Final Posting in this travel blog series

This is a duplication of a posting by Jeff Vail, from his blog, JEFFVAIL.NET.  Go to his original article for links to other articles in this series. 

This writing especially resonated with me and my own observations as my trip to Brazil was unfolding. This and the insight offered to me by Ben on this topic is perhaps the most valuable lesson I am bringing back to Northwestern North America. What is unfolding with our current resource depletion and coincidental economic unfolding has a endpoint not completely understood by anyone. Especially yours truly 

The next posting will be a link to a new blog series. Best wishes to all readers. This journey has been interesting and eye opening. Not the least of all is my new friendship with some sincere people in Angatuba.

MONDAY, DECEMBER 08, 2008

A Resilient Suburbia 4: Accounting for the Value of Decentralization

This series has been considering the role of suburbia in a post-peak future. One necessary, though generally ignored, element of any analysis of suburbia is a consideration of the value of decentralization per se. The decentralized mode of suburbia presents problems (greater energy requirements for transportation), and advantages (greater potential for individual self-sufficiency), but what about the economics and politics of decentralization itself?
This post will argue that, when measured from the perspective of the median participant, decentralization offers a superior structure for both economic and political organization, a structure that may prove far more sustainable in a post-peak world than our current, centralized, hierarchal patterns of organization. Suburbia, not as a model for material consumption, but as a legal and social lattice of decentralized and more uniformly distributed production land ownership, has the potential to serve as the foundation for just such a pioneering adaptation—a Resilient Suburbia.

There are many efficiencies gained through centralization and specialization (of both place and activity, or, as Jaques Ellul termed it, “technic”). These two principles combine to lay the foundation for most of “classical” economic theory. These efficiencies, however, also produce externalities—side effects that are generally unrecognized and unaccounted for when weighing the value gained by centralization and specialization. I’ve termed these “anti-economies.”

When weighing civilizational choices, it is also important to considering the dueling perspective of the median vs. the mean. A policy that grows overall wealth in an economy (raising the mean wealth) does not necessarily increase the wealth of most people within that economy (which is best measured by the median wealth). Is an overall richer society comprised of one super wealthy Tiger Woods and 100 destitute peasants preferable to an overall poorer society comprised primarily of a “middle class” at some level of wealth above destitute peasantry? How do we weight the value—from the perspective of economics, politics, sociology, sustainability, etc.—of equality of distribution versus overall wealth distributed? This is a question that is critical to any consideration of the value of decentralization, and represents a lens through which we must view the relative value of suburbia and its alternatives, their present failures, and future potential.
While, to some extent, the economics and politics of centralization cannot be separated, there are clear economic benefits to centralization and specialization. Great cities from New York and London in the present to the Hanseatic free cities or Phoenician trading bases of the past demonstrate this in spades.

If the economic advantages of urbanization are so clear-cut, what are its economic disadvantages? First, as an expression of hierarchy, a boundary analysis of cities must include their constituent hinterland—the region that produces the raw materials for urban production and consumes the services and products produced in the urban core. In our increasingly globalized world, this hinterland is also global—for example, the Vietnamese factory worker churning out products designed by the downtown LA design firm and financed by New York banks, or the peasant farmer’s income impacted by the cheap, subsidized grains produced on industrial farms and exported through the ports of major US cities. (Which comes first: the masses of urban poor dependent on government and aid organizations or the flight of farmers from small plots where they cannot compete with subsidized western agricultural exports?) In addition, peer-polity competition for control and coordination of this hinterland makes the hierarchal model of urbanization fundamentally growth-driven, and therefore unsustainable. Cities are peer-polities, competing with each other to coordinate and control the economic activity of the largest possible share of a limited hinterland. If one city were to focus on a sustainable, no-growth approach to this game, it would be out-competed by others more concerned with near-term growth and intensification. This is natural selection among polities. Cities, by virtue of their necessary participation in the global peer-polity “eco-system,” are forced to adopt unsustainable practices—or they are out-competed in the game for near-term survival by those who do. Where a superficial sustainability-consciousness exists, its effects are generally limited to token measures within the city’s political jurisdiction, rather than the relevant and vastly larger economic reach to its effective hinterland.

It is also important to consider the “success” of urbanization through the mean/median lens. Urbanization, and the industry, trade, and centralization of economic activity that it supports, certainly increases the mean wealth within its bounds, but what does it do to the median wealth? Further, if the requisite hinterland is included within the bounds of our analysis, does urbanization even increase the mean wealth within that boundary, or does it simply affect an increasing concentration of wealth? These are the structural disadvantages of the urban form. Do they outweigh its advantages? We simply don’t have the data to answer that question definitively. What we do know is that, especially within American and European cities, the environmental damages and marginalization of the “hinterland” population largely falls outside our borders, onto the fragile ecosystems and massive poverty of the second and third worlds. This civilizational accounting failure represents a massive subsidy to urbanization—perhaps the greatest subsidy in history, and one that is incredibly damaging and short-sighted.

No matter how energy-efficient cities may be (especially when compared to presently extant alternatives like suburbia), they are most fundamentally the manifestation of hierarchal structures engaged in peer-polity competition—a mode of human organization that, I believe, is at its core the root of humanity’s unsustainability (because it drives our demand for growth) and it is, itself, undesirable (because it emphasizes the mean at the expense of the median, marginalizing the vast majority of participants).

Not only are there distinct, structural disadvantages to the urban model, but there are also nascent advantages of decentralized, non-hierarchal organization. The potential for distributed manufacturing is one example. The potential, and advantages of decentralized innovation is another. 2000 small farmers each trying to develop a better system will develop and evaluate more theories than a single, equivalently-sized industrial farm, and the dispersed effort will also develop more locally-appropriate solutions. The advantage of decentralized innovation is particularly apparent in military innovation—the decentralized innovation laboratory of insurgents in Iraq, for example, has equaled or bettered the worlds single largest, centralized R&D facility (the US military-industrial complex), despite dramatic differences in funding, personnel, education, and other resources. Localized self-sufficiency and increased liberation from the peer-polity competition additionally frees innovators to focus on producing quality of life for the median, rather than intensifying the empire of the mean. The mindset of the 20th century was that physical aggregation was necessary for the hierarchal coordination of complex economic activities. The mindset of the 21st century may be that physical distribution excels, and is even preferable, when pursuing non-hierarchal, open source, and emergent coordination of complex economic activity.

There seems to be a nearly endless stream of skeptics who claim that physical proximity (e.g. the city) is necessary for the kind of complex economic activity that underlies our quality of life. Usually, in my opinion, these theories rely on an outdated or misinformed understanding of economic coordination. These doubters seem broadly unfamiliar with advances in open-source, distributed manufacturing; of platform-driven systems; of the potential for tying vernacular resource bases into global networks of open-source innovation. They usually focus on the services and amenities that cities can provide to the privileged few, while ignoring at great moral hazard the concomitant impact of these structures on the vast majority of its citizens—those that live beyond political borders but well within the economic hinterlands. Others point to the opportunities for interaction in urban areas—while it is certainly possible to see and interact face-to-face with more people in an urban setting on a constant basis, the attractiveness (or horror) of this situation seems far more closely tied to individual personalities and psychological adaptation than to any fundamental economic advantage of cities. Both evolutionary psychology and modern commerce suggest that cities may actually be counter-productive in these functions.

Dunbar’s number, for example, shows that human interaction functions best with group sizes of roughly 150--the norm in our ontogeny, and something that does not depend on the human density of cities. Additionally, cities may be liabilities when considering the theory of weak networks--the notion that the most powerful way to leverage humans’ limited capacity to form connections is to form several very strong, very close connections, and then several extremely distant and weaker connections. Cities present an environment more susceptible to tight-group isolation (though they don’t force such an arrangement), whereas the reliance by more distributed settlement on fairs (historically) and the internet (in modernity) may actually tend toward more powerful structure to coordinate economic activity.

This is not meant as a dispositive proof of the superior economic potential of distributed systems, but rather as food for thought—we tend to assume without questioning that cities are necessary and desirable for economic functioning, all the while ignoring significant evidence that this may be the result of little more than inertia. When readers wish to discuss a complex niche topic with other interested parties—a classic analogue for economic coordination—they are generally better served by a highly distributed virtual community (such as The Oil Drum) than by the kind of permanently physically collocated group one would find in a city. My guess is that even a well-connected individual in a “flagship city” like New York would be hard pressed to find the quality of discussion on a topic such as Peak Oil equal to what exists daily on this site. This same advantage spreads from agriculture to Medicine, to military theory--just one anecdote: go to the physical epicenters of military theory, such as the Army War College or one of the service academies, and you will fail miserably to find face-to-face discussions of the caliber you can find daily at John Robb’s blog between people from all over the world.

Additionally, highly centralized and specialized economic structures tend to require a great degree of “middle men” to effectively coordinate complex economic activity on a large scale. As a result, a huge majority of “workers” are not actually performing “end production,” but rather are performing some kind of coordination, command, or control activity. This is generally referred to as “Span of Control”—on the simplest level, one person can only effectively command so many subordinates. Historically, militaries have settled on a span of control of 5 (only 3 of which are operational). This leads to massive “middle management” in large-scale organizations. A similar effect exists in economics—while a massive dairy farm may reap significant economies of scale, it also tends to involve large behind-the-scenes forces performing management, compliance, legal, finance, marketing, transportation, human resources, and other non-milk-producing functions. Open source networks of innovation have the potential to fundamentally replace this mode of economic coordination in a manner that eliminates the need for this middle-management. Every producer a part-time innovator/theorist, and every innovator/theorist a producer. This might sound like a hippy fantasy-world to some, but it is happening right now from commodity coordination by individual peasant farmers in Africa (via cheap, disposable cell phones) to a revolution in insurgent tactics in Asia. Ask yourself, do you actually make anything? Do you even know anyone who actually makes anything? Or do you and most of your associates engage in one of these “coordinating” functions? If this is the “efficiency” of our current, city-centric economic structure, it looks more like a target of historic opportunity to me.

Finally, the same structural tendencies of our economic systems have dramatic effects on our political systems and the course of our civilization. Centralization and specialization are the opposites of self-sufficiency and independence. When we centralize production of something we require, as individuals or communities we become dependent on the system that provides continuing access. We’ve been so indoctrinated to the benefits (and hidden from the externalities) of these interlacing networks of dependency that we rarely realize the degree to which we have ceded our own potential for sovereignty. The implications are striking

Riparian Vegetation of Sao Carlos County, Sao Paulo

Retrieved from SciFLO, Brazil.

ABSTRACT

A map of the native vegetation remaining in São Carlos County was built based on aerial images, satellite images, and field observations, and a projection of the probable original vegetation was made by checking it against soil and relief surveys. The existing vegetation is very fragmented and impoverished, consisting predominantly of cerrados (savanna vegetation of various physiognomies), semideciduous and riparian forest, and regeneration areas. Araucaria angustifolia (Bertol.) Kuntze, found in patches inside the semideciduous forest beginning at a minimum altitude of 850 m, has practically disappeared. By evaluating areas on the map for different forms of vegetation, we obtained the following results for original coverage: 27% cerrado (sparsely arboreal and short-shrub savanna, and wet meadows); 16% cerradão (arboreal savanna); 55% semideciduous and riparian forests; and 2% forest with A. angustifolia. There are now 2% cerrados; 2.5% cerradão; 1% semideciduous forest and riparian forests; 1.5% regeneration areas; and 0% forest with A. angustifolia.

This is interesting to me because I have been looking for lists of species, discussion of ecosystem structure and current conditions.

Below are some interesting bits of information from this article, published in the Brazilian Journal of Biology
More...
''The territory of the district is rough. There are open savannas and forests. They generally extended through the mountainous region and have been largely felled by the farmers, who have replaced them with verdant coffee plantations. In these areas the soil is, as a rule, very fertile. There are vast stretches of land whose soils are formed by the oxidation and breaking down of igneous rock – diorite (commonly known as ironstone), which has turned into the famous purple soil, of inexhaustible fertility. The open savanna is usually slightly undulating and abundantly sandy; and, specially in the southwest, by the Campo Alegre station, it is adorned with beautiful meadows, of pleasant aspect''. Regarding hydrology he mentions: ''The district is bathed by the Rivers Feijão, Lobo, Onça, Pinhal, Quebra-Canella, Mello, Monjolinho, Chibarro, Mineirinho, Corrente e Jacaré, which discharge into the Tietê; and by the Águas Turvas, dos Negros, Quilombo, da Água Vermelha, das Araras and das Cabeceiras brooks, tributaries of the Mogy-Guassú river, that also bathes the district''.

The devastation of the original areas of vegetation was a consequence of the large-scale use of soil for agriculture and pasture, beginning with the expansion of coffee planting after 1860. Until then, activity had been restricted to subsistence crops and breeding carried out by the inhabitants, useful also in supplying muleteers and travelers as they moved toward Brazil's central region (Truzzi, 2000).

In this period, semideciduous forest yielded to agriculture due to the demand for more fertile soils for coffee plantation expansion. Besides the loss of good part of the forests, even the remaining fragments were used to produce coffee seedlings and, consequently, the underwood was cleared, causing impoverishment and reduction of biodiversity in these areas, in the interior of which numerous coffee plants may still be found (Martins, 1991; Silva & Soares, 2000) The native pine [Araucaria angustifolia (Bertol.) Kuntze], which is used as the official symbol of the county, and was apparently found in patches in the semideciduous forest, has practically disappeared, due to its use for timber and its felling during land occupation. Today, only a few isolated individuals survive.



Here is the projection of the original distribution of semideciduous and riparian forest, forest containing A. angustifolia, cerrados, and cerradão. The estimated total areas of the various vegetational forms, given as percentages of the total area of São Carlos were: 27.74% cerrado, 16.14% cerradão, 54.36% semideciduous and riparian forest, and 1.76% semideciduous forest with A. angustifolia (Table 1).



This is a graphic of what remains of this flora



How does this level of change in vegetation structure compare to the Pacific Northwest. The truth is that the impacts in both places is very similar. My work seed collecting in the Williamette Valley is a struggle to find intact plant populations to sample seed sources.

To finish here is text from this article describing the main vegetation types in this county and their species diversity.

Cerrados and cerradão

In São Paulo State, savanna occurs in the form of islands or branches, mainly in a central strip from the northwest to the southeast, which includes São Carlos County (Borgonovi & Chiarini, 1965). These islands comprise the physiognomies of cerradão (arboreal savanna), cerrado, (sparsely arboreal savanna), campo cerrado (short-shrub savanna), and campo sujo (grassland sparsely shrubbed), following Coutinho's classification (1978).

Silva (1994) compared the vegetation and soil characteristics in different savanna physiognomies on Canchim Farm, São Carlos, and concluded that the dominant factor in the distribution of physiognomies was the presence of more or less sandy soils. The sandier soils, with smaller amounts of clay, are poorer in nutrients and more easily washed away by strong summer rainfalls. In richer soils, vegetation is denser and higher but as the soil becomes sandier and poorer, the arboreal and shrub vegetation becomes lower and sparser. This author found, besides the variation in physiognomy, variation in morphological characteristics such as hair density, presence of protective scales, and hardness and size of leaves.

For the São Carlos it was concluded that cerrado predominated over other physiognomic forms. We believe that campo sujo and campo cerrado occurred only in some very restricted areas, mainly in old sandy alluvial deposits.

Similarly, the wet meadow region formed where a water sheet bursts out between riparian forest and adjacent savanna formations (cerrado, campo cerrado, and cerradão), which is common in many areas of the country, is restricted in São Carlos County, when it occurs at all, to a strip of a few meters.

Much of the remaining savanna formations have a considerably more open physiognomy than the original, due to fires and pasture formation. The cerrado and campo cerrado characteristic species regenerate more easily than the cerradão when the area is abandoned. Although regeneration is facilitated by the species' ability to sprout from the subsoil, it only occurs in places where the agricultural practices do not involve digging deep into the soil. Thus, the surviving savanna does not always reflect past physiognomy.

In the cerrado the underwood and the interlacing branches of stunted trees, growing just above the ground, form a typical landscape: low, dense, and tortuous, hindering attempts to walk through it. From this characteristic derived the term cerrado for this vegetational physiognomy. Researchers like Coutinho (1978) extended the use of this term to more open savanna physiognomies and taller arboreal savanna, owing to the similarity of their flora. The latter, although very similar, within its different physiognomies, varies in density of each species, with sometimes more arboreal species developing and sometimes more shrubs or herbs.

Cerradão is the forest physiognomy of this vegetation. The trees can reach 20 m in height, with stem diameters exceeding 50 cm. Lianas are found everywhere while the herbaceous stratum is very poor. It occurs generally on soil of average fertility.

This savanna has a rich flora in terms of species. Many of them are valued as decorations and used in arborization of streets and public squares (Almeida et al., 1998), or cultivated for their medicinal properties (Siqueira, 1981) or fruits (Almeida, 1998).

In the regional cerradão we found predominating, in the arboreal stratum, species like Anadenanthera falcata Speg., Bowdichia virgilioides H. B. & K., Copaifera langsdorffii Desf., Dimorphandra mollis Benth.., Hymenaea courbaril L., H. stigonocarpa Hayne, Pterodon pubescens Benth., Qualea grandiflora Mart., Q. parviflora Mart.; Virola surinamensis Warb, Vochysia tucanorum Mart., Machaerium acutifolium Mart ex Benth., M. villosum Vog., Sweetia dasycarpa Benth., Miconia rubiginosa Benth,and Kielmeyera coriacea Mart. A more detailed description of the specific composition and structure of this vegetation in the county can be found in Silva (1996).

Species like Annona cacans Warm., A. coriacea Mart., A. crassiflora Mart., Syagrus flexuosa (Mart.), Ocotea pulchella Mart, Ouratea spectabilis Engl., Stryphnodendron barbadetiman (Vell) Mart., S. polyphyllum Mart., Pouteria torta Radlk, Xilopia aromatica (Lam.) Mart., Caryocar brasiliense Cambess., Myrcia lingua (O. Berg.) Mattos, and Roupala montana Aubl. are some of the short trees and bushes commonly found in the savanna of São Carlos. These species also occur in the cerradão.

In more open formations of campo cerrado we found several species of Campomanesia spp., Solanum lycocarpum A. St. Hil., Casearia sylvestris Sw., Setaria poiretiana Kunt, Bromelia antiacantha Bertol, Andira humilis Mart ex Benth., Cochlospermum regium Pilger, Didymopanax vinosum March, Aspidosperma tomentosum Mart., Hancornia speciosa Gomez, Mandevilla velutina K. Schum, Baccharis dracunculifolia D.C., B. subdentata D.C., B. trimera D.C., Calea cimosa Less, C. hispida (D.C.) Baker, Memora axillaris K. Schum., Gochnatia polymorpha Herb. Berol ex D.C., Mikania cordifolia Willd, M. micrantha H. B. & K., Vernonia apiculata Mart. ex D.C., V. brevifolia Less., V. ferruginea Less., Anemopaegna arvense (Vell.) Stelfeld ex de Souza, Arrabidaea brachyopoda Burr., Jacaranda caroba D.C., Pyrostegia ignea Presl., Tabebuia aurea Benth and Hook f. ex S. Moore, Tabebuia caraiba Bureau Mart., Zeyhera montana Mart., Ananas ananassoides (Barker) L.B. Smith, Bauhinia holophylla (Bong) Steud., Cassia spp., Kielmeyera variabilis Mart., Davilla rugosa Poir., Diospyros hispida A.D.C. Erytroxylum spp., andlianes of the genera Banisteria, Banisteriopsis, and Byrsonima. Trees and short trees of higher physiognomic formations are also, though sparsely, among these species.

In the wet meadows we observed terrestrial orchid species of the genus Habenaria; Xyris jupicai Michx., X. metallica Klotzsch ex. Seub., X. hymenachne Mart., X. savanensis Miq., X. teres Alb. Nilsson., Andropogon leuchostachyus H.B.K., several species of Miconia and Leandra, Heleocharis interstincta (Vahl) Roem. & Schult, H. mutata (L.) Roem. & Shult, Rhynchospora exaltata Kunth., R. globosa (Kunt) Roem. & Schult, Scirpus cubensis Kunth., Scleria hirtella Bach., Eriocaulon aequinoctiale Ruhl., E. modestum Kunt., E. pygmaeum Dalz., Paepalanthus blepharocnemis Mart ex Koem, P. speciosus (Bong.) Koern, Syngonanthus caulescens (Poir) Ruhland, S. fischerianus (Bong.) Ruhland, S. xeranthemoides (Bong) Ruhland, and others such as Hydrocotile bonariensis Lam., Lycopodium spp., Nymphoides indica (L.) O. Ktze. (which develop from the edge of the water bodies), Ludwigia elegans (Cambess) Hara, L. leptocarpa (Nutt.) Hara, L. longifolia (D.C.) Hara, L. multinervia (Hook & Am.) T.P. Ramamoorthy, L. suffruticosa Walt., Pontederia cordata Larranaga, and P. lanceolata Nutt.

Riparian forest

The forests that extend along the riversides have received, through the years, denominations such as alluvial, riparian, gallery, and ciliate forest, among others. According to Ivanauskas et al. (1997) these formations have received the most varied designations owing to the variety of local characteristics, such as relief, soil, declivity, physiognomy, position in the landscape, and so on. Velozo & Goes Filho (1982) named them alluvial forests and, when alluvial soil under laid the meadows, they were called fluvial alluvial forest (Campos, 1912) or marshy forest (Lindman & Ferri, 1974; Fernandes & Bezerra, 1990). Bertoni & Martins (1987) called them meadows and Troppmair & Machado (1974), used the term condensation forest, when they occupied the valley bottom, where thick fog occurred at certain periods of the year.

As these formations border the water like eyelashes (Campos, 1912), they were also called rampart forest (Lindman & Ferri, 1974) and ciliary forest (Sampaio, 1938; Hueck, 1972; Bezerra, 1975). In the State of São Paulo, the term ciliary forest (mata ciliar) was sanctioned by Leitão Filho (1982), who defined it as broad-leaved wet forest with periodic flooding.

The ciliary forest designation has been used as a synonym for the term gallery forest (Joly, 1970; among others). However, the Ecology Glossary (Aciesp, 1987) differentiates between these terms based on forest width and the vegetational physiognomy of adjacent areas. According to this work, gallery forest is forest formations along watercourses, in regions where the interfluvial original vegetation is not forest. For regions where interfluvial original vegetation is also forest, the glossary suggests the term ciliary forest or waterside forest. The term ciliary forest, defined by Aciesp (1987), has been substituted by riparian forest (Bertoni & Martins, 1987; Catharino, 1989; Mantovani, 1989; Rodrigues, 1992), reserving the term ciliary forest, as used in the current legislation, for more generic commonly used designations (Rodrigues, 2000).

Swamp forest, also described as almost permanently flooded broadleaf wet forest (Leitão Filho, 1982), although frequently appearing associated with riparian and gallery forest, is distinct from the others, because of almost permanent presence of water in the soil. This saturated soil contributes to the selectivity of species occurring in this formation, and results from their specialized physiology adapted to hydric saturation (Ivanauskas et al., 1997).

According to Leitão-Filho (1982), swamp forest exhibits a relatively small number of very specific species, generally not deciduous, whose uppermost stratum reaches an average of 10-12 m in height.

Swamp forest is restricted to meadows or flood plains, on low, more or less flat land, found close to sources or in well-defined locations on riverbanks, by lakes, or in natural depressions. In these places there are hydromorphic soils (organic and gley; quartzose and hydromorphic sands; and plinthitic soil among others) forming a relief of low mounds and small superficial channels and presenting an irregular surface where the water flows in a definite direction.

The factors that lead to the occurrence of woods (forest physiognomy) or wet meadow (predominantly herbaceous physiognomy) on typically wet soils are still little known. However, it is believed that some of them relate to drainage, and to the presence of physical impediments in the soil and/or alteration of the original topography. In areas where water remained in the soil for long periods, to the point of almost stagnating, herbaceous vegetable formations would develop; and where the water movement was well-defined in superficial channels, forest formations would develop.

Because of its predominance on hydromorphic soils, swamp forest has a naturally restricted distribution in São Paulo State. In addition to this fragmentation, swamp-forest occupied areas have been greatly reduced in the recent past, due to programs stimulating agricultural use of the meadows and to construction of hydroelectric plants, the latter inundating a large part of these remnants. Riparian forest, besides protecting the hydrological characteristics of water bodies and the associated fauna, provides ecological corridors for biota. Such corridors can be found in São Carlos County, where the riparian forest of one hydrographic basin is continuous with the riparian forest of another, uniting two large hydrographic basins of São Paulo State drained respectively by the Mogi-Guaçu and Tietê rivers. The link is made through tributaries such as the Jacaré and Quilombo rivers (Fig. 2).

Studies of the flora and plant associations in riparian forest in the basins of the Mogi-Guaçu, Tietê, and their tributaries in São Carlos County show that the following species are common in the area, if we ignore the ecological variations from place to place: Cyclolobium vecchii A. Sampaio, Alchornea triplinervia Muell. Arg., Guarea trichilioides L., Genipa americana L., Duguetia lanceolata St. Hill., Inga vera H. B. & K., Syagrus romanzoffiana (Cham.) Glassm., Eugenia spp., Picramnia warmingiana Engl., Calophyllum brasiliense Camb., Hymenaea courbaril L., Copaifera langsdorffii Desf., Ixora gardneriana Benth., Lonchocarpus guilleminianus (Tul.) Malme, Aspidosperma peroba Saldanha da Gama, Luehea divaricata Mart, Protium heptaphyllum March, Cecropia pachystachya Trec., Talauma ovata A. St. Hill, Drymis brasiliensis Miers., Calophylum brasiliense Camb., Podocarpus sellowii Klotz. ex Endl., Inga affinis D.C., Rapanea guyanensis Aubl., Cyathea delgadii Sternb., Euterpe edulis Mart, Metrodorea nigra A. St. Hil., Croton floribundus Lund. ex Didr., Xylopia brasiliensis Spreng, and Rollinia silvatica Mart (Bertoni & Martins, 1987; Rodrigues, 1992; and collection of HUFSCar herbarium).

Semideciduous forest

Semideciduous forest is known by several names according to the region and the authors. It is distributed on the inland plateaus and in peripheral depressions of the Serra do Mar and Serra Geral towards the interior of the continent (FIBGE, 1993). For some authors, such forest should be categorized as Atlantic forest (SOS Mata Atlântica), although there are floristic differences between them that depend on location (Giulietti, 1992). The forest can be increased by including swamp forest in the northeast and on the upper Uruguay River, on the border between Rio Grande do Sul and Santa Catarina States.

Torres et al. (1997) established relations among climate, soil, and arboreal flora in the São Paulo State forests, based on the possible influences of abiotic factors on the distribution of species and arboreal families. Thirteen surveys in São Paulo State were selected, representing different conditions (location at the ends of coordinates and altitudes, succession stadiums, surveying methods). By constructing phenograms the authors verified that the species studied formed two floristic blocks: hygrophilous (annual average rainfall higher than 2000 mm and no dry season) and semideciduous forest (total annual average rainfall of about 1400 mm, and variable dry season). The semideciduous forest block was divided in two groups: high altitude (average altitude higher than 750 m, average frost frequency higher than three days/year) and low altitude (below 700 m). Each of these groups was subdivided according to soil properties (texture, eutrophy, acid or alkaline dystrophy, iron content).

São Carlos County falls in the semideciduous forest block containing both floristic divisions (below 700 m and above 750 m).

Of São Paulo State, several surveys of the flora and structure of vegetation have been made, such as those of Pagano & Leitão Filho (1987), and Martins (1991). Of São Carlos there are the studies of Hora & Soares (2002) and Silva & Soares (2000) in Fazenda Canchim reserve, one of the best-preserved remnants of this forest in the county.

Remnants of semideciduous forest are, in general, very impoverished due to human interference and their reduced extent, which leads to diversity decrease. Observations in Fazenda Canchim showed that the dense soils of these forests prevent trees from rooting deeply. Roots are therefore predominantly superficial and cannot always withstand strong wind pressures on the treetops, especially those projecting above the canopy. Hence, trees fall, forming clearings. In addition, forest fragmentation makes treetops more wind vulnerable, mainly at the forest edges, and the smaller the fragment, the larger the effect of the winds is.

According to Silva & Soares (2000) the semideciduous forest shows, in general, an emerging stratum, formed by species that rise above the forest canopy; an arboreal stratum, forming a continuous canopy of about 20-30 meters; and one of smaller trees, less than 10 meters high, besides the shrub and herbaceous strata.

These authors cites as the most common species in the highest stratum Cariniana estrellensis Kunthze, Piptadenia gonoacantha Macbride, Chorisia speciosa St. Hil., Enterolobium contortisiliquum Morong.and, among species that predominate in the forest, Metrodorea nigra A. St. Hil., Pachystroma longifolium I. M. Johnston, Aspidosperma polyneuron Muell. Arg., Aspidosperma ramiflorum Muell. Arg., Savia dictyocarpa Muel. Arg., Ocotea odorifera (Vell) J. G. Rohwer, Machaerium stipitatum Vog., Holocalyx glaziovii Taub. ex. Glaziou., Cabralea cangerana Saldanha da Gama, Inga marginata H. B. & K., Actinostemon communis Pax., Actinostemon concolor Pax., Centrolobium tomentosum Guill. ex Benth. Cavassan et al. (1984) and Martins (1991) also mention, as common species in this forest, Croton salutaris Casar, Guarea trichilioides L., Acacia polyphylla Clos., Nectandra megapotamica (Spreng) Mez., Piptadenia rigida Benth., Gallezia gorazema Moq.,and Balfourodendron riedelianum Engl.

Semideciduous forest with Araucaria angustifolia

The presence of Araucaria angustifolia (Bertol.) O. Kuntze in the forest is striking. This species is shaped like a chandelier and the trees occupy within the forest structure an emerging position. When the population is sufficiently dense, the tops touch forming a continuous canopy, a configuration more common on higher plateaus in southern Brazil.

Araucaria species are typical in South American temperate and cold regions (Duarte, 1993). Their distribution in Brazil in earlier geological periods was more widespread, with only remnants remaining (Backes, 1983).

Two hypotheses are offered to explain the presence of Araucaria in São Carlos:

Paleoclimatic: occurrence a colder and drier paleoclimate in the tertiary, with Araucaria remaining in places where ecological conditions were favorable (Troppmair, 1974). Ledru et al. (1996, 1998) suggested dating the transition from a dry to a moist climate in 17,000 14 C. yr. BP and also that the presence of Araucaria, Podocarpus, and Drymys pollencan indicate high-moisture conditions in some places. In this case, the existence of A. angustifolia has a singular importance in the region of São Carlos, evidencing an ancient ecological condition.

Anthropic: indigenous populations during their migrations might have brought seeds, either planted or left behind while camping, that grew in places where favorable ecological conditions were found.

The forest with Araucaria in Southern Brazil shows a group of plant species differing little from the Atlantic formations (Jarenkow & Baptista, 1987). Thus, we believe that in the São Carlos region, Araucaria angustifolia occurred together with the semideciduous forest species, forming associations of larger or smaller density.

Treatment wetlands

Thinking about first design of simple biological water treatment systems and how chemicals are bound an otherwise immobilized. Next we need to look into how to monitor performance.

Interesting basic info below

From Wikipedia,key words, treatment wetland comes a link to this article by University of Florida wastewater treatment wetlands, by William F DeBusk

Wetlands are commonly known as biological filters, providing protection for water resources such as lakes, estuaries and ground water. Although wetlands have always served this purpose, research and development of wetland treatment technology is a relatively recent phenomenon. Studies of the feasibility of using wetlands for wastewater treatment were initiated during the early 1950s in Germany. In the United States, wastewater-to-wetlands research began in the late 1960s, and increased dramatically in scope during the 1970s. As a result, the use of wetlands for water and wastewater treatment has gained considerable popularity worldwide. Currently, an estimated one thousand wetland treatment systems, both natural and constructed, are in use in North America.
The goal of wastewater treatment is the removal of contaminants from the water in order to decrease the possibility of detrimental impacts on humans and the rest of the ecosystem. The term "contaminant" is used here to refer to an undesirable constituent in the water or wastewater that may directly or indirectly affect human or environmental health. Many contaminants, including a wide variety of organic compounds and metals, are toxic to humans and other organisms. Other types of contaminants are not toxic, but nevertheless pose an indirect threat to our well-being. For example, loading of nutrients (e.g., nitrogen and phosphorus) to waterways can result in excessive growth of algae and unwanted vegetation, diminishing the recreational, economic and aesthetic values of lakes, bays and streams.

Wetlands have proved to be well-suited for treating municipal wastewater (sewage), agricultural wastewater and runoff, industrial wastewater, and stormwater runoff from urban, suburban and rural areas. Municipal wastewater originates primarily from residential and commercial sources. Wetland treatment systems for municipal wastewater vary greatly in size and scope, from single-residence backyard wetlands to regional-scale systems such as the 1200- acre (480-ha) Iron Bridge treatment wetland in central Florida. Agricultural wastewater may include runoff from crop lands and pastures, milking or washing barns and feedlots. Among the types of industrial wastewater that are amenable to treatment in wetlands are those associated with pulp and paper manufacturing, food processing, slaughtering and rendering, chemical manufacturing, petroleum refining, and landfill leachates.

More...

A number of physical, chemical and biological processes operate concurrently in constructed and natural wetlands to provide contaminant removal. Knowledge of the basic concepts of these processes is extremely helpful for assessing the potential applications, benefits and limitations of wetland treatment systems.

Physical Removal Processes

Wetlands are capable of providing highly efficient physical removal of contaminants associated with particulate matter in the water or waste stream. Surface water typically moves very slowly through wetlands due to the characteristic broad sheet flow and the resistance provided by rooted and floating plants. Sedimentation of suspended solids is promoted by the low flow velocity and by the fact that the flow is often laminar (not turbulent) in wetlands. Mats of floating plants in wetlands may serve, to a limited extent, as sediment traps, but their primary role in suspended solids removal is to limit resuspension of settled particulate matter.
Efficiency of suspended solids removal is proportional to the particle settling velocity and the length of the wetland. For practical purposes, sedimentation is usually considered an irreversible process, resulting in accumulation of solids and associated contaminants on the wetland soil surface. However, resuspension of sediment may result in the export of suspended solids and yield a somewhat lower removal efficiency. Some resuspension may occur during periods of high flow velocity in the wetland. More commonly, resuspension results from wind-driven turbulence, bioturbation (disturbance by animals and humans) and gas lift. Gas lift results from production of gases such as oxygen, from photosynthesis in the water, and methane and carbon dioxide, produced by microorganisms in the sediment during decomposition of organic matter. Problems with eventual buildup of sediment to detrimental levels may need to be addressed over the long term.


Biological Removal Processes

Biological removal is perhaps the most important pathway for contaminant removal in wetlands. Probably the most widely recognized biological process for contaminant removal in wetlands is plant uptake. Contaminants that are also forms of essential plant nutrients, such as nitrate, ammonium and phosphate, are readily taken up by wetland plants. However, many wetland plant species are also capable of uptake, and even significant accumulation of, certain toxic metals such as cadmium and lead. The rate of contaminant removal by plants varies widely, depending on plant growth rate and concentration of the contaminant in plant tissue. Woody plants, i.e., trees and shrubs, provide relatively long-term storage of contaminants, compared with herbaceous plants. However, contaminant uptake rate per unit area of land is often much higher for herbaceous plants, or macrophytes, such as cattail. Algae may also provide a significant amount of nutrient uptake, but are more susceptible to the toxic effects of heavy metals. Storage of nutrients in algae is relatively short-term, due to the rapid turnover (short life cycle) of algae. Bacteria and other microorganisms in the soil also provide uptake and short-term storage of nutrients, and some other contaminants.
In wetlands, as in many terrestrial ecosystems, dead plant material, known as detritus or litter, accumulates at the soil surface. Some of the nutrients, metals or other elements previously removed from the water by plant uptake are lost from the plant detritus by leaching and decomposition, and recycled back into the water and soil. Leaching of water-soluble contaminants may occur rapidly upon the death of the plant or plant tissue, while a more gradual loss of contaminants occurs during decomposition of detritus by bacteria and other organisms. Recycled contaminants may be flushed from the wetland in the surface water, or may be removed again from the water by biological uptake or other means.

In most wetlands, there is a significant accumulation of plant detritus, because the rate of decomposition is substantially decreased under the anaerobic (oxygen-depleted) conditions that generally prevail in wetland soil. If, over an extended period of time, the rate of organic matter decomposition is lower than the rate of organic matter deposition on the soil, formation of peat occurs in the wetland. In this manner, some of the contaminants originally taken up by plants can be trapped and stored as peat. Peat may accumulate to great depths in wetlands, and can provide long-term storage for contaminants. However, peat is also susceptible to decomposition if the wetland is drained or otherwise dries up. When that happens, the contaminants incorporated in the peat may be released and either recycled or flushed from the wetland.

Although microorganisms may provide a measurable amount of contaminant uptake and storage, it is their metabolic processes that play the most significant role in removal of organic compounds. Microbial decomposers, primarily soil bacteria, utilize the carbon (C) in organic matter as a source of energy, converting it to carbon dioxide (CO2) or methane (CH4) gases. This provides an important biological mechanism for removal of a wide variety of organic compounds, including those found in municipal wastewater, food processing wastewater, pesticides and petroleum products. The efficiency and rate of organic C degradation by microorganisms is highly variable for different types of organic compounds.

Microbial metabolism also affords removal of inorganic nitrogen, i.e., nitrate and ammonium, in wetlands. Specialized bacteria (Pseudomonas spp.) metabolically transform nitrate into nitrogen gas (N2), a process known as denitrification. The N2 is subsequently lost to the atmosphere, thus denitrification represents a means for permanent removal, rather than storage, of nitrogen by the wetland. Removal of ammonium in wetlands can occur as a result of the sequential processes of nitrification and denitrification. Nitrification, the microbial (Nitrosomonas and Nitrobacter spp.) transformation of ammonium to nitrate, takes place in aerobic (oxygen-rich) regions of the soil and surface water. The newly-formed nitrate can then undergo denitrification when it diffuses into the deeper, anaerobic regions of the soil. The coupled processes of nitrification and denitrification are universally important in the cycling and bioavailability of nitrogen in wetland and upland soils.


Chemical Removal Processes

In addition to physical and biological processes, a wide range of chemical processes are involved in the removal of contaminants in wetlands. The most important chemical removal process in wetland soils is sorption, which results in short-term retention or long-term immobilization of several classes of contaminants. Sorption is a broadly defined term for the transfer of ions (molecules with positive or negative charges) from the solution phase (water) to the solid phase (soil). Sorption actually describes a group of processes, which includes adsorption and precipitation reactions.
Adsorption refers to the attachment of ions to soil particles, by either cation exchange or chemisorption. Cation exchange involves the physical attachment of cations (positively charged ions) to the surfaces of clay and organic matter particles in the soil. This a much weaker attachment than chemical bonding, therefore the cations are not permanently immobilized in the soil. Many constituents of wastewater and runoff exist as cations, including ammonium (NH4+) and most trace metals, such as copper (Cu2+). The capacity of soils for retention of cations, expressed as cation exchange capacity (CEC), generally increases with increasing clay and organic matter content. Chemisorption represents a stronger and more permanent form of bonding than cation exchange. A number of metals and organic compounds can be immobilized in the soil via chemisorption with clays, iron (Fe) and aluminum (Al) oxides, and organic matter. Phosphate can also bind with clays and Fe and Al oxides through chemisorption.

Phosphate can also precipitate with iron and aluminum oxides to form new mineral compounds (Fe- and Al-phosphates), which are potentially very stable in the soil, affording long- term storage of phosphorus. In the Everglades, and other wetlands that contain high concentrations of calcium (Ca), phosphate can precipitate to form Ca-phosphate minerals, which are also stable over a long period of time. Another important precipitation reaction that occurs in wetland soils is the formation of metal sulfides. Such compounds are highly insoluble and represent an effective means for immobilizing many toxic metals in wetlands.

Volatilization, which involves diffusion of a dissolved compound from the water into the atmosphere, is another potential means of contaminant removal in wetlands. Ammonia (NH3) volatilization can result in significant removal of nitrogen, if the pH of the water is high (greater than about 8.5). However, at a pH lower than about 8.5, ammonia nitrogen exists almost exclusively in the ionized form (ammonium, NH4+), which is not volatile. Many types of organic compounds are volatile, and are readily lost to the atmosphere from wetlands and other surface waters. Although volatilization can effectively remove certain contaminants from the water, it may prove to be undesirable in some instances, due to the potential for polluting the air with the same contaminants.


Conclusions

A wide range of physical, chemical and biological processes contribute to removal of contaminants from water in wetlands. These processes include sedimentation, plant uptake, chemical adsorption and precipitation, and volatilization. Removal of contaminants may be accomplished through storage in the wetland soil and vegetation, or through losses to the atmosphere.
An understanding of the basic physical, chemical and biological processes controlling contaminant removal in wetlands will substantially increase the probability of success of treatment wetland applications. Furthermore, a working knowledge of biogeochemical cycling, the movement and transformation of nutrients, metals and organic compounds among the biotic (living) and abiotic (non-living) components of the ecosystem, can provide valuable insight into overall wetland function and structure. This level of understanding is useful for evaluating the contaminant-removal performance of constructed wetlands and for assessing the functional integrity of human-impacted, restored and mitigation wetlands. More detailed discussions of wetland biogeochemistry and contaminant removal in treatment wetlands can be found in the references listed below.


References

Kadlec, R.H., and R.L. Knight. 1996. Treatment wetlands. Lewis Publishers, Boca Raton, FL.
Mitsch, W.J., and J.G. Gosselink. 1993. Wetlands. Van Nostrand Reinhold, New York.

Reddy, K. R., and E. M. D'Angelo. 1994. Soil processes regulating water quality in wetlands. p. 309-324. In Mitsch, W. J. (ed.) Global wetlands: old world and new. Elsevier Science, Amsterdam.

Terra preta, biochar and agriculture

The Oil Drum has an excellent posting on terra preta. The link with images and charts can be found heretext of article below fold
More...Terra Preta: Biochar And The MEGO Effect
Posted by Big Gav on September 28, 2008 - 10:27am in TOD: Australia/New Zealand
Topic: Alternative energy
Tags: agrichar, agriculture, biochar, black earth, carbon sequestration, original, pyrolysis, terra preta [list all tags]
This month's edition of National Geographic has a feature article on "Soil", which looks at the steady degradation of agricultural land and the problem this poses in world where the population is heading for 9+ billion people - effectively calling attention to the "peak dirt" problem (however soil is renewable, so any "peak" should be able to be reversed if sufficient time and effort is put into doing so).
The article uses an acronym I've never come across before to describe the problem faced by those trying to draw attention to the issue: MEGO (My Eyes Glaze Over) - a phenomenon which should be familiar to anyone who has ever talked about peak oil, global warming or any of the other "limits to growth".

This year food shortages, caused in part by the diminishing quantity and quality of the world's soil, have led to riots in Asia, Africa, and Latin America. By 2030, when today's toddlers have toddlers of their own, 8.3 billion people will walk the Earth; to feed them, the UN Food and Agriculture Organization estimates, farmers will have to grow almost 30 percent more grain than they do now. Connoisseurs of human fecklessness will appreciate that even as humankind is ratchetting up its demands on soil, we are destroying it faster than ever before. "Taking the long view, we are running out of dirt," says David R. Montgomery, a geologist at the University of Washington in Seattle.
Journalists sometimes describe unsexy subjects as MEGO: My eyes glaze over. Alas, soil degradation is the essence of MEGO.

One subject that features in the article is soil restoration, including a look at "terra preta" - rich, fertile artificial soils found in the Amazon. In this post I'll have a look at modern day techniques to produce terra preta (often called biochar or agrichar) which have the potential to increase soil fertility, generate energy and sequester carbon all at the same time.
The History Of Terra Preta

Terra Preta ("black earth") was discovered by Dutch soil scientist Wim Sombroek in the 1950's, when he discovered pockets of rich, fertile soil amidst the Amazon rainforest (otherwise known for its poor, thin soils), which he documented in a 1966 book "Amazon Soils". Similar pockets have since been found in other sites in Ecuador and Peru, and also in Western Africa (Benin and Liberia) and the Savannas of South Africa. Carbon dating has shown them to date back between 1,780 and 2,260 years.

Terra preta is found only where people lived - it is an artificial, human-made soil, which originated before the arrival of Europeans in South America. The soil is rich in minerals including phosphorus, calcium, zinc, and manganese - however its most important ingredient is charcoal, the source of terra preta's color.

It isn't entirely clear if the Amazon Indians whose old settlements terra preta is found at deliberately created the soils or if they were an accidental by-product of "slash and smoulder" farming techniques, though the emerging consensus seems to be that the Indians deliberately created the material, with some early European accounts in the area noting the practice still being performed.

The key ingredient is apparently the activated carbon in the charcoal. Activated carbon has a complex, spongelike molecular structure - a single gram can have a surface area of 500 to 1,500 square meters (or about the equivalent of one to three basketball courts). Having this material in the soil has several beneficial effects, including a 20% increase in water retention, increased mineral retention, increased mineral availability to plant roots, and increased microbial activity.

It has also been shown to be particularly beneficial to arbuscular mycorrhizal fungi, which form a symbiotic relationship with plant root fibers, allowing for greater nutrient uptake by plants. There is speculation that the mycorrhizal fungi may play a part in terra preta’s ability to seemingly regenerate itself.


Pyrolysis and Eprida

Modern day producers of biochar (agrichar) take dry biomass and bake it in a kiln to produce charcoal. Biochar is the term for what is left over after the energy is removed: a charcoal-based soil amendment - this process is called pyrolysis. Various gases and oils are driven off the material during the process and then used to generate energy. The charcoal is buried in the ground, sequestering the carbon that the growing plants had pulled out of the atmosphere. The end result is increased soil fertility and an energy source with negative carbon emissions.

Eprida is a company founded by Danny Day, which is attempting to commercialise the idea by building systems that turn farm waste into hydrogen, biofuel, and biochar (see here for a short movie explaining their process).

The Eprida technology uses agricultural waste biomass to produce hydrogen-rich bio-fuels and a new restorative high-carbon fertilizer (ECOSS) ...In tropical or depleted soils ECOSS fertilizer sustainably improves soil fertility, water holding and plant yield far beyond what is possible with nitrogen fertilizers alone. The hydrogen produced from biomass can be used to make ethanol, or a Fischer-Troupsch gas-to-liquids diesel (BTL diesel), as well as the ammonia used to enrich the carbon to make ECOSS fertilizer.
We don't maximize for hydrogen; we don't maximize for biodisel; we don't maximize for char...By being a little bit inefficient in each, we approximate nature and get a completely efficient cycle.


The potential power of biochar lies in this closed loop production process , where agricultural practices involving biochar production see increasing returns of crop yields, energy and soil fertility over time.

Biochar also has potential to address problems such as waste disposal and rural development. A significant proportion of the world's population relies on charcoal as a cooking fuel, the production of which drives deforestation in Africa and other places.

Replacing traditional charcoal kilns with modern pyrolysis units could reduce the demand for wood from forests by increasing the efficiency of energy production and adding the ability to use any source of biomass, including agricultural waste products. This would also help to reduce respiratory diseases in the developing world, particularly amongst children.


There has also been speculation that pyrolysis could be a useful technique for dealing with the huge swathes of Canadian forests that have been killed by pine beetles recently.

Some industry participants believe that energy, rather than agriculture, will be the key driver for adopting biomass pyrolysis. Desmond Radlein of Dynamotive Energy Systems has been quoted as saying "It is wishful thinking that people will switch to renewable fuels unless it is cheaper. All of this is tied to the price of oil; as it goes up, many more things are possible."

Another company active in the pyrolysis sector is Best Energies. Technical Manager Adriana Downey recently had an interview with Beyond Zero Emissions, talking about some of the pilot programs they have been running and plans to build the first fully commercial scale pyrolysis plant in Australia.

Lukas's program with the NSW DPI (Department of Primary Industries) in Northern NSW have basically taken some of the agrichar material that we've made here at Best Energies and they've been trialling that material in different agronomic applications to see how the agrichar, when its applied, can help crop-productivity and improve the sustainability of agriculture as well as, and what you guys are more interested in, sequester carbon long-term in soils and also decrease the potent greenhouse gas nitrous oxide emissions from soil. ...
The agrichar when it's applied to the soil has a good effect on the general physical structure of the soil. Because the agrichar has a really high surface area, it means that there's lots of pores in the soil which can then retain moisture and act as little reservoirs for the water to be retained in the soil. As well as this, all of the surface area helps to bind nutrients in the soil and also provides a microhabitat for micro organisms in the soil which are essential for the natural processes in the soil which allow micro organisms to flourish.


Carbon Capture Potential

There is a large difference between terra preta and ordinary soils - a hectare of meter-deep terra preta can contain 250 tonnes of carbon, as opposed to 100 tonnes in unimproved soils from similar parent material, according to Bruno Glaser, of the University of Bayreuth, Germany. The difference in the carbon between these soils matches all of the carbon contained in the vegetation on top of them.

The ABC's "Catalyst" program last year had a feature on "Agrichar – A solution to global warming ?" (shown below) in the lead up to an international biochar conference in Terrigal, NSW, which included Tim Flannery talking about the potential for sequestering gigatonnes of carbon in the soil.


This year's International Biochar Initiative conference has just been held in Newcastle-upon-Tyne in the UK.


It is not yet clear what the limits are to how much biochar can be added to the soils using these techniques, however some fairly extravagant claims about biochar's capacity to capture carbon have been made. Soil scientist and author of "Amazonian Dark Earths: Origin, Properties, Management" Johannes Lehmann believes that a strategy combining biochar with biofuels could ultimately offset 9.5 billion tons of carbon per year - an amount equal to the total current fossil fuel emissions. Lehmann also notes that unlike biodiesel and corn ethanol, biochar doesn’t take land away from food production.

If true, this would be an interesting form of geoengineering to try and reverse the effects of global warming (and one far less risky than some of the alternatives proposed) but I would still question our ability to turn all the world's oil, coal and gas reserves back into rich soil via burn - atmosphere - pyrolysis loop.

Criticisms

A number of criticisms have been made about biochar. These include:

* The technology to implement the process is still immature.
* Scientists don’t know how much charcoal farmers should use, how they should apply it, or which feedstocks work best.
* Farmers are reluctant to spread unproven products on their fields, so the few companies manufacturing biochar have struggled to find buyers.
* Charcoal production can generate toxic waste if performed incorrectly.
* The energy needed to produce, transport, and bury biochar could outweigh the carbon savings.
* Some analysts say the economics of the process will not be acceptable until carbon markets are established, allowing farmers to earn carbon credits for applying biochar to their fields.
* Some environmental activists claim that applying the process on a large scale would result in further rainforest clearing which would actually degrade soil quality and increase global warming.
Rhizome In The Amazon

Jeff Vail recently had a post on a "Rhizome Template in the Amazon ?", which looked at a paper by Mark Heckenberger suggesting that a dense civilization of networked villages once existed in the Amazon, which Jeff noted was interesting because it "appears to show a form of organization that permits density without significant hierarchy".

The paper shows that the Xingu region of the Amazon was once populated by a grid-like pattern or villages, each connected by a precisely aligned network of roadways (the Xingu river is the Amazon's second longest tributary, with the region currently experiencing tension over plans to dam the river).

Here's an alternate mode of organization--a networked "grid," "lattice," or "peer-to-peer" structure of small, minimally self-sufficient villages, or "rhizome" as proposed in my article The Hamlet Economy. The Xingu settlement structure seems to consicously model itself in the latter pattern. Heckenberger even notes that each village was surrounded by a buffer zone of "managed parkland," exactly the kind of fall-back, resiliency-enhancing production zone that I recommended for rhizome. Here's a link to a satellite image of one section fo Xingu settlement.
Did this Xingu civilization really develop a dense, ecologically sustainable civilization without hierarchal structure? Or did they simply find a new way to impose hierarchy without developing the signatures of "central places"? Was this a conscious reaction to prior abuses of hierarchy, or simply an expedient to survival in the dense forrests and poor agricultural soils of the Amazon? We don't know the answers to these questions at this time, but the research of Heckenberger and his colleagues suggests that there is still a great deal for us to learn from the past about how we can best live in the future

Heckenberger also examined the terra preta pockets in the region, which is described briefly in an interesting article by Charles Mann in The Atlantic Monthly called "1491".
Scientific American also notes the correlation between the lost cities of the Amazon and terra preta in "Ancient Amazon Actually Highly Urbanized", as does The Vermont Quarterly in "Pay Dirt".

Terra preta, Woods guesses, covers at least 10 percent of Amazonia, an area the size of France. It has amazing properties, he says. Tropical rain doesn't leach nutrients from terra preta fields; instead the soil, so to speak, fights back. Not far from Painted Rock Cave is a 300-acre area with a two-foot layer of terra preta quarried by locals for potting soil. The bottom third of the layer is never removed, workers there explain, because over time it will re-create the original soil layer in its initial thickness. The reason, scientists suspect, is that terra preta is generated by a special suite of microorganisms that resists depletion. "Apparently," Woods and the Wisconsin geographer Joseph M. McCann argued in a presentation last summer, "at some threshold level ... dark earth attains the capacity to perpetuate—even regenerate itself—thus behaving more like a living 'super'-organism than an inert material."
In as yet unpublished research the archaeologists Eduardo Neves, of the University of São Paulo; Michael Heckenberger, of the University of Florida; and their colleagues examined terra preta in the upper Xingu, a huge southern tributary of the Amazon. Not all Xingu cultures left behind this living earth, they discovered. But the ones that did generated it rapidly—suggesting to Woods that terra preta was created deliberately. In a process reminiscent of dropping microorganism-rich starter into plain dough to create sourdough bread, Amazonian peoples, he believes, inoculated bad soil with a transforming bacterial charge. Not every group of Indians there did this, but quite a few did, and over an extended period of time.

When Woods told me this, I was so amazed that I almost dropped the phone. I ceased to be articulate for a moment and said things like "wow" and "gosh." Woods chuckled at my reaction, probably because he understood what was passing through my mind. Faced with an ecological problem, I was thinking, the Indians fixed it. They were in the process of terraforming the Amazon when Columbus showed up and ruined everything.

Scientists should study the microorganisms in terra preta, Woods told me, to find out how they work. If that could be learned, maybe some version of Amazonian dark earth could be used to improve the vast expanses of bad soil that cripple agriculture in Africa—a final gift from the people who brought us tomatoes, corn, and the immense grasslands of the Great Plains.

All in all I think biochar is worth exploring further in some depth.
Further Reading:

Nature: Putting the carbon back "Black is the new green": http://www.nature.com/nature/journal/v442/n7103/full/442624a.html

Biochar overview from Cornell University: http://www.css.cornell.edu/faculty/lehmann/biochar/Biochar_home.htm

Terra Preta web site from the University of Bayreuth http://www.geo.uni-bayreuth.de/bodenkunde/terra_preta/

The Earth Science Forum: http://forums.hypography.com/earth-science/3451-terra-preta.html

Biochar summary from Georgia Tech: http://www.energy.gatech.edu/presentations/dday.pdf

Terra preta mailing list: Terrapreta@bioenergylists.org http://bioenergylists.org/mailman/listinfo/terrapreta_bioenergylists.org

FAO: Organic Agriculture And The Environment http://www.fao.org/docrep/005/Y4137E/y4137e02.htm

WorldChanging: A Carbon-Negative Fuel http://www.worldchanging.com/archives/007427.html

Hen and Harvest: Black Magic http://henandharvest.com/?p=118

Peak Energy: On population growth and the green revolution - "The Fat Man, The Population Bomb And The Green Revolution" http://peakenergy.blogspot.com/2007/10/fat-man-population-bomb-and-green.html

Peak Energy: On worms and soil - "The Turning Of The Worm" http://peakenergy.blogspot.com/2007/01/turning-of-worm.html

Peak Energy: On Mycelium - "Nature's Internet: The Vast, Intelligent Network Beneath Our Feet" http://peakenergy.blogspot.com/2008/07/natures-internet-vast-intelligent.html

(Hat tip to Erich J Knight and Aaron Newton for providing some of the links used in the post)

Cross-posted from Our Clean Energy Future.

Shade and seedling propagation

Managing the intense sunlight of the tropics is a critical issue. At our temperate zone nursery we field raise our plants direct seeded in seedbeds. Here also we are concerned about ensuring survival of seedlings in the harsh reality of spring sunlight. We use overhead irrigation in early spring until our drip irrigation is installed. As the root emerge from the surface sown seed sunlight and desiccation is deadly. Seedlings are also tender and need to be protected until they have roots to sustain their leaves.

We use remay a rayon fabric used as a spring crop cover in our own special application This and more under the fold
More... This is the remay we use on our crops



These are emerging seedlings



Now, last few days I have been looking for literature helpful in our interest of restoration ecology in Sao Paulo State. This and the series of recent posts is topical for this purpose. Here is a link to a FAO article,Management of Forest Nurseries, the chapter on the use of shade is here



Noteworthy is the use of natural materials to build shade structures and supporting structure.