[HN Gopher] The dual nature of Japanese Knotweed
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The dual nature of Japanese Knotweed
Author : dnetesn
Score : 34 points
Date : 2024-06-05 11:59 UTC (1 days ago)
(HTM) web link (worldsensorium.com)
(TXT) w3m dump (worldsensorium.com)
| blackeyeblitzar wrote:
| This thing is incredibly invasive and is all over the Northwest
| and other parts of America near waterways. It spreads underground
| like bamboo. It's super expensive to get rid of, because it you
| have to fight it for many years consistently for it to die out.
| And even then you may just be unlucky enough for it to spread
| into the area again from some adjacent area or from fragments in
| the water.
| janice1999 wrote:
| It's stupidly irresponsible to encourage people to forage
| Japanese Knotweed in countries where it is a major threat to
| existing ecosystems. Even small fragments on shoes or in water
| can cause outbreaks. That's why dealing with contaminated soil is
| extremely expensive.
|
| https://emmaplusthree.com/home/japanese-knotweed-understandi...
| pclmulqdq wrote:
| I had almost half an acre of this crap on my property, and still
| have about a quarter of an acre after thoroughly removing one big
| patch. There is nothing good about Japanese knotweed in the US,
| and everyone who forages it is part of the problem. It evolved on
| the sides of volcanoes, so if you cut anything off of it (or burn
| it), it triggers a chemical signal that encourages virulent
| growth from the attached rhizome. By cutting down small amounts
| of it, you are actually propagating it. That is the furthest
| thing from "environmental stewardship."
| hosh wrote:
| There are many plants that have survival adaptations like that.
|
| The question is: what are the other animals that would normally
| eat it and keep it in check?
| fredley wrote:
| Lava flows?
| hosh wrote:
| According to this article:
|
| > This BBC article from 2010 points out that Japanese
| knotweed isn't really a problem in its native country -
| while common, the plant "doesn't rage out of control like
| it does in the UK, thanks to natural predators that keep it
| in check".
|
| > In Japan, knotweed has many natural predators in the form
| of nearly 200 insect species and a variety of fungi.
| Certain psyllids (plant lice) have proven to have an
| appetite for Japanese knotweed sap - the organisers of the
| Chelsea Flower Show have looked at using psyllids to keep
| Japanese knotweed at bay, and one species (Aphalara
| itadori) has even been released into the wild in an effort
| to combat the UK's knotweed problem.
|
| https://www.taylor-weed-control.co.uk/news/post/what-eats-
| ja...
| zukzuk wrote:
| Same with Dog Strangling Vine in Europe vs North America.
|
| I volunteer every week helping with ecosystem stewardship
| here in Southern Ontario, and DSV is absolutely out of
| control in parks and forests. It spreads like wildfire
| and wraps itself around anything and everything, choking
| out most other plants and creating mass monoculture.
|
| Meanwhile, in France, where I just spent a week hiking,
| you see the occasional vine here and there, minding its
| own business, acting like a well-behaved member of the
| forest community.
| pclmulqdq wrote:
| Japanese bacteria, fungi, and lava. It's nearly defenseless
| against the microorganisms in its ecosystem because it spent
| all its evolution points on growing on the sides of
| mountains.
| hosh wrote:
| There are probably some kind of microorganism and insects
| native to the US that would like to eat them.
| hosh wrote:
| I find it interesting that many permaculturists would include
| "invasive" species in their designs. (What makes something
| invasive has more to do with few, if any, ecological links to
| other species within the area). Anything from horseradish,
| asparagus, to autumn olives, sea buckthorne, jujube.
|
| There's a particular case of the Tree of Heaven, an aggressive
| tree species that can live on land polluted by copper tailings.
| They get everywhere, grow back more prolific if you tried pulling
| them, and do not have a pleasant odor. The mayor of Jerome, AZ
| seeded them to help stop erosion in Jerome. And it worked.
|
| Even running bamboo can be managed -- the key is to consistently
| harvest the edible sprouts.
|
| This demonstrates the power of regeneration in living systems, be
| they ecologies or individual plants. It's aligning this
| regenerative power with the interests of human civilization that
| can restore wastelands, reverse desertification, while yielding
| something useful for humans.
| throwup238 wrote:
| _> The mayor of Jerome, AZ seeded them to help stop erosion in
| Jerome_
|
| Kudzu, cheatgrass, knotweed, tree of heaven, saltcedar, crown
| vetch, english ivy, giant reeds, iceplant... the list goes on
| and on. It's absolutely ridiculous how many invasive plants
| have been spread intentionally to control erosion. I found out
| later in life that most of the iconic plants I associate with
| the places I grew up are invasive.
| hosh wrote:
| But, if they develop relationships with other species within
| that ecology, then those form networks that allows
| participation in the local ecology. They would no longer be
| invasive.
| throwup238 wrote:
| That doesn't help all the plants they displace or drive
| extinct altogether. That's why they're called invasive, not
| because they're incapable of forming new ecological
| relationships.
| hosh wrote:
| The displacement is only a bad thing if there are no
| interactions between the native ecology and the new one.
|
| If there are interactions, then the ecologies start
| merging and adapting. The native species can still thrive
| because there is participation among both old and new.
| throwup238 wrote:
| So even by your standard of weapons grade copium, it's
| always bad. Invasive species outcompete native ones by
| definition so they _can 't_ thrive.
|
| Seriously, go look at the iceplant covering California's
| coasts [1]. Or the himalayan blackberry all over the
| pacific north west [2]. Or the kudzu vine all over the
| south east US [3]. They smother native competitors and
| eliminate them everywhere they go, turning once diverse
| ecosystems into monocultures.
|
| The ecosystems don't adapt, they get wiped clean of any
| native plants whose niche overlaps even slightly with the
| invader. If the native species could adapt, the
| introduced species wouldn't be called "invasive" but
| "naturalized"
|
| [1] https://www.fiscaliniranchpreserve.org/images/Photo%2
| 01%20NP...
|
| [2] https://extension.oregonstate.edu/sites/default/files
| /styles...
|
| [3] https://upload.wikimedia.org/wikipedia/commons/4/4c/K
| udzu_on...
| hosh wrote:
| I can't reply directly to that.
|
| You have to introduce species that bridges the gap and
| creates those links.
|
| To give an example with kadzu:
|
| https://www.smithsonianmag.com/science-nature/true-story-
| kud...
|
| Tldr: kadzu turns out not to be as invasive as people
| thought, and the kadzu bug has been eating its way
| through them.
| exDM69 wrote:
| Previous owner of my property planted this damn plant here in two
| separate patches.
|
| I'm on year four trying to get rid of it and it's still showing
| signs of vitality. If I let my guard down, it's gonna be back
| with a vengeance in a year or two.
|
| I dug out about 600 kg of roots from about 6 square meter area
| and have culled every shoot every day from the patch almost every
| day for four years.
|
| The other patch was first treated with herbicide and then covered
| it with a light blocking tarp made for this purpose. It's still
| going after 4 years in the dark.
|
| Please do not pick it up or mess with it. It is a terrible plant
| and destroys everything around it.
| rimunroe wrote:
| I believe cutting every day is counter-productive because it
| causes it to spread. I'm in Massachusetts. The strategy we're
| using is cutting once in early summer. Then we let it grow
| (completely undisturbed) until right after it flowers in early
| fall. At that point we cut and inject concentrated glyphosate
| into the stumps. The idea is to inject the herbicide right as
| the plant is drawing stuff back into its root system for the
| winter.
| bjacokes wrote:
| I've read about this strategy and am giving it a shot this
| year.
|
| If I understand it correctly, the reasoning is that until the
| late summer, the underground root system is putting its
| energy towards growing the stalks and leaves, so you _want_
| it to grow as much as possible. If you trim daily, you'll
| never let it get into the rapid growth stage where it's
| really depleting its energy reserves. In other words if you
| trimmed daily or monthly til the end of time, eventually
| you'd kill the plant, but it might ironically die more
| quickly if you trimmed monthly.
|
| It's a bummer knowing that it'll be hard to fully eradicate
| it given how widespread it is in the area (I'm also in
| Massachusetts), but I guess there aren't really any permanent
| victories in life when you think about it.
| foobarian wrote:
| Wonder if this plant would be helpful for greening up deserts
| or converting co2 to biomass. Apparently it doesn't even need
| light!
| fatnoah wrote:
| It is a very tenacious plant. I had exactly one stalk grow to 3
| feet in a mulched area of my yard. I didn't think too much about
| it because I didn't know what it was and hadn't heard of it.
| While testing a trial of a plant identification application, I
| successfully identified it.
|
| As someone loathe to use chemicals, I thought perhaps that the
| tenacity of the plant was overhyped, so I simply pulled the stalk
| out of the ground. Over the next several months, I'd notice 3-4
| new stalks popping up each week over a roughly 15 foot radius
| area. That continued through the next spring when I finally
| decided enough was enough and got the glysophate.
|
| From June through winter (I'm in the northeast US), I'd let a
| plant grow for a week or two and then spray it with the
| glysophate and leave the plant in place. I did this for the
| entirety of the following year as well. Now, in year 3, I finally
| have no more shoots popping up, and can't begin to imagine what
| managing a true infestation looks like.
| krunck wrote:
| I had a situation similar to yours. I was able to eliminate the
| single plant by chopping it out every time it popped up. No
| glyphosate needed.
| foobarian wrote:
| At some point even highly invasive plants like JK have to
| respect laws of thermodynamics. You get it eventually!
|
| On that note, the dried knotweed stalks are fun to burn
| because their bamboo-like segments are divided by a membrane
| that seals them shut, so they pop quite satisfyingly. Our
| kids were sad that they ran out of it at some point after a
| while harvesting the stalks behind our yard.
| zikduruqe wrote:
| If it pops up again, eat it.
|
| https://www.eattheweeds.com/japanese-knotweed-dreadable-edib...
| Modified3019 wrote:
| When you get to the point where you realize a herbicide might be
| nice, but aren't set up for spraying or dealing with potential
| drift (droplet size is important, a mist means chemical is
| floating away to touch something you don't want), look into stem
| injectors which is a common method to limit risk. Keep in mind
| timing will be important though.
|
| As always, take the PPE notice on the label seriously (sit down
| and read the entire damn thing), and always wear chemical
| resistant gloves and a splash guard for the face.
| err4nt wrote:
| It just occurred to me - we only call these 'invasive' not
| because they invade nature, but because they invade the spaces we
| as humans have carved into nature. If our presence wasn't there,
| perhaps the natural ecosystem wouldn't have space or room for
| some of these species to enter, but because of human activity, a
| space is carved out for these other species to grow in, and
| that's what causes us the stress.
|
| Isn't it weird how we're so acutely aware of the effect of the
| species that invade our space, but so ignorant so often of our
| effect on the same spaces when we invade them?
|
| I think I learned something valuable today chewing on this
| article.
| resizeitplz wrote:
| Invasive species aren't 'invasive' for invading _human_ space.
| They 're invasive for invading _other species_ space.
| enlyth wrote:
| The term "invasive species" never made sense to me. It just
| means something can evolutionary outcompete other things,
| because it is better at utilizing that environment.
|
| Basically putting a label on things we don't like.
| cmyr wrote:
| This is definitely true, but there is a useful distinction
| between the usual evolutionary competition between species in
| an ecosystem and the very sharp situation of an ecologically
| novel species being introduced into that ecosystem and out-
| competing the incumbents, and 'invasive species' is the best
| term we currently have for this second case.
| ppseafield wrote:
| We don't like it because it can cause widespread damage to
| the ecosystem, not just to us. Life didn't evolve in a
| vacuum, and the balance of natural ecosystems can be fragile.
|
| > [Feral pigs] are invasive and cause millions of dollars in
| agricultural damage each year, rooting and trampling through
| a wide variety of crops. They prey on everything from
| rodents, to deer, to endangered loggerhead sea turtles,
| threatening to reduce the diversity of native species. They
| disrupt habitats. They damage archaeological sites. They are
| capable of transmitting diseases to domestic animals and
| humans.
|
| https://www.smithsonianmag.com/smart-news/feral-pigs-are-
| inv...
|
| > Interestingly, in their native range in Europe and Asia,
| pigs do not cause as much ecological damage. In fact, some
| studies indicate that they may modify habitat in important
| ways for species that have evolved with them, such as frogs
| and salamanders.
|
| https://theconversation.com/feral-pigs-harm-wildlife-and-
| bio...
| raffraffraff wrote:
| My wife read about an endangered butterfly called the Small
| Blue. The female feeds exclusively on a plant called kidney
| vetch. Isn't that crazy? One fucking plant! This isn't a
| plant that you can buy in a garden center.
|
| That's the magic about ecosystems. They develop over aeons,
| and have intricate interdependencies. Many species are
| extremely picky about how they mate, where they lay their
| eggs, what they eat when they're larva, what they eat as
| adults etc. If you wipe out a single plant, you could wipe
| out an insect that exclusively feeds on it, which could wipe
| out some other thing that feeds exclusively on that insect.
| If an invasive species that threatens a single native
| species, this isn't just "something we don't like", it can
| cause a chain reaction of extinctions.
| jasonpeacock wrote:
| There are many natural ecosystems being wiped out by invasive
| species that do not have human presence.
|
| https://education.nationalgeographic.org/resource/invasive-s...
|
| But humans are almost always the reason for the introduction of
| invasive species either by accident or purpose.
| fmajid wrote:
| Here in the UK, it's considered incredibly bad news because it
| destroys the foundations of houses, and is well-nigh impossible
| to eradicate.
| throw46365 wrote:
| This is why when you see a house on rightmove that has heavy
| plastic tarpaulin over a considerable patch of the garden, you
| ask questions... Bit of an issue in some of the areas I've been
| looking.
|
| It is possible to kill it -- it's possibly easier to kill than
| Horsetail/Mare's Tail, which spreads even faster at root level
| and is very difficult to remove, but thankfully does not damage
| buildings.
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