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sexta-feira, 29 de maio de 2015
ZERO DEFORESTATION IN THE AMAZON. IS IT POSSIBLE!?
quinta-feira, 28 de maio de 2015
CULLING FOR REDUCTION OF 'PEST ANIMALS' IS NOT ALWAYS FEASIBLE
Cullers beware - killing 'pest' animals can increase their abundance
Christopher Johnson
8th May 2015 - reproduced from:
A study of feral cats in Tasmania shows that culling them to reduce their impact on native wildlife had a paradoxical effect - their population went up! If you can't take 'pest' animals out faster than they can reproduce and move in from nearby areas, writes Christopher Johnson, you're better off not bothering at all.
What went wrong?
What seems to have happened in these cases is that young animals quickly moved in from surrounding areas to replace dominant adults removed in the cull. Most of these young animals would normally have died. The sudden increase in their survival allowed abundance to overshoot pre-cull levels.
[...]
The more general problem is that removing some animals from a population creates more space and food for those that are left, and can disrupt social controls on breeding. Survival, reproduction and immigration all increase as a result, and the population quickly rebounds.
For culling to produce a lasting reduction in abundance, it is essential not just to accomplish the relatively easy task of removing animals from a high-density population. We also need to be able to continue removing animals at rates that equal or exceed the capacity for increase of a population with improved survival and reproduction.
[...]
terça-feira, 19 de maio de 2015
IN THE PANTANAL, BRAZIL: AN ATROCITY THAT IS HARD TO BELIEVE THAT IT IS STILL COMMON ON!!!
segunda-feira, 18 de maio de 2015
DEATH IN COLOMBIA LANDSLIDE: IT'S NOT THE FIRST AND REGRETTABLY IT WILL NOT BE THE LAST ONE!
Colombia landslide kills dozens
At least 48 people have been killed in a landslide in Antioquia province in north-west Colombia, officials say. Bodies are still being recovered and the authorities expect the number of fatalities to rise. Heavy rains caused the river Liboriana, in the town of Salgar, to burst its banks, triggering the landslide. Much of the village of Santa Margarita, south-west of the provincial capital, Medellin, was swept away when the landslide hit early on Monday.
Other tragedies (see below):
domingo, 10 de maio de 2015
THAT'S WHAT I HAVE BEEN SHOWING TO MY STUDENTS: ONE ROAD THROUGH THE FOREST IS THE BEGINNING OF HUGE DESTRUCTION
Last great regions of pristine wilderness from Asia to Amazon under threat from massive road-building projects, scientist warns
“The best analogy I can use is that deforestation acts like a cancer. When the first road is built into a forested or wilderness area, deforestation tends to spread contagiously along the road route,” Professor Laurance said.
sábado, 9 de maio de 2015
IGNORING THE LESSONS OF THE DUSTBOWL!?!?!?
Future dustbowl? Fracking ravages Great Plains land and water
Tim Radford
4th May 2015
As reported on http://www.theecologist.org/News/news_round_up/2852559/future_dustbowl_fracking_ravages_great_plains_land_and_water.html
The fracking boom has caused massive vegetation loss over North America's rangelands, writes Tim Radford, as 3 million hectares have been occupied by oil and gas infrastructure and 34 billion cubic metres of water have been pumped from semi-arid ecosystems.
Fossil fuel prospectors have sunk 50,000 new wells a year since 2000 in three Canadian provinces and 11 US states, and have damaged the foundation of all economic growth: net primary production - otherwise known as biomass, or vegetation.
Brady Allred, assistant professor of rangeland ecology at the University of Montana's College of Forestry and Conservation, and colleagues write in the journal Science that they combined years of high-resolution satellite data with information from industry and public records to track the impact of oil drilling on natural and crop growth.
They conclude that the vegetation lost or removed by the expansion of the oil and gas business between 2000 and 2012 added up to 10 million tonnes of dry vegetation, or 4.5 million tonnes of carbon that otherwise would have been removed from the atmosphere.
Lost fodder equivalent to 120 million bushels of wheat
Put another way, this loss amounted to the equivalent of fodder for five million cattle for one month from the rangelands, and 120 million bushels of wheat from the croplands. This wheat equivalent, they point out, adds up to the equivalent of 13% of the wheat exported by the US in 2013.
Net primary production - the biomass that plants make from photosynthesis every day, all over the world - is the basis of all wealth and food security. It underwrites all other human and animal activity.
Human wealth depends ultimately on what grows in the ground, or what can be dug from the ground, and most of the latter - such as coal, oil and peat- was once stuff that grew in the ground.
The same net primary production is the basis of what economists sometimes call ecosystem services on which all civilisation depends: the natural replenishment of the water supply, the pollination of crops, the provision of natural nitrogen fertilisers, and the renewal of natural habitat for wild things.
'Long-lasting and potentially permanent' impact
And what worries the conservation scientists is that this loss of net primary production is likely to be "long-lasting and potentially permanent, as recovery or reclamation of previously drilled land has not kept pace with accelerated drilling."
"This is not surprising because current reclamation practices vary by land ownership and governing body, target only limited portions of the energy landscape, require substantial funding and implementation commitments, and are often not initiated until the end life of a well."
They say that the land actually taken up by wells, roads and storage facilities just between 2000 and 2012 is about 3 million hectares. This is the land area equivalent to three Yellowstone National Parks.
The hydraulic fracturing, or 'fracking', used to extract oil and gas is between 8,000 cubic metres and 50,000 cubic metres per well, which means that the total quantity of water squirted into the ground at high pressure during the 12 years to 2012 could exceed 33,900 million cubic metres - almost 34 cubic kilometres of water. At least half of this was used in areas already defined as 'water-stressed'.
Ignoring the lessons of the dustbowl
The researchers considered the drilling of new wells in Alberta, Manitoba and Saskatchewan in Canada, and in Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah and Wyoming in the US.
Although there is legislation, it is limited to lands subject to federal jurisdiction, and 90% of all drilling infrastructure is now on privately-owned land - at least, in the US.
The study's authors want decision-makers to confront the challenges of this kind of ecological disruption. There are lessons from history in all this, they warn.
"In the early 20th century, rapid agricultural expansion and widespread displacement of native vegetation reduced the resilience of the region to drought, ultimately contributing to the Dust Bowl of the 1930s", they write.
"It took catastrophic disruption of livelihoods and economies to trigger policy reforms that addressed environmental and social risks of land-use change."