Alien Plants Benefit the Environment

A native Eastern Tent Caterpillar feeding upon an alien Multiflora Rose shrub in Albemarle County, Virginia.

ALL TEXT AND PHOTOS © Marlene A. Condon

 Originally published in The News-Virginian (Waynesboro, Virginia daily newspaper) on October 27, 2022

 

https://newsvirginian.com/opinion/columnists/condon-many-alien-plants-benefit-the-environment/article_5d18e73c-557c-11ed-8f02-8375034e2011.html

 

On June 8, 2011, the journal Nature published a commentary by 19 ecologists who urged conservationists to “assess organisms on environmental impact rather than on whether they are natives”.

 

https://www.nature.com/articles/474153a

 

“Classifying biota [the plants and animals of a region] according to their adherence to cultural standards of belonging, citizenship, fair play and morality does not advance our understanding of ecology [the relations of organisms to one another and to their physical surroundings]. Over the past few decades, this perspective has led many conservation and restoration efforts down paths that make little ecological or economic sense”.

 

This other side to the story regarding alien species—in particular, nonnative “invasive” plants—is rarely publicized, yet it needs to be. It’s been eleven years since this essay appeared and was ignored by virtually everyone. As a result, the general public, government at every level, scientists, the media, and especially environmental groups and the people that support them have now instituted a scorched-earth policy that’s bringing about much destruction of viable habitat and the poisoning of our environment via herbicides.

 

Many people fervently believe that so-called invasive alien plants pose a dire threat to native insects, undoubtedly due to the 2007 book, Bringing Nature Home, by entomologist Doug Tallamy. In it, he wrote that “scientists who know what they are talking about” developed “an extensive body of theory” that predicts that native plant-eating insects “should be able to eat only vegetation from plants with which they share an evolutionary history”.

 

This assertion, which holds that herbivorous insects eat only those plants they have co-evolved with under the same environmental circumstances, sounds logical to the uninitiated. However, it disintegrates under scrutiny.

 

Dr. Tallamy tells us that these 6-legged critters that feed upon plant tissues are limited to feeding upon “no more than a few plant lineages [a single line of genetic descent through time]”, thus making them “specialists”. However, each plant lineage can include hundreds, if not thousands, of species around the world—which means an insect is likely to be able to feed upon at least some of the plants that are related genetically, regardless of their country (geopolitical boundary) of origin.

 

In other words, specialist insects aren’t usually limited to just one plant species, contrary to what this University of Delaware professor would have his readers believe. Because we know that countries share plant lineages (and even some species), phytophagous (herbivorous) insects should be able to eat vegetation from other areas on the Earth even though they evolved in concert with only some of the plant species in a lineage—and, indeed, they do.

 

In Bringing Nature Home, Doug Tallamy recounts the plight of native Eastern Tent caterpillars (Malacosoma americanum) that ran out of cherry leaves on a tree too small to feed them adequately. He mentions that leaves were still available to the caterpillars in the form of a Japanese Honeysuckle vine (Lonicera japonica) that had climbed the little tree, but he points out that the caterpillars “had not taken a single bite out of the alien plant…even in the face of starvation”.

 

This tale gives the reader the impression that the caterpillars could have eaten the honeysuckle if only it had been native, thereby having evolved with the insect. He does not point out that the caterpillars would have faced starvation even in the presence of a native vine, tree, or shrub if—like the alien honeysuckle—it wasn’t a member of the Rose Family, as is this caterpillar’s preferred native host plant, the cherry.

 

Several native Eastern Tent caterpillars feeding upon an alien Multiflora Rose shrub in Albemarle County, Virginia.

I have documented myself tent caterpillars feeding on a relative of the cherry—a nonnative, unevolved with, and much despised Multiflora Rose (Rosa multiflora) growing at the base of a leaf-stripped Black Cherry tree (Prunus serotina).  A factuality is that you can find native insects feeding upon nonnative plants, but, of course, you need to look!

 

People have been manipulated into believing alien plants serve no ecological purposes in the environment, when, in fact, they very much do, in very many ways, for innumerable insect (and other) species. As the 19 ecologists wrote in their paper, “[A] valuable step would be for scientists and professionals in conservation to convey to the public that many alien species are useful”, and that “Natural resource agencies and organizations should base their management plans on sound empirical evidence and not on unfounded claims of harm caused by nonnatives.”

 

Amen.

 

 

NATURE ADVICE:

 

Don’t remove alien plants just because they are alien plants. If you see critters using them, ask yourself if putting in new plants will immediately provide as much food and shelter/nesting sites as the nonnative plants presently there, or will it take many years for the new plants to provide habitat. Plant natives where you are increasing the amount of habitat on your property, rather than where you are destroying it.

Non-native Trees May Help the Environment

Enlargement of photo below of leaf-footed bug 

 Native leaf-footed bugs, closely tied to ash trees that are being pesticided against Emerald Ash Borer, will be killed along with the alien borers. We should be keeping nonnative Princess Trees to help our leaf-footed bugs to survive.

ALL TEXT AND PHOTOS © Marlene A. Condon

 Originally published in The Daily Progress (Charlottesville, Virginia) on August 24, 2022

 

One day I observed fresh stumps of Paulownia tomentosa (commonly known as Princess Tree) along a roadway. I knew why the trees had been cut down: they’re from Asia. Current dogma (a set of beliefs people are expected to accept without any doubts, and which they normally do accept without question because of peer pressure) insists these trees be gotten rid of because they’re not native to the United States.

 

I had observed these specific trees for many years. In spring, the lovely large bell-shaped lilac flowers had fed numerous pollinators, the first group of insects to be recognized as disappearing from our world—due largely to habitat loss.

 

The alien Princess Trees had allowed pollinators to find food where none would otherwise be forthcoming because lawn comprised the landscape to one side of the trees and a river flowed past them on their other side.

 

Additionally, American Goldfinches and other seed-eating birds were aided by the fertilization of the Paulownia flowers that then produced pods of tiny seeds that fed them during the harsh cold days of winter. And native sap-sucking leaf-footed bugs (taxonomically classified as Family Coreidae) are found regularly (singly and in mating pairs) on Paulownia.

 

Now, however, the impacted area won’t provide food for any of these animals. In a world of dwindling insect and bird populations due to habitat replacement by development, it’s not helpful to further reduce habitat by removing wildlife-friendly plants along a somewhat wild waterway.

 

Habitat basically refers to the array of physical and biological resources in an area that allows the survival and reproduction of a variety of species. If numerous kinds of critters are surviving and reproducing well somewhere, then the area meets the definition of habitat.

 

Only a confused environmentalist could insist upon getting rid of certain plants simply because they are non-native and don’t always feed native leaf-eating insects (such as caterpillars)—the main reason for the push these days to rid the environment of alien plants.

 

People don’t realize that the natural world must meet the needs of all kinds of critters, not just this subset of arthropods. When government officials and environmentalists are swayed by such limited and unsound thinking, much harm befalls numerous species of wildlife.

 

For example, as I walk along roadways in winter lined with Japanese Stiltgrass (Microstegium vimineum), I invariably see dozens of migratory Dark-eyed Juncos and White-throated Sparrows feeding upon the seeds of this foreign species that readily grows where the soil has been compacted by years of highway-department mowing.

 

Knowing these birds would be affected, I was saddened one late-summer day to see an area of stiltgrass pesticided along someone’s property. The landowner’s concern about this much-despised alien species resulted in needlessly adding poison to the environment: Stiltgrass can be controlled, if desired, by mowing it in late summer before the flowers go to seed.

 

Sixty years ago, employing pesticides was anathema to environmentalists after author Rachel Carson pleaded for folks to prevent a silent spring, devoid of birdsong. Nowadays, however, much government money is being spent to rid the natural world of plants quite helpful to wildlife because of the erroneous environmental narrative that pesticides and bare ground are less harmful than alien plants.

 

However, our wildlife needs food and shelter now, not tomorrow. Native plants put into the ground today will take years to develop into a functioning ecosystem.

 

Without critical reasoning, better judgement, and making the effort to study the merits of alien plants, we will continue our scorched-earth policy and all manner of wildlife will simply continue to disappear—something we simply can no longer afford.

 

 

NATURE ADVICE:

 

Before buying into the pervasive myth that alien plants are useless to wildlife, take time to observe them. You will probably be surprised by what you discover.

 

Time to See the Light Regarding Loss of Insects and Birds

This Christiansburg, Virginia, plaza could be planted with native trees and still not support caterpillars, thanks to the excessive lighting that is a prime killer of moths.

Plenty of native trees exist in the eastern United States to support moth caterpillars, but when moths spend the night circling artificial lights—such as the street lamps seen here among an abundance of large native trees—they die without reproducing.

ALL TEXT AND PHOTOS © Marlene A. Condon

Originally published in The News-Virginian (Waynesboro, Virginia) on July 16, 2022

https://newsvirginian.com/opinion/columnists/condon-time-to-see-the-light-regarding-loss-of-insects-and-birds/article_6d0f3322-03eb-11ed-8317-53ceb5edb5ab.html#tracking-source=home-top-story

On summer nights, when I was a child, my mother would scream at us kids to quickly get into the house before all the insects (mainly moths) circling our carport light had a chance to come inside with us. Nowadays, I can put on my own carport light with hardly any insects—certainly not moths—coming to it.

The reigning assumption regarding the loss of insects and birds (derived from research published in 2017, “Native plants improve breeding and foraging habitat for an insectivorous bird”,

 

https://www.sciencedirect.com/science/article/abs/pii/S0006320717305153)

 

is that the most crucial step people can take to save the environment is to grow native plants. But is this theory truly the environmental panacea for our time?

 

Bringing Nature Home by Doug Tallamy also stressed the importance of growing native, rather than nonnative, plants. In this book, the author showed a nighttime image of the United States aglow with lights [page 28, 2007 advance reading copy]. He captioned it, “A composite image from space of the United States at night shows the extent to which we have converted natural areas [i.e., native plants] to developed landscapes [i.e., alien plants]”.

 

True enough. However, the more ominous takeaway is the dire effect of all those lights upon insects, especially the moths whose caterpillars have always been essential to birds raising their young. These larvae are now largely gone because adults are largely gone. Moths that circle lights all night until they are exhausted, or where they are easily caught by predators (such as bats and owls), are moths that don’t reproduce.

 

Why am I so sure that lights are the problem rather than a decrease in the number of native plants? I’ve lived in my home for more than 36 years. My yard has always been surrounded by mature oak forest, and I’ve watched through the decades the trees growing so tall that I can no longer view the Blue Ridge Mountains only a few miles to the west.

 

Nevertheless, despite the ever-increasing woody mass of native trees and shrubs around me, the numbers and kinds of insects and birds have decreased in my yard, just as they have elsewhere. I’ve never employed pesticides on my property, and I have gardened in full agreement with Mother Nature (hence my 2006 book on this subject).

 

The argument that there’s not enough native woody plants doesn’t work here because mature forests have comprised a substantial percentage of my property as well as the surrounding area. In fact, this idea doesn’t apply to much of the eastern United States.

 

Travel in a plane between New England and the South or fly in a hot-air balloon over your local area, and—unless you live in the concrete jungle of a city—you are going to observe plenty of large native trees in yards, parks, and “natural” (i.e., managed) areas.

 

In 2017, German researchers made world-wide headlines with their paper published in the journal, Nature, in which they detailed their own discovery of insects disappearing. Many suggestions have been put forth for the loss, including such things as pesticides (over 1 billion pounds a year are deployed in the United States, https://www.brownfieldsummit.com/how-many-pesticides-are-used-in-the-us) and loss of natural habitat due to development.

 

None of these considerations explains the loss of insects on my property over the course of almost four decades. A more plausible explanation is the ever-increasing number of lights needlessly burning all night around homes, churches, schools, libraries, businesses, barns, vineyards, American flags, and in parking lots and even national parks. Indeed, despite living in a rural area, it’s now difficult for me to view the Milky Way, thanks to light pollution.

 

Light constitutes an insidious menace because its allure to insects is so strong and its effect upon them so deadly, while people are oblivious to its ramifications. There’s no harm in growing more native plants, but this action is not going to prevent the loss of more insects.

 

If you truly want to help our insects and birds, you need to shut off lights burning all night, every night, for no good reason. Then we might see a light at the end of the tunnel for saving what’s left of our insects and the birds dependent upon them.

NATURE ADVICE:

 

In addition to limiting the amount of time you leave exterior lights burning after dark, you should take into account the amount of light exiting your windows. This light also attracts insects and keeps them “glued” to windowpanes instead of reproducing. To prevent light from escaping your windows, please use curtains or blinds.

 

And please keep in mind that lighted yard decorations also contribute to the loss of insects.

 

 

Bradford Pear—Nativists Making A Big Stink about Nothing

This huge Bradford Pear has obviously grown for decades in this Albemarle County, Virginia, yard. If its spring blossoms were truly as “bad-smelling” as virtually every nativist-written article declares, you can bet it would have been long since removed.

ALL TEXT AND PHOTOS © Marlene A. Condon

According to the “fact” sheet (much of the information is inaccurate or misleading) of the Blue Ridge Prism (“a volunteer-driven organization dedicated to reducing the negative impact of invasive plants in the northern Blue Ridge Mountains of Virginia”), the Bradford Pear (Pyrus calleryana) is “a scourge upon the agricultural and natural world.”

 

https://blueridgeprism.org/wp-content/uploads/2021/09/Bradford-Pear-Factsheet-2021-9-9-v1-FINAL.pdf

 

The reason given in support of this statement is that it “quickly spread[s] and replace[s] desirable plants in invaded areas.” However, the proclamation that alien plants “replace” or “push out” native plants is misleading.

 

For example, I regularly walk along a section of nearby road where I’ve been watching the spread of Burning Bush (Euonymus alatus) for the past 36 years.

 

 

What I’ve observed with these plants (and all the alien plants I’ve taken photos of over the course of decades) is that they germinate in spots where there is nothing else occupying that site. Indeed, physics tells us this must be the case as no two physical objects can occupy the same space simultaneously.

 

Thus, so-called invasive plants usually start life where there is an empty site for them to grow. The only way they can spread is if there’s plenty of barren land for them to fill, as often happens with Autumn Olive (Elaeagnus umbellata) growing in worn-out (devoid of nitrogen from years of use) farm fields.

 

The only way any plant can “replace” another plant is if its growth habit over the course of years provides it with some advantage that other plants vying for the space don’t possess. But! The erroneous assumption always made by nativists is that native-plant species were growing in that field prior to the arrival of the Autumn Olive and they were outcompeted, which simply isn’t true. Very few native plants can survive in poor soil, and the ones that do—mainly Virginia Red-cedar (Juniperus virginiana), Broomsedge (Andropogon virginicus), and Virginia Pine (Pinus virginiana) where I live—often join Autumn Olive in such areas.

 

It’s a truism that anywhere you see lots of nonnative plants growing, you can bet the soil has been disturbed and is not conducive to the growth of native plants. If it were, indeed, capable of supporting such “desirable” plants (a prejudiced judgement on the part of the PRISM writer), you can trust there would be native plants growing there.

 

So why are some people making such a big stink about Bradford Pear trees? Well, according to nativists, these tree blossoms do literally stink, and you shouldn’t plant them.

 

The PRISM “fact” sheet calls them “malodorous” and “bad-smelling”, and suggests “the flowers give off a stink reminiscent of unwashed gym socks.” Other writers suggest a much worse odor. A Raleigh, North Carolina News & Observer newspaper writer wrote, “Their stench has been compared to rotting fish, urine and other pungent bodily fluids.”

 

https://www.newsobserver.com/news/local/article259195743.html#storylink=cpythem

 

Yet the dishonesty of all these descriptions is easy to discern. Do you really think anyone would leave these trees standing in their yards if they smelled as bad as suggested above? Of course not. These trees can be viewed in an abundance of yards, and their size tells you they’ve been growing there for numerous years. One can only conclude the owners don’t have a problem with these early spring-blooming floriferous trees.

 

I can provide an especially telling example to illustrate that people who suggest Bradford Pears stink are either not familiar with them, or they are deliberately spreading disinformation to try to keep people from buying/planting them.

 

I have taken the same road to Charlottesville, Virginia, for the past 36 years. In 1994, a humongous house was constructed on this road (5500 finished square feet comprises the house, and 1600 of 3400 square feet are finished in the basement). The owners had dozens of Bradford Pears planted; many went in along both sides of their long driveway right to the house, and quite a few were planted along the road to either side of their driveway.

 

These folks lived in their house until 2013, and they never removed the Bradford Pear trees, which they could have well afforded to do if they had to endure a stench every spring. Even the people who moved in when the house was almost twenty years old have kept the trees along both sides of the driveway for the past nine years. (They did eventually replace the ones along the road that were broken when severe winds [a possible tornado] went through the area.)

 

I can assure you that if these trees provided a foul stench every spring, either of the two different owners could have afforded to get all of them removed—after all, we are talking about people who can afford to live in a house valued at three million dollars.

 

So, if you have Bradford Pear trees on your property, should you get rid of them based upon the information provided by the PRISM writer or the newspaper writer? Absolutely not.

 

Either out of dishonesty or ignorance, the PRISM writer basically blames “starlings, an introduced species” for spreading these “weed trees across the built and natural landscape”. But several native species find survival assistance from the fruits of Bradford Pears. Flocks of American Robins and Cedar Waxwings, both of which depend upon fruits in winter, relish these fruits. Which is a better choice for the environment—keeping trees that provide for wildlife or pesticiding these trees and adding poison to our landscape?

 

Pay no heed to these folks who’ll say anything to manipulate you.

NATURE ADVICE:

 

The push for folks to remove so-called invasive plants is misguided because it’s extremely destructive of functioning habitat. It also makes much use of pesticides, which can kill animals as well as plants, including microorganisms within the soil. Lastly, the folks pushing this agenda do not really know why they are against these alien plants, other than that they believe we need more native plants. But their arguments do not pass muster.

 

It’s much better for our world to allow wildlife to call the shots. If nativists observed these alien plants with open minds, they would clearly see that our wildlife makes abundant use of “invasive” species. Mature plants—even if alien—provide habitat while bare ground does not. Even if young native species are planted where “invasives” are removed, it will be years before the area yields habitat.

 

It's bad enough our wildlife is losing ground to buildings and pavement covering the ground, as well as people’s ideas of what a created landscape should look like (mainly lawn). We don’t need people crazily demanding the removal of alien plants when they don’t have valid reasons for doing so.

 

 

 Panic and Pesticides: Response of Government and Environmental Groups to Arrival of Spotted Lanternfly

The Spotted Lanternfly is a strong jumper but a weak flyer. It therefore prefers to walk to get to where it’s going, as this insect was doing at a gas station in Pennsylvania in October 2021.

ALL TEXT AND PHOTOS © Marlene A. Condon

 

With the arrival in 2012 of the Spotted Lanternfly (a planthopper from Asia), government and environmental entities entered panic mode and began pushing everyone to get rid of the so-called invasive Tree of Heaven (Ailanthus altissima). The justification given for this action is that “Tree of Heaven is the preferred host of Spotted Lanternfly.”

 

https://nysipm.cornell.edu/environment/invasive-species-exotic-pests/spotted-lanternfly/spotted-lanternfly-ipm/hosts/

 

However, that statement is not quite true. According to a September 2021 article in Entomology Today, the Spotted Lanternfly (Lycorma delicatula), known for relying on the Tree of Heaven (Ailanthus altissima) “to fuel its rapid spread through the eastern United States, uses a wider-than-assumed range of host plants during its lifecycle”, as reported in Environmental Entomology.

https://academic.oup.com/ee/article/49/5/999/5892805

 

The writer tells us the two researchers of this study “found that 60 percent of plant types adult lanternflies used for feeding were also egg deposit sites.” And, "As the spotted lanternfly continues to increase its North American range, it will continue to encounter new host plants.”

 

https://entomologytoday.org/2020/09/10/list-known-host-plants-grows-invasive-spotted-lanternfly/

 

Therefore, getting people to destroy Tree of Heaven will simply send Spotted Lanternflies to lay eggs on a large variety of plant species we would probably prefer they not impact. In other words, government and environmental groups of every sort now need to employ critical thinking instead of sticking to the original knee-jerk reaction to destroy Ailanthus trees.

 

Unfortunately, due to the emotion that surrounds the entire “invasive-plant” issue, it’s likely that these insects will continue to be employed as an excuse to pressure people into wiping out a supposedly invasive plant.

(Please see, "The Plant Police Are Coming for You", In Defense of Nature, May 2021)

But consideration must be given to the negative environmental impacts of people using poisons to get rid of Tree of Heaven.

 

According to a web page of the Piedmont Master Gardeners of Charlottesville, VA (a group affiliated with the Virginia Cooperative Extension Service), the “Blue Ridge PRISM (Partnership for Invasive Species Management) warns that simply cutting Tree of Heaven to the ground is not enough to eradicate plants. The freshly cut stump must be treated with an herbicide...”

https://piedmontmastergardeners.org/now-is-the-time-to-tackle-tree-of-heaven/

Can you imagine the quantity of herbicides added to our environment if folks took seriously the mandate to get rid of all Ailanthus trees, a species that has become part and parcel of our natural world after more than two centuries here? In a direct rebuke of the icon of the environmental movement, Rachel Carson—who warned us about chemical use in her book Silent Spring—a majority of environmentalists have now bought into the idea that pesticides are virtually harmless. But they couldn’t be more wrong.

 

Studies are showing that microorganisms living within soil, where they perform vital roles in maintaining plant growth and health, can be negatively affected by herbicides. A “number of herbicides have an impact on soil microorganisms...especially on mycorrhiza [fungi that have a symbiotic relationship with the roots of many plants], bacteria and actinomycetes [a type of anerobic bacterium that shares a number of characteristics with fungi]”. Additionally, a “number of herbicides showed reduced population of these soil microorganisms with transient inhibition up to 7–10 days.”

 

https://www.researchgate.net/publication/345140580_Impact_of_Herbicide_Use_on_Soil_Microorganisms

 

Why people who profess to care about the environment would think plants, such as Ailanthus, pose more of a problem for our world than dousing the land with deadly chemicals is not something I can comprehend. After all, Ailanthus does serve wildlife (some species of birds and Gray Squirrels eat the seeds) and they grow in disturbed areas where conditions do not suit most native plants, thus providing habitat where there might otherwise be bare ground.

 

I also can’t understand why government and environmental entities panic every time a new insect species shows up here from elsewhere. We’ve been through this scenario repeatedly, yet we never learn that Mother Nature, given time, will eventually knock down the number of alien insects to a level we can—indeed, must—live with, by the far superior method of non-toxic predation.

 

Patience is a virtue, especially when considering the use of pesticides in a vain effort to eradicate a new six-legged visitor. But rather than wait, we spray the heck out of our environment in a panicked effort to reduce the numbers of these animals, killing all manner of unintended victims along with them (the collateral damage we can no longer afford because insect numbers are way down).

 

Just because we’ve invented pesticides does not mean we must use them, especially as they have never successfully eradicated nonnative insects. We still have Japanese Beetles, Gypsy Moths, Asian Ladybugs, Brown Marmorated Stinkbugs, Emerald Ash Borer...and we will continue to have the Spotted Lanternfly, no matter how much pesticide is brought to bear upon this situation.

 

Please, people, wake up to reality. Humans bring these unwanted insects to the United States, but humans can do nothing to get rid of them. This job is best left to the expert: Mother Nature.

  

NATURE ADVICE:

  

Please ignore the doomsayers and leave Ailanthus trees alone, unless you have a better reason than the Spotted Lanternfly for removing them.

 

Trees—including Ailanthus—provide perching sites for birds and a get-away for climbing animals trying to escape predators on the ground. In addition to Gray Squirrels, which I’ve personally observed feeding upon Tree of Heaven seeds, the Pine Grosbeak and White-winged Crossbill have been reported to feed on these seeds as well. And White-tailed Deer sometimes eat newer leaves.

 

www.illinoiswildflowers.info/trees/plants/tree_heaven.html

A Little Knowledge Is a Dangerous Thing 

A hot-air balloon ride over the Charlottesville, Virginia, area makes clear there are plenty of native trees in long-since-developed towns and the rural landscape that surrounds them.

A Tiger Swallowtail is just one of many kinds of pollinators that obtain nectar from an Autumn Olive (Elaeagnus umbellata) in the author’s yard.

NOTE TO READERS: Due to conditions over which I have no control, I will, of necessity, be posting to this blog only occasionally rather than once a month. If you wish to be notified of posts as they are published, please subscribe by entering your e-mail address in the box on this page. I would appreciate your continuing interest!

ALL TEXT AND PHOTOS © Marlene A. Condon

 

You may be familiar with the expression, “A little knowledge is a dangerous thing.” In other words, a limited amount of information fools people into thinking that they know more about a topic than they really do, leading to errors in their judgement.

 

The truth of this saying is currently evident in the popular response to what has been named the Sixth Mass Extinction. "Drastically increased rates of species extinctions and declining abundances of many animal and plant populations are well documented...", according to Robert Cowie, a research professor at the University of Hawaii Manoa Pacific Biosciences Research Center.

 

https://www.sciencedaily.com/releases/2022/01/220113194911.htm

 

Cowie and his co-authors recently published a study in which they estimated that since the year 1500, Earth could already have lost between 7.5 and 13% of the two million known species on Earth, which amounts to 150,000 to 260,000 kinds of organisms. So, what has been the main response to this situation?

 

From Extension offices across the land (think Master Gardeners and Master Naturalists) to environmental and conservation groups (think Nature Conservancy and Audubon) to the press (think The New York Times and many other newspapers), the public is bombarded with the idea that there’s a dearth of native plants, mainly referring to trees that support moth caterpillars and sawfly larvae that feed birds.

 

We are told again and again that it’s up to us to start growing more native plants in our yards, especially oaks and other tree species, because native animals evolved with them and therefore require them. Additionally, everyone is made to feel guilty if they don’t remove so-called invasive alien plants that have supposedly replaced native plants. Yet all of this is balderdash that, rather than helping our environment, is instead further harming it.

 

Fly in a plane or hot-air balloon and you will see that plenty of large native trees exist in older suburban areas, whether around houses or in nearby parks. In rural areas, large swaths of forest (comprising native trees) exist between homes and farms. It should be obvious that a dearth of native trees is decidedly not the reason for the dearth of herbivorous insects (the most common life form sometimes closely tied to native plants).

 

Yet virtually everyone has bought into this fallacious idea, mainly because of Doug Tallamy, an entomologist at the University of Delaware who has popularized it in articles, books, and talks. All the folks repeating Dr. Tallamy’s nonsensical thesis (including him) demonstrate how a little knowledge is a dangerous thing.

 

Bringing Nature Home, Tallamy’s first book (published in 2007), made clear his limited knowledge of the environment in its entirety. Unaware of the bigger picture that includes other forces at work, this professor’s ability to discern the real reasons behind decreasing biodiversity was affected by his narrow view of life.

 

Indeed, the origin of his entire thesis was based upon anecdotal evidence. He had bought former farmland, the degraded fields of which had filled with “at least 35 percent (yes, [he] measured it)...aggressive plant species from other continents that were rapidly replacing what native plants [he] did have.” (From page 11, Bringing Nature Home, advance reading copy).

 

Dr. Tallamy did not possess the necessary understanding of soil science and life processes to realize that the alien plants were not “aggressive”, nor were they pushing out the native plants on his former farm property. The reality is that farmland consists of soil compacted by half-ton animals and/or heavy farming equipment running over it, and very few native-plant species can grow in that situation.

 

In fact, if the “multiflora roses, the autumn olives, the oriental bittersweets, the Japanese honeysuckles, the Bradford pears, the Norway maples, and the mile-a-minute weeds” (From page 11, Bringing Nature Home, advance reading copy) had not grown there, he would have found far less diversity of plant life, which necessarily would have meant less diversity of animal life.

 

The nonnative plants Dr. Tallamy disparages do support many kinds of organisms, just not the ones (herbivorous insects) he wanted to see. Birds, mammals, and reptiles undoubtedly obtained food and found nesting or sheltering sites among these plants. Arachnids and pollinators would have been found here, too.

 

If, instead, his former farm fields had been hosting Black Locust (Robinia pseudoacacia), Virginia Redcedar (Juniperus virginiana), and Broomsedge (Andropogon virginicus), the primary native species capable of germinating and growing well in the nutrient-poor soil conditions of his property, a much smaller variety of animals would have been found. And Dr. Tallamy would not have found a slew of herbivorous insects on these native plants either.

 

Not only is Tallamy’s simplistic thesis erroneous on many fronts (a subject for another article), but it also encourages the removal of so-called invasive plants that is often accomplished with the use of pesticides. Removing these plants removes wildlife habitat because mature native plants are not going to immediately replace them. And poisoning plants to kill them has unintended consequences, such as killing any organisms aboveground on the sprayed plants as well as those in the soil.

 

Chemicals eventually leach into soil where they kill or alter the micro-organisms living there. These creatures are important because they break down organic material to fertilize plants. Toxic chemicals can persist in the soil for years, making it impossible for microorganisms to exist there.

 

https://www.researchgate.net/publication/289580547_Effect_of_pesticides_on_soil_microorganisms

 

To make proper decisions about how best to care for the environment, it’s vital to take into account knowledge obtained from familiarity with the natural world in its entirety. Doug Tallamy views the natural world through the narrow lens of an entomologist who has mainly studied moths and butterflies.

 

But moths and butterflies, as well as other leaf-eating insects and the birds that feed upon them, cannot be the sole focus of conservation efforts. We must maintain biological diversity to keep the natural world running properly, and to accomplish that goal, we need to maintain habitat, which doesn’t necessarily mean native plants. We must embrace plants that survive well in the modern world (so-called invasives) and stop poisoning them and the very critters we are trying to help survive.

NATURE ADVICE:

Reality is what it is, so it trumps theory. Tallamy’s insular speculation overlooks the numerous other factors that have been at work to cause the Sixth Mass Extinction.

 

·          Any time you must be out at night, observe the houses, buildings, and parking lots. You’ll notice how many unnecessary bright lights are burning. In warm weather, they attract insects—especially moths—which end up dying rather than reproducing.

 

·          Note on social media how many people mention employing pesticides inside their houses as well as outside to kill a variety of critters. There’s always collateral damage when people use pesticides outdoors.

 

·          Consider the amount of land now covered over with housing and businesses, thanks to the exploding human population. Many such sites nowadays do not contain much land around them to host plants to host animals, obviously depleting the amount of habitat available.

 

·          And the more housing and businesses there are, the more windows there are for birds to smash into and die.

 

https://www.sciencenews.org/article/windows-may-kill-988-million-birds-year-united-states

 

·          Additionally, the more people there are, the more cats there are. Cats take a tremendous toll on birds, as well as other critters.

 

https://abcbirds.org/program/cats-indoors/cats-and-birds/

·           Consider the toll traffic takes on wildlife. On my 90-minute walks almost every day throughout the year, I’ve found on the roads dead birds (such as a cardinal, Cedar Waxwing fledgling, a Carolina Wren) in addition to uncountable mammals, reptiles, amphibians, and even insects, depending upon the season. Ask yourself if you could do better to limit the number of vehicle trips you make every day throughout the year. Because the more you drive, the more you contribute to the loss of wildlife.

·          Recognize that alien plants provide habitat; removing them destroys habitat. (You can verify this statement by simply observing how many birds and other animals make use of such plants.)

 

In other words, a variety of reasons account for the loss of insects and the birds that feed upon them, but a dearth of native trees is not one of them.

 

If you truly wish to help save the natural world, shut off unnecessary lights and urge others to do the same; avoid the use of pesticides by catching insects and spiders inside your home to put them outside; never, ever use pesticides outdoors (they are unnecessary in a nature-friendly garden); look up ways to make your windows less reflective of the outdoors so birds won’t fly into them (I keep my curtains and blinds closed as much as is possible so birds can see there’s something there); keep cats indoors while urging others to do the same; limit vehicle trips to as few as possible; and leave so-called invasive plants in place. It may be easier to plant a native tree than to take any of the above steps, but it will do absolutely nothing to curtail the Sixth Mass Extinction.