Arbor Day, April 27, is nearly upon us. Many of us are receiving solicitations in the mail about ordering trees through the National Arbor Day Foundation. But you should think carefully about what trees to order.

The Arbor Day Foundation remains behind the times when promoting tree-planting, because they barely mention problems with invasive trees on their site, and in none of the junk mail literature I have received. Although an entire page is devoted to invasive species that harm trees, the only reference to invasive trees is buried its FAQ:

10. Are the trees offered by the Foundation invasive?
The Foundation follows the guidelines of the National Invasive Species Information Center. Plants found to be invasive or problematic by this agency are removed from the lists of trees and shrubs offered by the Foundation. In addition, we take into consideration recommendations found in the publication entitled, Invasive Plants, Changing the Landscape of America, by the Federal Interagency Committee for the Management of Noxious and Exotic Weeds.

Naturally I'm not complaining about their policy, it shows they are at least paying some attention to the problem of invasives. What I object to is that the NADF, throughout the web site, promotes and sells trees purely by horticultural zone, as does every gardening catalog. The gardening catalogs, though, are about business, and up to this point, businesses spreading species around have not been held accountable for invasive outbreaks, so in their case this policy is understandable.

However, the NADF promotes itself as an organization that cares about ecology and the environment. Aside from fortunately not selling nasty invasive trees such as Russian olive and saltcedar, they do absolutely nothing to promote the idea that we should be cultivating local species, which is by now a standard ecological concept. Even if your exurbian front yard is hardly definable as a natural habitat, NADF should be attempting to instill in you the idea that what makes ecology important, and sustainability possible, is the recognition that certain species of trees belong in certain areas because they are used to interacting with the other species found in that area. Such a visible organization could be making great strides in promoting local habitat ecology, but they are making absolutely no effort to do so.

What difference does it make, if none of the trees they sell will become invasive? First of all, every time we move a species, or even an individual, around to where it doesn't belong, we are conducting an biological experiment. Maybe there are no problems 9,999 times out of 10,000; but the more often we do this, the more often number 10,000 comes up.

In addition, the homogenization of the planet comes with several costs. One cost is giving up the buffer that having millions of species across hundreds of ecosystem provides against our own foolhardy exploitation of resources. The honeybee "crisis" everyone is clamoring about now is a perfect example of this. Bring an alien species to a large region to replace hundreds of native species that could do the job, albeit less efficiently from a human perspective, and one disease, one environmental problem, and you are in trouble.

Another cost is to our own human sense of place. When distinctive plants and animals disappear from places - a good example here is of pacific islands, whose endemic plants and animals have been decimated, and replaced with a few ubiquitous species now found on nearly all the islands - we lose some of the wonder we have for the natural world. In fact, each successive generation has less appreciation its own corner of the planet, because fewer species remain to distinguish it from anywhere else on earth.

Perhaps these issues are just too abstract for an organization that wants to promote one simple idea, that "trees are good" - not even always true, in an ecosystem that was historically treeless, another distinction NADF fails to make in its black-and-white view of ecology. Perhaps there's no point in anything but pooh-poohing those of us who wish for a different ethic - many of these have been cultivated for generations, and some are human-created hybrids, so really what difference does it make where we plant them? I argue only that these are minor points in the greater struggle to convince humanity, especially that small portion of humanity that has the time and money to support any sort of environmental ethic that it chooses, that ecology and biodiversity are not actually words that can describe numbers of species over an entire planet. They much more aptly describe the mosaic of species assemblages that found a way to evolve in every possible environment that is found on earth. If we lose that idea, then biodiversity itself is a meaningless concept.

Labels: biodiversity, ecology, invasive species, nature

Almost as a reiteration to my earlier post, here is another article close on the heels of the last, about drying conditions in the West. Climate change is not a vague, unproven myth that wacko lefties perpetuate in order to undermine Big Business. It's here, folks, and because it is being combined with other fast-acting anthropogenic effects (that I previously discussed), ways of life and species assemblages in the West will be radically changing in the next couple of decades.

And, having done ecological research (my dissertation) in high altitude zones of the "sky islands" myself, on species that may cease to exist in the southern half of Arizona within my lifetime, it is not exactly with glee that I draw your attention.

Labels: biodiversity, ecology, environment, evolution, invasive species

The western U.S. has been under "drought" conditions on and off for the last ten years or so. Why is "drought" in quotes? Because drought is a relative condition, referring to less rain than normal - a level of rain considered drought in the Alaka`i Swamp would cause major flooding in Tucson.

So what is really going on in the West? The quick answer is that we probably don't have enough data really to know. Ten years of dry conditions is a blink in the long term. The ultimate question is if the current drier trend is something that will continue in the long term, or is really just a blip, and the truth is that no one can know for sure.

But what we can know about is the long term climate of the past. A panel of scientists analyzing conditions in the southwest noted the following (from a NY Times article [sub. req'd]):

...the water allocation agreement for the basin, the Colorado River Compact, was negotiated in 1922 based on river flow records dating to the 1890s, when gauging stations were established. The agreement assumed that the annual river flow was 16.4 million acre feet -- enough to cover 16.4 million acres to a depth of one foot.

But for some time, the panel said, researchers have known that the early 20th century was unusually wet and that 15 million acre feet was a more accurate estimate of the flow. Recent studies based on tree rings put the figure lower still -- as low as 13 million acre feet -- and suggest that "drought episodes are a recurrent and integral feature of the region's climate."

The harsh reality is apparently that over the last couple of centuries at least, the typical amount of water in the west jibes pretty closely with conditions we are seeing more recently, and the period when the west became heavily settled coincides with an unusual wet spell, combined with technology (dams, etc.) that allowed people to use more of the water that is there.

The long term implications for this trend are far-reaching. Biologically, the landscape of the west has been irreparably altered by the introduction of dams and cattle. Both of these in turn have facilitated establishment by lots of invasive weeds that are massively altering the landscape further. Two examples: Salt cedar and Russian olive have taken over many riparian areas in the southwest, and are spreading north (probably helped by human-enhanced climate change). Salt cedar not only crowds out native plants and lowers the water table, but its excretion of salt changes the chemistry of the soil, making restoration of these areas especially difficult. Native riparian trees such as willows can compete with salt cedar under the natural cycle of floods, but thousands of dams (built to provide water and power to an increasingly unsustainable western human population) have disrupted this cycle, under which conditions salt cedar easily takes over, disrupting the entire ecology of the system, because so many animals, vertebrate and invertebrate, depend on the native willows.

Cheatgrass is an invasive grass that produces intense fires that occur much more often than the normal fire cycle to which the animals and plants of the Great Basin are adapted. Neither are cows, so in addition to drought itself, cheatgrass has gotten a lot of attention because it impacts "traditional" ranching in the area.

But the effects of the West suddenly finding itself quite overpopulated given the amount of water we can expect in the near future reach into the sociological as well. As one example of many, our local Women's Resource Center, which provides support primarily to victims of domestic violence, has to gear itself up every summer for a big run on its services; the drier the summer, the more domestic abuse, presumably because of family stress about financial problems.

The bottom line is that at the very least, the level and methods of ranching and agriculture that people have become accustomed to over the last few generations in areas defined as desert, based on their low rainfall, is no longer sustainable. There are different ways of ranching cattle that can significantly reduce problems associated with overgrazing, but people are slow to change. If we are not actually experiencing a "drought," but rather emerging from a wet period, dark times are ahead for rural western economies, because the cities will be grabbing the resources to sustain millions of people living in the desert. Forget about the cows...which if you are an ecologist such as myself, would be a silver lining in all of this, if the native ecosystems that are left weren't going to disappear along with them.

Labels: biodiversity, ecology, environment, invasive species

I was just getting ready to order some more dark amber maple syrup from my favorite sugarhouse, Green's Sugarhouse in Poultney, Vermont, when this article (subscription req'd - why, I'm not sure...) about the recent poor sugaring seasons due to warm temperatures this winter grabbed my eye. Here's a snippet:

Warmer-than-usual winters are throwing things out of kilter, causing confusion among maple syrup producers, called sugar makers, and stoking fears for the survival of New England's maple forests.

''We can't rely on tradition like we used to,'' said Mr. Morse, 58, who once routinely began the sugaring season by inserting taps into trees around Town Meeting Day, the first Tuesday in March, and collecting sap to boil into syrup up until about six weeks later. The maple's biological clock is set by the timing of cold weather.

For at least 10 years some farmers have been starting sooner. But last year Mr. Morse tapped his trees in February and still missed out on so much sap that instead of producing his usual 1,000 gallons of syrup, he made only 700.

...Over the long haul, the industry in New England may face an even more profound challenge, the disappearance of sugar maples altogether as the climate zone they have evolved for moves across the Canadian border.

Are U.S. maple forests going to be a thing of the past in a couple of generations? Remember, in much of the northeast American chestnut was the dominant tree until early in the last century, when the introduction of the chestnut blight via imported Asian chestnut trees destroyed our native species within 50 years.

Such a dramatic and destructive consequence of humans' compulsion to move species around the world (many for frivolous purposes), one might imagine, should have sparked a reassessment of the risks of such practices. But industry interests, i.e. short-term economic gain, have remained more powerful than the long-term interests of ecosystem health, even when one of the continent's most prominent and visible species was impacted, to everyone's knowledge at the time. The nicks and cuts on our native habitats from thousands of alien species and housing developments scattered here and there are relatively less noticeable.

So it's likely a losing battle with industries, not to mention very lifestyles, that contribute to climate change, but have a much more indirect impact than a fungal disease jumping from an imported to a native species. Those who would rather not deal with the issue often take the attitude that change happens, and whether or not humans are causing the current changes is irrelevant, because there were plenty of pre-human climate change episodes in earth's past, plenty of mass extinctions we had nothing to do with. One real difference between those events and the current one, however, is not only the accelerated speed at which these changes are occurring - the dinosaurs actually took millions of years to die out, while the loss of the chestnut was relatively instantaneous - but that a species is here to witness it that understands the implications of what it is witnessing.

No one growing up today knows the difference between a life with chestnuts and a life without. A hundred years ago though, those who depended on chestnuts for a living had to go through the agony of watching their very lives disappear with the trees. So it will probably be for those running the sugarhouses, many of which have been in the same family for generations. One reason I would feel the loss of this agricultural industry is that it is nearly the only one left that can't be converted into a factory farm. The most high tech sugarhouses run tubing from the trees to their boilers. Green's still does it the old-fashioned way: everyone in the family works nearly round the clock for a few weeks hauling buckets from the forest on a yoke. (The demanding nature of this work became particularly clear to me when I witnessed an 80ish, humpbacked grandmother stoke the flames with a log six feet long and the width of a telephone pole.)

In another hundred years, no one in Vermont will feel an emotional loss for the sugaring industry, because they will never have known it. But one more piece of the landscape will be gone, one more thread will be pulled out of the fabric of our environment. If humans weren't around, would it happen? Possibly. Would it matter? That one is a question for the philosophers. I'd like to know what you think.

Labels: ecology, environment, invasive species

One of the most species-rich families of plants in Hawai`i is the Rubiaceae, or coffee family. Several of these will be apparent as you walk along the boardwalk in the Alaka`i Swamp. While 22 species of the rubiaceous genus Hedyotis are listed in the Manual of the Flowering Plants of Hawai`i (Wagner et al. 1999, Bishop Museum, Honolulu), one species, Hedyotis terminalis (manono), has dozens of subspecies and varieties listed. The Manual says that this species "is probably the most polymorphic species among Haaiian flowering plants except perhaps Metrosideros polymorpha" [ohi`a, described in Part 1].

You can say that again. As I began my research project, I brought specimens of most of the plants to the botanists at the National Tropical Botanical Garden in Lawa`i for identification. After a few months I had learned the local species well enough, but in the process I believe I brought specimens of H. terminalis to one botanist at least four times. It got to be a bit embarrassing, but eventually I got a feel for the gestalt of this species.

Which brings me back to the end of Part 1, in which I suggested that the word 'species' itself may be inadequate to describe the current state of Hawaiian plants along the evolutionary continuum. The Manual admits there is no easy way to classify either H. terminalis or M. polymorpha into multiple species. Similar problems exist in some insect groups. Those doing DNA analysis of island endemics usually find similar genetic variation within a species to that between related species, which means it is nearly impossible to find genetic markers to distinguish species. Only by doing an analysis of multiple genes and seeing where an individual insect falls out on a plot of other known insects is it possible to identify it genetically. As I did with some plants, I had similar problems recognizing with certainty one moth species, Scotorythra rara, the most common one in the swamp. Once again, with the help from an expert in that genus, I understood the range of variation in that species enough to recognize it on site.

But given these difficulties, how do we know these moths or plants are all in the same species? Morphology is certainly useful, and in many insects, genitalia structure is key for separating species. But is it definitive? I'm not sure. For most Hawaiian insects, some major information is missing - their ecology and behavior. Entomologists in the islands work almost entirely with dead specimens, knowing little about how they live their lives. Among the hundreds of insects I reared and called S. rara, there were not only dozens of food plants, but multiple morphologies of the larvae (which are inchworms). When I first began rearing the insects, I assumed all these would be different species. And no one has a clue about their mating behavior, which is theoretically crucial to the actual definition of a species - if two individuals can interbreed and produce fertile offspring, they are usually (but not always, especially in plants!) considered the same species.

There is another genus of moths that positively exploded in its radiation in Hawai`i, called Hyposmocoma. There are over 300 described species of Hyposmocoma, and many in description limbo. I would not be surprised if there are actually over a thousand (as there are of a more studied fly genus in Hawai`i, Drosophila). Unfortunately, these are tiny moths, and even less is known about their life histories than about Scotorythra. An eminent entomologist I worked with on occasion at the British Museum of Natural History had tried to work on the taxonomy of the group, and had simply given up. Many specimens he studied with similar genitalia had different wing morphology, and vice versa. The larvae are case bearers, meaning they hang out in a little silken bag, and for some species the structure of the case seemed to be distinctive. But for most, it is apparently not.

Why are species so hard to separate in Hawai`i? Evolution is a continuous process, that has no endpoint. But because the Hawaiian Islands are so recent in geological time, and it is so rare for any living thing to arrive there on its own over vast expanses of ocean, I believe we are still witnessing the messy sorting out of niche-filling. The traits of different species drift and become more distinct from each other through several processes, including physical separation (via geological events, for example) and assortative mating (in which more similar individuals mate and reproduce). In Hawai`i, we have to ask, who knows what a species is? because we have not found a way to actually watch how individuals from all of these different groups interact with each other, and the environment. Speciation is not an instantaneous process, and in Hawai`i, along the boardwalk of the Alaka`i Swamp, we are watching it happen.

The plants and insects of the swamp are finding their way. Unfortunately, the evolutionary process can no longer stay on its natural course in Hawai`i, because of the habitat destruction and thousands of alien species that are invading the natural areas like the swamp and creating selection pressures that would not have been there without humans. I feel fortunate to live during the time that I do, that I had a chance to see a glimmer of what Hawai`i was really like. Of course, I don't know an ecologist there who doesn't wish we could go back in time a couple hundred years before Europeans came, or even a couple thousand years before humans were there at all. We have to be content with the few slivers of the real Hawai`i that are left, and do our best to protect them, although the future looks bleak. When I am in the Alaka`i Swamp, I forget about the continuing destruction below me. As I peer through the mist, all I think about is the wonder of evolution.

For more about the moths and plants of the Alaka`i Swamp, click here.

Labels: environment, evolution, Hawaii, invasive species

Although Walking the Berkshires beat me to it, I'm still going to put in my two cents about the latest problems plaguing beekeepers these days. After all, I am a hymenopterist (lover and researcher of the order containing ants, wasps, and bees), and I hobnobbed with scientists at the U.S.D.A. Bee Lab in Tucson when I lived there.

One scientist at the lab (no longer there) was Steve Buchmann, who advocated tirelessly for the study of the use of native bees as pollinators. Clearly one reason why this idea hasn't taken off is that native bees probably can't ever be big business, because they are (as far as I know) all solitary rather than social. This means you can't keep several thousand in a box and lug them around.

But even hardworking honeybees are not just a bunch of equipment. They are living organisms that have basic biological needs. The idea that we are just pushing the colonies we have left too far is an intriguing one. The reason bees are overextended is that there are too many disease pressures on them now, especially the notorious varroa mite. Certainly being trucked around the country to work isn't something bees' evolutionary history prepared them for.

Here's one site that claims we aren't as dependent on honey bees as we think. Note that it is from a vegan site advocating that vegans avoid honey, but it makes some valid points about problems with having a large dependence on a single alien species.

Perhaps an answer to the problem would be the use of "Africanized" (a.k.a. "killer") bees. Beekeepers from South America to Mexico have had no choice but to use these, because they always take over as they spread. Africanized bees were introduced to the Americas in the 1950's when researchers in Brazil hybridized African and European honeybees, hoping to create a super pollinator. Not only did they actually create a super agressive hybrid that is hard to handle, but of course the bees escaped and have been making their way north ever since. They have created problems for many native American bees along the way, able to outcompete them for resources in some areas. They are moving northward in California, so perhaps there will be enough wild colonies there soon to do the job.

Bottom line: when domesticated honeybees are around in droves, they may push competitors out. I'm betting the void will be filled, if not by wild Africanized bees, than by all the natives out there that just want a chance at their slice of the pollen pie.

Labels: bees, invasive species, USDA

The Alaka`i Swamp on the island of Kaua`i is not easy to get to. It used to be you could drive any rental car to the head of the Pihea trail and from there be quickly on your way into the swamp, but more often than not now the last mile or so of the road is closed due to potholes and persistent underfunding of the Hawai`i state parks system.

But in any case, the hike in is quicker from the Alaka`i Trail head. The 3-mile drive there, though, is not for the faint of heart these days. I was lucky; I began my research there in 1998, in the midst of a 4-5 year dry spell during which the road had just been graded; this may happen only every decade or so, probably whenever a bit of money can be freed up to do the work. By my last summer in the swamp in 2002, it was wet again, and the choice in many places was between trenching through foot-deep ruts or skating along the slick edges, while gunning the engine to get uphill, and beyond a steep drop-off to the deep canyon below.

From the trail head it is about a half mile until the beginning of the boardwalk. The boardwalk, built around 15 years ago, is a huge boon to hikers and researchers alike, and has helped protect a fragile ecosystem from constant erosion and trampling. The plants along this first part of the trail, including alien eucalyptus, fire trees, and the beginning thickets of strawberry guavas, are likely foreshadowing the future of the swamp; each time you return you notice the aliens have encroached a bit farther in. It's not just plants; it was a shock for me to discover ants in the swamp in 2002, never having before seen them in all the long days I worked there. (There are no native Hawaiian ants, but 40+ alien species have arrived on the islands, mostly via the horticulture trade.)

Finally, as you leave the edge of the boardwalk behind and march deeper into the Alaka`i Swamp, most of the alien plants melt away, and you are transported into a wonderland of island biogeography. Islands tend to have unique native flora and fauna, with many endemic species (occurring nowhere else). The farther the island from a continental land mass, from which species have naturally invaded over the millenia, the fewer the number of common ancestors that the island's species have. In taxonomic terms, this means you can end up with hundreds or even thousands of species within a single genus, as the descendents of a single common ancestor -- the seed washing up from the ocean, blown on the wind or stuck to a bird; the gravid female moth or ballooning spider blown off course for a thousand miles -- diversify rapidly (in geological time) to fill a whole new land of empty ecological niches. At the same time, whole taxonomic families of plants, insects, and birds do not exist in the islands, because serendipity did not bring them here.

This results in the unique jungle you pass through along the boardwalk, with one of the richest native plant assemblages remaining in the islands. The invaders are working their way in, though. To a local ecologist, the tangles of thorny blackberry plants and the sweet August aromas of kahili ginger blooms jar the senses, and turn the stomach. These don't belong here. They come from places distant enough that they could not have arrived by any method other than active human husbandry. But the blackberry is reaching farther and farther from the trails, its thorny branches and leaves standing out. No Hawaiian natives have thorns, including a native blackberry that supposedly occurs in the swamp, but that I have never seen in the wild. No native herbivorous mammals means no need for thorns; the imported pigs and deer here find the native plants quite succulent, and eschew the aliens with their defenses in place.

The ginger starts in a thick clump and spreads from there, quickly dominating light gaps before the slower native plants can gain a foothold. Despite the ecological damage this plant is doing, several species species of ginger are still sold as ornamentals. Apparently the profits of the horticulturists are more precious to Hawai`i's government than an ecosystem being slowly wiped forever off the face of the earth.

But these are the only two plants to gain a strong foothold in the swamp so far. Why? Is it because of the conditions here, which at times are decidedly untropical? On a winter day, the temperature can range from freezing to over seventy degrees farenheit; in summer the highs are much higher, the sun scorching at this altitude when the clouds have dissipated. The rainfall here is upwards of twenty feet a year. Rather than a true swamp, it is really a cloud forest, with most water provided in a constant dripping of condensation off the leaves, as opposed to torrential downpours.

Ohi`a, the dominant native plant, thrives under these conditions. It also thrives along the new lava flows of the kona coast of the Big Island, where barely a plant has yet gained traction, fresh water is only an occasional visitor, and the hard black lava radiates hundred-degree heat back on the trees from below. But you might suspect that a mutual transplant experiment would not work. The coastal Big Island ohi`a and the high-altitude Kaua`i ohi`a are two of dozens of subspecies of this plant classified within a mere three species, and they have clearly adapted to local conditions. But Hawaiian plants do not lend themselves easily to human-imposed Linnaean classification. The word "species" itself is completely inadequate to describe the multitudinous forms of life that occur in the world only on these islands.


To be continued...

Labels: environment, evolution, Hawaii, invasive species

A post at the invasive species weblog sums up a lot of the important issues surrounding invasives. One of my favorites for class discussion in my invasive species course is number 8: What is the definition of natural? Seems easy to define on the surface, but murky waters lie beneath. And the answer to this question is so incredibly important to how we regulate, control, and even think about species assemblages.

Difficult questions: Is everything humans do unnatural? Are only some things humans do unnatural? Why? There are some purists who fiercely contend that because humans evolved on this earth as every other species did, whatever we do is an extension of natural processes. The problem is that the logical conclusion of this particular natural process is the extinction of the majority of species on this planet. Of course for us ecologists, this is a painful idea, because we have built careers on our fascination with the diversity and complexity of life. Perhaps for most laypeople that appreciation just isn't there, and so I'm simply biased. One analogy I like to imagine is that of the linguists out there witnessing the extinction of hundreds (thousands?) of the world's languages as different cultures are wiped out or assimilated. Like species, they cannot be brought back. But for me the idea of lost languages is not emotionally charged as is the idea of lost species.

So I have to justify my belief that the movement of species around the globe by humans is an unnatural process, because it results in the loss of biodiversity. But I continue to struggle with the philosophical question of whether biodiversity has inherent value, or only a value imposed by humans (in the sense that gold and diamonds have value). Because I am human, I cannot answer this question completely. Biodiversity does have value to me, because life itself is awe-inspiring. Habitat diversity, an extension of biodiversity, is similarly important - i.e., India looks different from South Africa which looks different from Antarctica. This is partly what gives us our "sense of place" as so eloquently presented by Jeff Lockwood at the University of Wyoming. Many of us are disheartened by the strips of chain stores that characterize so many American cities now. (I literally have trouble remembering what state I'm in sometimes when cruising down such a strip.) The rapid, constant movement of species around the globe is resulting in the same phenomenon on the level of habitat. Look at the plants on most tropical islands these days, and they pretty much look the same, unless you find a really remote spot.

Such is the value of biodiversity to me. That's pretty much why I fervently believe that nearly all post- (and some pre-) industrial movements of species are unnatural and destructive. Even in the best-case scenario, when native species are not destroyed, when alien species quietly integrate themselves into a habitat with no overt ecological impacts, the habitat still suffers slow death by a thousand cuts.

Unfortunately, as far as policy-makers are concerned, short-term economics trumps all. Which means we pay a lot more down the road for control of invasives than we would now for prevention of species movements. And we only bother paying for the control of those which have a current economic impact. In this country, protection of biodiversity is hardly on the radar. Even in Australia and New Zealand, which have much stricter controls than the U.S., the political force of "free trade" (I'll leave the loaded definition of that term to the economists) is becoming overwhelming, with continual pressure to roll back what regulations there are. Which brings me full circle to a previous post.

Labels: biodiversity, invasive species

Perhaps this is advice to reiterate a little closer to the (northern hemisphere) growing season. But without any other pressing topics asking me for a rant at the moment, I would like to warn would-be gardeners out there to pay attention to what you are planting.

If you can, avoid big-box gardening centers such as Walmart and Home Depot. While I avoid them for other reasons as well, a biggie is that they distribute similar plants and seeds to all their stores around the country. So, many plants native to different areas (and different countries) are distributed to where they do not belong. I know that the Walmart in Butte, Montana goes so far as to sell seeds of plants forbidden by the state's Noxious Weed list. Every single year, the local weed folk have to go to Walmart and have them remove the illegal seeds from their shelves, because they don't bother to learn from their mistake - I suppose there are no legal repercussions available, which is unfortunate. Apparently the idea of being a good corporate citizen hasn't occurred to them either, when put up against the cost of keeping noxious weeds from non-native areas. The homogenization of our business communities and the homogenization of our landscape are not just parallel phenomena, they are inextricably intertwined.

Seeds meant for planting are not the only source of invaders - checkout the Invasive Species Weblog for info on an attempt by Oregon to start regulating birdseed. With all these unregulated pathways still existing -- despite the spread of significantly destructive invaders such as sudden oak death and the Asian longhorned beetle caused by free-trade-trumps-all thinking -- the fight for the conservation of biodiversity and habitat diversity truly seems an uphill climb.

Labels: invasive species