Theoretically, we have the power to change our mindset. If we go about business as usual, the grand sum of humanity, those who have been in harmony since before we were this species and those who chose to fill and subdue without thought or restraint for the last 6,000 years will effectively be that we are both an invasive species to most of the planet and a mass extinction event. There are other options, though.
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I feel like it depends, overall I think the management of invasive species should be more focused on recovering the habitat after the removal of the invasive species. (mainly focusing on plants here)
It is always frustrating to see the county and state departments simply âmanageâ invasive plants by going along and endlessly spraying glyphosate off to the sides of the road. It always comes right back the next season as they always spray it too late after much of it has already flowered, pollenated and reseeded. I see this most often with Poison hemlock, Himalayan blackberry, Tansy and St johns-wort.
The most effective way to truly eradicate invasive species (in my experience), is to actually go out in the field with the proper equipment and remove it all manually, roots, flowers everything. The other important aspect I donât see addressed when dealing with invasive, is actually returning to the site after the cleanup, and continuing to work on removing any of the plants you may have missed that have popped up in the meantime. Most of the time they just spray herbicide and then leave it all to come back the next year.
The other most important aspect that needs to be recognized, is recovering and reestablishing the site with native plants so it can keep things under better control and so it wont just get filled with weeds again as unused land.
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Just removing invasives without replacing them with hardy natives is asking for erosion and habitat loss. With more urbanized micro-climes we need to be sensible about which natives will thrive. Mountain Laurel is native to South Carolina, but it certainly doesnât thrive in my yard: too much asphalt, too much sun, and way too much humidity. And please plant bald cypress near water. I feel frustrated that many well meaning people plant natives without considering how suitable they are for a given area. Also the climate shift might be changing this whole discussion.
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May I ask why you think Baldcypress needs to be near water? I know itâs a swampy plant but surely a Baldcypress on dry land has more wildlife value than some Asian ornamental.
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I want native trees to be happy. A bald cypress would not be happy (or safe) high and dry on a slope in the middle of turf grass which was where they were going to plant one in my neighborhood. I told them it would grow better on the stream bank at the edge of the neighborhood. Lawn mowers slice into the bald cypresses developing knees with devastating effect.
Many invasive ornamentals have a lot of immediate wildlife value. On one hand, Birds and bees love Chinese Privet. Bees pollinate privet and ensure abundant seed set, and birds eat the seeds and plant them all over. The same with Mimosa. But both of these grow so well and crowd out other plants that they foster a monocultureâlessening the biodiversity among the animals in the long term
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Hartbeespoort dam was COVERED in water hyacinth.
Yes it can be used for phytoremediation to clear excess nutrients.
But we have insects for biocontrol and this year the cover is down to 5%
Clearing woody invasives, Australian wattles and Eucalyptus and pines - provides employment for small entrepreneurs, saves water against drought, opens up space for wild seeds to germinate, and we are burning that wood.
Biocontrol research continues as we seek solutions for our plants which have become invasive in other countries.
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Actually, years ago I knew an activist who was advocating for human-free habitat â as in off limits to all humans, including researchers and conservationists. When I asked him how it would be enforced, he said that a big part of the deterrent would be to make it known that there would be no search-and-rescue if anything befell someone in there.
And then the Gulf War started, and his newsletter shifted focus to advocating against the war, and I lost interest.
Which is a big part of the reason for the extinction of megafauna in prehistoric and pre-industrial times.
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This is a good point. Iâm trying to make sure our lil slice of woods remains native; but Iâm just now learning a couple of the wildflowers are actually invasive (at least - non native) - oxeye daisy, queen annes lace, common vetch, to name a few - I reallly didnât realise until scrolling my project here on iNat. I see butterflies on a lot of these, I canât see myself bothering to remove them or even trying to.
I am however, ensuring it stays privet free (a few lil ones every now and again, I have seen it 4 miles away, itâs probably closer in some spots), took out the princess tree (wtf?), persian silk tree (those are bad in the area, but there were only 2 I have found!), and recently figured out the source of another shrub thatâs invasive and I canât spell it - dude before us planted them probably in the 80âs or 90âs, and I only figured it out spoting one in the forest as I never bothered to ID any of the planted flowering shrubbery, so finding the runaway wild one helped me source that. The ones in the forest are out, the two planted ones are huge and will be coming out soon. I can keep track of these things much easier, and just maintain the ecosystem as not having them, rather than fight off an onslaught.
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Just a quick off-topic âhey!â - and welcome! Glad to see youâre interested in such an important discussion.
Most (not all!) pollinators are generalists, using nectar and pollen from any of the plants where they can access it. After all, the plants usually donât put dangerous chemicals in nectar, because they âwantâ lots of visitors, visitors who are willing to visit other flowers of the same kind.
The relationship of caterpillars and other larvae to plants is usually more intimate. They eat the plant body or seeds. These are parts the plant âwantsâ to protect from being eaten. These are often full of chemicals that make the plant poisonous or at least inedible to many herbivores. The larvae that can eat a given species have evolved ways to neutralize those toxins. However, this ability is metabolically expensive, so no one larva can neutralize many different toxins. Therefore, the larvae tend to eat only closely related species.
Therefore, invasive species that support lots of native insects as pollinators may support no native species as larvae. And insects that pollinate can use native plants (if theyâre present!) as pollen sources. Therefore, preserving invasives just because they supply nectar and pollen is usually not justified (although there are lots of complications, including what will replace the invasives if theyâre removed).
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I think I agree with what you said. Our impacts are everywhere. Saraha Desert
It seems, before human impacts, the Saraha was a complexly different ecosystem.
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Research on our wild honey bees at Cape Point, shows that the bees collect and store the pollen from different plants in different sections of the natural hive. (In the same way that honey looks and tastes different, depending on which plants it ultimately came from) The bees plan how to use their resources as different plants come into flower.
This bee has her saddle bags carefully packed with Serruria pollen
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I think the problem isnât so much that invasive species donât provide resources for other animals and plants, but that they often reduce the diversity of the ecosystem. For example, in the city I live in pretty much every non-forested hillside is completely covered with invasive knotweed which has choked out the other plants. The knotweed probably supports a handful of generalist pollinators, but not the larger diversity of insects (and their associated food chain) that was previously supported by the native flora. And hopefully I donât need to even mention Kudzu. Luckily not all invasive species are as wildly successful and destructive as these. Like I have a hard time feeling concerned about the little patches of honeysuckle in my yard. Yes, theyâre invasive, but so far they havenât killed off the other plants and they donât seem to be doing much harm. I know a lot of people feel differently though, and look at non-native honeysuckle as a pest. Iâm not saying theyâre wrong, I just donât feel the same way.
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a natural area we know of in the Midwestern USA is struggling to convert former ag plots to native prairie because the oregano canât be controlled or contained. Herbicide and fire will not eradicate it or stop it from spreading. The pollinators favor the oregano. But land managers donât want monoculture. And we saw a bee-centric web site encouraging people to plant oregano for the bees. We worry people will listen and plant it without realizing how aggressive oregano can be
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Invasiveness of honeysuckle depends on which honeysuckle and which location. In Iowa (middle of U.S.A.) honeysuckles have invaded woodland, replacing native shrubs and perennial herbs with a dense layer of honeysuckle. Terrible invasives â there.
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Same here with canadensis and gigantea, good for honey, but kill off everything native, live for years and take huge places.
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