Emerald bracelets to solve three of the world’s biggest environmental problems

Rabbit in a cloverleaf on natural grass in Somerville, Photo: R. Moir

Three of the world’s biggest environmental problems are increasingly being encountered and mitigated in residential neighborhoods across Massachusetts. The dastardly trio is nutrient pollution that causes harmful algal blooms (ocean dead zones), degradation and loss of natural places (habitat loss), and climate change (global warming). Imagine a car with a flat tire, a broken battery and no spark plugs. Solving the most obvious problem or two won’t get us very far down the road. The solution is to fix all three at once.

Fortunately, there are cost-effective nature-based solutions, because plants don’t charge for the labor of sucking up water and carbon dioxide, using solar energy, and photosynthesising carbohydrates that become plant fibers. and black carbon.

The plants open their stomata to release water vapor which evaporates and cools the microclimate during the hottest hours of the day, while in the cold of dawn the plants open their stomata again to release water. water vapor that condenses into dew to warm the microclimate. Plant actions mean a little less uncomfortable conditions for all of us. Having more plants in the ground, in pots or on the roof is a nature-based solution.

Of all those in the plant kingdom, it is the grasses: salt marsh grasses, eelgrass, turtle grasses, prairie grasses and even lawn grasses that reign supreme in extracting carbon dioxide from the environment. air and store it in the ground.

Grasses pump about 50% of the carbon into the soil as carbohydrates. In Massachusetts, a natural residential lawn can make one inch of soil in a year, and four inches of soil will hold seven inches of rainwater to better protect our homes from extreme weather. One ton of carbon in the soil is the result of plants extracting eight tons of carbon dioxide from the atmosphere (about half for plant fiber and about half for soil).

That is, unless we know with nature spreading fertilizer or the worst chemicals on lawns. With the nutrients at the top, the base takes the easy route by staying on the surface where the nutrients are. The roots do not penetrate the soil to associate with fungi and bacteria. Surface roots cause plants to spread out with patches of soil between them. These plagues, where the ground cooks, compacts and dies, we call them “solar spills”. Here, only the toughest weeds will grow. Meanwhile, wimp grass, which turns green quickly, lacks soil nutrients and chews pests easily.

We blame lawns for needing lots of water when the fault lies with exposed thirsty roots. Lawns are also accused of polluting and causing harmful algal blooms. No surprise, the culprit is us spreading fast-release fertilizers. Meanwhile, the lawns of Falmouth have not been fertilized for eight years and are only green like the neighboring towns which are generously sprawl. We pay to pollute, while communities with closed beaches curse the lawns that stretch to the water’s edge.

Without any fertilizer, the grass grows deep, opens up the ground and merges with the mycorrhizal fungi. It is difficult to tell where the plant ends and the fungus begins because the mycorrhizal strands penetrate the plant touching every cell. Walking on grass stimulates the plant to repair itself and grow. Plant cells signal, probably via enzymes, what they need in the fungal network, the “Wood Wide Web”.

Bacteria specialized in various substances, including fixed nitrogen (created without the high consumption of fossil fuels), pick up the message and put the requested ingredients back on the web. Bacteria can freely exchange genes to create new enzymes which are also made available to plants. The reported request of one plant benefits all plants. And so, walking on grass further stimulates the uptake of carbon from the soil.

Sixteen lawns established in Springfield were observed for wildflowers and bees. The lawns have not been watered, as the bees do not like to be bombarded with droplets. The lawns received no fertilizers, pesticides or herbicides. A third of the lawns were mowed weekly, a third every two weeks and a third every three weeks. Grass clippings were left on the lawn. Nestled between the blades of grass, the lawns had 36 species of plants (clover, sorrel, horseweed, etc.). Lawns cut every three weeks were found with 64 species of bees. The lawns cut every two weeks had 96 species of bees! Apparently the bees prefer shorter grass than lawns cut every three weeks.

Nitrogen, phosphorus and carbon cycles are accelerated by the work of soil organisms, including worms, microbes, archaea, springtails, nematodes, rotifers and tardigrades. Carbohydrates and minerals in the soil are chemically transformed into humus, a nutrient-rich substance that holds water and takes thousands of years to break down. Thus, healthy soils are seen as long-term carbon storage silos. Decaying wood from forests over hundreds of years is a relatively short-term store of carbon – we need both.

We can keep lawns from polluting our waterways and stop the runoff of nutrients that cause harmful algae blooms by not applying quick-release fertilizers. The need for pesticides and herbicides is absent for lawns with healthy soils. We can reduce global environmental issues while enjoying our lawns and further driving carbon reduction.

Boston’s Emerald Necklace is made up of 1,100 acres of greenery connected by boardwalks and waterways. We have opportunities and options with over 2,000 square miles of residential lawns in Massachusetts. When lawns are not fertilized with a quick-release fertilizer, not watered and cut every two weeks, lawns become wild lands that also offer us refuge from the hustle and bustle of city life.

Natural grasslands provide forage to a wide variety of wildlife, especially bees. Connected between neighborhoods, natural lawns provide wildlife corridors connecting larger parks to green spaces with healthy soils – good for the yard, good for wildlife, good for mitigating climate change, and better for people’s health.

Dr. Rob Moir is a nationally recognized and award-winning conservationist. He is President and Executive Director of the Cambridge-based Ocean River Institute, a not-for-profit organization providing expertise, services, resources and information not available at a localized level to support the efforts of environmental organizations. Please visit www.oceanriver.org for more information.

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