12 October 2015, Yale Environment 360, The Rapid and Startling Decline Of World’s Vast Boreal Forests. Scientists are becoming increasingly concerned about the fate of the huge boreal forest that spans from Scandinavia to northern Canada. Unprecedented warming in the region is jeopardizing the future of a critical ecosystem that makes up nearly a third of the earth’s forest cover. The boreal forest wraps around the globe at the top of the Northern Hemisphere in North America and Eurasia. Also known as taiga or snow forest, this landscape is characterized by its long, cold and snowy winters. In North America it extends from the Arctic Circle of northern Canada and Alaska down into the very northern tip of the United States in Idaho, Washington, Montana, and Minnesota. It’s the planet’s single largest biome and makes up 30 percent of the globe’s forest cover. Moose are the largest ungulate in the boreal, adapted with their long legs to wade in its abundant marshes, lakes and rivers eating willows, aspen and other plants. In the southern boreal forest of northern Minnesota, moose were once plentiful, but their population has plummeted. Thirty years ago, in the northwest part of the state, there were some 4,000; they now number about a hundred. In the northeast part, they have dropped from almost 9,000 to 4,300. They’ve fallen so far, so fast that some groups want them listed as endangered in the Midwest. Read More here
Tag Archives: forest response
8 October 2015, TomDispatch, Welcome to a New Planet Climate Change “Tipping Points” and the Fate of the Earth By Michael T. Klare. Not so long ago, it was science fiction. Now, it’s hard science — and that should frighten us all. The latest reports from the prestigious and sober Intergovernmental Panel on Climate Change (IPCC) make increasingly hair-raising reading, suggesting that the planet is approaching possible moments of irreversible damage in a fashion and at a speed that had not been anticipated. Scientists have long worried that climate change will not continue to advance in a “linear” fashion, with the planet getting a little bit hotter most years. Instead, they fear, humanity could someday experience “non-linear” climate shifts (also known as “singularities” or “tipping points”) after which there would be sudden and irreversible change of a catastrophic nature. This was the premise of the 2004 climate-disaster film The Day After Tomorrow. In that movie — most notable for its vivid scenes of a frozen-over New York City — melting polar ice causes a disruption in the North Atlantic Current, which in turn triggers a series of catastrophic storms and disasters. At the time of its release, many knowledgeable scientists derided the film’s premise, insisting that the confluence of events it portrayed was unlikely or simply impossible. Fast forward 11 years and the prospect of such calamitous tipping points in the North Atlantic or elsewhere no longer looks improbable. In fact, climate scientists have begun to note early indicators of possible catastrophes. Read More here
4 September 2015, Climate News Network, Global tree census highlights need to restore forests. Mapping the density of forests reveals that there are far more trees on the planet than previously thought – but humans are destroying 15 billion a year. An international collaboration of scientists has just completed the ultimate green census – by calculating that the planet is home to 3.04 trillion trees. The latest estimate is far higher and almost certainly more accurate than any previous attempt. But the bad news is that humans are removing trees at the rate of 15 billion a year – and there are now about half as many as there were at the dawn of civilisation. For every person on Earth, there are 422 trees – in total, more than 3,000 billion deciduous or evergreen growths with woody trunks greater than 10 centimetres at breast height. The researchers based their study on close analysis of satellite imagery, and of data from 429,775 plots of trees as measured on the ground in 50 countries on every continent except Antarctica. Statistical techniques. They counted forests in 14 “biomes” − or different kinds of climate, soil and topography − and in places not normally associated with trees, such as deserts, savannah, swamps, tundra and high mountains. They then they used statistical techniques that could extend their sample density measurements to the whole terrestrial world. The scientists report in Nature journal that the tropical and subtropical forests are home to 1.39 trillion trees, while the boreal forests of the north contain 0.74 trillion, and the temperate zones hold 0.61 trillion. Read More here
29 August 2015, Climate News Network, Climate models may misjudge soils’ carbon emissions. How soil organisms cope with decaying vegetation is much less certain than climate models suppose, researchers say, and carbon emission estimates may be wrong. Some of the microscopic creatures which live in the soil are able to digest dead plants and trees, turning their contents into gas and minerals. But researchers say their work show that our understanding of how organic material is decomposed is fundamentally wrong, calling into question some current climate models. The researchers, from Lund University, Sweden, and the University of New Hampshire, USA, have published their study in the journal Ecological Monographs. They say it means that climate models which include micro-organisms in their estimates of future climate change must be reconsidered. When plants or trees die, their leaves and branches fall to the ground and the organic matter which is absorbed by the soil is then decomposed, mainly by the activity of fungi and bacteria, which convert the dead materials into the main greenhouse gas, carbon dioxide, and mineral nutrients. Until now, the Lund team says, scientists had thought that high-quality organic materials, such as leaves that are rich in soluble sugars, were mainly decomposed by bacteria, leaving the lower-quality matter, like cellulose and lignin, to be broken down mainly by fungi. Expectations confounded. Previous research has suggested that organic material decomposed by fungi results in less CO2 and nutrient leakage compared with matter decomposed by bacteria. This is important for the climate models in use today, as any change in the loss of CO2 and mineral nitrogen would alter the soil’s contribution to greenhouse gases and eutrophication, the process in which the release of excessive chemical pollution causes algal blooms in watercourses. Read More here