[Terrapreta] The Science of Terra Preta Formation

[Jim Joyner]

Thanks David. Lots of stuff I didn't know.

My point, however, (a guess, really) is that much of what ever nutrient 
came into the Amazon, however it got there, had to stay in order to 
support the apparent large human population; That there was likely no 
internal significant source of nutrient to exploit or "mine". I think 
that means that there had to have some kind of serious waste/nutrient 
management going on. This management may not have been consciously 
directed for that purpose but without that management or manipulation of 
waste, populations couldn't have been supported.

Reclaiming waste is nothing new -- would not have been new then. My 
speculation: Given the heat and humidity in the tropics, this could not 
have taken place without some extraordinary method and/or substance 
(char) -- something we still have yet to fully understand.

Jim

David Hirst .com wrote:
> Jim,
> It may be that there are a few nutrient recycling opportunities that are
> natural, although how far they apply in the Amazon I do not know. For
> example;
> 1.	The bodies of Salmon bring nutrients from the sea far up river, and,
> after spawning, usually get caught by bears. They tend to take a few bites,
> and leave the bulk of carcass in the forest, where the nutrients recycle.
> The forests seem to suffer from the loss of salmon. Do any Amazon fish swim
> upriver from the sea so brining up nutrients (perhaps via several food
> chains)?
> 2.	Aeolian dust. Quote significant volumes of dust get blown about, and
> land far from where they originated. In the Amazon, I guess most traces get
> lost in the forest but I though Laos was build on blown dust. Some of the
> dust is alive, and even scorched islands seem quite quickly to have seeds
> land and germinate. Some spiders use threads to fly off and travel long
> distances.
> 3.	Volcanoes. They are also a contributor to dust.
> 4.	Sulphur is also cycled from the sea as particulates (and cloud
> condensation nuclei). Algae, when they get too hot tend to release DMS,
> which helps form clouds (and so cools them).
> 5.	Tectonic movements. Upriver, there are the Andes, which are still
> being pushed up, and so can carry on eroding and feeding nutrients
> downstream.
> Many of these are quite slow acting, but most nutrients get recycled close
> to home. I understand that most rain is from evaporation within the forests.
> I imagine that forest fires do occasionally occur during dry spells, and
> would tend to leave some charcoal.
> Most sources seem to think that TP is anthropogenic, and I am not arguing.
> But natural sources cannot be entirely ruled out on nutrient cycling
> grounds.
> Cheers
> David
>
> David Hirst
>
> direct:     +44 (0) 1723 570113    
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>
> -----Original Message-----
> From: terrapreta-bounces at bioenergylists.org
> [mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Jim Joyner
> Sent: 08 April 2008 16:02
> To: Terrapreta
> Subject: Re: [Terrapreta] The Science of Terra Preta Formation
>
> If I might add a few things:
>
> I find it very difficult to believe that dark earth in Amazonia had a 
> natural start. Much of the muck soils in the US Midwest were due to 
> catastrophic events through the ice ages. These nutrients became a 
> treasure trove of nutrients that farmers are still mining. There is 
> nothing comparable in the tropics that I know of. (Well, there the 
> occasional guano deposits found, but even these are not soils)
>
> There is practically no way that carbon can naturally accumulate in the 
> tropics for any length of time. The one exception to that seems to be 
> charcoal but that is not what we would call natural.
>
> Also, in terms of nutrient (I'm speculating, but bear with me). For 
> thousands, many hundreds of thousands of years, nutrient  has flowed 
> into the Amazon from the mountains above. Some of these nutrients are 
> soaked up into above ground jungle/rain forests. Some, of course, are 
> bound up in aquatic life. Most are washed out to sea. But there is no 
> source of nutrient in the tropics to "mine" like there are in the 
> temperate zones. There is no soil deposit to mine simply because, if it 
> had existed, it would  have quickly disappeared.
>
> This means, I think, to have supported what seems to have been huge 
> populations, there had to be a serious form of economizing and cycling 
> of nutrient. Basically, people had to take from the rivers and some from 
> the forests (so far that is gather-hunting which will not support large 
> populations), but in time as they keep their waste (somehow), they 
> recycled and accumulated nutrient. This recycling is not unusual (Asians 
> ahve done for millenia), but it is difficult in the tropics simply 
> because the medium that is necessary (for the most part) to hold these 
> nutrients, in a usable way, is carbon. And most carbon under normal 
> natural conditions in the tropics will will simply evaporate (actually, 
> the process is burning or oxidation).
>
> Somehow, it seems the people discovered a medium to collect, hold and 
> recycle nutrients and carbon. Our guess, of course, some form of char.
>
> Jim
>