K'JIPUKTUK, HALIFAX - Northern Pulp, Pictou's infamous pulp and paper plant, needs wood. Lots of wood.

In January, 2013, an accommodating former NDP government offered Northern Pulp access to an additional 125,000 tonnes of green fibre a year. That arrangement more than doubled the government's previous annual commitment.

And why not, what's the harm? Wood is a renewable resource, it will just grow back.

Or maybe it won't.

"It's a bit like a farmer cultivating a field," David Patriquin tells the Halifax Media Co-op. "A farmer has to fertilize the land, because growing a crop takes out nutrients like phosphorus and nitrogen faster than rain and the weathering of rocks can replace them.

"If you take more out, over the long term it needs to be balanced by what comes in or the fertility goes down."

Patriquin is a retired Dalhousie biologist. He believes that many of Nova Scotia's forests may be approaching the breaking point. Some forest systems can sustain a clearcut every so often, Patriquin says, but here in Nova Scotia we have a problem or two.

One problem is our soil. Or rather, the lack of nutrients in our soil.

"We are dealing with very nutrient-poor soils to begin with," Patriquin says. "Nova Scotia forests have some of the poorest bufering capacities of soils anywhere in North America and Europe. Maybe as much as 60 or 70 percent have an extremely low ability to replace nutrients."

The second problem is acid rain. Emission controls introduced in response to acid rain problems have reversed trends in much of North America, but not in Nova Scotia. Nutrient-poor soils are thought to be one of the main reasons, Patriquin explains.

Add to that mix of problems a forest that is already stressed to the max. "On average our Nova Scotia forests have been cut over at least five times since the arrival of the Europeans. We have one of the most intensely exploited forests in North America," Patriquin says.

Stressed forests, poor soil and acid rain spell trouble for Nova Scotia's intention to engage in "biomass harvesting" of this "renewable resource" for all eternity.

The Department of Natural Resources (DNR), the steward of our forests, knows about this. Sort of.

"A couple of years ago it became obvious that we needed to look at those nutrient pools. DNR developed a project. They talked about it on their website. They said that this tool would be available in the next couple of years," says Patriquin.

The DNR's nutrient management tool would be a way to understand soil chemistry and fertility all across Nova Scotia. Towards that end, DNR engaged University of New Brunswick Professor Paul Arp, an expert in forest soils, and soil information was mapped and delivered.

But then the nutrient management tool disappeared.

An email from Bruce Nunn, DNR spokesperson, to the Halifax Media Co-op, explains that the tool just wasn't very good.

"The Nutrient Budget Model is being calibrated for NS (Soil mapping information is being updated because the model version received had significant errors). The model is not in a state where we can share it, but we intend to do so once calibration for Nova Scotia is complete. The model remains under internal development at DNR but there are no final results to release."

"I can't comment on the quality of the model because it isn't available," Patriquin says. " I have written DNR and asked for it, but they do not respond."

Matt Miller, forestry coordinator for the Ecology Action Centre, believes that the issue isn't the science so much, as it is what the model tells them. He believes that heeding the model would mean a drastic change in current forestry practices.

"I get nervous," Miller tells the Halifax Media Co-op. "This is a completely non-transparent internal process to change something that was done by an independent third party.

"Dr. Arp is the soil expert at the University of New Brunswick, which is the leading forestry institution in Eastern Canada. To think that DNR is denying your request to see it? It's unbelievable."

See also:

Letter by David Patriquin, on behalf of the Woodens River Watershed Environmental Organization.

Feeding the boiler. NS Power's biomass plant and the health of our forests

Draft plan shows sensitive forests in Western Nova Scotia open for harvesting

New book tackles old growth on our East Coast

Follow Robert Devet on Twitter @DevetRobert