Reforestation Stores More Carbon Than Industrial Tree Farms

Australian researchers examining environmental restoration projects have found that reforesting damaged rainforests captures carbon more efficiently than softwood industrial monoculture plantations — or big tree farms planted with a single species.  

The research, which was published in Ecological Management & Restoration, throws a wrench into the long-held belief that monoculture plantations can capture more carbon than a replanted forest-great news for fans of biodiversity, except for one problem: reforestation may be more effective, but it also costs more.  

Monoculture plantations are grown in Australia as a source of resources, including timber and rubber. But some ecologists aren't exactly thrilled with these resource farms, calling the plantations a "green desert," evoking images of a uniform wave of green that seems contrary to the variations in natural forests.  

The new research contradicts policy that has maintained that monoculture plantations can sequester more carbon that reforested forests. While the Australian Government's National Carbon Accounting Tool Box indicates monoculture plantations sequester an estimated 40 per cent more carbon than reforestation plantings in northern Australia, researchers found the reverse to be true.  

The researchers found the reforested rainforest stored on average 106 tonnes of carbon per hectare, 41.5 percent more than the 62 tonnes per hectare stored in monoculture plantations of native conifers. The replanted rainforests also stored about 19 percent more carbon than mixed species timber plantations, which on average stored 86 tonnes of carbon per hectare.   

The restocked rainforests presented a picture of a more diverse and healthier ecosystem, explains the paper's co-author and Australian Wildlife Conservancy regional ecologist, Dr. John Kanowski: "Compared to the monoculture plantations, reforestation projects were more densely stocked, there were more large trees and the trees which were used had a higher wood density then the conifers at the plantation.  

Now that researchers can demonstrate how effective reforestation is over monoculture plantations, they have a new problem to tackle: They have to find a way to make reforestation cheaper so it's economically competitive with plantations.  

The key is to make reforestation attractive to the carbon market, or the cap-and-trade system of reducing greenhouse gas emissions. It's going to mean an overhaul of the way reforestation is carried out, says Kanowski. "In order to be an attractive prospect for the markets, new reforestation techniques and designs are going to be required< he says. "New designs will have to ensure that restoration can provide a habitat for rainforest life and store carbon at a cost comparable to industrial monoculture."  

While the research presents challenges for markets, it also underscores nature's ability to work far more efficiently and effectively than it does when we try and mold it to fit human interests. And that is something we need to pay more attention to.