Tuesday, June 27, 2006

Progress update: Work on the Barnes home

I'd published earlier the draft for the Barnes home in Toronto. Looking again at where I'd started:

Here is what has been happening. First, seed trays were prepared:

To prepare the ground, all pulled weeds, tree prunings and even some light waste lumber was placed on the ground, which was then treated with kelp meal as a soil amendment.

Next, the ground was watered and covered with cardboard sheets as a weed deterrent. The Portugese on the cardboard says "one tonne of paper equals 17 to 20 adult trees, 10,000 litres of water and 25% to 60% of energy."

On top of this was placed about 20 cm of hay mulch.

On top of this was placed about 3 cm of compost, except over the paths.

Finally, a 5 cm layer of woodchips was placed over everything and this was sowed with nitrogen-fixing clower as a groundcover.

Friday, June 09, 2006

Beavers and humans as groundwater rechargers

We already knew this, but it is still interesting. News from the American Geophysical Union via Eurekalert:
Beavers, long known for their beneficial effects on the environment near their dams, are also critical to maintaining healthy ecosystems downstream. Researchers have found that ponds created by beaver dams raised downstream groundwater levels in the Colorado River valley, keeping soil water levels high and providing moisture to plants in the otherwise dry valley bottom. The results will be published 8 June in Water Resources Research, a journal of the American Geophysical Union.


The researchers suggest that the elevated moisture levels found in soil surrounding the dams would otherwise require water from a very large natural flood, which they estimate as the 200-year flood, to achieve the same expansive water availability to the valley bottom. Additionally, beaver dams built away from natural river channels further redirect water across the valley, enhancing the depth, extent, and duration of inundation associated with smaller floods; they also elevate the water table to sustain plant and animal life during the dry summer season.

People achieve the same results through the use of water catchment systems including dams, swales, and gabions, which are common features of permaculture systems.