[Gasification] [Digestion] Cattails

[Richard Haard]

On Dec 21, 2007, at 7:38 PM, Mark Ludlow wrote:

> Richard,
>
> Can you please describe what (if any) kind of equipment is available  
> for
> harvesting starchy tubers that have a minimal impact on benthic  
> ecosystems?
A a general principle agriculture is a system that simplifies the  
ecosystem to a single component - your crop species. If any other  
benthic species are associated they would change from the natural  
because of the regular disturbance to a new community reflecting the  
changes caused by cultivation.

There may be an application such as aquaculture of fish, frogs or  
shrimp that could cohabit such a system, maybe.

If the purpose of a proposed site is ecosystem enhancement then there  
is no way to accomplish any kind of harvest. However if the site is  
for waste water treatment then such uses would apply. I do not know  
what regulations are in your area but out here marshes are not  
considered ecological wastelands. In some places though such as in  
drylands that are irrigated and summer fallow wheat production causes  
saline seeps that may be diverted to a new kind of agriculture.

As in Australia where irrigation in the desert has ruined soils with  
saline build-up they have created the oil mallee project to allow land  
owners to derive income from these once ag lands with native shrubs  
with essential oil and biomass energy. There they are making charcoal  
and collecting carbon credits.

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>
> Can they be pulled free by their stalks? How would they be  
> regenerated?
No way to harvest root or tuber crops without disrupting soil. It's  
kind of like clam digging. The Wapato may have smaller propagules  
remain and the cattail rhizomes would reprout. Cattails also are  
readily reseeded and grow rapidly.

> Do
> any of the species you mention host denitrifying or nitrogen-fixing
> bacteria?

These plants are all hosts for beneficial mycorrhizal fungi but  
nitrogen fixing is not necessary in these bottomland habitats as they  
are places where waste water brings in nutrients leached from our use  
of fertilizer and of all of the other soluble materials we allow loose  
in the environment. Many of these materials are toxic organic  
chemicals and these wetlands do a service to our ecosystem by  
capturing the nutrients and converting into biomass and also by  
microbial activity degrade these toxic materials into harmless  
metabolites.

If one was going to use such a place for agriculture and biomass  
production then you would have to demonstrate that your proposed  
activity , at least , accomplishes these ecosystem roles because  
biological diversity will have been reduced.

>
>