Roy L Hales/ Cortes Currents - “Most of what’s left is up in the mountains and the coast range or the Rockies and so not the productive sites anymore. Most of what was easy to get is gone,” said Bruce Ellingsen, one of the founders of the Cortes Community Forest Co-operative, in reference to British Columbia’s old growth trees. In the first of two articles about current forestry practices, Ellingsen looks to nature for models of a more sustainable consumption rate.Landsat satellite data published by the University of Maryland (and reproduced at the top of this page), show that there has been alarming loss of the forests on Vancouver Island and in the interior of British Columbia during the past 20 years. Less easily accessible areas in the north of the province, or in the coastal and rocky mountains, are relatively untouched. In a previous interview Bruce Ellingsen explained that the discrepancy between the government and satellite descriptions of the province’s forest coverage may be because trees less than 5 metres high do not show up in Landsat images. So much of the light coloured areas that appear as tree loss in the university’s map may be covered by what are in effect tree toddlers. These trees will be harvested once they are between 50 to 80 years old. To use a comparison with humans, then they will effectively be pre-teens, with a far greater proportion of sapwood than is present in mature trees. “We’re the ones that are managing it and we’re the ones that are going to have the impact. If we want to do it in a sustainable way, then we’ve got to look for indicators that will give us a guidance as to whether we are going to be able to achieve that goal of having that ecosystem that grows trees for us be able to sustain,” said Bruce Ellingsen. Ellingsen says he came up with the idea of studying predation rates from an old report about the dynamic between Peregrine Falcons and Ancient Murrelets on the Nature of Things. After 17 years of studying, researchers concluded that the Peregrines were probably taking around 15 to 20% of the mean annual seabird population increase.“That got me thinking that possibly there’s indicators in natural system dynamics in the world that we could look at,” explained Ellingsen.He discovered a similar predation rate between polar bears and ringed seals, after a visit to Churchill, Manitoba, in 2003. That led him to to the work of Dr Ian Sterling, who has been studying polar bears since the early 1970s. Sterling and his colleagues believe that every year polar bears were consuming between 13% and 22% of the seal populationA similar statistic was reported in a New York times about Central America’s Leaf Cutter Ants. Scientists found that the ants were only taking 13 to 20% of the shrubs, trees and other vegetation in their area and that has probably been going on for millions of years. The only human example he found comes from the South Island of New Zealand and the Rocky islands offshore, where the Maoris have been harvesting about 18% of the seabird eggs every year. “This has been going on for about 700 years and obviously you can start to say that’s a reasonably sustainable dynamic for a population that is reproducing annually,” said Ellingsen. He added that forestry ecologists like Herb Hammond, of the Silva Forest Foundation, and Jerry Franklin, from the University of Washington, seem to agree that maybe 25% of what grows in a forest is extra and the forest needs everything beyond that to keep itself alive and healthy.