The study shows that West African rainforest deforestation reduces precipitation over neighboring trees by about 50 percent due to increased surface temperatures of croplands, which affect raincloud formation.
The authors say the findings have important implications for future decisions about land management in this region and other rainforests, including the Amazon.
"We already know from satellite observations that changes in land use can have a big impact on local weather patterns," says Luis Garcia-Carreras with the University of Leeds School of Earth and Environment, lead author of the recent study. "Here we have been able to show why this happens."
"Our findings suggest that it's not just the number of trees removed that threatens the stability of the world's rainforests. The pattern of deforestation is also important."
Garcia-Carreras and his colleague present their new findings in an article accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
The forests of West Africa and the Congo Basin are the second largest in the world after the Amazon rainforest. They serve not only as a habitat for a vast and diverse ecosystem but also as a carbon sink, removing a large proportion of the carbon dioxide in the Earth's atmosphere and slowing down climate change.
For many years deforestation has been occurring widely in Africa, with tree canopies being removed for agriculture, plantations and other non-forest uses.
While the removal of trees has an immediate impact on the forest, this new study suggests that there also may be a secondary effect caused by the reduced rainfall.
"African rainforests already have the lowest rainfall of any rainforest ecosystem on Earth, which could make them particularly sensitive to changes in local weather patterns," Garcia-Carreras says. "If rainfall is reduced even further as a result of deforestation, it could threaten the survival of the remaining forest by increasing the trees' sensitivity to drought."
To investigate the effects of different vegetation on locally-produced rain in West Africa, the researchers used a Met Office computer model to simulate rainfall under different land-use conditions.In rainforests where stands had been converted to cropland, the total amount of precipitation was largely unaffected, but the rainfall was distributed differently.
Rainfall was four to six times higher over warm areas (cropland) than when no deforestation has occurred, while rainfall over the remaining forest was half or less.
The difference in rainfall is caused by the temperature change between cropland and forest, which produces winds that converge over the crop area and form clouds.
And the results in West Africa could apply elsewhere, adds Doug Parker, a study co- author with the University of Leeds. "While our study only focused on a small region in Africa, it's reasonable to suggest that this mechanism could be common in other global forests based on similar observations of rainfall in Amazonia," he says.
"This has implications for planners in terms of how deforestation is managed. If forest must be removed to create cropland, we need to think about what are the shapes and distributions of deforestation that will be least damaging to the adjacent forests and national parks."
The research was funded by the UK's Natural Environment Research Council as part of the international African Monsoon Multidisciplinary Analysis (AMMA).Title:
Kate Ramsayer | American Geophysical Union
Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union
UM researchers study vast carbon residue of ocean life
19.10.2016 | University of Miami Rosenstiel School of Marine & Atmospheric Science
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences