Your Biologically Diverse Home Garden: Why It Matters
A biologically diverse home garden has a positive impact on our water, our wildlife and our climate. Plus, it's fun to watch.
Just the other day, I saw this American nursery web spider on my purple coneflower.
This is the third growing season for this garden. Before that, it was a lawn.
In the first growing season, I don’t remember seeing any spiders. In the second growing season, I saw this vividly colored yellow garden spider.
I expect that this year, spiders will be a common occurrence.
I’m seeing an increase in biological diversity over the course of time.
In year one, I saw a hummingbird only three times all summer. In year two, I saw a hummingbird every single day for two months. This indicates increasing biological diversity over time.
Pictured below are fungi appearing in my home garden over the last two months.
I’m noticing an increasing diversity of fungi over the course of time.
Two questions: Why is biological diversity a good thing? And how do you build it?
Why is biological diversity a good thing?
Biological diversity represents a high functioning ecosystem, with a high number of species, each performing unique functions.
A biologically diverse ecosystem is resilient in the face of hot and cold, wet and dry, pests and pathogens.
A biologically diverse ecosystem is more entertaining, with more daily surprises.
A biologically diverse ecosystem absorbs more carbon from the atmosphere and stores it in the ground.
A biologically diverse ecosystem tends to have more biomass, which is to say that where there is diversity of species, there tends to be a greater quantity (by weight) of living things in a given area.
A biologically diverse ecosystem absorbs more rainfall and holds onto it through the dry spells.
A biologically diverse ecosystem will hold onto the water and gradually release it into the streams and waterways. Water that gets released gradually and gently is cleaner and less polluted.
A biologically diverse ecosystem will include a diversity of plants, all of which cast shade and transpire water, creating a cooling effect.
If you can make your home garden a more biologically diverse ecosystem, then it will be good for the outside world, including the water, the wildlife, the soil and the climate.
How is a biologically diverse garden good for the CLIMATE?
A biologically diverse garden is good for the climate because it absorbs carbon.
More precisely, when a garden is growing in biological diversity it is constantly absorbing carbon. The reason is that all living things are made of largely of carbon. By weight, we are mostly water, and then carbon comes second. We are made of carbohydrates, proteins and fats, all of which consist of carbon.
Plants take carbon dioxide from the atmosphere and use it to make carbohydrates, proteins and fats. Meanwhile, they exude some of these compounds out of their roots, attracting bacteria, fungi and other microbes.
As this system grows, CARBON moves from the air into the plants and soil.
Conversely, an ecosystem that is being degraded tends to move carbon into the atmosphere.
A biologically diverse garden captures rainfall and holds onto that water, which then evaporates, creating a cooling effect.
This has a positive effect on your climate, locally and otherwise.
Here’s how that works.
The presence of water makes plants grow. Plants then transpire (perspire) water. This means they push water out through their leaves. This creates a cooling effect. Evaporating water has a cooling effect. I call this evaporative cooling. It’s like when you step out of the shower or the swimming pool. You feel cold because evaporating water has that effect.
Every liter (about a quart) of water that evaporates requires 590 kilocalories of energy. In other words, it takes a measurable amount of energy and converts it from sensible heat (heat you can feel) to latent heat, which means hidden heat, heat that you cannot feel.
According to the US Forest Service, a medium sized tree transpires about 11,000 gallons of water per year. By my calculations, that’s about 50 gallons or 200 liters per day during the warm season.
This is why you feel cool when you walk into the forest or under a shade tree. It’s not just the shade. It’s the cooling effect of evaporating water.
A biologically diverse garden, like a forest, has a role to play in every stage of the water cycle, including evaporation, condensation, cloud formation and precipitation.
As noted above, your garden causes water to evaporate, thus contributing to the next rainfall.
Your garden plays a role in making condensation possible, because as plants exude water, they also exude bacteria and organic compounds that make condensation possible, because water can only condense if it has a solid to cling to. Bacteria and organic compounds—emitted by plants—serve this role, by giving the water something to cling to.
By causing condensation, your garden plays some role—if a small one—in cloud formation.
And then your garden plays an important role in creating a cool, moist environment which mitigates the urban heat island, making it more likely that a raindrop might reach the ground without evaporating.
So, given that a biologically diverse garden provides all these benefits, how do we make this happen?
That will be the subject of the next article.
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If you enjoy this content, I invite you to join me in my upcoming course: Healing Our Land & Our Climate. Click here to learn more.
What if addressing climate change starts in your own backyard, in your home landscape? What if this work is at least as important as reducing your emissions or your carbon footprint?
What if we could drawdown carbon dioxide rapidly by healing our land, first?
What if, in addition, to drawing down carbon dioxide, we could cool our climate with plants, as described above? And what if this is one of the most neglected strategies for dealing with climate change?
Many of us think just that. Many of us think that the climate conversation is dysfunctional because of the obsessive focus on carbon dioxide.
And then one might reasonably ask whether the people obsessed with carbon dioxide have a plan for dealing with it. Will solar power, wind power and electric vehicles really make a big difference? Some of us have our doubts.
That’s the kind of thing we’ll talk about in Healing Our Land & Our Climate.
It starts on July 9, but we have a free webinar coming up on June 25.