Glomalin and Conservation in Humboldt County The 1996 discovery of the soil glue glomalin is changing our understanding of the impact of elevated carbon dioxide, while giving important clues to forest health, watersheds, revegetation, wildfire and carbon sequestration. Here I share what I have found so others may read and draw their own conclusions, and relate it to my own experience, Humboldt County issues and stories from the news.

Sunday, July 11, 2004

48. Two Days of Culmination 

This week I spent two days in southern Humboldt wwrapping up two long in the works projects. Thursday BLM, MRC,MMC and Humboldt Redwoods State Park Interpretive Center Operator Dave Stockton walked parts of Gilham Butte for writing management options for the Coopereative Management Plan. Public efforts to "Save Gilham Butte" have abounded three times since 1976; it has finally been spared the harvesting saw.
We walked through oldgrowth Douglas fir forests that needed minimal treatmnet. We walked through younger stands of tanoak with good spacing and a closed canopy, a hardwood stand also needing little or no treatmnet. Adding in remote and difficult access, this area has little cost effective needs.
This mangemnt option is where forestry, glomalin, recreation, wildlife and fire risk converge. First we must fix the machinery of the forest, then it should be allowed to run for a while to get back on track. Large old trees fix lots more CO2 than many little ones and so need to be preserved as ongoing operations. This is an operating forest managed for maximum forest efficiency, not a hands off preservation policy. We salute BLM for developing TSI standards for non-harvestable lands like King Range wilderness areas and Headwaters.
Next day I met with Good Roads Clear Creeks coordiator Dylan Brown and site assessor Joel Munschke on my property on Middle Creek. It burned in 1981 and has been subject of a dozen hikes with MRC and others like Scott Downey and MSG since 1987 and peaking with the sediment inventory done in 2001. The work clearly shows that road drainage diversions cause downslope ground failuires. What we have really been after is help with costs and permits for instream improvements. We needed to stabilize the slopes first. About all you can do is roadwork and revegetation.
In the creek itself, several days of excavator work will move the entire creek away from the failing soil bluffs and into an old channel already shaded by conifer regrowth. There is a lot of rock onsite to secure it, and to use all the available money for machine time, rather than hauling rock in. This will vastly improve around 500 yards of salmonid spawning habitat. GRCC expects to accomplish this landscape sized task in the next month.
Here we cannot rest however, revegetation has now become a fire risk. Thinning and release cuts are needed on large scales. Funneling the growing power of the land to restore system functions and lower risk need active management. Land in the ceanothus need replanting with forest trees. Douglas fir are full of cones this year and we will get another round of direct seeding from trees fifteen to twenty years old.
We salute MRC for this ambitious project, and its cookie cutter repeatability. These treatments, on a one time around basis, coupled with time and natures healing ability, should accelerate reccovery to the point of landscape stability even in heavy precipitation events.
Long-Term Effects of Elevated Atmospheric CO2 on Soil Fungi
--------------------------------------------------------------------------------
Reference
Rillig, M.C., Hernandez, G.Y. and Newton, P.C.D. 2000. Arbuscular mycorrhizae respond to elevated atmospheric CO2 after long-term exposure: evidence from a CO2 spring in New Zealand supports the resource balance model. Ecology Letters 3: 475-478.
What was done
The authors examined several characteristics of arbuscular mycorrhizal fungi associated with the roots of plants growing for at least 20 years along a natural CO2 gradient near a CO2-emmitting spring in New Zealand to determine the long-term effects of atmospheric CO2 enrichment on these beneficial soil fungi.

What was learned
Elevated CO2 significantly increased percent root colonization by arbuscular mycorrhizal fungi in a linear fashion - and by nearly 4-fold! - in going from 370 to 670 ppm CO2. Similarly, fungal hyphal length experienced a linear increase of over 3-fold along the same atmospheric CO2 gradient; while total soil glomalin (a protein secreted by fungal hyphae that increases soil aggregation and stability) experienced a linear increase of approximately 5-fold.

What it means
As the atmospheric CO2 concentration continues to rise, it is likely that the positive responses of arbuscular mycorrhizal fungi identified in this study will continue to become even more pronounced. If, for example, less than a doubling of the air's CO2 content has produced 3-, 4- and even 5-fold increases in fungal hyphal length, percent root colonization and total soil glomalin concentrations, respectively, what's to keep further increases in atmospheric CO2 concentration from producing 6-, 7- and 8-fold increases in these parameters? It would appear that the sky's the limit! And as these dramatic underground changes continue to occur, soil losses via wind and water erosion should be significantly reduced, due to CO2-induced glomalin-mediated increases in soil aggregate stability, which should benefit terrestrial ecosystems worldwide.

Page printed from: http://www.co2science.org/journal/2001/v4n14b2.htm Copyright © 2004. Center for the Study of Carbon Dioxide and Global Change


Rising Atmospheric CO2 Concentrations Reduce Soil Erosion: Lessons for the New Millennium
Volume 3, Number 25: 4 October 2000

--------------------------------------------------------------------------------
Over the course of his career, our father has studied a vast array of subjects related to the ongoing rise in the air's CO2 concentration; and whenever he has gained sufficient insight into a topic, he has not been afraid to state his view of its implications for the future.
One of his more prescient predictions within the context of this multifaceted subject area concerns one of earth's most valuable natural resources - its soil. Writing in his second book on the topic - Carbon Dioxide and Global Change: Earth in Transition (Idso, 1989) - our father stated that "as a result of the direct effects of atmospheric CO2 enrichment upon the primary plant processes of photosynthesis and transpiration … many plants will greatly expand their ranges with augmented water use efficiencies, stabilizing the soil and protecting it from erosion."

This prediction went against the grain of nearly all thinking on the subject at the time it was made. Starting in the 1970s and continuing almost to this day, study after study had concluded that soil erosion, via both wind and water, was running at a high sustained rate. In fact, in a recent Policy Forum article in Science, Trimble and Crosson (2000) note that "some sources have suggested that recent erosion is as great as or greater than that of the 1930s," just as some sources are suggesting that global temperatures are greater now than they were in the 1930s (Crowley, 2000; Mann 2000).

If factual, this assessment would clearly refute the prediction of our father; for with the large increase in atmospheric CO2 concentration experienced over the past 70 years, one would surely have expected to see some positive consequences, i.e., reductions in soil erosion, by now, just as one would also have expected to see significant global warming by now, if predictions of that phenomenon were correct. But herein lies the problem, or the solution to the problem, depending on one's point of view: this assessment is not factual, just as the highly-hyped global warming of the past seven decades is not factual either (see our editorials of 15 June, 1 July, and 15 July 2000).

The "remarkable feature" of the long-held belief in continued high, or even increasing, soil erosion, in the words of Trimble and Crosson, "is that it was based mostly on models," just as the global warming scare was (and still is!) based mostly on models. Indeed, they state that "little physical, field-based evidence (other than anecdotal statements) has been offered to verify the high estimates," noting that "it is questionable whether there has ever been another perceived public problem for which so much time, effort, and money were spent in light of so little scientific evidence," which almost begs us to suggest that the "perceived public problem" of CO2-induced global warming is no different, and that it will soon outstrip the soil erosion problem in this regard, if it has not already done so. But we digress; for the good news, according to Trimble and Crosson, is that "available field evidence suggests declines of soil erosion, some very precipitous, during the past six decades," which is exactly what would be expected on the basis of our father's prediction.

So what confused the issue for so many years? The problem was largely a failure to realize that most of the soil particles removed from one part of the land, by either wind or water, were deposited in nearby areas, so that the net loss of soil was only a very small portion of that which was moved about by the forces of nature.

In reviewing this shift in our perception of U.S. soil erosion history, it is interesting to note that our perceptions of several ancillary phenomena may need some adjusting too. Trimble and Crosson note, for example, that some studies have warned that "increasingly eroded soil profiles will allow less rainfall to be infiltrated and stored," leading to "increased overland flow, erosion, and flooding." But as they further note, detailed hydrologic studies indicate that just the opposite is occurring: "runoff is decreasing, flood peaks are smaller, and in some places, the base flow is greater." In addition, in their words, "these field studies show that more water is infiltrating into the soil and, in some cases, … significantly more water is being transpired by plants."

These real-world observations are also what would be expected on the basis of our father's prediction. With gradually increasing atmospheric CO2 concentrations gradually enhancing plant water use efficiencies, more plants should gradually be covering the ground, reducing rates of surface runoff and allowing more water to infiltrate into the soil, thereby providing more water to be extracted from the soil by more plants for subsequent transpiration into the air.

These hydrologic improvements, in turn, tend to improve the status of still other aspects of the planet's natural resource base, such as by increasing the stability of streams; and a good visual testament to the reality of this phenomenon is provided by a pair of photographs in the Trimble and Crosson article. Both photos show the same view of a portion of Bohemian Creek, La Crosse County, Wisconsin. The first, taken in 1940, shows an "eroded, shallow channel composed of gravel and cobbles, with coarse sediment deposited by overflows on the floodplain." The second, taken a quarter of a century later in 1974, shows that the stream channel "is narrower, smaller, and more stable." Also, "the coarse sediment has been covered with fine material, and the flood plain is vegetated to the edge of the stream." What is more, the authors note that conditions improved even more over the following 25 years.

In reviewing these many real-world manifestations of the benefits of the ongoing rise in the air's CO2 concentration for our nation's (and the world's!) important soil and water resources, we are gratified that our father had the courage to speak out on this subject as he did in his 1989 book, as well as in his earlier book (Idso, 1982). We also hope that the lesson taught by Trimble and Crosson, about the "myth and reality" of U.S. soil erosion history, will not be lost on those currently struggling with the reality of rising atmospheric CO2 concentrations and the myriad myths that have been associated with this phenomenon, such as catastrophic global warming and its attendant host of soon-to-be-experienced horror stories.

In conclusion, we agree wholeheartedly with Trimble and Crosson, who rightly state in the concluding paragraph of their important Policy Forum article that "no problem of resource or environmental management can be rationally addressed until its true space and time dimensions are known," something which has yet to be achieved in the climate change arena. And we agree even more wholeheartedly - if such is possible - with their conclusion that "the uncritical use of models is unacceptable as science and unacceptable as a basis for national policy." Unfortunately, many nations of the earth have yet to learn this lesson; and if they do not learn it soon, we could all very shortly find ourselves in a world of economic hurt, brought on by our own naivety.

Dr. Craig D. Idso
President Dr. Keith E. Idso
Vice President


References
Crowley, T.J. 2000. Causes of climate change over the past 1000 years. Science 289: 270-277.

Idso, S.B. 1982. Carbon Dioxide: Friend or Foe? An Inquiry into the Climatic and Agricultural Consequences of the Rapidly Rising CO2 Content of Earth's Atmosphere. IBR Press, Tempe, AZ.

Idso, S.B. 1989. Carbon Dioxide and Global Change: Earth in Transition. IBR Press, Tempe, AZ.

Mann, M.E. 2000. Climate change: Lessons for a new millennium. Science 289: 253-254.

Trimble, S.W. and Crosson, P. 2000. U.S. soil erosion rates - myth and reality. Science 289: 248-250.



Page printed from: http://www.co2science.org/edit/v3_edit/v3n25edit.htm
--------------------------------------------------------------------------------

Copyright © 2004. Center for the Study of Carbon Dioxide and Global Change
Comments: Post a Comment

This page is powered by Blogger. Isn't yours?