For Volcano, what a vicious invasive!
Not so bad for down-country and near
sea-level, but this one seems to love
the higher elevations above 2000'.
Try to love the beauty of this little ground
cover as much as I can since it seems to
want to grow everywhere in my yard.
Hedychium gardnerianum, or Kahili ginger
is another invasive. Takes more than 50%
of my gardening time removing it from the
forest. Again another beautiful plant, unfortunately
a ginger spread by small peppercorn size seeds,
becoming epiphytic in the rainforest, and can
tolerate frost conditions. Yikes!!!
Down here we are choking from Pilea - it is horrible!!!! Only really nasty chemicals take it out and when you hand pull it you get covered in the seeds. Just walking on it spreads the seeds...as if the plant didn't do a great job 'shooting' the seeds all over.
"Weeds" are perhaps most destructive to islands
since islands tend to have isolated populations of
native organisms that have speciated over time
and in many cases the natives have less competitive
abilities. Hawaii is the worst case scenario: we
have lost uncounted species of native plants and
animals, and the remaining natives are constantly
under threat of displacement. Hence the remarks
that Hawaii is the "Extinction Capital of the World".
Upside is that most of our weeds are beautiful in
some way...and they keep me busy and give me
Hey Carol, Pilea is under control in my
garden and not much concern. Quite a
difference the altitude change makes.
Waiawi seems to be less agressive here
too, but we have a very nasty problem
in Myrica faya. Think the Kilauea area of
the national park will be completely over-run
by Myrica in time, since they have a fraction
of the workers needed to combat this pest.
Parts of the Byron Ledge trail near the
caldera are dominated by large Myrica trees.
OK, I'm going to get some tomatoes thrown at me here: that hedychium gardnerianum is really nice-looking. I wish the wind blew hard enough to get some of those seeds all the way here. I could plant a patch of these, even though I am basically useless with seeds. If the only process involved is to spread them in the ground, I can manage that.
While we were on TBH, we visited the botanical garden in Papaikou: delightful place. I still dream of it. I photographed those, which I was told were "cat whiskers".
Hey Lourspolaire, the epithet for cat-whiskers is Orthosiphon aristatus.
Hedychium gardnerianum does not make seed in the warmer parts of Hawai'i. It likes the higher elevations and cooler temperatures of Volcano where it is an invasive pest.
It is also a pest in the Azores, where it blocks streams and displaces agricultural crops.
I'm sure that if you really tried, it could be a pest in your neighborhood too!
When I read talk of "weedy" and "invasive", I just cringe because of how people react to nature. When volcanic islands are first formed, they are totally barren. They would remain barren if if weren't for "invasive" plants. Only the most durable, aggressive plants can colonize a barren landscape and make it fit for more timid plants and animals to move into. Therefore, IMHO, the people and organizations that are devoted to the destruction of "invasives" (often funded by big pesticide corporations) are doing no one any favors.
Please remember that our gardens, lawns, parks, farms and other man-made "biomes" are often totally unnatural and out of balance. That means that nature will try continually to rearrange things and restore something that looks like a balance again. We call the process "invasive". I wonder what terms the natural world would use to describe humans?
So pull your weeds if you must, but please consider what is really happening.
LariAnn - your words are well founded. However, when we are speaking 'invasive' here...we mean that it is choking out EVERYthing...food crops, ornamentals, 'natives', canoe plants etc. It chokes up grazing areas. Control is essential -
I do not believe that the past justifies the present nor the future...it just serves as a good teacher!!!
Hawai'i had a diverse, in balance, natural habitat before humans arrived. Through time and evolution plants adapted to specific habitats or niches. Our rarest native plants can only exist in their specific habitats.
The invasive plants that we worry about can adapt and grow almost anywhere, such as strawberry guava and kahili ginger.
These invasives didn't arrive to fix the mess that humans have made of the environment. Rather they are here because humans turned them loose on the environment.
Humans have learned to adapt to almost any habitat on Earth, to the demise of many species.
In a couple thousand years of human activity in Hawai'i, humans have wasted many of the rarest organisms on the planet.
It is of some solace that we can try to control some of the species that have been brought here. This is now the only method for preserving many rare species.
Humans have shown a remarkable ability to change environments, it is good that we can also learn to preserve some!
Well, it is a fact that wherever humans are trying to maintain an unbalanced biome, such as monocrop acreage, landscaping around homes, golf courses, etc., some kind of ongoing control is necessary because nature will not leave an unbalanced situation alone.
Years ago I remember hysteria about the water hyacinth and how it was going to "choke" all the waterways in Florida and mutate and go on to cover the oceans as well. It didn't happen, though.
BTW, here's a link to an article about the water hyacinth. It starts with the "hype" but goes on to present the facts about how the "problem" actually got started. Funny that the "problem" happened because of how humans have altered the ecosystem (industrial agriculture, dam construction and deforestation). So, we should blame the plant?
Yes, humans have introduced the so-called invasive plants. Yet I don't believe that nature "invades" itself. Nature checks and balances itself, and when out of balance, something that looks like an "invasion" will occur. In time and if left alone to complete the process, integration and balance will be restored. If climate changes, or a severe storm knocks down all the trees, some species that were docile in the past may become "invasive". Nature uses whatever species are available in the current "palette" to begin the process, and this must necessarily include whatever "exotics" are on the palette. A plant may not be here to "fix the mess", but nature will use it if it works for the purpose of restoring balance.
Sadly, too often humans are wildly impatient and want to destroy the alleged 'invaders', and in so doing, prolong or prevent the restoration of balance, ultimately leading to the loss of "native" or specialized niche plants as well (throwing out the baby with the bath water).
We don't know anywhere near enough to engage in wholesale destruction of "invasive" species, yet some continue to advocate that, mainly because human activities are being adversely affected, not because of a desire to protect pristine wilderness. I believe that genuinely intact natural biomes don't get "invaded"; it is overgrown, abandoned farmland or land where the forests have been cut down, monocrop acreage, roadsides and picnic areas in "managed" parks, etc. that have the biggest problems with "invasives". Unfortunately, that includes almost all the areas that surround us everyday.
Lori - I appreciate your point of view and of course, your education and knowledge. Living on an island we have limited environments for habitat, food resources, water etc. (remember we have an active volcano here hellbent on taking her part as well) and it is a precious balance between what is here and what is coming in to destroy it.
There is no evidence that Nature is correcting itself when left to its' own devices.
Nature is constantly changing. When a catastrophic event happens, the elements of Nature move in to resettle the area (whatever species are there at the time) until by succession there appears to be what an ecologist might call stability. The stability or balance happens amongst the species which are the most dominant at competing for air, water, space, and nutrients. Over time things always change. That is what evolution is; biological change.
Humans and all other life forms have changed over time to meet the pressures of environmental stress. Long ago our ancestral species did not look like we do. If our species survives ages from now they won't look like us.
Hawai'i evolved under isolation from continental competition. This is true of many Islands. Because of this, many rare forms of life occur here. Over time as more competitive species arrived here, the rare life forms have become threatened with extinction.
Rather than sit back and let Nature run it's course and have Hawai'i become a bunch of strawberry guava, kahili ginger, albizia trees, fountain grass, and other highly competitive species, I will use my education to save the rare life forms.
Life is not a TV show (something to watch); it is rather something to be a part of.
I cultivate many species of rare plants, as well as food crops. I remove highly competitive invasive species from the Islands native forests. I will do so till my last day!
I find it curious that while you state that Nature is constantly changing, and you, yourself, participate in that change by growing food crops (how many of which are exotic?), you nonetheless resist change to your dying day by destroying plants you don't think should be there. If your evolution is true, then the worth of particular plants and animals is only in terms of ability to outcompete others. It is those that can survive the best that will make it, and that means the "invasives" should be favored as they compete the best ("might makes right").
For the record, I believe that the worth of life forms is much more than "survival of the fittest". I agree that nature is constantly changing, and what we do is part of that change. Because of this, rare plants may have to be established in more favorable habitats when their "native" habitat is no longer suitable for survival. This short-circuits "natural selection", but will preserve the rare species. By contrast, many "nativists" believe that plants should not be moved, and in that case, many will perish as their habitats deteriorate due to man-made influences.
BTW, I propose that the entire natural pre-human history of this planet constitutes evidence that nature corrects itself when left to its own devices. If this were not the case, I expect we'd have a very different world of very few species instead of the diversity we have now. Extinction and "invasion" have been a part of processes here for millions of years, yet we still have a planet full of abundant diversity.
LariAnn...I repeat that while I admire you knowledge, the ecosystems of Hawaii are so fragile and so unique that blanket statements by someone not familiar with these island are really not valid. Believe me...there are plants here that are found NO WHERE ELSE IN THE WORLD. Should we lose them to Ageratum and Kahili Ginger????
Wouldn't it be interesting to jump in a time machine forward
10,000 or a million years to see what Hawaii will be like? There
will be "correction", to the demise of some organisms and to
the delight of others. All is in constant flux, and response
to powers of the universe. Part of the creation of this wonderful
world we live in, will be the complete destruction and removal of
everything as we know it. We likely won't see that but it will
happen eventually...the ultimate "correction".
Hawaii is so ideal for imported things..in fact it probably provides the ultimate conditions possible for many..which is obvious from the rapid rate of propagation.
I've seen those wood rose vine on Kauai..hmm..it's netted the whole island.
In any case, it would seem that we, being part of nature are also part of what influences the outcome, and though as humans we may become full of ourselves, it's probably Mother Nature using us for an end to a means, and not the other way around.
In the evolution of volcanoes, the final episodes are violent blasts of ash and tephra. Meaning life will get very hard on this Island for anything that relies on breathing fresh air.
Geologically speaking: Humans are only going to be here for a short period of time.
While it would be interesting to see what survives here, let's not be in a hurry for things to change!
Wow! What a thread. Wondered how I missed this and looked at the dates. Had spinal surgery Aug.12, 2008 and spent the next 5 days in ICU. Will need to read again as there are many different ideas and all are worth listening to.
I've only just come upon this thread and found it interesting. It becomes problematic when you personify "nature". Nature is not a rational being that is constantly manipulating to achieve some predetermined outcome. Nature is a collection (massive collection) of selfserving organisms that will ruthlessly take advantage of any window of opportunity.
All creatures must reach homeostasis, but all are not so ruthless at doing so. That is why we have species that are considered invasive, and others that are vulnerable to extinction.
Being human gives us a different twist on nature than other species experience. We have the ability to enhance life, as well as the ability to destroy it!
Very late reading this thread,,, but like the rest of you, I found it fascinating. Jjon made the comment above about how life is different on an island. Try mine! 3 1/2 by 1/2 miles...we are very small...tiny! If we did not "manage" the invasives they would overun the island in a matter of months. I, personally do not consider tomatoes, bananas, papayas and breadfruit "exotic" for this area, since they are dietary staples of the indigenous people. And even they (the Marshallese), "manage" the invasives. Just because something is natural does not mean it is beneficial to the environment. And after all, are we not part of nature as well?
Well, as gardeners, we all have our weed crosses to bear! What I find fascinating is to research these invasives in the phytochemical databases. Many times they are powerful medicine plants, or have other uses.
Twenty years ago, I used to collect all the ginger flowers on the roadsides for lei making. Then I got the "bright" idea of planting the roots so I wouldn't have to drive around. Well, nowadays pulling the gingers up is part of everyday weeding.
As for Hedychium garderianum, it has set seed here in my garden on 26th in HPP. I sent them to JL Hudson Seedsman as part of their seed swap deal. The kahili doesn't spread here as much the others, though. My least liked weed is Maile pilau and a philodendron which escaped and is covering trees.
It is interesting to see what plants are invasive in one place and well behaved in others. I was stunned to see persacaria recently while visiting Hawaii. I was staying in Volcano Jon and I did wonder if the plant was as invasive as it is around here (at sea level actually) I have managed to remove it from my tiny garden with a combination of hand pulling and Round Up but I still get little bits popping up each spring.
While visiting with Carol she expressed dismay with Selaginella pallescens (although I believe you called it something else.) That one is a valuable plant here and it is not easy to keep healthy. Funny isn't it?
Most hedyciums will take over here if they have enough moisture in the soil. Our soil never goes below 55 degrees in the winter and although the tops die off the rhizomes flourish. I have seen seeds on mine but I have never tried to germinate them. I do not have to pull them up every day but it is a semi annual chore.
Watching plants establish themselves in such harsh conditions was fascinating to me. You live in a constantly changing environment.