Elephants prop up the forest and savannah ecosystems we need to store carbon. To stabilise the climate, we must stop their slaughter by ivory poachers
August 12, 2016 — Today is World Elephant Day, when people with a passion for pachyderms come together to celebrate the wonder of elephants and raise funds to protect them. It seems paradoxical that the largest land animal, which has come to symbolise strength and sagacity, should be so vulnerable – but across Africa and Asia numbers are dwindling as human activities and expanding agriculture squeeze elephants into smaller and smaller patches of fragmented habitat.
Even where habitat remains, the elephants themselves – despite legal protection – are hunted by criminal gangs for their front teeth, for their meat and for their babies (to be beaten into submission for a life of servitude in entertainment, temple ceremonies or tourist attractions). And on top of all this, elephants – like every other species – are suffering as climate change raises average temperatures, disrupts rainfall patterns and brings more drought and extreme weather events.
Why should we care? A glance through the literature of organisations dedicated to saving elephants gives a clear idea of why people care about elephants. We find their size impressive; their improbable shape and sometimes comical behaviour endear them to children; their matriarchal society and cognitive capacity fascinate us; their ability to suffer and show compassion strikes an empathic chord in us; and they are high on the list of “must-see” animals on wildlife-watching holidays in Africa and Asia, so they bring in tourist revenues.
All these reasons are perfectly valid, if largely anthropocentric, but they do rather miss the point of what elephants are for, ecologically speaking. The role they evolved to play in the forest-savannah mosaic that covered Africa and Asia is not just of academic interest.
Fly across parts of Africa and Asia, and rainforests stretch to the horizon like a carpet of broccoli. The bumps on this broccoli are the emergent trees, rising above the surrounding canopy on massive trunks, the base of which would require several people hand-in-hand with arms outstretched to encircle. How did these centuries-old rainforest giants get there? Five or six hundred years ago, maybe a thousand in some cases, an ecological event took place: a monkey, bird or elephant ate some fruit, chewed and swallowed the seeds, then deposited them far from the parent plant in their droppings – in effect, nutrient-rich packets of fertiliser – which dung beetles then buried. In tropical forests, between 75% and 95% of tree species have seeds dispersed by animals, rather than by wind or water.
Until recently, tropical forest trees were valued economically by the outside world only for their beautiful hardwood timber. Enshrined in the Paris climate agreement, however, is a new economic value – the sequestration and storage of gigatonnes of carbon. The inclusion of forest carbon in the United Nations Framework Convention on Climate Change (UNFCCC) climate negotiations has been slow and complicated because of the tricky question of permanence. A forest can be here today and felled or burned tomorrow, so how can we guarantee the same storage of carbon per unit area long into the future? The answer is think of forests not as “sticks of carbon” but as forest ecosystems, comprised of thousands of interdependent species of plants, animals, fungi and micro-organisms. And carbon sequestration and storage is only one of several ecosystem services these forests and woodlands provide.
Elephants, because of their size, appetite and migratory habits, disperse more seeds of more species further than any other animal. Tree species with small seeds such as figs can have them dispersed by birds, fruit bats, antelope, etc. Species with large seeds, such as mangoes and durian, need big animals such as apes and elephants to disperse them, sowing the seeds of the trees of tomorrow. Their dung is important, too, as fertiliser. An adult elephant produces about one tonne of first-class organic manure every week. Germination and seedling survival are much higher for seeds given such a good start in life. This is why ecologists refer to elephants as mega-gardeners of the forest – though elephants play this role in savannah-woodlands too, spreading acacia seeds far and wide (and in so doing, protecting the seeds from weevils that concentrate around the parent tree).
The current wave of ivory poaching is killing some 30,000 African elephants a year. This is a tragic loss to the surviving members of each elephant’s family, and to the potential revenues from tourism, but think of the ecological impact. Think of the loss of soil fertility of 30,000 fewer tonnes of manure a week and millions of seeds not dispersed. Consider this in a broader timescale: before the advent of modern firearms, it is thought there were some 10m elephants across Africa. Even the most optimistic estimates today put the figure at under half a million. We have already lost 95% of the workforce of the forest and savannah. This is why the vast majority of the countries with natural elephant populations are calling for an end to the ivory trade everywhere. As long as ivory is coveted and sold anywhere, elephants are not safe. You cannot protect an animal with a fortune on its face, especially in a continent awash with guns and poverty.
There is one more twist to the carbon story relevant to elephants. Botanists have reported a correlation between seed size and wood density. Tree species with big seeds, it turns out, store more carbon per unit volume of wood than tree species with small seeds. Thus, to maintain the high rates of carbon storage in Africa’s and Asia’s tropical forests, elephants are essential – not just in small, fenced protected areas but across what is left of their former range.
The fact is that to stabilise the climate, we need elephants (and other “gardeners of the forest”) to keep doing what they do as much as they need us to leave them alone.