Despite ongoing threats to rain forests in the Amazon and Congo river basins and in Indonesia, losses were greatest in those boreal forests, followed by humid tropical, dry tropical and temperate forests.
“This study quantifies all stand-replacement disturbances regardless of land use,” said South Dakota State University professor Matt Hansen, co-director of SDSU’s Geographic Information Science Center of Excellence.
“Human disturbances, such as clear-cuts in managed forests and deforestation, as well as natural disturbances such as fire, disease and storm damage, are all included. What we found was a widely varying dynamic across the globe’s forests.”
Hansen was lead author of the study, “Quantification of global gross forest cover loss,” which appeared online on April 26, in the Proceedings of the National Academy of Sciences. Hansen’s co-authors were Peter Potapov, also of SDSU’s Geographic Information Science Center of Excellence, and Stephen Stehman, of the College of Environmental Science and Forestry at State University of New York in Syracuse.
Using images from two satellite-based sensors, the study tracked gross forest cover loss, or GFCL, defined as the area of forest cover removed because of any disturbance, including both natural and human-induced causes.
The study found North America has the greatest area of gross forest cover loss, followed by Asia and South America. North America alone accounts for nearly 30 percent of global GFCL and features the highest proportional GFCL of 5.1 percent. Africa has the lowest proportional GFCL of 0.4 percent, reﬂecting a lower overall use of forests for commercial development.
Combined, North and South America account for more than one-half of the global total area of GFCL. South America has the largest remaining intact forests within the Tropics, areas that are under increasing pressure from agro-industrial development. North America features a spatially pervasive GFCL dynamic with logging and ﬁre as primary causes.
Nationally, Brazil lost the largest area of forest over the study period — 165,000 square kilometers or about 64,000 square miles — followed by Canada at 160,000 square kilometers, or about 62,000 square miles. Of the countries with more than one million square kilometers of forest cover, the United States showed the greatest proportional loss of forest cover and the Democratic Republic of Congo showed the least.
The United States includes both temperate forests and, in Alaska, boreal forest cover. It showed the highest percentage of year 2000 GFCL (6.0 percent). Although ﬁre is a major contributor, particularly in Alaska and the western part of the country, logging is a primary and widespread cause of GFCL. Regional centers of logging are found mainly in the southeastern states, but also along the West Coast and in the Upper Midwest.
Hansen cautioned that gross forest cover loss is only one component of net change, and that the processes driving forest loss and recovery differ by region. Those are areas future research can explore.
“For example, the majority of estimated gross forest cover loss for the boreal biome is due to a naturally induced ﬁre dynamic. To fully characterize global forest change dynamics, remote sensing efforts must extend beyond estimating gross forest cover loss to identify proximate causes of forest cover loss and to estimate recovery rates,” Hansen said.
Nearly 60 percent of the boreal forest cover lost is due to ﬁre, Hansen said, while the remaining 40 percent of loss in boreal forests is attributable to logging and other change dynamics such as insect and disease pressure. For example, mountain pine beetle infestations are an important factor in loss of forest cover in British Columbia, Canada.
The study looked specifically at the seven nations of the world that have more than one million square kilometers of forest cover. The Russian Federation has the most extensive forest cover, followed by Brazil, Canada, the United States, the Democratic Republic of Congo, China and Indonesia.
Those seven countries account for more than 57 percent of the world’s forests.Matt Hansen, co-director of SDSU’s Geographic Information Science Center of Excellence
Matt Hansen | Newswise Science News
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy