Wildlife in Trouble from Oil Palm Plantations, Researchers Say

ScienceDaily — Forest fragmentation driven by demand for palm oil is having a catastrophic effect on multiple levels of biodiversity, scientists from Queen Mary, University of London have discovered.

The researchers are worried that unless steps are taken to safeguard and manage the remaining forest, then certain species will struggle to survive.

The study, which focused on bats as an indicator of environmental change, was published in the journal Ecology Letters.

The team conducted bat surveys in pristine forest and also in forest patches of varying size in central Peninsular Malaysia. They recorded the numbers of different species present and also assessed the level of genetic diversity within populations of some species.

Lead author Matthew Struebig, jointly based at Queen Mary University of London and the University of Kent, said: "We found that smaller forest areas support fewer species, and that those species that remain face an eventual decline, potentially leading to local extinction in the long-term."

When the team compared the number of species present to genetic diversity within populations they found that fragmentation appeared to have an even greater impact on genetic loss, which might also be important for long-term population viability.

"We found that in order to retain the numbers of bat species seen in pristine forest, forest patches had to be larger than 650 hectares, however to retain comparable levels of genetic diversity, areas needed to be greater than 10,000 hectares," he said.

Co-author Stephen Rossiter, also at Queen Mary, emphasised that the findings could have important implications for forest management in the face of the ever-growing demand for oil palm plantations.

He said: "We found that while more species existed in larger forest patches, even small fragments contributed to overall diversity. Therefore, conservation managers should aim to protect existing small fragments, while seeking to join up small forest areas to maximise diversity."

Source: Sciencedaily.com

Natural Gas from Shale Contributes to Global Warming, Researchers Find

ScienceDaily (Apr. 12, 2011) — Natural gas extracted from shale formations has a greater greenhouse gas footprint -- in the form of methane emissions -- than conventional gas, oil and coal over a 20 year period. This calls into question the logic of its use as a climate-friendly alternative to fossil fuels, according to Robert Howarth and colleagues, from Cornell University in New York.

Shale gas has become an increasingly important source of natural gas in the United States over the past decade. Shale gas is extracted by a high-volume hydraulic fracturing (fracking) process. Large volumes of water are forced under pressure into the shale to fracture and re-fracture the rock to boost gas flow. A significant amount of water returns to the surface as flow-back within the first few days to weeks after injection and is accompanied by large quantities of methane.

Howarth and team evaluated the greenhouse gas footprint of natural gas, obtained by high-volume hydraulic fracturing of shale formations, focusing on methane emissions. They analyzed the most recently published data -- in particular, the technical background document on greenhouse gas emissions from the oil and gas industry (EPA 2010), as well as a report on natural gas losses on federal lands from the General Accountability Office (GAO 2010).

They calculated that, overall, during the life cycle of an average shale-gas well, between four to eight percent of the total production of the well is emitted to the atmosphere as methane, via routine venting and equipment leaks, as well as with flow-back return fluids during drill out following the fracturing of the shale formations. Routine production and downstream methane emissions are also large, but comparable to those of conventional gas.

Methane is a far more potent greenhouse gas than carbon dioxide, but methane also has a 10-fold shorter residence time in the atmosphere. As a result, its effect on global warming falls more rapidly. Methane dominates the greenhouse gas footprint for shale gas on a 20 year horizon, contributing up to three times more than does direct carbon dioxide emission. At this time scale, the footprint for shale gas is at least 20 percent greater than that for coal, and perhaps twice as great.

Robert Howarth concludes: "The large greenhouse gas footprint of shale gas undercuts the logic of its use as a bridging fuel over coming decades, if the goal is to reduce global warming. The full footprint should be used in planning for alternative energy futures that adequately consider global climate change."

Source: ScienceDaily.com