Sweet potato: key to Hawaiian dryland agriculture systems?

New archaeological studies from the famed Kona Field System appear to confirm the dramatic expansion in organized Hawaiian agriculture starting as early as the year 1300, and certainly by the late 1400s.

In terms of calories produced, one of the key crops of the drylands was the sweet potato. Did the late arrival in the Islands of this rich source of carbohydrates prompt the development of extensive, highly organized dryland agriculture? It's possible, researchers said. The crop was popular enough that large sections of land were dedicated exclusively to its production.

(Image: Sweet potato in a modern dryland agricultural application.)

The new study, published in the May 2009 issue of the Journal of Archaeological Science, includes a dozen radiocarbon dates from the Kona agricultural fields, but the authors also studied pollen, starch grains and cellular material from plant materials found in the soil at a dozen locations.

The paper is “Sweet potato (Ipomoea batatas) and banana (Musa sp.) microfossils in deposits from the Kona Field System, Island of Hawaii,” by Mark Horrocks, of The University of Auckland School of Geography, Geology and Environmental Science in New Zealand, and Robert Rechtman, of Rechtman Consulting in Keaau, Hawaii.

“The oldest radiocarbon ages of the sampled deposits are 1300–1625 AD and 1310–1470 AD,” the authors write.

The Kona Field System is perhaps the most famous dryland agricultural system in the archipelago. It is a vast area on the slopes between Kailua and Honaunau on the Big Island, where plantings of sweet potato, paper mulberry, breadfruit, dryland taro, bananas and other crops were grown in elevation zones linked to the species' moisture requirements.

Researchers have suggested that this kind of large-scale, organized agriculture could not have occurred without a centralized governing authority, and the establishment of the Kona Field System has been linked by some to the first island-wide governance, perhaps by the famed chief 'Umi-a-Liloa.

Horrocks and Rechtman said they were able to identify various kinds of pollen, and the remains of banana leaves and starch from the roots of plants, including of sweet potatoes.

They found that pollen evidence for trees and shrubs appeared to suddenly decline as the cultivated plants appeared—suggesting land clearing of forested areas for agriculture. There was also evidence that sweet potatoes were being grown exclusively in some specific areas.

“The apparent absence of starch and xylem remains of other tuberous crops archaeologically identified elsewhere in Polynesia suggests that tuberous cropping within the study area was mono-specific,” the authors wrote.

Other places in Hawai'i also had agricultural field systems. There is another well-known field system at Kohala. And on Moloka'i, there is recent evidence that the Kalaupapa peninsula, whose agricultural fields were once believed to be post-European, extended well back into the prehistoric period.

Researcher Mark McCoy, now an anthropologist with San Jose State University, conducted extensive research on the peninsula that juts northward from the base of Molokai's cliffs. In a paper published in 2005 in the Journal of the Polynesian Society, “The Development of the Kalaupapa Field System, Moloka'i Island, Hawai'i,” he cites dates similar to those of the Kona Field System.

“This field system was largely ignored in previous discussions of Hawaiian agriculture because it was initially assessed to be a 19th century construction,” he wrote.

Radiocarbon dates of botanical material found on the peninsula and in adjacent valleys suggest that there may have been humans there perhaps as early as 800 AD and almost certainly by 1200 AD.

There are questions about the validity of the earliest dates, but certainly by 1200, Hawaiians were in the area and beginning to establish settlements. And while there is some evidence of agricultural activity, it appears this was not particularly intensive for another 250 years.

That's when the serious land clearing started.

“Widespread burning across the Kalaupapa Peninsula, which signals of the beginning of the Kalaupapa Field System, does not commence until 1450-1550,” McCoy wrote.

The field system appears to have been abandoned at Kalaupapa in the late 1700s, and then reopened about 1850, as Hawaiian farmers began providing potatoes and other crops to the participants in the California gold rush.

This revival of agriculture at Kalaupapa was halted in 1866, when the crown relocated native residents of the Kalaupapa region to establish the Hansen's disease colony there.

In general, McCoy said that the field system studies, along with other archaeological work, tends to suggest that residents settled and farmed the wetter regions of the Islands first, and then moved into the drier areas.

Why did the move from wet to dry occur about the same time in many areas? Perhaps it was population pressure. Perhaps it was the arrival well into the last millenium of the sweet potato, a crop from South America. Sweet potatoes, 'uala in Hawaiian, do not appear in the earliest archaeological sites, suggesting they had not yet arrived.

“There are a number of equally attractive, alternative hypotheses to explain concurrent construction of field systems in the Hawaiian Islands, including the late introduction of the sweet potato, population pressure, an increased demand for social production to fuel the political economy, or a combination of some or all of these,” McCoy wrote.

© Jan TenBruggencate 2009

Electric cars: Hot, hot, hot!

The hottest car in the world may be an electric car.

For those of us accustomed to thinking about golf-cart-like electric car models, something like Tesla's Roadster is the game changer.

It's what car magazines would call “smoking hot,” a sexy low-slung sports car that goes 0-60 in four seconds, and whose top speed is double the highest posted speed limit in Hawai'i.

Touch the car with a finger and go “Sssss.” (Image: Tesla Roadster. Credit: Tesla Motors.)

There are a couple of them in Hawai'i already and more coming, bought by well-heeled customers. (They run a bit north of $100,000.)

Tesla just picked up $465 million in federal loans for efficient cars, which Tesla will use most of to produce its latest product, the $49,900 Model S, a seven-passenger family sedan with four doors and a range, depending on battery package selected, of up to 300 miles per charge. (More than my truck gets between fillups.)

But Tesla's far from the only player in the field, and Tesla's not what we're talking about when we say the hottest car in the country may be electric. Rather, we're talking about categories.

In Hawai'i, Project Better Place has planted its flag. The company has a new paradigm for electric cars, creating a charging and battery replacement network that it expects will make ecars the standard. (Charge them at home or at work—no gas stations. Need a quick charge? Just swap the battery pack.)

The Hawai'i Legislature this year passed a bill to allow Project Better Place to issue $45 million in special revenue bonds in Hawai'i “for the planning, designing, construction, and development of transportation infrastructure, equipment, and apparatus to support electric vehicles in Hawaii.”

Gasoline is the place where cars have been, and electric sure looks like the place the automobile is going.

Tesla got its half-billion from Uncle Sam, but it was just a bit player.

The U.S. Department of Energy has a $25 billion box of cash for energy efficient vehicles, and a fair chunk will be focused on the electric vehicle. Tesla's loan came from there. Nissan is slated for a $1.6 billion loan to build, in the United States, electric vehicles, as well as to build a new battery manufacturing plant.

Nissan's first electric car is scheduled out by the end of next year. That one is to be built in Japan, but using the federal money, Nissan expects to produce an American-built ecar by 2012.

Ford is in for a big chunk of change for efficient vehicles, about $5.9 billion, and

is promising multiple models of pure electric and hybrid cars in the coming years.

The American-made electric vehicle that's probably gotten the most news play is troubled General Motors' Volt. It's been argued that the company is pinning its entire future on the success of this car, which is not technically a pure electric car, but a plug-in hybrid. They're talking about a $30,000 price.

Chevy just showed off the production model, which thankfully is far more attractive than its boxy concept style, has a couple of really nice exterior features, but overall seems rather staid to this reviewer. (Image: Volt. Credit: GM.)

But it could be worse. Tata has announced an electric version of its Nano. (Think golf cart). (Image: Nano. Credit: Tata Motors.) And there are lots of electric cars in the golf cart style, like Norway's Buddy, and India's Reva. (Go ahead and Google, Yahoo or Bing them). Cute, but it's not clear you'd feel comfortable on the freeway.

The Mini Cooper has a Mini-E, its electric counterpart. It takes twice as long 0-60 as the Tesla Roadster, but this car has its own brand of cool.

China has announced it plans to be a world leader in electric cars in as little as three years.

Ecars, once ridiculed, are filling all the vehicular niches: your small cars, your big cars, your hot cars, your cute cars, even your dorky cars.

This is a wave. Might want to start paddling.

© Jan TenBruggencate 2009

Repairs as art--beyond recycling!

There was a time when you just fixed broken stuff, no questions asked.

Busted handle on a teacup? You glued it.

Cracked metal on a mower, you got a neighbor with a torch to weld it.

Today that stuff ends up at the dump, and there's a thriving market on eBay and in stores for replacement gear.

We toss things out casually, often when they are still functional, and only challenged aesthetically.

A Dutch design firm, Platform21, and the Dutch magazine BRIGHT are collaborating on a contest for repairs that are not only functional, but creative and attractive. Dremel will give away a multifunction tool to winners. Winners will also get the repair award seen in the photo above, by artist Jan Vormann.

“Have you ever repaired something that unintentionally turned out to be more beautiful or extra handy? A repair that you were very proud of? Or is there something broken in your home that is in bad need of repair, but you need some encouragement to start fixing? Now is the chance,” they said in a press release.

“Whether it is a torn car seat, an exploded bread toaster, or your ripped jeans, if you didn’t throw it out but repaired it with love and care instead, we would like to see it... We invite submissions of clever, funny, skilful or creative repairs, with their stories attached, from all over the world.”

It's a great idea. A lot of us are doing what we can with the three Rs—reusing, recycling and reducing—but how much fixing is there?

Repairs as art. What a concept.

Entries with photographs can be emailed to info@platform21. For more information, see the websites www.platform21.nl and www.bright.nl. The deadline is August 30, 2009.

Platform21 has developed (you can see it at the website) its Repair Manifesto. Some of the points:

Things ought to be designed so they can be fixed.

Repair is independence.

Repaired things are unique, and collect memories. Furthermore, “even fakes become originals when you repair them.”

The design company argues that there should, in fact, be not three Rs, but four of them.

“Stop recycling. Start repairing,” it says.

© Jan TenBruggencate 2009

Need a jump, sugar? A sweet new battery technology.

You got your lead-acid batteries, your lithium batteries, and of course, those sugar batteries.

Sugar batteries?

Battery technology has been identified as a key factor in the future of alternative energy, and lots of folks are working on ways to advance battery science. Some of it tweaks existing technologies, and some is going to entirely new places.

Two researchers from the University of Hawai'i's Hawai'i Natural Energy Institute, Daniel Scott and Bor Yann Liaw, have just published a report on a new way to use sugar to produce power in a battery.

The paper is “Harnessing electric power from monosaccharides—a carbohydrate-air alkaline fuel cell mediated by redox dyes,” printed in the journal, Energy & Environmental Science. The link: http://www.rsc.org/publishing/journals/EE/article.asp?doi=B906770A.

“Here we show a simple, inexpensive approach to harness chemical energy from glucose, converting it directly into electric power without a precious metal, enzyme or microorganism to promote monosaccharide oxidation,” they write.

There's still a long way to go before you can power your cell phone with a spoonful of cane sugar. The researchers are still working out the details of the system, but their laboratory battery produces power, and produces it for an extended period of time without a lot of fuss. Scott and Liaw feel there's potential in their system.

“This approach might open the door to a broader possibility in using such monosaccharides in energy storage and harvesting to power small devices,” they write.

There have been sugar-based batteries before, but most have problems that interfere with their movement into commercial production—problems like cost, complexity, short operating times and so forth.

The Scott-Liaw battery system uses off-the-shelf components, and functions at room temperature and pressure.

“The resulting current and power density surpasses any existing glucose fuel cell designs. It is simple to assemble and operate with a variety of inexpensive raw materials. The process uses materials that are abundant and therefore is not projected to be resource limited.”

© Jan TenBruggencate 2009

(Just for the record, the image of a spoonful of sugar with a couple of electrical probes in it is a joke.)

Climate dogs that won't hunt

Remember the cold weather of January, February and March?

They were days and nights so chilly that some climate change deniers of my acquaintance actually cited them as proof against climate warming.

Well, that's just so last season.

April warmed up some. The fifth warmest April since records have been kept. Here's the citation for that, from NOAA: http://www.ncdc.noaa.gov/oa/climate/research/2009/apr/global.html.

Next? May was hot, too. The fourth warmest ever. Here's that citation: http://www.ncdc.noaa.gov/oa/climate/research/2009/may/global.html.

As you might expect from those figures, the spring season as a whole is also turning out pretty warm. March to May had the fifth warmest record for any northern hemisphere spring.

It wasn't that hot everywhere all the time, of course. In fact, NOAA cites Hawai'i's cool late winter and early spring:

“March-May 2009 temperatures were above average across Mexico, Europe, southern South America, northwestern Alaska, northwestern and southern Africa, parts of Australia, and most of the contiguous U.S., and Asia. Cooler-than-average temperatures occurred across the Hawaiian Islands, Canada, and parts of the north central and northwestern United States,” the agency said.

Climate, after all, is variable on any number of scales. It's variable over time. It's variable over geography. If you can't step back and see the bigger picture, it's hard to draw reasonable conclusions.

The graphic at the upper right of this post shows how January to May temperatures around the world have differed from the average since about 1880. Over an extended period of time, the short-term variations fall into the background and the warming trend is quite clear.

But it is also clear that there's a significant amount of variability within the larger trend.

Some folks point to the flat to downward trend of the past five or six years as proof of a cooling climate. That's a little like claiming that a cool week in February is proof of cooling.

To descend into hackney, we'll just say this: That dog won't hunt.

© Jan TenBruggencate 2009

Sea levels rising, responses needed on land

New sea level science suggests the oceans will rise faster this century than previous predictions have suggested.

The suggested rise puts most beach parks under water, along with coastal roads, and, of course, Waikiki.

(Image: An Hawaiian coastline.)

The United Nations Intergovernmental Panel on Climate Change suggested oceans could rise a couple of feet, give or take, by 2100. But that estimate entirely excluded the impact of two immense reservoirs of frozen water—Greenland and Antarctica.

It left them out because the science of determining how they might melt and impact ocean levels was not clear.

Science is now slowly gaining clarity, and for coastal places like Hawai'i, things don't look good.

A recent study by scientists from the University of Alaska Fairbanks found that the Greenland ice sheet is contributing a quarter of all sea level rise over the past 13 years, and that sea levels are rising 50 percent faster than the average of the last century. This scientific paper by Sebastian H. Mernild, Glen E. Liston, Christopher A. Hiemstra, Konrad Steffen, Edward Hanna, and Jens H. Christensen, in the journal Hydrological Processes, is entitled “Greenland Ice Sheet surface mass-balance modelling and freshwater flux for 2007, and in a 1995-2007 perspective.”

Researchers are predicting that the East Coast of the United States could face by 2100 sea level rise of six feet. Presumably Hawai'i will have levels somewhere close to that. But how to respond?

“Recognition of the need for an adaptive approach necessarily counsels governments to implement initial adaptation measures that will be beneficial to coastal communities regardless of how far the oceans encroach and how fast they do so,” wrote Florida State's Robin Kundis Craig in a paper in the Widener Law Review. The abstract is available here: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1119563#.

Craig said coastal areas need special planning approaches.

There are two problems, Craig says. One, we don't have planning systems capable of responding to a crisis that builds over multiple decades and centuries. And two, the science may tell us it's coming, but it can't yet be clear about how high the sea will rise when.

If planners can't bring themselves to actually do land use planning in response to the threat, at least they could do some public health planning, she argues.

“Taking a public health approach to sea-level rise can provide governments and planners with immediately implementable and no regrets adaptation measures that will be beneficial to coastal communities regardless of the eventual actual impacts of sea-level rise in particular areas of the country,” Craig wrote.

She cites three examples: to ensure drinking water supplies will be protected in a rising sea level environment; protecting medical infrastructure to address disease exposure problems; the potential that ocean water will be contaminated by toxic materials from the nearshore land.

A Hawai'i example is University of Hawai'i coastal geologist Chip Fletcher's assertion that during high tides in a high sea level environment, coastal sewer lines could be compromised.

It's just another caution.

© Jan TenBruggencate 2009

Bufo decline a towering mystery

Hawai'i's population of bufos is in big trouble, and that unfortunately is good for termites.

This is purely an anecdotal observation, but there's lots of anecdotal data.

(Image: The death of this particular bufo is no mystery. It was run over by a car.)

For some years, longtime Hawai'i residents have commented there seem to be fewer dead bufos on the road. And that you see fewer bufos sitting out on the road on rainy nights.

My own unscientific addition to this body of evidence derives from the annual termite swarms of early summer. On calm, hot nights of late May and early June, termite alates swarm out of their colonies before sunset, and go looking for new sources of cellulose on which to gorge. They do it, probably, by the tens of tens of millions.

They are attracted to lights. That means you'll see a living halo of flying insects around every street light. And if your lights are on in the house, they'll soon be inside, dropping their wings and slipping behind molding and into furniture, looking for the right environmental conditions to launch new colonies.

Like many Hawai'i residents, I'll reduce house lights to a minimum and fire up a lantern and set it out in the yard. The termites soon swarm to the lantern light.

And this attracts bufos, which proceed to gorge on termites. Sometimes they fill up so completely they can barely hop.

Several years ago, I counted 17 bufos one night, circling the lantern, all of them feasting.

Last week, one night when the termites swarmed, only three bufos appeared. Last night, just one bufo.

What this means in the larger picture, I don't know. But around here, clearly there are fewer bufos this year than just a few years ago. Lots fewer.

Bufo marinus, the giant neotropical toad or cane toad, was brought to Hawai'i to control insects, and it does. It is an invasive critter, and in some parts of the world (Australia, for instance) it is a real problem because it primarily eats native creatures. Here, it's mainly eating aliens.

The bufo will eat rats, mice, cockroaches, termites and ultimately, almost “any terrestrial animal” it can fit down its gullet, according to the Global Invasive Species Database (http://www.issg.org/database/species/ecology.asp?fr=1&si=113.)

It's best not to handle the bufos, or to let your dog or kids play with them, as they exude a powerful toxin through their skin. (My dog Socrates died in convulsions after chewing on a bufo.)

But it appears to be suffering from the mysterious decline that is affecting frogs and toads globally—all of them, except the coqui frog in Hawai'i, it seems.

In Australia, an epidemic disease has been identified as a culprit killing rain forest frogs of multiple species. But in most cases, the causes are not clearly understood. Amphibians are being lost around the world, with more than 100 species extinct in recent decades (http://amphibiaweb.org/declines/declines.html.)

Among the suspects in the decline are habitat loss, an unpronounceable fungal disease called chytridiomycosis, climate change, chemicals, and ultraviolet radiation from the sun.

In many cases, frogs and toads are being found with bizarre deformities. Extra legs. Extra eyes.
The U.S. Fish and Wildlife Service is looking into the possibility that it might be some kind of contaminant (http://www.fws.gov/contaminants/Issues/Amphibians.cfm.)

I'm not aware that anyone has identified a factor in the Hawai'i bufo decline, but it seems clear there are fewer of them.

Which is good, unfortunately, for termites.

© Jan TenBruggencate 2009

El Nino this summer: wind to blow heavy, maybe

Trouble is coming.

Or, at least, in the careful terminology of government agencies, there is a slightly increased chance of unusual storm activity and low rainfall as the result a shift in the cyclical El Niño Southern Oscillation pattern.

We haven't had a strong El Niño event since 1998, when 13 named storms and nine full hurricanes launched themselves in the Eastern Pacific. Only three named storms were in the Central Pacific that year, and only one of those a hurricane. It was a low year.

But that's not the standard. The standard is more hurricanes than normal in El Niño years, when waters south of Hawai'i and east toward Central America are warmer than normal. Warm water feeds tropical cyclones. (Here's a nice primer on what's involved in an El Niño: http://www.physicalgeography.net/fundamentals/7z.html.)

Since 1998, the Pacific has had a succession of La Nina (cooler than normal waters) and weak El Niño events. Storm activity for us in Hawai'i has been below normal for a decade now.

Let's do the math.

1999: Nine named storms in the Pacific, a low number. Hurricane Dora slipped by south of Hawai'i.

2000: Twenty-one named storms, but few significant ones. Tropical storm Upana went past well to the south and Hurricane Daniel cruised by, skirting the Islands to the north as it weakened.

2001: Nineteen named storms, almost all of them remaining in the eastern Pacific. Narda came in our direction but died hundreds of miles away. Tropical Depression 2C made a brief appearance far to our south.

2002: Nineteen named storms again. Tropical Storm Alika passed south but didn't pose a significant threat. Hurricane Ele formed south of us, drove west to the International Date Line, and then skittered north, well out of Hawaiian waters. Late in the season, Huko followed a vaguely similar pattern.

2003: Seventeen named storms, none threatening Hawai'i. One tropical depression formed briefly far south. A couple of storms slipped into the Central Pacific from the east but quickly dissipated.

2004: Seventeen named storms, none posed a risk to the Islands.

2005: Seventeen again, with only Kenneth threatening the islands—and only as a dissipating system.

2006: Nineteen named storms. Hawai'i was never at risk, but powerful Ioke pounded Johnston Atoll and then went on to flood and severely damage facilities on Wake Island. Daniel looked like it might cause trouble, but didn't. And Fabio brought some rain.

2007: Only 15 named storms in 2007. Cosme passed south. Flossie barely skirted South Point, but then weakened and turned southwest.

2008: Nineteen named storms. A July hurricane named Elida was briefly forecast to reach Hawai'i, but never did. A month later, Genevieve slithered in from the east, but had little more than rain showers when it finally reached the Islands.

So, a decade of largely quiet hurricane seasons for the Islands.

Why believe things might change? They might not, but after two years of La Nina conditions, we're entering another El Niño. The folks at NOAA's Climate Prediction Center on Thursday announced that there's a better than even chance that we're moving into it this summer.

Here's how they put it: “Conditions are favorable for a transition from ENSO-neutral to El Niño conditions during June − August 2009.”

These climate folks have an array of tools for prediction. They caution that some of their tools say it may simply be a neutral year—neither El Niño nor La Nina. But a pile of tools, which they call their “dynamical models” are leaning strongly toward El Niño. Read their summary at http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf.

In an average year, we get three or four named storms in the Central Pacific. (Named storms are simply the term for tropical systems strong enough to be given a name.)

In an El Niño year, there's on average about one more named storm, but shoot, that's nearly a 30 percent increase.

So, there could be trouble. Probably not. But it pays to check the front of your phone book and be sure you have your hurricane kit up to date, and you know what you're going to do if the wind blows heavy.

© Jan TenBruggencate 2009

Wind energy isn't just spinning propellors any more

Among the primary concerns about wind energy: the appearance of giant towers with massive spinning blades; and the risk that those blades kill birds and bats.

Traditional spinning rotor windmills work. They're well understood. Big companies use them to produce utility-scale power, and sailboat owners use them to charge their batteries. But they're hardly the only players in the wind space.

(Images, top to bottom:

Cleanfield Energy Turbine http://www.cleanfieldenergy.com/;

Quiet Revolution eggbeater design http://www.quietrevolution.co.uk/;

A Windspire turbine http://www.windspire.info/;

Helix Wind's curved shape http://www.helixwind.com;

Windation's rooftop box http://www.windation.com/;

Leviathan's Wind Lotus http://www.leviathanenergyinc.com/wind-lotus.html)

In part because of the bird strike concerns, a great deal of research is going into alternative wind generators that don't have really high speed propellor tips.

A traditional windmill has what's called a horizontal axis—meaning the shaft that is spun by the props lies parallel to the ground. An alternative is a vertical axis unit, in which the spinning shaft sticks up in the air like a flagpole.

And there are absolutely dozens of these vertical axis designs: ones that

look like egg beaters, ones that look like a geneticist's double helix, ones that look like oil barrels with the sides ripped open.

The American Wind Energy Association (http://www.awea.org/faq/vawt.html) says there are two basic kinds—lift-based and drag-based.

The little wind-speed devices with three spinning cups are drag-based. The cups never move faster than the wind speed, and generally move slower. The old Savonius Rotor system is another drag-based unit. These generally don't work real well to generate electricity.

There are lots of lift-based designs. They look, as mentioned above, like egg beaters. They can have vertical blades spinning around a vertical shaft. And there are those intriguing helix designs.

Many of them are unlikely to cause bird strikes, largely because they appear from a distance like a solid object.

The longer our energy crisis goes on, the more options present themselves.

If there are companies out there with different designs, send up an image and some background and we'll be pleased to post it. The email is hawaiiwriter@gmail.com.

© Jan TenBruggencate 2009