Thank you for this great repetition on ecology and biochemistry. I agree, detrivores are much cooler! I admired the fungi picture, never knew of that species! Great photos set.
Atop the highest canopy of the Amazon rainforest and across the vast plains of the Serengeti (two places that couldn’t seem more different) there’s this incredible principle of life that ties these ecosystems together – nutrient cycling.
To see it, we need to stop looking at nature like this:
And rather start looking at it like this:
Pretty complex right? I know but give me a second to explain. Nature is full of drama, beauty, cuteness, and odd things. But what if predators, prey, and plants are just cool ways of moving nutrients, elements, and atoms around. Many people think that looking at nature in this way, a way of moving base elements around from one place to another, takes the fun out of it. But I beg to differ.
This movement of elements is known as nutrient cycling and it is vital in our ecosystem. Everything at Londolozi is kept in its equilibrium state because of nutrients travelling back and forth from one state to another – and these nutrients play the most vital role in keeping the ecosystem functioning.
Taking life to give life
So where do we begin when we’re talking about nutrient cycling? We could begin anywhere really because nutrient cycling is exactly that: a cycle – the repetition of a series of events. For this explanation, I’m going to start at the end, the end of a life that is.
With almost every set of guests, I get asked a question along the lines of “Have you ever seen a kill?”. To which my response is that it’s such a rarity seeing a predator hunt and actually succeed. I’ve only seen a successful hunt twice in my guiding career so far. The most stand-out hunt was that of a lion pride and a wildebeest.
So, what does this have to do with nutrient cycling? Well, after succeeding in the hunt of that wildebeest, the lions quickly started to eat. This kill is necessary; firstly to feed the hungry lions, but there is much more to this that goes on. The soft tissue of the wildebeest decomposes quickly, but half of a wildebeest’s body mass is bone and those take a lot longer to break down – months, even years sometimes. And locked inside those bones are nutrients, like calcium, phosphorus, carbon, and nitrogen. These are elements that other components in the ecosystem need to grow. For this example, I am going to use nitrogen as the primary nutrient.
Nitrogen is extremely important to all living creatures. We require nitrogen because it is a building block of amino acids, the same amino acids that build our cells and help our bodies work. They are part of our DNA, hormones, enzymes, and countless other functionalities in all animals. These continue up the food chain from the prey to the lions and other predators until it eventually returns back to the soil or into the atmosphere by decomposers or as waste.
So, how do essential nutrients, elements like nitrogen, carbon, phosphorus, and potassium, get cycled through from old bones to soil? We have so many small organisms to thank for this.
The Dignitaries of Decomposing
Despite scavengers (by the likes of hyenas and vultures) getting the last remaining bones, there are still certain parts of the skeletons left behind that even these scavengers don’t clean up. In each bone, there’s a variety of minerals.
At this point I’d like to add in a twist: there’s another key element at play in our ecosystem, but you’re not going to find it on the periodic table. It’s the element of time. Over a long period, these bones are exposed to the sun and eventually they start to crack. The sun exposure and these cracks make it possible for microscopic organisms to enter and begin eating away at the bone, thus releasing those important nutrients. So, weather and microscopic organisms take over and eventually every part of this creature makes its way back into (what I think is the most under appreciated and overlooked part of this entire ecosystem) the soil.
It may not look like it from the surface, but there is extreme chaos occurring in the soil. This chaos ensues from organisms that feed on the bones and other dead matter, and are referred to as detritivores. These recyclers are not big creatures like hyenas, they’re organisms like fungi, termites and microbes, which frankly I think are even cooler.
Take fungi, for instance, they live in symbiotic relationships with the roots of plants. So they feed the plants nutrients and in turn, are helped gain access to water. In exchange, they get some of that fuel, the products of photosynthesis. In the Lowveld, fungi only make up less than 1% of all the living biomass, but they put back twice as many nutrients into the ecosystem as all of the other animals combined.
The entire mass of all the termites here in Londolozi probably outweigh the mass of all the other mammals put together. And they’re burying unimaginable amounts of dead plant matter down into their underground fungal farms and recycling that back into the soil.
Microbes and bacteria are vital in recycling both plant and animal matter back into the soil. Nitrogen is the main element in both plant and animal matter, and it makes up about 78% of the air. Plants have a very specific bacterium around their roots, a bacterium that synthesises nitrogen. Without this special bacterium, plants would not be able to grow and life on the planet wouldn’t be possible.
Completing the circle (of life)
Now that all the organic matter and nutrients have filled the soil, the addition of sunlight and water enables a great variety of vegetation to grow. This vegetation is what feeds the wildebeest, which ultimately feeds (and brings us back to) the lion.
Life is just a collection of elements moving between living and non-living things. In a place like Londolozi, there’s so much drama and action happening on the surface, but what happens on the earth in a big way is dependent on what happens in the earth.
Filed under Wildlife
Detritivores are definitely a critical link in our ecosystem! Thanks for the comment, Francesca!