It’s that time of year again for me and many others who suffer from hay fever. Spring is in the air, literally. Trees are flowering, grasses are growing and pollen hangs as an invisible dust in the sky. What if plummeting global insect and herbivore numbers are contributing to the huge excess of pollen? When it comes to animal impactWhat is Animal Impact? Without wildlife, Earth would not be habitable for humans, because it's animals that stabilise ecosystems. It’s a fundamental law of nature that animals (and humans) exist because we are the most likely lifeforms to minimise environmental chaos. Animal impact, therefore, is a measure of how much all wildlife is collectively responsible for creating a habitable Earth. The More, we are well aware of the role of insects in pollination. A Google Scholar search for ‘pollination’ reveals 724,000 references. What we hardly talk about though, is the role of pollen in ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More, particularly its consumption by animals. There is a word for this ‘palynivory’. Google Scholar only has 51 references and 112 for ‘palynivore’. Is it too much to imagine that a lack of animals might be contributing to this epidemic of suffering? I don’t think so. It’s extraordinary science hasn’t linked how to prevent hay fever and animal decline!
How to prevent hay fever and the decline of pollen-eating animals
There are two types of pollen-eating animals. There are the herbivores that graze on the grasses and trees that produce it, inadvertently consuming pollen and depositing it back onto the ground. Earth used to be covered in grassy woodland where abundant herbivores would maintain a closely-cropped grass sward. Rye grass was relatively uncommon and pollen would quickly be absorbed into the carbon cycle. These days, most unused grassland flowers uncontrollably.
Let’s recycle the important statistics on animal decline that I repeat ad nauseum.
- Almost seventy per cent of all wild animals on Earth have disappeared in the last 50 years, including most of the ground herbivores that would once have grazed on grasslands.
- Insect populations are in global free fall through the use of insecticides, herbicides and other poisons, as well as light pollution. Almost 50% of beetles, bees and grasshoppers have disappeared in just 10 years.
- Climate change is increasing the length of the growing season world wide, so Earth’s vegetation cover today, is greater than it was a few decades ago. A warmer, damper Earth promotes more growth.
Now let’s take a look at the role of pollen-eaters and how restoring animal populations could reduce the interminable allergies and how to prevent hay fever for its sufferers.
What insects eat pollen and help prevent hay fever?
The short answer is, most of them. And it’s something that has been going on since flowering plants evolved about 130 million years ago. Research has found ancient evidence of pollen consumption by flying insects, springtails and mites and the bee fossil record, while poor, dates their evolution at about the same time.
While microscopic consumption might not seem significant, the average density of springtails in soil can be as many as 8,000 per square metre. These tiny animals are incredibly diverse and important for soil function(Of an ecosystem). A subset of ecosystem processes and structures, where the ecosystem does something that provides an ecosystem service of value to people. More. They are also uniquely adapted to digest chemicals in pollen that can’t be digested by most other animals and insects. Scale their impact up to all the world’s soils and then consider that springtails eat a lot of pollen, and you have an important ecosystem processThe chains and cycles by which energy flows through an ecosystem. Processes can include the amplification or recycling of nutrients, storage of carbon, decomposition and any number of other systems that maintain ecosystem stability. More.
Springtails
Check out this amazing web page about springtails by Andy Murray.
Springtails, officially known as Collembola, are a small and common invertebrate. Read more
It’s not just the microscopic invertebrates though. Ants eat pollen too, possibly far more than we imagine. One of the critical roles ants play is in burying waste underground and they are among the most widespread, abundant and diverse groups of insect on Earth. Their effect on soils is enhanced in the presence of large herbivores, that create necessary structure and nutrition. They are delivering the spent pollen to the springtails, fungi and other soil fauna and flora.
Bees of course, consume it on an epic scale, with the average honey bee colony consuming 40 kilos a year. Spiders even supplement their diet with it. Pollen can even be the entire diet of some grasshoppers and most beetles eat pollen too. There are even beetle pollen diet specialists.
In short, pollen is consumed on a vast scale by invertebrates because it is really protein-rich. It is, after all, one half of what’s needed to create new life.
How much pollen is produced globally?
Plants, like animals, produce a vast excess of male gametes. That’s all pollen is – plant sperm. Plants produce millions of tonnes of pollen every year which can be swept around the Earth. Pollen was a significant component of a storm in Northern Europe in 1991 that deposited 50,000 tonnes of material, each square centimetre containing up to 1,170 pollen grains … enough to turn snow yellow.
‘This impact that pollen has on plants, animals, and man is the direct consequence of its mass production’.
Linskens, 1992. Mature Pollen and its impact on plant and man.
Pollen has even found to be an important food source for the ocean. The pollen from pine trees dominates deep ocean trench sediment off New Zealand. It’s extraordinary enough that pine pollen is so abundant, when plantations have only been around since European settlement. It’s even more surprising to think that pollen could be an important source of food for animals in the deepest ocean!
To give you a better idea. Alder trees in a single street are capable of producing tonnes of pollen. One hectare of pumpkins can produce 160kg of pollen. Linksens (1992) quotes various studies. The lifetime pollen production of a single beech tree has been estimated at 20.5 billion pollen grains … another study estimated 12.8 billion grains per square metre of mixed vegetation. In 1969, 8.8 – 16.2 pollen grains per square millimetre of air were estimated every 24 hours, 50 km off the coast.
The quantity really defies explanation. What you’re beginning to understand, hopefully, is that pollen production is absolutely vast! When it comes to natural particulates, pollen is one of the main constituents of air that enters your lungs when you breathe. Dogs, cats, horses and other animals can also get hay fever just like us.
What happens when insects and herbivores go extinct?
When you have something microscopic produced in excess, it doesn’t take much to cause a problem. For example, the Crown-of-Thorns Starfish produces hundreds of millions of eggs. Remove a few predatory snails and add a bit of extra nutrientEnergy and nutrients are the same thing. Plants capture energy from the Sun and store it in chemicals, via the process of photosynthesis. The excess greenery and waste that plants create, contain chemicals that animals can eat, in order to build their own bodies and reproduce. When a chemical is used this way, we call it a nutrient. As we More in the water, you suddenly have an infestation that can kill whole coral reefs.
Remove ground herbivores and insects, you create the perfect gap-in-the-market for the most highly virile plants to breed on previously wildlife-rich grassland. Bright yellow oil seed rape fields are notorious pollen producers. We spray nasty insecticide all over them, to kill pollen beetles. Very quickly, there is nowhere for the excess pollen to go but into your lungs. How to prevent hay fever and animal decline are linked.
Just like with other socio-ecological problems, we tend to jump to climate change as the explanation. Sure, warming climate is a contributor but if we weren’t destroying ecosystems and over-consuming fossil fuels, we wouldn’t have that problem. No-one, as far as I can tell, is looking at the effect of declining animal abundance. Yet again, the impact of animals in maintaining habitable ecosystems for humans (another animal) is the last thing we seem to consider.
Plants breathe carbon dioxide and need warmth for photosynthesisMeaning how plants extract energy by absorbing water and using radiation from the Sun to combine it with carbon dioxide to create sugars. More. As I have described earlier, plants are a destabilising factor for animal survival and represent a threat to our future, if we allow things to get out of control. We cannot live without other animals.
Science hasn’t linked how to prevent hay fever and animal decline. If there are any students reading this, here is a very simple honours or masters project. You’re welcome : )
