When I was a child growing up in Brazil, I would play by stepping on cow's poop barefoot just to feel the warm and soft sensation of the digested organic matter going through my toes.
(Laughter)
But for my family, animal waste had another level of importance. My grandma would sell the manure and split the money with my mom. That was my mom's only income as a housewife, raising her four children, while my father worked in our farm. That's my grandma. On that very farm, my grandpa had a stroke of genius. Instead of ordinary fences, he carved out some ditches surrounded by trees, creating forest corridors for animals to cross. It was like Mother Nature's highway system, allowing critters to commute from one leafy paradise to another. My mom never wanted me to rely on animal waste for a living. My grandpa did not know he was increasing the landscape connectivity for animals to cross, but they were both working on nature-based solutions before the term became trendy.
Two aspects of ecosystem restoration: investing in soil fertility and increasing the landscape connectivity. Bringing back the nutrients, bringing back the forests: both with positive consequences for the entire system.
I believe a healthy ecosystem should stand behind every plate of food. So today, as a scientist, my role is to understand how to produce food while we let animals working in ecosystem resilience in a changing world. So I started where those changes are happening, in the tropics, in Brazil, in the Amazonia. And it's in there, in the wilds of the tropical forests, the tropical South America, that beholds the star of our tale: the lowland tapir.
Those pig-like creatures grace the landscape from the Amazonia to the Pantanal. Aren't they cute?
(Audience murmuring)
When it comes to big animals, they tend to eat a lot of low-energy food like leaves. But tapirs are different. Up to 36 percent of their diet is based on fruit, and they have a very long digestive system. And they love to go for a walk. So let's picture that. They go for a walk. They find fruits along the way, they eat them while they process. And they keep walking in degraded areas, and eventually they poop. And when they poop, they help to spread the seeds in the fruits they love to eat. Tapirs are big, tapirs are tough, and tapirs poop ... a lot. And how do I know that? Because at the research station that I work on, at the Southeast Amazonia, among many other things, we wash poop.
(Laughter)
We walk in the forest looking for their latrines, and latrines are something like a toilet but without the large bowl, just a lot of poop together. We find them, collect, wash, count and identify as many seeds as possible. In one dung, we find on average 733 seeds belonging to up to 24 different species. We can see hundreds of seedlings emerging from one dung. And they can become trees, big trees. And because large-seeded trees tend to be deep rooted and drought resistant, those seed dispersers are helping to create a tree community that’s resilient and resistant.
But sometimes, as you can see, tapirs poop too many seeds in one place, leading to competition among the seedlings. So other animals come in to help, luckily. Some of those animals [are] the dung beetle. Dung beetles help to disperse the seeds throughout the forest. There are two kinds of dung beetles dispersing seeds: rollers and tunnelers. Rollers roll the poop away from the source and bury it underground, while tunnelers bury the poop right by the source. When they bury the seeds, they revolve around the soil and may make it better for the seeds and [increase] the chances of them to grow into plants. These animals’ interactions can really reseed the forests, but we must preserve their habitats to increase their chances of survival.
When people ask me if forests can regrow without our help, I say we always have to help, even if it is just to get out of the way. But another, more active way to help is by leaving forest patches in the landscape. Forest patches are something like VIP lounges for plants and animals, where critters can hop, skip and jump from one leafy hot spot to another. And when they do that, they act like real gardeners, bringing back the forests. And they need to do that because the future of those forests is at stake.
As scientists, we are concerned with deforestation and degradation. Deforestation takes away those forests those animals are helping to plant for thousands of years. Degradation makes those forests less healthy, harboring fewer animals. I truly believe that those animals are trying to bring back the spring, despite all the efforts to stop them.
So let me throw you some questions. How powerful is the tapirs’ poop? How far can they travel? How charming do my friends, totally unconcerned with social conventions, need to be in order to revert the tipping point we are possibly about to reach? My colleagues and I at the Woodwell Climate Research Center and at the Instituto de Pesquisa Ambiental da Amazônia are trying to answer those questions, but we already know some of the answers. We know that the resilience of those ecosystems is on the diversity of plants and animals living there. Our future is intertwined with the future of those animals, and it depends on how good a job we do trying to protect them. And people, I’m not afraid to say: our future lies in poop.
Thank you.
(Applause)
