we no longer have salmon swimming in abundance in rivers, it is difficult to ascertain what effect their absence has had as we are unable to test trees for nitrogen levels because as Wohlleben states, since the Middle Ages, forests have either been cut down or “so heavily exploited that all the ancient trees have disappeared”. It is a sad but surprising fact that in Germany forests which are commercially managed have no tree older than eighty.
Alongside other fascinating relationships examining ‘Why Deer Taste Bad to Trees, ‘Is the Bark Beetle All Bad?’, and ‘How Earthworms Control Wild Boar’, Wohlleben addresses many of the myths which surround biodiversity. In particular the idea that if we manage to save one particular animal or plant we are doing a good thing for the environment, the effect this then has on the survival of several other species is often ignored. Wohlleben highlights the fact that in Germany alone there are 71,500 known species, meaning we can never know how many will be destroyed by the anthropocentric decision to alter the environment to ensure the survival of one.
The Secret Network of Nature is an accessible, illuminating, factual account of how anthropocentric management of the environment can interrupt the balance of life. The notion of cause and effect reminds me of the 1952 Science Fiction short story ‘A Sound of Thunder’ by Ray Bradbury. Set in 2055 the protagonist Eckles pays a lot of money to return to the past to hunt a Tyrannosaurus Rex. Eckles and his fellow hunters are given strict instructions to remain on the path and only shoot when instructed so they do not cause any damage in the past that will have consequences in the future but, panicked at the sight of the T-rex Eckles runs into the forest straying from the path. On their arrival back in 2055 subtle changes have taken place which indicate something must have gone wrong. On examining his shoe, it becomes clear that Eckles has crushed a butterfly when he deviated from the path. The story concludes on a sound of thunder resonating from the past highlighting the damage caused by anthropocentric actions. Wohlleben’s book is a sound of thunder in the Anthropocene, our current actions will and do have far reaching consequences; but understanding the ‘network of nature’ may help us stick to the path and ensure the balance of these relationships.