9 September 2016, The Conversation, EcoCheck: the Grampians are struggling with drought and deluge. Our EcoCheck series takes the pulse of some of Australia’s most important ecosystems to find out if they’re in good health or on the wane. The Grampians National Park is a large conservation reserve, sprawling across 168,000 hectares embedded in western Victoria’s agricultural landscape. With a rich cultural heritage and regionally important flora and fauna, it is a hugely significant area for conservation. But in recent years it has been subjected to a series of major wildfire events, a flood, and long periods of low rainfall. Our research shows that this has sent small mammal populations on the kind of boom-and-bust rollercoaster ride usually seen in arid places, not temperate forests.The fire and the flood We began studying the Grampians in 2008, investigating how small mammals had responded to a catastrophic wildfire that burned half of the national park in 2006. What started as a one-year study has turned into a long-term research program to investigate how the past few years of hypervariable rainfall and heightened bushfire activity have affected the animals that live in the park. Fortunately (for our study, at least), the beginning of our research in 2008 was in the middle of a long run of very poor rainfall years, as the Millennium Drought reached its height. The drought was broken at the end of 2010 by the Big Wet, which led to well-above-average rainfall and floods in the Grampians. But soon after, rainfall rapidly dipped back to below average. It has stayed there ever since. We also saw two more major fire events, in 2013 and 2014, which together with the 2006 fire burned some 90% of the Grampians landscape. Read More here
Tag Archives: native forests
5 September 2016, CSIRO ECOS, Wired woodlands signal stress as climate dries. In 2015, the normal ‘breathing’ pattern of the Great Western Woodlands in south-western Australia became erratic. In response to lack of rain, the old-growth woodland started to ‘breathe in’ oxygen and ‘breathe out’ carbon dioxide – the opposite of what occurs in normal plant photosynthesis, and a sign the trees were ailing. Lift your eyes above the orange- and gold-hued gimlets and salmon gums that characterise these woodlands and you can see the key to understanding this reversal of nature; a 36m tower equipped with highly sensitive instrumentation.It’s the technology in that tower that has been tracking the trees’ struggle for survival; collecting data on the activity of the woodland by the second and updating daily CSIRO researchers based in Perth. The tower, run by CSIRO researchers Dr Suzanne Prober and Dr Craig Macfarlane, is a part of Australia’sTerrestrial Ecosystem Research Network (TERN) OzFlux Facility. A series of 24 OzFlux towers and 10 associated Supersites have been established as sentinels of change across the country. Toward the TERN goal of creating a national ecosystem observatory, each monitors changes in carbon, water and biodiversity in a nationally significant landscape. Read More here
6 March 2016, Climate News Network, Risk level rises for North American forests. The speed at which the climate is changing is outstripping forests’ ability to adapt to drier, hotter conditions across vast swathes of the US and Canada. Drought and climate change are now threatening almost all the forests of the continental US, according to new research. Scientists from 14 laboratories and institutions warn in the journal Global Change Biology that climate is changing faster than tree populations can adapt. Existing forests, effectively and literally rooted to the spot, are experiencing conditions hotter and less reliably rainy than those in which they had evolved. “Over the last two decades, warming temperatures and variable precipitation have increased the severity of forest droughts across much of the continental United States,” says James Clark, professor of global environmental change at Duke University, North Carolina. He and colleagues synthesised hundreds of studies to arrive at a snapshot of changing conditions and a prediction of troubles ahead. Ominous predictions Other research has already delivered ominous predictions for the forests of the US southwest, but the scientists warn that other, normally leafier parts of the continent face increasing stress. Dieback, bark beetle infestation and wildfire risk may no longer be confined to the western uplands. “While eastern forests have not experienced the types of changes seen in western forests in recent decades, they too are vulnerable to drought and could experience significant changes with increased severity, frequency, or duration in drought,” the authors say. Professor Clark puts it more bluntly: “Our analysis shows virtually all US forests are now experiencing change and are vulnerable to future declines. Given the uncertainty in our understanding of how forest species and stands adapt to rapid change, it’s going to be difficult to anticipate the type of forests that will be here in 20 to 40 years.” Read More here
22 February 2016, The Conversation, Queensland land clearing is undermining Australia’s environmental progress. Land clearing has returned to Queensland in a big way. After we expressed concern that policy changes since 2012 would lead to a resurgence in clearing of native vegetation, this outcome was confirmed by government figures released late last year. It is now clear that land clearing is accelerating in Queensland. The new data confirm that 296,000 hectares of bushland was cleared in 2013-14 – three times as much as in 2008-09 – mainly for conversion to pastures. These losses do not include the well-publicised clearing permitted by the government of nearly 900 square kilometres at two properties, Olive Vale and Strathmore, which commenced in 2015. Map showing the amount of habitat for threatened species cleared between 2012 and 2014. WWF. Alarmingly, the data show that clearing in catchments that drain onto the Great Barrier Reef increased dramatically, and constituted 35% of total clearing across Queensland in 2013-14. The loss of native vegetation cover in such regions is one of the major drivers of the deteriorating water quality in the reef’s lagoon, which threatens seagrass, coral reefs, and other marine ecosystems. The increases in land clearing are across the board. They include losses of over 100,000 hectares of old-growth habitats, as well as the destruction of “high-value regrowth” – the advanced regeneration of endangered ecosystems. These ecosystems have already been reduced to less than 10% of their original extent, and their recovery relies on allowing this regrowth to mature. Alarmingly, our analysis of where the recent clearing has occurred reveals that even “of concern” and “endangered” remnant ecosystems are being lost at much higher rates now than before. Read More here