Speaking at a January 12, 2009 symposium "Will the Rainforests Survive? New Threats and Realities in the Tropical Extinction Crisis*," hosted by the Smithsonian Institution, Gregory Asner of the Carnegie Institution's Department of Global Ecology presents new estimates of the global human impact on rain forests, including not only deforestation but also the extent of selective logging and forest regeneration.
Asner and his co-authors Tom Rudel of Rutgers University, Mitch Aide from University of Puerto Rico, Ruth DeFries of Columbia University, and Ruth Emerson from Carnegie compiled their estimates using data from satellite observations, published field surveys, and a sampling of Google Earth™ images. They highlight that roughly 1.4% of the world's tropical humid forests was deforested between 2000 and 2005, and that as of 2005 more than half of the forests contained 50% or less tree cover.
"Selective logging is more difficult to recognize and quantify than outright deforestation, so there have been few estimates of its impact," says Asner. "But we found that around 28% of humid tropical forests are undergoing some level of timber harvesting."
"The overall impacts of selective logging on biodiversity are far less dramatic than the wholesale losses incurred by deforestation," he adds, "but nonetheless it can fundamentally alter forest habitat."
The researchers also found that at least 1.7% of humid tropical forests are in some stage of secondary regrowth, mostly in hilly or mountainous regions marginal for large-scale agriculture and ranching.
But Asner emphasizes that the precision of these estimates is limited by current technologies, especially considering the difficulty of resolving fine-scale vegetation changes. New technologies to resolve subtle forest changes, such as the new sensors being developed by the Jet Propulsion Laboratory and Carnegie, will be necessary as the rainforest "tsunami" continues to sweep through tropical ecosystems in the coming decades.
Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen
Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
16.08.2018 | Life Sciences
16.08.2018 | Earth Sciences
16.08.2018 | Life Sciences