10 December 2015, Science Daily, Trees either hunker down or press on in a drying and warming western US climate. In the face of adverse conditions, people might feel tempted by two radically different options — hunker down and wait for conditions to improve, or press on and hope for the best. It would seem that trees employ similar options when the climate turns dry and hot. Two University of Washington researchers have uncovered details of the radically divergent strategies that two common tree species employ to cope with drought in southwestern Colorado. As they report in a new paper in the journal Global Change Biology, one tree species shuts down production and conserves water, while the other alters its physiology to continue growing and using water. As the entire western United States becomes warmer and drier through human-made climate change, these findings shed light on how woody plants may confront twin scourges of less water and hot weather. The authors, UW biology graduate student Leander Anderegg and biology professor Janneke Hille Ris Lambers, wanted to understand if different tree species employ similar coping strategies for drought, and how these strategies would affect their future ranges in a warmer and drier climate. They compared how two common tree species differ in terms of shape, growth rate and physiology across wet and dry portions of their native ranges. “We really wanted to identify the entire suite of strategies that a plant can use to grow in drier environments, as well as which of these strategies each tree would employ,” said Hille Ris Lambers. Read more here
Category Archives: Ecosystem Stress
7 December 2015, Huffington Post, Will Climate Change Break the Global Food System? Extreme weather events scuttling harvests. Skyrocketing food prices causing famine for millions and driving multitudes into poverty. Governments toppling – again – in Pakistan and Ukraine. Massive floods driving millions of refugees from their homes in Bangladesh and putting pressure on neighboring India. Droughts devastating harvests in traditional bread baskets like the U.S. and Brazil. The E.U., in a panicked move, suspending its environmental rules for agriculture and instituting a tax on meat. The world’s top greenhouse gas emitters ultimately banding together to raise a global carbon tax.The events described above are not the real world, but they could be. They were part of what transpired at Food Chain Reaction a few weeks ago, a high-level crisis simulation in Washington, DC that brought together 65 international leaders to explore how climate change may strain the world’s food system from 2020 to 2030. What the simulation taught us, is that policymakers attending this week’s U.N. climate summit in Paris cannot afford to neglect food security. The world’s population is on a path to 9.5 billion by mid-century. That means we will have to grow up to 70 percent more food. To make matters more complicated, we’ll have to do so in a changing climate that alters the very way we grow our crops. We must figure out how we can make that happen within the limits of the Earth’s natural resources. We’ve talked long enough. It is time to decide on a course of action that will actually improve the situation. Read more here
6 December 2015, Climate News Network, Scientists post extreme weather warning. COP21: Climate change means that temperate Europe faces the twin threat of life-threatening heatwaves and periods of bitter cold over the next 20 years. New research warns that longer, hotter and more frequent heatwaves than those that killed 55,000 Russians in 2010, or 72,000 in France, Portugal, Italy, the Netherlands, Germany and the UK in 2003, will hit Europe in the next two decades. But, over the same period, Europe could also begin to get colder as a consequence of a drop in solar activity, and a century-long chill could be on the way, according to a study of long-period climate cycles. And if global warming accelerates, and average global ocean temperatures rise by 6°C or more, most of the living, breathing world could in any case begin to suffocate, according to ominous calculations by a mathematician. At some point, the providers of oxygen could begin to perish. All three uncomfortable projections were published as 30,000 delegates, politicians, observers, pressure groups, and journalists gathered in Paris for COP21, the UN summit on climate change, which is meeting to try to forge an agreement that could, ultimately, limit global warming to a planetary average of 2°C or less. Magnitude index Simone Russo, a geophysicist, and colleagues from the European Union Joint Research Centre at Ispra in Italy report in Environmental Research Letters that they developed a heatwave magnitude index to cope with a problem once considered improbable for temperate Europe − extremes of heat. The index is a tool for statistical analysis, and provides a way of matching bygone events with possible future extremes. Deaths in Europe accounted for 90% ofglobal mortality from heat extremes in the last 20 years. And there could be more on the way. Read More here
25 November 2015, The conversation, Ashes to ashes: logging and fires have left Victoria’s magnificent forests in tatters. In February 2009 the Black Saturday bushfires swept through the Mountain Ash forests of Victoria, burning 72,000 hectares. These forests are home to the tallest flowering plants on the planet, and iconic species such as the Leadbeater’s Possum, Victoria’s animal emblem. In the six years since the fires, we and other scientists have been investigating how the forests have recovered, summarised in our new book. This research was in turn built on 25 years of research before the fires. There’s some good news and some bad. The forests and their inhabitants have a remarkable capacity for recovery from natural disturbances like fire. However, the forest ecosystem is in a precarious state, largely due to the continuation of Victoria’s logging industry. Winners and losers Some species seemed to fare well after the fires, or even to have benefited from them. In the week leading up to the 2009 fires, 18 Brushtail Possums were fitted with radio-tracking collars, and all were found alive two months later. After the fire, Flame Robins arrived in the forest in huge numbers to take advantage of hunting opportunities in the open burnt forest. The native Bush Rat and carnivorous Agile Antechinus (a minute relative of the Quoll and Tasmanian Devil), were hit hard by the fire. Their numbers were initially severely reduced but then recovered to be equally or more abundant in burnt than unburnt forest within three years. In contrast, other species have struggled in the post-fire environment, such as the Greater Glider and Leadbeater’s Possum. Read More here