Exotic earthworms in U.S. hardwood forests function similarly to those in Europe and many other places. They break down the undecomposed mat of organic matter (which in Europe is considered characteristic of relatively nonproductive soil), turning it into soil that promotes rapid tree growth. The conversion of leaf detritus to mineral compounds is a key process in the recycling and utilization of organic matter and does not rob plants of nutrients.
Clive A. Edwards
Ohio State University
HALE REPLIES: Tennesen’s article represents the consensus of many researchers and peer-reviewed publications, in particular a set of articles in the September 2006 Biological Invasions with over a dozen authors.
Edwards has built a career on the beneficial impacts of earthworms, based on research in agricultural systems, which we do not disagree with. I make a point of telling my audiences that everything they have heard about earthworms being good for agricultural systems is true. But our research is based on native forest ecosystems of North America. Edwards’s contention that earthworms function basically the same in European forests as in North American forests is correct insofar as where earthworms are present they consume the litter layer, but beyond that the parallel falls apart. Earthworm-free, cold-temperate North American hardwood forests are diverse and naturally reproducing forests. Most hardwood forests in Western (and parts of Eastern) Europe, however, are beech-dominated. Earthworms are often absent in these forests because of very low pH. And when pH is increased, earthworms invade: the litter layer decreases, fertility and tree growth increases, but the increase in fertility is largely the result of the change in pH, not the earthworms.
Note: This article was originally printed with the title, "Letters."
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18 Comments
Add CommentEditor,
Reply | Report Abuse | Link to thisI have been reading Scientific American for 50+ years.
Matthew L. Walds reply to Jeremy Gormans letter was the worst Ive seen in your magazine. Im surprised you published it.
Wards reply is arrogant, pretentious, condescending, patronizing, overbearing, insolent, contemptuous, supercilious, and wrong.
Clearly, Wards myopic view has left him bereft of any appreciation or understanding for distributed efficiency and costs versus concentrated efficiency and costs.
His reply is appalling and disgustingly common these days from self-convinced experts, and I am disappointed you published it.
In these later years, your magazine is going the way of the media in general, a trend toward self-destruction exemplified by the New York Times, willful diminution of long-standing quality and credibility for a wider, and perhaps more fickle audience.
You can keep Ward and his ilk all to yourself.
Please cancel my subscription.
Ralph Nebiker
San Diego, CA
Re: In Brief, p. 30, Humanity's Ground Zero, July Issue;
Reply | Report Abuse | Link to thishappened at east latitude and south longitude?
Nebiker
Reply | Report Abuse | Link to thisThere is no advantage to "distributed" efficiency. Large plants are more efficient than small plants; it's as simple as that. It's more expensive to install 100- 50KW solar panels than one 5,000 KW solar panel; and the maintenance on 100 - 50KW panels in separate locations (this includes disconnect switches, cables, grid connections, batteries if any, etc.) is prohibitively expensive compared to one 5,000 KW solar panel in one location.
If you can quote me any authoritative text(not environmental propaganda) that states otherwise, I may listen to you. But I doubt you can do that.
I am all for local energy solutions where it makes sense. However, at this point in time, Ward got it right. At least here in Illinois. Here you will find very few small windmills, but a number of large wind plants. Why? Because the economics are hugely dependent on the height of the windmill. It is not affordable for me and each of my neighbors to put a windmill at 100 feet (or more) above ground to capture the energy. A large plant solves this problem as well as the critical maintenance point raised by Clemen.
Reply | Report Abuse | Link to thisHowever, the argument for Centralized Power avoids two other significant factors. 1) The cost of power distribution and the losses involved in distribution and 2) the continued security vulnerability of centralizes plants.
Reply | Report Abuse | Link to thisCentralized systems rather than point of use systems are argued as being more power for the dollar spent, but like any system, the more that are installed the more the unit price decreases. Distributed systems have the advantage of distribution, able to collect wind and sun over a much broader geographic region. Because the power is then mostly utilized locally with excess uploaded to the Grid, the transmission losses are insignificant.
Secondly, from a national security issue, having distributed power versus centralized power makes a significant reduction in vulnerability. No matter how many roofs with solar panels are taken out in a bomb, there are thousands more available to provide their own power as well as provide excess to the grid. With centralized power, significant costs are incurred protecting these centralized targets. The proponents of centralized power don't want to account for these ancilliary costs because their increase in efficiency is no longer significant.
Let the market decide what power source and it's distribution is best. Consumers will purchase the lowest cents/kwh option. Government subsidizes and picks options based on politics , not economics and science.
Reply | Report Abuse | Link to thisInnovation is the key and thsi innovation has to be driven by the market and yes greed. The desire to make a profit. It's what drives cell phones and computers it can also drive the power industry.
Get the government out of it and we will all be better off.
Mr. Nebiker,
Reply | Report Abuse | Link to thisYou seem to have gone quite bonkers over what I believe to be a fairly polite and well reasoned response by Mr. Ward. I'm suspecting you may have installed your own small wind or solar system and you are shooting the messenger who is telling you that your investment might not be so great. Or maybe you oppose both global warming and large corporations and are offended that anyone could think otherwise. I would like to hear any facts you have that could rebut Mr. Ward, if you have any.
Unfortunately Mr. Truthe2141, utilities is one area where Government Involvement is absolutely required. Without Federal Intervention the National Highway system would not have been built, without Federal Direction, the Power Grid would not exist. Without Federal mandates, radios, cell phones, telephones would compete with each other rather than operate fairly seamlessly.
Reply | Report Abuse | Link to thisYou are correct that we are at a political cusp, do we wish distributed power with each individual making their own power and selling the excess to those incapable of slacking their demand or do we want to perpetuate the big business model of always having to purchase every bit of power, being perpetual slaves to utility companies?
I push for individualism because I still forsee excellent opportunities for excess power brokerage and systems maintenance etc. It is simply a way to overthrow the status quo and the forced dependency and subsequent monthly bills which keep us chained to constant employment.
TPDibble
Reply | Report Abuse | Link to thisThere are two problems with your statement "Distributed systems have the advantage of distribution, able to collect wind and sun over a much broader geographic region". Point 1: The small distributed wind systems have a much lower efficiency than large wind parks because of the small height of the towers (as pointed out by Jojo), and the small size of the local sited generator. Both factors result in more materials utilized to produce less power. Solar power has a very low efficiency (solar to electrical) in either case (large or small). Point 2: This "larger" geographic region that you envision requires extensive transmission lines; otherwise you will not be able to upload your "excess to the grid" as you stated. Also, the grid (transmission lines) will be required to supply power to your house when the wind is not blowing (zero wind generation), or the sun has set. Therefore, distributed systems are low efficiency, high cost, high maintenance systems that still require extensive transmission lines.
I see them as beneficial to a limited degree. They should be used where they can be justified economically, and without government tariffs propping them up.
There are advantages and disadvantages to both centralized and distributed power. I would say that both are on about equal ground. While the large centralized stations tend to be more effecient and more cost effective for the amount the produce, you waste quite a bit of energy in transmission. In fact, up to 70% of the power generated is used simply to transmit that power around. So unless the power stations are more than three times as efficient as the small solutions, it doesn't matter. Of course, that percentage varies based on your distance from the stations, but the point is still valid.
Reply | Report Abuse | Link to thisThe main problem with small local generation isn't the efficiency of the systems, it's the storage of the excess. Batteries are costly and wear down. The setup can be complicated as well. Also, energy is lost in storage as heat so some of it is wasted this way.
The second issue is that small local generation is that the amounts produced are fairly small in comparison to centralized power. However, if the buildings being powered were built properly and efficiently, at least for homes they could theoretically use less than 20% of the energy used to power the average American home. This means these small local systems wouldn't need to be as big if the buildings were built better. Essentially, you could build a more efficient home for the same price as the average custom home of the same size and power it with solar/wind generation using a system that costs 80% less than that of one required to fully power the average home.
We have to think all inclusively. Looking at just a small piece of the picture does not address the complexity of the entire system.
Nebiker,
Reply | Report Abuse | Link to thisLike you I have been reading Sciam for a long time. I wish to express my support for your stand, I see many comments deriding what you say. I would not however cancel my subscription. I read a lot of stuff, like the bible, not for what it says - for me it is a history of man's ethical development. Lot saw no harm in offering his daughters to the thugs of his town to save his guests honour, I am sure you would not. Reading things that oppose your existing concepts tests these concepts and may even reinforce them.
Most of those that oppose you do so on financial grounds, these people do not understand money. Most of the money on the planet is debt - see "Money as Debt" on Utube. Money is the biggest con perpetuated on the common citizens of the world. The bulk of the money in the world is created by banks against the value of assets. You and I can not do this.
Why can't nation states create money based on the assets they are creating? Banks do exactly the same thing when they build themselves a fancy headquarters.
A distributed generating system will generate more jobs or self employ the owners, it will also protect the masses from the meltdown of big businesses brought on by corrupt management. Examples - the American banking system & the investment management firms. Think what would have happened to the world if the American government had not forgiven the criminal activities of its bankers and used taxpayers money to save the perpetrators of fraud.
Smaller banks and investment houses could not have caused this problem. Smaller generators will protect the citizenry from the corrupting power of big business. Yes you will need more capital, but that is only an intangible, non existing number on paper, that will reduce to nothing because we must have inflation for our economic system to work.
Correction:-
Reply | Report Abuse | Link to thisThink what would have happened to the world if the American government had not forgiven the criminal activities of its bankers and used taxpayers money to save the perpetrators of fraud.
This should read:
Think what would have happened to the world if the American government had not forgiven the criminal activities of its bankers and used taxpayers money to save the victims of fraud.
Nathaniel
Reply | Report Abuse | Link to thisYour statement that "...up to 70% of the power generated is used simply to transmit that power around." is totally false. I was involved in several transmission line designs, and know that they are designed for a "maximum" power loss of 10%. Many of the transmission lines are in the 5% power loss range because they are designed for a 30 to 50 year life with future expansion capabilities taken into consideration.
Please explain to me where you obtained your facts that transmission lines "absorb" 70% of the power generated from central facilities.
And, of course, energy storage is the problem. This is not only true for small, distributed energy facilities, but also large wind generation plants. That is why the largest wind energy producer in Spain is building three large pumped storage facilities. I was responding to TPDibble's comment expressing the fact that you could sell your excess "distributed" power to the grid, thereby having negligible transmission losses. This scenario does not acknowledge that you must have a "substantial" upgrading of the grid (read this as transmission lines) in order to accept all the distributed power he envisions.
TPDibble,
Reply | Report Abuse | Link to thisIt is true the transmission and distribution system is a right of way like the highway system and thus would require government regulation. However there is no reason for the government to be sticking their noses into the generating stations. The reason cell phones, TVs etc. have evolved into the products they are today is because of the free market and the government staying out of it. The govt allocates frequencies to prevent chaos but does not subsidize one type of cell phone over another.
Government is sticking their nose into our power system by subsidizing certain forms of generation with tax payer dollars. This will stifle competition and innovation and drive up the cost of electricity.
If AGW is real, and that is still pretty debatable, then have the govt set limits on CO2 emissions (no cap and tax scam) just like other emissions and step back and let private industry solve the problem.
Electricity is a large and lucrative business. I cant see how a sane consumer would want the govt meddling beyond the minimum level needed to prevent chaos. Would you want the govt telling Motorola what cell phone design to pursue next? Not if you want a good cell phone at a reasonable cost.
Let's see, I want to pay outrageous money to utilities when I can easily make my own power and sell it to them?
Reply | Report Abuse | Link to thisUnlike the people talking here I do RE and you can buy a good, reliable 1kw windgenerator now for $1k for home use. If handy one can make a good windgen for $300 in parts. Yahoo Axial Flux for info or join one of the many RE groups.
As for solar a CSP unit not only make 25-35% eff power but makes heat, hot water too for a home making it much more eff than a solar farm.
Now add homeowners pay 2x's as much for their power and payback is much faster, in /2 the time plus no transmission lines, land, labor which can cost as much as a solar/wind farm does.
Personally I can build my own equipment for 1/10th going prices so my payback is in a yr or so. In fact make money getting a check each month from the utility.
So go for distant wind, solar farms but myself I'll have my own and save, make a lot more than big RE ever could.
If connected to the grid no storage is needed and even if not storage is not that expensive. Nor is it a burden on the utility by being variable as they are already set up for that as loads are even more variable. And solar happen when most needed so is actually more valuable.
In fact one can make money even charging batteries at night cheaply and selling it back in the day.
So the author and those agreeing with him need to take your heads out of the sand and do some real math instead of the uninformed armchair quarterbacks your posts show you to be.
I thoroughly enjoy a good debate on ditributed versus centralised power generation. Very few people seem to think about how that power is used. Just looking at the average housing unit, you will notice that 80 % of the energy used is for low grade heat energy. That is, space heating/cooling and domestic hot water. If we took care of that usage using distributed units, then the need for centralised systems would be reduced to 20% of current values. Using daytime solar thermal systems for the Domestic hot water and heating, and night sky radiation for cooling could be used with the heat stored in thermal mass. Thermal mass is available in local water/earth/rock everywhere on Earth. Let's save high grade electricity for my electronics, self cleaning oven, and other labour saving devices around my home. have a great day, everybody!
Reply | Report Abuse | Link to thisWard obviously has an ax to grind, aligned with the conventional, and, as such, his views must be taken with several grains of salt. Me, I prefer thayt of j. Gorman, wherein I can opt to install my own devices (at my expense) to address renewables!
Reply | Report Abuse | Link to thisWard obviously has an ax to grind, aligned with the conventional, and, as such, his views must be taken with several grains of salt. Me, I prefer thayt of j. Gorman, wherein I can opt to install my own devices (at my expense) to address renewables!
Reply | Report Abuse | Link to this