(Press-News.org) Conservationists are always looking for ways to halt the pace of deforestation in tropical rainforests. One approach involves recultivating abandoned agricultural land. An international team* investigating this concept has just published its findings in Nature Communications. Working in the mountainous regions of Ecuador, the researchers found afforestation and intense pasturing to be particularly effective, clearly increasing the environmental and economic value of abandoned farmlands.
Every year, 130,000 square kilometers of rainforest disappear from the face of the earth - an area equivalent to the size of Greece. The majority of this land is cleared for agricultural development - even in tropical mountain areas. These fields are quickly overgrown with weeds, however. Bracken is particularly tenacious. It cannot be permanently eliminated using herbicides or by burning the land. As a result, farmers often abandon the land after a few short years and start clearing new areas of forest.
"This cycle has to be broken," explains Prof. Thomas Knoke from the Institute of Forest Management at Technische Universität München (TUM). Prof. Knoke is lead author of the study that has just been published. "We've been investigating whether this abandoned pasture land can be recultivated, and if so, how."
The team did not just look at economic benefit when evaluating the different concepts. For the first time, this study also took environmental and socio-cultural criteria into consideration, factoring in issues such as the amount of carbon dioxide and nitrogen assimilated by plants and soil, biomass production, soil quality, impact on climate, water management and acceptance among farmers.
Sustainable land use
The area under investigation (around 150 hectares) is located in the Ecuadorian Andes at an altitude of between 1,800 and 2,100 meters. The researchers looked at five different concepts:
No land use - abandoned land is left to nature
Afforestation - planting a native species of alder
Afforestation - introduction of a non-native pine species
Extensive pasturing - mechanical weed control followed by initial fertilization and land use
Intense pasturing - chemical weed control and land use with regular fertilization
Afforestation with alder and pine species proved particularly sustainable. In addition, forested regions offer the best protection against erosion in the long term. "Our study also showed that afforestation with the native Andean alder had a much more positive impact on the climate and water balance than the other land use options," adds Prof. Jörg Bendix from Phillips-Universität Marburg.
Engaging the farmers - a key factor
Typical rainforest flora and fauna are also able to gradually recolonize afforested regions. Intense pasturing scored much higher on the ecological scale than extensive pasturing. Economic benefits stemmed from the sale of wood (afforestation) or the sale of meat and milk (pasturing). Alder plantations achieved the greatest financial returns.
A survey conducted among land users showed that the majority of livestock farmers also viewed afforestation as the best land use option due to the positive ecological balance and greater long-term earnings potential. "If we want recultivation concepts to be a success, the people using the land have to be engaged," elaborates Bendix.
Reference project for other tropical mountain regions
The sustainable land use concepts all come at a cost, however. Over a period of twenty years, farmers who do not use slash-and-burn techniques are exposed to an annual loss of earnings. This amounts to 87 dollars per hectare for afforestation and 100 dollars per hectare for intense pasturing. The researchers regard compensation for recultivation as an important incentive for encouraging famers to replant abandoned grazing land. In the long term, trade with CO2 certificates could also provide an additional source of income.
The researchers also believe that their study could be used as a reference for evaluating recultivation concepts in other tropical mountain forests, for example in Brazil or Africa. "Abandoned agricultural land is a huge resource that is not being harnessed," summarizes Thomas Knoke. "The German Research Foundation (DFG) is currently funding a number of projects that are working with farmers in Ecuador to implement the findings of the study," concludes Erwin Beck, professor at the University of Bayreuth and the man who started the project in Ecuador 17 years ago.
INFORMATION:
*Scientists from the following institutes participated in the study: TUM; University of Bayreuth; Phillips-Universität Marburg; Universität of Erlangen-Nuremberg (FAU); TU Dresden; Justus Liebig University Giessen; National University of Loja, Ecuador; Universidad Técnica Particular de Loja, Ecuador; FLACSO, Quito, Ecuador; CATIE, Turrialba, Costa Rica.
Project website: http://www.tropicalmountainforest.org
Pictures for download: http://go.tum.de/660883
The study was sponsored by the DFG (research areas 402 and 816).
Publication
Afforestation or intense pasturing improve the ecological and economic value of abandoned tropical farmlands; Thomas Knoke, Jörg Bendix, Perdita Pohle, Ute Hamer, Patrick Hildebrandt, Kristin Roos, Andrés Gerique, María L. Sandoval, Lutz Breuer, Alexander Tischer, Brenner Silva, Baltazar Calvas, Nikolay Aguirre, Luz M. Castro, David Windhorst, Michael Weber, Bernd Stimm, Sven Günter, Ximena Palomeque, Julio Mora, Reinhard Mosandl & Erwin Beck, Nature Communications, DOI: 10.1038/ncomms6612.
Contact:
Prof. Dr. Thomas Knoke
Technische Universität München
Institute of Forest Management
Tel: +49 8161 71-4700
knoke@tum.de
http://waldinventur.wzw.tum.de
This news release is available in German.
A drunken sailor staggers onto a square with lots of streetlamps on it. Sometimes he will run into one of the lamps, change his direction and keep moving. Does the time he spends on this square depend on the number of streetlamps? The surprising answer is: no.
No matter whether there is a streetlamp on every square meter or whether the distance between the lamps is large: on average, the drunken sailor will always spend the same amount of time on the square. Calculations at the Vienna University of Technology (TU Wien) ...
Neither quantum computers nor quantum cryptography will become prevalent technologies without memory systems able to manipulate quantum information easily and effectively. The Faculty of Physics at the University of Warsaw has recently made inroads into popularizing quantum information technologies by creating an atomic memory with outstanding parameters and an extremely simple construction.
Following years of tests in physics laboratories, the first quantum technologies are slowly emerging into wider applications. One example is quantum cryptography - an encryption ...
The ocean is undergoing global changes at a remarkable pace and we must change with it to attain our best possible future ocean, warns the head of The University of Western Australia's Oceans Institute.
One of the global leaders in ocean science, Professor Carlos Duarte has shared his insights on the future of the world's oceans in a paper published in the international open-access journal Frontiers in Marine Science.
In the paper Professor Duarte explains the grand challenge researchers face in addressing global change and the future state of the ocean.
"The ocean ...
This news release is available in German. Just four months after the final data package from the GOCE satellite mission was delivered, researchers are laying out a rich harvest of scientific results, with the promise of more to come. A mission of the European Space Agency (ESA), the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) provided the most accurate measurements yet of Earth's gravitational field. The GOCE Gravity Consortium, coordinated by the Technische Universität München (TUM), produced all of the mission's data products including ...
The value of a piece of chocolate cake can change. Someone who happens to be on a diet is more likely to choose a fruit dessert and judge the calorie-laden cake as unhealthy. Previous studies have shown that a specific network in the brain is active when a person must decide between various choices that vary depending on context. They emphasize the interaction between neurons in two brain areas of the prefrontal cortex - the controlling area on the front side of the brain.
Prefrontal cortex shows increased activity in all decisions
Sarah Rudorf and Todd Hare of the ...
On 24 October 2014, Sweden called off the hunt for a submarine after a week-long underwater search in the Stockholm archipelago. Triggered by a reported sighting of a Russian submarine, the alleged 'invasion' had been widely anticipated by military specialists and the media.
"Our assessment is that in the inner archipelago there was a plausible foreign underwater operation," Rear Adm. Anders Grenstad commented, "But we believe that what has violated Swedish waters has left."
"Whatever was there could not have been a conventional submarine," Grenstad said, but a "craft ...
This news release is available in Japanese.
The deep ocean seems so remote that it is difficult to imagine any sort of human-generated change making an impact on deep-sea life. It is even more difficult to collect or examine evidence from the deep ocean to determine what those impacts might be. Enter the barnacle; a hard, sessile creature that looks like a tiny volcano and attaches to rocks, boat bottoms, and other hard substrates, where it filters ocean water to feed on tiny organisms. The barnacle holds clues about how climate change is affecting the deep ocean. ...
KNOXVILLE - Warfare not only hastened human technological progress and vast social and political changes, but may have greatly contributed to the evolutionary emergence of humans' high intelligence and ability to work together toward common goals, according to a new study from the National Institute for Mathematical and Biological Synthesis (NIMBioS).
How humans evolved high intelligence, required for complex collaborative activities, despite the various costs of having a big brain has long puzzled evolutionary biologists. While the human brain represents only about two ...
Published in the journal Nature, the discovery could revolutionise fuel cells and other hydrogen-based technologies as they require a barrier that only allow protons - hydrogen atoms stripped off their electrons - to pass through.
In addition, graphene membranes could be used to sieve hydrogen gas out of the atmosphere, where it is present in minute quantities, creating the possibility of electric generators powered by air.
One-atom thick material graphene, first isolated and explored in 2004 by a team at The University of Manchester, is renowned for its barrier properties, ...
NGC 3532 is a bright open cluster located some 1300 light-years away in the constellation of Carina(The Keel of the ship Argo). It is informally known as the Wishing Well Cluster, as it resembles scattered silver coins which have been dropped into a well. It is also referred to as the Football Cluster, although how appropriate this is depends on which side of the Atlantic you live. It acquired the name because of its oval shape, which citizens of rugby-playing nations might see as resembling a rugby ball.
This very bright star cluster is easily seen with the naked eye ...
