While dead trees don’t provide the same benefits as live ones, they still perform several important services.
First, a dead tree continues to sequester carbon. When a dead tree is cut down and fed into a wood chipper, the carbon that it stored over decades is rapidly released into the atmosphere, where it contributes to global warming. Left in place, the tree will slowly release its carbon to the soil, another safe storage location.
Dead trees also serve as important habitat elements. Some species, like woodpeckers, require standing dead trees to complete their life cycles. When dead trees are removed from suburban yards and even from relatively-wild parks, these species suffer.
Dead trees are not a significant hazard. In a year, about 30 Americans – or one in ten million – are killed by falling trees or branches. This is equal to the number of Americans who are killed when their own furniture falls on them, and would be lower if not for the very high rate of fatal accidents among people who cut down trees for a living.
Several species of ash trees are native to the United States. Almost a quarter of street trees in Madison are ashes, because the city planted so many after Dutch Elm Disease decimated our urban forest. Now, the city plans to pre-emptively destroy many of the ash trees because they might become infected by emerald ash borer.
Emerald ash borer (EAB) is an invasive insect that lays its eggs in ash trees. In its native range EAB does not harm ash trees, but in the United States ashes are sometimes killed by the actions of the insect’s larvae.
EAB is naturally very slow-moving, but its dispersal has been sped up by the transport of infected firewood. It was first found in Madison in November 2013. It lives in all species of true ash trees, but not in mountain ashes.
Like all trees, ashes provide many benefits to people. There are many effective treatments against EAB, including trap, decoy, barrier, and chemical techniques, that seek to eliminate harmful invasive insects, rather than beneficial native trees. A Facebook group has been created to protest Madison’s decision to destroy healthy trees rather than protecting them against the chance of infection.
Ash trees in yards can be given an opportunity to fight off infection on their own, or may be helped out through one or more treatment methods. They are not doomed to die and become hazards, as some sources would have you believe.
When a homeowner goes out to mow their lawn on a Sunday afternoon, they probably aren’t thinking about climate change. Once the connection is pointed out, however, it isn’t hard to see.
All gas-powered equipment, including lawnmowers, contributes to climate change by consuming fossil fuels and producing greenhouse gases. While yard equipment may be small, it doesn’t have to meet the same standards as bigger equipment, like cars. This means that it often emits a surprising amount of carbon and other pollutants.
How lawnmowers stack up to cars depends on how the test is run, but as an example, this test concluded that a leafblower idling for eight minutes produces more carbon emissions than an SUV being driven 200 miles.
While drivers are typically insulated from their car’s emissions, a person using yard equipment is directly exposed to the emissions being produced. This page describes the contents of those emissions, and their effects on health and climate.
Lastly, while cars put greenhouse gases into the air, lawnmowers also reduce the ability of vegetation to reabsorb and sequester those gases. As described in this post, turf grass can’t provide enough air-cleaning services to offset the emissions produced by its own maintenance.
Greenhouse gas emissions and vegetation loss are the two main drivers of climate change. Turf grass contributes to both of them.
It’s probably being used as sheet mulch.
What is sheet mulch?
Any place where a gardener might want to put some new plants is probably already occupied by other plants. There are several ways to get rid of old plants in order to make room for new ones. For example:
Digging. Old plants can be dug up, creating a space of bare soil. This is a lot of work!
Poisoning. Old plants can be killed by spraying herbicide. This exposes the gardener to toxic chemicals.
Smothering. Also known as sheet mulching, this involves placing an opaque cover over the old plants, depriving them of the sunlight they need to survive. Though this method can take a long time to kill the plants underneath, it is very easy to do.
How is sheet mulching done?
While sheet mulching can be accomplished using landscape fabric or black plastic, natural gardeners usually prefer to use organic materials like cardboard, newspaper, carpet, or even old pairs of blue jeans. These materials are laid over the planting area, making sure to fully cover the plants underneath, and overlapping the edges of the materials to prevent plants from growing up through the cracks.
Soil or a loose mulch is then placed over the top, as a medium for the new plants to grow in. Organic sheet mulch will gradually decompose, along with the buried plants, creating more soil for the new plants to use. Once the new plants are established, it’s usually hard to tell there’s cardboard underneath them!
When someone needs to do a big lawn-mowing project, they buy a bigger lawnmower or hire a service. When someone needs to do a big natural yard project, they organize a group of friends to help.
Such a gathering is known as a work party. People go to them to learn more about natural yards, to “pay forward” help they received at a work party in their own yard, or simply to enjoy seeing a natural yard in the company of like-minded friends.
A work party can be called by naming a time and place, describing the type of work that will be done, and suggesting what tools or other items to bring. It’s best to have a well-defined project in mind – otherwise, everyone will bring their own opinion on what should be done and how to do it!
Invitations are generally open and RSVPs are not required. All who are willing to pitch in are welcome to attend.
Sitting on a lawnmower is easy, concedes Dr. Doug Tallamy, author of several books on natural landscaping. Converting a lawn to a natural yard, on the other hand, is a major project.
Homeowners with the means to do so can accomplish much of the conversion in a short amount of time by hiring a professional landscaper. Others may choose to do the work themselves, gradually replacing turf with native plantings. Either way, the new plants will take time to become established and look like what the homeowner had in mind.
During that time, the homeowner will continue to work by clearing invasives that try to move in, replacing plants that fail with others of the same or a different species, watering plants to help them get established, and so on. This is a very different kind of work from regular mowing, so it’s hard to say whether the overall effort is more or less.
Once natural plantings are established, the work involved in maintaining them decreases. They become better at resisting invasives and typically need very little water. The yard develops into a largely self-sustaining ecosystem.
In the long run, natural yards can be less work!
Pesticides are chemicals formulated to kill living organisms. The suffix “-icide” means “to kill”.
Pesticides are divided into categories such as insecticides, fungicides, and herbicides. While a pesticide typically targets one or a few types of organisms, its effects are often not confined to the target. Some of the ingredients in pesticides are known to be human carcinogens, while many of the ingredients have not been tested for their human health effects.
For this reason, pesticides can be more dangerous than the organisms they’re meant to eliminate. Dandelions are harmless, and fewer than 1% of insects cause any trouble for people. In Madison, insect problems are rare enough that preemptive pesticide use is not warranted. If a problem does arise, ask a qualified entomologist for advice. Be wary of asking an exterminator – remember that they have a financial incentive to exaggerate the problem.
If you do choose to use pesticides, read the label carefully and follow the instructions exactly. Using a pesticide in any other way is a violation of federal law.