Biodiversity has always fascinated me. As a child, I discovered the surprising logic of nature: a plant doesn’t just grow somewhere at random, and an insect needs specific plants. After years of practice, I was able to make some predictions around my home environment. If I saw greater yellow-rattle growing by the reeds, I knew there might be wild orchids around too.
Constant investigating an orchid. Dirk Hilbers for NEMO Kennislink.
It was magical, the first few times these predictions were correct. But fascinating, too, because it became apparent that plants and insects (as well as birds and mammals etc) live together in predictable, co-dependant ways. So what does it mean when species vanish from these communities?
Unfortunately, this is the reality: it recently emerged that 75% of insect biomass in nature reserves along the German border has disappeared in just a few decades. Our wild plants are not doing well either. Time for action! But how? Because while everyone has good intentions when it comes to nature, you still end up with totally different opinions.
An apparent contradiction
I think the biggest problem with this is the proximity and visibility. You would never tell a surgeon where to make an incision, because you don't know anything about it. But it's different with ecology. We all see the same thing: beautiful woods or fields, with a bird here and a butterfly there. But this is where things go awry. Because an ecologist will see how those beautiful woods are largely populated by introduced species (plants that have been brought in by humans rather than being indigenous to that country), and anyone who has been monitoring the natural environment for a number of years will notice the decline in the birds and butterflies. And if you think you’re looking at the same thing when you actually aren’t, misunderstandings emerge. The ecologist might remove an introduced species from an ecosystem and regard this as an environmental benefit, while someone else might see this as the brutal destruction of something beautiful.
Beautiful or not? For some, this may be a lovely vista. For an ecologist, it represents the decline of biodiversity in a raised bog caused by invasive purple moor-grass, a species that dominates the landscape when there's a surplus of nitrogen. Constant Swinkels for NEMO Kennislink.
I felt this most vividly two years ago, when my grandmother took me to see a tree she thought was really beautiful. It inspired her, with its symbolism of a kind of power: the ultimate expression of the capriciousness of nature. When we got there, what I saw was an introduced species. It was so clear to me: I didn’t see what she saw, and I fully understood how that was a shortcoming on my part. She also couldn’t see what I saw, but then she hasn’t spent years studying what I have.
How I see it
So I see things differently. I research the relationships between species within ecosystems. If you map these relationships, you see a complex web of interactions. It’s very complicated yet also very clear: even if we identify all the species within a system, we still can’t capture all of the complexities of nature. What's worrying about the current state of affairs is that the loss of a species isn’t simply bad news for that species. It’s also bad news for all of the species that depended on it. Introduced species often don’t take part in these interactions within a system. They behave more like an island (or tumour) within the natural network of interactions that has developed over thousands of years of evolution.
I look at the interactions between plants and insects. You might see a pretty flower and a bee here, but it’s also a mini plant-pollinator network! If this plant, the field scabious, were to vanish then the bee, a mining bee, would vanish with it. Constant Swinkels for NEMO Kennislink.
So for me, a healthy natural environment is more than just a beautiful tree or a rare species. It encompasses groups of species that live together in complex ways. I'm seeing these networks of species slowly disintegrate across the natural environment as a whole, largely due to human behaviour. This goes back to my childhood, because there were places then where the presence of a few species meant I could guess what else would be there. That doesn't work anymore. The rarer species have vanished, the communities have been hollowed out and the magic is gone.
Biodiversity
Knowing this, why would we even do any ‘gardening’ in nature? The idea behind this is that nature is constantly changing and we, as humans, shouldn’t be determining what counts as nature or not. And while this is fundamentally correct, it doesn’t fully do justice to the current situation.
Communities of species have developed over thousands of years. Of course these communities are constantly changing, but those changes occur very slowly. At the moment, we’re making high-speed changes to nature. So we're really gardening already, but without realising it. And by doing so, we’re determining what types of nature will continue to exist, or not. The original species can’t adapt that quickly. So what we’re really doing is ensuring that nature can’t behave naturally. From that point of view, occasional ‘counter-gardening’ seems to me perfectly legitimate.
Anyway, at the end of the day, it’s not for me to tell my grandmother, or anyone else, what to make of their beautiful tree, even if it is an introduced species. But what I really hope is that you understand how much more complicated it is. Biodiversity sounds so simple, but really it takes years of study to even start to understand it. And it’s really important that people do study it, given that in the end we all depend on nature to provide us with a healthy living environment. Let’s keep the conversation going, but let’s also make sure we discuss the substance of biodiversity!
This blog by Constant Swinkels was previously published on the Faces of Science page at NEMO Kennislink. Photo at the top of the article is by Constant Swinkels.