In light of several comments on a recent post, it seems as though a more complete discussion of cost-benefit analysis might be useful. It is a process that is useful in many aspects of biology, from resource management to health issues.

The basic premise is that to make decisions, you need to estimate both qualitatively and quantitatively the potential costs and benefits of the possible choices, and use that information to make the best choice. The magnitudes of both cost and benefits are important, because balancing a large cost against a small benefit will result in a different choice than when the cost is small but the benefit is large.

The mistake most people make when making choices is to consider only the potential benefits, or the costs, but not both simultaneously. For example, the anti-vaccine movement exists mainly because of fears of side effects, specifically autism (a link which has not been established). Yet even if all the potential side effects do occur, they are extremely rare, relative to the benefit received in resistance to disease, many of which can be fatal. True, if only a few school children are unvaccinated they may get by given that disease is less likely to travel through a group that is mostly vaccinated. But this cheating can be harmful even for some vaccinated children, for vaccines that are not 100% effective (such as whooping cough).

The point is that to focus on a vanishingly small cost to vaccination which confers a huge benefit in protection from common disease is a completely irrational choice.

Another context where cost-benefit analysis applies is in the area of climate change. Here, the problem is a bit tougher, because the costs and benefits of trying to do something about it, versus not doing anything, are harder to estimate. One major consideration in this case, of course, is that we only get one chance to do something (and the opportunity to do it may already be vanishing rapidly). We don't get to figure out what we did wrong this time and fix it the next. So what do we do? We first must acknowledge the possibility that climate change could be catastrophic, no matter how small. This is a potentially huge cost to ignoring the issue. The benefit to ignoring it is easier to grasp - short term economic pains in readjusting our energy usage around the world, which is clearly a monumental task, would be avoided.

The benefit to doing all we can to avert a possible worldwide catastrophe is two-fold; first, we potentially save a lot of the planet, and second, many of the measures taken could have positive geopolitical results as well, e.g. reduction in demand for oil, and spurring economic growth in new alternative-energy industries. The cost mirrors the benefit for not doing anything - it is the difficult inertia needed to radically change the way we produce and use energy. The biggest part of the problem in looking at these costs and benefits is that if we choose to do something, the costs are biggest here and now, while the benefit seems far down the road. Most of the people setting policy in the powerful industrial countries that could take a stronger lead on this will likely be dead before the jury comes in on the outcome.

This video goes into more detail about these trade-offs, and convincingly makes the argument that the eventual benefits of doing something now outweigh the costs.

A similar case involves the control of invasive species. Even though most of the time the benefit in controlling them early far outweighs the potential cost of doing nothing, and having to control them later, we still tend to ignore them until they are too late to control. The reason for this is that our political system for government (which is responsible for making and acting on these decisions) overly discounts future benefits. So, time after time, we wait to see whether an introduced species gets out of control before we do anything to control it, and end up spending millions more than it would have cost to control it early on.

Another health example is cancer treatment. With all the progress that has been made, we still know very little about what we are doing in this area. In this case, people tend to focus on hoping for a strong benefit, and accept all sorts of hellish treatment (a significant cost) that may or may not benefit them. But this is one case in which it is very difficult to be objective, because we are dealing with our own mortality, and we buy into the idea that anything that can possibly help is worth doing. Is it possible to make a rational decision? For some people it is, but they are in the minority.

And come to think of it, it is way too much to ask the multi-headed government beast to be rational too. At least it is easy to make the rational choice about anti-bacterial soap.

Labels: economics, environment, health, invasive species

The mountain pine beetle (Dendroctonus ponderosae, Coleoptera: Scolytidae) is native to western North America. A finer resolution of its range, however, reveals that it is historically native to some parts of the West, but not others. Specifically, it has generally had a limited presence in Canada, primarily due to very low winter temperatures. Although the pine beetle's cold tolerance is incredibly high because they have the anti-freeze compound glycerol in their bodies, generally sustained (5 or more days) temperatures below -30F kill most of them off. This has reduced the likelihood of mountain pine beetle outbreaks in Alberta, and thus susceptible trees there have historically been protected, but are now exposed and being attacked (Rice et al., 2007).

In the last 5-10 years, however, conditions in the West, including Alberta, have changed. Rising temperatures have meant that for several winters in a row, the northern Rockies have not reached low enough temperatures to kill off the mountain pine beetles infesting the trees there. Even in the U.S., the historical trend was that every few years most of the beetles are killed due to cold, and thus the outbreaks were knocked back. So the pine beetles, which are a native species, have begun behaving like an invasive one: they are multiplying rapidly without a natural check, and expanding their range, attacking populations of trees that are not adapted to them.

Compounding this problem is the recent history of fire suppression in the West. One of mountain pine beetle's favorite hosts, lodgepole pine (Pinus contorta) is a fire-adapted species; it is common for lodgepole stands left undisturbed to burn once or twice a century, and be replaced by seeds from serotinous cones (cones in which the seeds are sealed unless they reach the high temperatures of a fire). Lodgepole stands are striking in that usually all the trees are the same age and size due to the burn regimen. Mountain pine beetles prefer older, larger trees. The larger the tree, the more food available for the developing beetle larvae, and the larger the increase in population the next year, if there is not a sustained hard freeze. By suppressing natural fires in lodgepole habitat, we may have enhanced the long term outbreak we are seeing now.

But here's the flip side: mountain pine beetle outbreaks make lodgepole pine stands more susceptible to fire down the road (Page and Jenkins, 2007). For instance, the 1988 Yellowstone National Park fires were highly correlated spatially with trees affected by a mountain pine beetle outbreak about fifteen years before (Lynch et al., 2006). What we may be experiencing now is a mega-outbreak, due to warming and fire suppression, which will eventually contribute to massive forest fires throughout the West in the future (also increasing of course from drier weather), which may have the benefit of being a different kind of check on mountain pine beetle populations. But instead of the historical ecology, in which mountain pine beetle outbreaks occurred for maybe 3-4 years, decades apart, a whole new, different ecology driven by constant high beetle populations decimating the forest, which as a result may burn more often, will remake the landscape in ways that we cannot yet imagine.

Of course there are those who believe that we can replicate the ecological benefits of fire, while keeping the timber available for human use. However, thinning trees mechanically is a blunt instrument that does not mimic the effects of fire at all in the case of lodgepole (Sibold et al., 2007). In fact, there is the danger of unintentionally increasing the density of trees (and necessitating, further, constant thinning effort) if enough of the canopy is opened to encourage new seeds to germinate and grow. There are those who believe humans are all powerful and can easily control insect outbreaks and fires through management if only the wicked, meddling environmentalists would let them (never mind that somehow the forests managed themselves just fine for millennia). In fact, many species are adapted to respond to biotic (e.g. herbivory pressure) and abiotic (e.g. weather) influences in ways we don't even understand. Global climate change is now accepted by anyone rational to be at least partly enhanced by the massive release of carbon dioxide into the atmosphere by industrial humans that would not have occurred otherwise. Fire suppression is an active (and expensive) choice that trades short-term convenience for long-term ecological disruption, whose consequences we are barely beginning to understand. Those who blame "environmentalists" for the hundreds of acres of brown pines they see spreading like a cancer in the West, would find that ecologists (pretty much environmentalists by default) only wish they had such god-like power to affect the ecology of our forests, so they could save them from 150 years of disastrous "management."


References

Lynch, H.J., Renkin, R.A., Crabtree, R.L. & Moorcroft, P.R. (2006) The influence of previous mountain pine beetle (Dendroctonus ponderosae) activity on the 1988 Yellowstone fires. Ecosystems, 9:1318-1327.

Ono, H. (2003) Mountain Pine Beetle Symposium: Challenges and Solutions. Kelowna, British Columbia. T.L. Shore, J.E. Brooks, and J.E. Stone (editors). Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Information Report BC-X-399, Victoria, BC. 298 p.

Page, W.G. & Jenkins, M.J. (2007) Mountain pine beetle-induced changes to selected lodgepole pine fuel complexes within the intermountain region. Forest Science, 53:507-518.

Rice, A.V., Thormann, M.N. & Langor, D.W. (2007) Mountain pine beetle associated blue-stain fungi cause lesions on jack pine, lodgepole pine, and lodgepole x jack pine hybrids in Alberta. Canadian Journal of Botany-Revue Canadienne de Botanique, 85:307-315.

Sibold, J.S., Veblen, T.T., Chipko, K., Lawson, L., Mathis, E. & Scott, J. (2007) Influences of secondary disturbances on lodgepole pine stand development in rocky mountain national park. Ecological Applications, 17:1638-1655.


Thanks to T. Etienne for initial information on mountain pine beetle

Labels: ecology, environment, forests, insects, invasive species

What do invasive species and chain businesses have in common? They exist in order to economically benefit a few people, at the expense of most people. They kill off local competitors, which has the long-term effect of destroying communities. We invite most of them into our landscapes and communities where they do their damage, and even help them establish, instead of making an effort to keep them out, or at least making them compete on the same terms as the locals. Each time we invite one in we think that this one couldn't possibly make a difference. We then complain and moan to the government to do something when the cumulative effect becomes obvious over time, but much too late to prevent. They homogenize communities, until over time, it's hard to remember where you are, just by looking around you.

Admittedly, these comparisons are apt only for intentionally introduced invasive species, but most of the worst ones are, because we gave them that leg up that helped them establish. Witness the many horticultural escapees, not to mention European starlings, which failed to establish more than once before an introduction finally took.

The ultimate reason that both invasive species and chain businesses exist is money. The few who expect to make a profit moving species around the world, and planting identical businesses around the world, benefit at the expense of the rest of us. We're the ones who have to expend time and money in a fruitless mission to eradicate pests such as purple loosestrife which was recently still available to buy in many states, even as it was belatedly placed on the noxious weed lists of dozens of other states. We're the ones who would prefer to get exercise, save money, and reduce pollution by walking to a nearby downtown to get what we needed, but who more and more every day have to get in the car and drive for miles to get the merest necessity.

The ecological community changes produced by invasive species and the human community changes produced by chain stores are slow in developing, so usually it is too late when we realize it is a problem. For some reason we do not learn from these mistakes, however. We continue to allow, apparently to serve general principles of economic freedom, importation of alien species which could become invasive, and we assign no responsibility to the importer if they do. We continue to compete for chain stores to open into our communities with tax breaks and other incentives because we are naively convinced by big business that the money brought into the community in the form of property taxes and minimum wage jobs from one employer is somehow better than the taxes and jobs provided by local businesses that will often be driven out of business by the chains. Somehow the profit that goes to local business owners, and thus stays in the local economy, versus the profit from chains that flies out of state seems always to be left out of the equation. Lower prices? Well, of course lower prices are necessary when there is less money in the community to spend. These stores don't arrive to serve an existing need; they create their clientele, rather like cheatgrass creates a fire-dependent ecosystem that extinguishes the natives unable to survive in it, but that suits the cheatgrass perfectly.

We need to stop the transformation of our ecological and economic communities. Downtowns are the heart and soul of small communities, and the small town leaders are letting them be gutted because they fear any consideration but short-term economics. This leads to exurb zoning where no one ever goes outside except to get in their cars. It is too late in many towns, but not all. Some are revitalizing city centers. Community leaders need to hear from those who believe that quality of life, including opportunities to walk and talk to other community members, is more important than a surfeit of minimum-wage jobs, just as nurseries need to hear from those of us who believe that it is not right to sell destructive invasives such as Russian olive trees, even if it is legal to do so.

Once the money, or the native species, leave the community, they are never coming back.

Labels: environment, humans, invasive species

The coqui frog Eleutherdactylus coqui, a native of Puerto Rico, gets its species name from the shrill call produced by males seeking mates, which is surprisingly loud for a beast the size of a quarter. Anyone from a part of the world with native tree frogs generally appreciates the lovely sound of calling peepers in the spring. Unfortunately, when the coqui was introduced to lands without its native predators to keep its populations in check, the lovely peeping sound in the distance was transformed into an overwhelming, piercing cacophony, which can be heard here at the site for Hawaiian Ecosystems at Risk (HEAR), where there is bountiful information on the hundreds of alien invasive species devastating Hawai`i's ecosystems. Listen to the recording. Then imagine playing it through your surround sound system at full wattage, and you will begin to get the idea of one of the problems caused by this species. After dusk, one literally has to yell to carry on a conversation at one house I have visited in Kurtistown (which lies between Hilo and Volcano on the Big Island).

Here is a youtube video of a single calling male. Well, puppies are cute too, but no one wants to live next to a kennel, do they? Even from a purely anthropocentric perspective, this invasive has much more direct effects on property values than any other. Control efforts are detailed at the University of Hawai`i College of Tropical Agriculture site.

While the attempted control of a tiny frog meets with far less opposition than previous plans to kill destructive feral cats in Volcanoes National Park, some PETA-types of course object. But even if you can tolerate the highly unnatural, deafening noise, anyone who cares about the ecological integrity of the Hawaiian Islands understands that coquis are a destructive pest that is incompatible with efforts to conserve endemic Hawaiian species (many of which are of course are living animals also).

Although predators in its native land clearly make an impact on coqui populations, it is remarkable how difficult it is, for humans at least, to localize a single calling frog. Apparently this is what the recent producers of smoke alarms were trying to emulate when they designed the system in which a dying battery causes the alarm to beep at long intervals. If your spouse, like mine, believes him- or herself to be the household's safety police, then you have about a dozen of these things littering your home, in every room. So, being able to find the one whose battery is dying is no trivial task. These contraptions strive to imitate the behavior of chirping frogs: as one attempts to hone in on the sound, they fall silent, in order to confuse and frustrate you, their predator.

As I have stalked around the second floor of the house, frozen for 30 seconds or more at a time, waiting for the next beep, my sympathies fall more into line with my father, who was decidedly not the Safety Monitor of our family. When smoke alarms first became available, my mother, whose very natural fear of house fires was grounded in personal experience, installed a single one in our split-level house. The first time it went off (the usual false alarm, of course, caused by kitchen smoke or whatnot) my father brandished a hatchet at the alarm, threatening over the excruciating whine to chop it to bits. Somehow my mother got the alarm away from him and turned off before he was able to make good.

My patience with the smoke alarms has run thin as well, every time I have to hurl one out the back door because my spouse insists on placing it in the kitchen, in defiance the manufacturer's instructions. "Ever heard of the smoke alarm that cried wolf?!!" I bellow.

But the Chinese-beeping-torture is the worst. I cannot move on with my life until I have ripped the innards from every alarm in the house, looking for the culprit, which is always the sixth or eighth one I've checked. My poor mother though, has seen the karma in her early support of smoke alarms. The Einstein who built the house she moved into several years ago placed a wired-in smoke alarm near the peak on the wall of their two-story living room, with only a narrow stair landing about ten feet below. Wired smoke alarms would seem like a better solution if they too did not have back-up batteries - after all, the power could be out when a fire starts. A note to contractors: even those batteries fail after several years - which my mother and her husband discovered when it started beeping - so, it would be a big help if those alarms were actually ACCESSIBLE! To get to this one required climbing a ladder placed on the landing at an alarmingly steep angle, a task most of us would rather not attempt, given our desire for the smoke alarm actually to save our lives, rather than end it. Thus, the residents had no choice but to wait two days for the services of their local fire department - who sent a fireman to make the climb and deactivate the alarm.

My mother called me shortly after the alarm had been firmly and permanently disconnected, and the haunted tone in her voice made me shudder at her recent trial. "It kept beeping..." she wailed, "Every. Twenty-six. Seconds." Though driven nearly to their wits end, their German short-hair pointer was clearly the most damaged of the three by the experience. Shortly after the beeping began he found the deepest recess of the downstairs guest room and burrowed within it, refusing to come out for anything but the quickest dash outside to relieve himself, after which he returned to his spot, trying, trying but (being a dog of very little brain) not succeeding in escaping the beeping torture. I witnessed his post-traumatic stress disorder on my next visit, when an inadvertent breaker pull caused one stray beep, and the terrified beast nearly knocked me over skidding to his designated burrow. Despite the fact that no more beeps were heard that night, the dog had to be crowbarred out of the corner of the room when I was ready to go to bed.

Really one of the stranger aspects of the low-periodicity beep torture is that it is not recognized as such by all vertebrates alike. Some friends, a family of four, invited us over for dinner once, and I noticed immediately upon crossing their threshold that they had a smoke alarm on the blink. I politely pointed it out to them, and astonishingly, the response I got was, "We know, it's been doing that for weeks now." Agog, I enquired with the grin frozen on my face, how they could stand it, and they just shrugged and said they didn't notice it after awhile. I tried to bear up under the strain, but by halfway through dinner I just couldn't keep myself from blurting out conversationally, "Wow, it's really amazing that the smoke alarm doesn't bother you." Being astute students of the subtleties of human communication, they finally got the hint, and one of them laughed as he went immediately to extract the offending battery.

I suppose that answers my question about why smoke alarms are programmed with predator-avoidance response. Those of us driven crazy by one are as likely to take a hatchet to it as a new battery (until we sigh to ourselves that maybe, just maybe it will save our lives one day), while the rest of everyone out there just can't be bothered to hunt them down (and may be selected out by unalarmed house fires). I just hope the people of Hawai`i have more success with accepting the grating chirp of the coqui than I have had with the grating chirp of a smoke alarm, because they will likely be there forever.

Labels: behavior, environment, humans, invasive species

Biological control of pest species has come under a lot of criticism in recent years. Employed by governments and private businesses since the late 1800's, the practice was largely unregulated until the 1980's, and regulation remains varied and complicated among different countries, and different states within the U.S.

Classical biological control specifically refers to the importation of an alien species to control pests that are usually aliens themselves. Traditionally, it has been employed in agricultural systems, in which the alien pest arrived in its new location accidentally. More recently, classical biocontrol has been undertaken to control pests in natural systems, which in the case of plants, were usually intentionally introduced through horticulture trade of botanical gardens. It is currently viewed by many ecologists as a critical tool in the battle against invasive alien species, which are growing into an ever larger economic and ecological problem.

The recent criticism of biocontrol has focused on the likelihood of "non-target" attacks, which occur when the introduced agent feeds on unintended prey or plant species, including natives. This is an especially important problem in areas with many endemic species - in the U.S., the states most affected are Hawai`i, California, and Florida because of their high native species diversity. The concern about non-target attacks is excessive, in the opinion of most biocontrol practitioners, including Messing and Wright (2006), who describe a scenario in which the peril to Hawai`i's agriculture and ecosystems is being increased by a bureaucracy that will not allow alien biocontrol agents to be imported, even to combat serious economic and ecological pests in Hawai`i that are contributing to the destruction of native ecosystems.

Certainly their concern for the native species of Hawaii is not misplaced. Invasive alien plants such as thorny blackberry crowd out natives and are less likely to be eaten by foraging alien herbivores such as pigs and goats. Generalist insects such as the two-spotted leafhopper consume hundreds of native plant species which have no natural defenses against the aliens feeding on them. So it does seem unreasonable that Hawai`i is so stingy with its species importation permits, when researchers do their best to show that their biological control agents will not feed on any native species. (I know both of the authors personally, and can verify that they are stringent in their criteria for potential non-target interactions.)

The problem with Messing and Wright's paper is the same problem with most discussions debating the use of biological control in the scientific literature, at conferences, and in online discussions. While we are focusing much energy and attention on predicting non-target interactions, which in many biocontrol programs has thus been adequately addressed, there is almost no discussion about doing a better job of predicting whether or not the introduced agent will actually be effective once introduced.

Messing and Wright themselves toss out that only 16% of effective biological control programs have been effective at controlling the target, and yet later in the paper complain about their inability to introduce agents, which is based on the assumption that the introduced agents will actually work. The high probability that (based on current practices) they will not work is never addressed in their paper. Twice the number of effective biocontrol agents, or around 33% actually establish -- probably an underestimate, since follow-up generally does not extend for years, and those that are not actively controlling the target could be missed early in monitoring -- and rarely has any follow-up been done to understand their role in the native ecosystems. If they are not attacking non-targets, and they are not controlling the pest, how are they interacting with native species?

It is true, as Messing and Wright point out, that in the current modern age of regulation, non-target effects have greatly decreased. But it is also true that even in the case where a known specialist was introduced, there can be indirect food web effects discovered when people have taken the trouble to look, which they rarely do. In one case (Willis and Memmott 2005), a native parasitoid attacking an specialist insect herbivore introduced to control an alien weed increased greatly in numbers and thus made native herbivores much more susceptible to attack, upsetting the food web in the system.

Effective biological control programs are indeed cost-effective, but a lot of money is spent for many years on the assessment of a single agent, and are we getting our money's worth if only 1 in 6 actually work? A whole new science may need to be developed to further our ability to predict the effectiveness of biological control agents. Those who are generally against biocontrol find the balance of effective agents vs. the risk of non-target effects, which while getting lower, will never be zero, to be unacceptable. What if biological programs could predict effectiveness 50% of the time? That would alter the equation, and make these programs more palatable to many ecologists such as myself.

How can something as notoriously unpredictable as species interactions be better assessed before release? One method which would give researchers much better data about the role of species in both native and alien habitats is the construction of quantitative food webs. Normally when biocontrol workers go the country of the target pest's origin, they observe only the two-species interactions between the target species an its natural predators or herbivores. This provides no predictive value because plants and animals do not interact in 2- or 3-species bubbles, they interact complexly both directly and indirectly with many species. Why don't we construct food webs of biocontrol agents in their native habitat and figure out why they seem to be effective there? We can also do retrospective studies on established biocontrol agents that are ineffective and use food webs in both the new and native habitats to try and understand why.

Of course, ecological research is conducted at the whim of funding agencies, largely NSF in the U.S. Politics and inertia often determine what is funded more than science does. Perhaps someday, however, people will realize that for both economic and political reasons, research into the prediction of the effectiveness of biocontrol agents makes clear economic, ecological, and political sense. We do need biocontrol as an option for saving some ecosystems. But we particularly need biocontrol that works.


References

Messing, R.H. and Wright, M.G., 2006. Biological control of invasive species: solution or pollution? Frontiers in Ecology and Evolution 4:132-140.

Willis, A.J. and Memmott, J. 2005. The potential for indirect effects between a weed, one of its biocontrol agents and native herbivores: A food web approach. Biological Control 35:299-306.

Labels: ecology, Hawaii, invasive species, USDA

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