23 February 2016, The Conversation, Aboriginal fire management – part of the solution to destructive bushfires. As destructive bushfires become more common there is increasing political discussion how we manage them sustainably. Inevitably these debates raise questions of the past ecological effects of Aboriginal fire usage. There are two well-known narratives about Aboriginal fire use. One, popularised by Tim Flannery, stresses the ecologically disruptive impact of Aboriginal fire use. This storyline argues that the megafauna extinctions that immediately followed human colonisation in the ice age resulted in a ramping up of fire activity. This then led to the spread of flammable vegetation which now fuels bushfires. Another, promoted by Bill Gammage, suggests that the biodiverse landscapes that were colonised by the British were the direct product of skilful and sustained fire usage. Such broad-brush accounts give the impression that the specific details of Aboriginal fire usage are well-known and can be generalised across the entire continent. Sadly this is not the case. So rapid was the socio-ecological disruption of southern Australia that researchers have had to rely on historical sources, such as colonial texts and images, and tree rings, pollen and charcoal in lake sediments, to piece together how Aboriginal people burned the land. Such records are open to interpretation and there remains vigorous debate about the degree to which Aboriginal people shaped landscapes. Piecing together the past There are only a handful of detailed observational studies of the ecology of Aboriginal fire usage, and all from northern Australia, so there is dispute whether their findings can be extrapolated in the south. These studies demonstrate skilful use of fire that created fine-grained burn patterns, designed to promote food resources. For instance, a prime motive for burning savannas is attracting kangaroos to nutrient-rich grass that sprouts after the fire. In the desert, Aboriginal patch burning increases the habitat for sand goannas. In sum, there is mounting evidence that sustained Aboriginal fire use shaped many Australian landscapes by sharpening vegetation boundaries, maintaining open vegetation, and creating habitat for game species. Read More here
Category Archives: Ecosystem Stress
18 February 2016, The Conversation, Revealed: why some animals and plants will thrive under climate change. It’s mid-February and along Britain’s south coast gilt-head bream are drifting from the open sea into the estuaries. Meanwhile, thousands of little egrets are preparing to fly to continental Europe for breeding season, though a few hundred will remain in the UK. Across northern Europe, young wasp spiders will soon scamper out of their silky egg sacs. And this summer, countryside visitors throughout the south of England will catch sight of iridescent blue flashes as small red-eyed damselflies flit across ponds. These events all have one thing in common: they’re happening much further north than they would have as recently as 20 years ago. It’s not just a European thing. Polar bears are on the move, umbrella trees are creeping northwards through the US, and tropical birds in New Guinean mountains are retreating uphill. Southern Africa’s iconic quiver tree, which provides refridgeration in its hollowed out trunks, is itself escaping the heat and heading away from the equator. Across the world species are moving from their natural habitats. Fingers point at climate change. As areas become too hot or dry, many wildlife populations are declining. But on the flip side, some species are showing up in places that were historically too cold or wet. The story we usually hear is of terrible declines in plants and animals. The Pyrenean Frog is languishing on mountaintops on the Spanish-French border, for instance, unable to move to cooler climes. Magellanic penguin chicks are dying in storms brought on by climate change. Costa Rica’s golden toads, which are actually a rather amazing bright orange, are thought to have been driven to extinction by warmer, drier weather, among other factors. 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
21 February 2016, Climate News Network, Fall in rain hits Southeast Asia food yields. Changing climate and weather are creating severe problems for some of the world’s largest producers of rice and other major agricultural crops.The boat moves sluggishly up the Ayeyarwaddy, the river formerly known as the Irrawaddy. Every so often it comes to a halt as the ferryman dips a bamboo pole in the shallow waters, checking for sandbanks. Even though it is the dry season, water levels in the Ayeyarwaddy – Myanmar’s main river, and one of Southeast Asia’s principal waterways – are unusually low. The ferry is carrying passengers and goods from the ancient temple site of Baganto the city of Mandalay. “The journey is taking longer and longer as the water level keeps dropping,” says the skipper of the creaking, wooden-hulled boat. “It has been so dry. For the last two years, the monsoon in this area has arrived late and the rains were not enough. Then, when it did rain, it was intense, and more and more sand and earth was washed downriver because the trees are being cut down further north. It makes the journey very difficult.” Damaged crops A similar story is being heard across much of the region – from the Brahmaputrain Assam in India, west of Myanmar, to the Mekong in Vietnam in the east. Unusual weather patterns and a lack of rain in many areas in recent years have caused drought and severely damaged crops in what are some of the world’s most fertile areas. When the rains do arrive the dry, caked earth often cannot absorb the water. Read More here