A blog maintained by Tevita Kete, PGR Officer
Secretariat of the Pacific Community (SPC), Suva, Fiji Islands
This weblog documents the activities of Pacific Agricultural Genetic Resources Network (PAPGREN), along with other information on plant genetic resources (PGR) in the Pacific.
The myriad varieties found within cultivated plants are fundamental to the present and future productivity of agriculture. PAPGREN, which is coordinated by the Land Resources Division of the Secretariat of the Pacific Community (SPC), helps Pacific countries and territories to conserve their crop genetic diversity sustainably, with technical assistance from the Bioversity International (BI) and support from NZAID and ACIAR.
SPC also hosts the Centre of Pacific Crops and Trees (CEPaCT). The CEPaCT maintains regional in vitro collections of crops important to the Pacific and carries out research on tissue culture technology. The CEPaCT Adviser is Dr Mary Taylor (MaryT@spc.int), the CEPaCT Curator is Ms Valerie Tuia (ValerieT@spc.int).
PAPGREN coordination and support
Mr William Wigmore
Mr Adelino S. Lorens
Dr Lois Englberger
Mr Apisai Ucuboi
Dr Maurice Wong
Mr Tianeti Beenna Ioane
Mr Frederick Muller
Mr Herman Francisco
Ms Rosa Kambuou
Ms Laisene Samuelu
Mr Jimi Saelea
Mr Tony Jansen
Mr Finao Pole
Mr Frazer Bule Lehi
Interested in GIS?
Thursday, December 20, 2007
Posted 1:02 PM by Tevita
Getting Ready for Changing Climates
Published by Jeremy on December 20, 2007 in Articles, Breeding and Threats.
From : Luigi
Four papers together give an insight into what global warming promises for agriculture and agriculturalists, and how to deal with it.
Some people will tell you that global warming is something we can cope with because it won’t actually create any new climates, just shift the old ones around a bit on the the surface of the Earth. They’re wrong.1 John Williams and his colleagues published an article in PNAS in the spring that shows conclusively that even the IPCC’s B1 scenario, in which modest reduction sees CO2 stabilized at 550 parts per million by 2100 AD, creates considerable risk of completely novel climates.
Williams and colleagues used the climate models to predict four variable within grid cells of about 2.8 degrees square. In each, they calculated an index that integrated four variables: mean rainfall and temperature for summer and winter. Then they asked whether the climate in that grid cell was novel, by measuring how different it was from the most similar modern climate, anywhere at all on earth. Given business as usual, “novel climates are likely to develop in lowland Amazonia, the southeastern US, the African Sahara and Sahel, the eastern Arabian Peninsula, southeast India and China, the IndoPacific, and northern Australia”. The same areas are affected under the B1 scenario, but at lower levels.
That’s the tropics and sub-tropics, where the poor people live, and where they depend on agriculture, which depends on climate. How much?
Changes in suitability for two crops, soybean and peanut, in China. Overall, peanut loses and soybean gains. from Jarvis and Lane, in press. Click to enlarge.
Andy Jarvis and Annie Lane, of Bioversity International and CIAT, used the same climate models to ask how the areas suitable for different crops will change. This one hasn’t been peer-reviewed yet, so I cannot really say too much about it. The idea was to plug the climates into FAO’s ECOCROP model of the growing conditions required by more than 1800 crop species. There are winners and losers. Geographically, northern temperate areas do OK, while the tropics suffer the biggest changes in areas suitable for agriculture. the greatest losses of suitable growing areas are predicted for sub-Saharan Africa and the Caribbean, regions least able to cope. Gains will be seen in Europe and North America, which perhaps need them least.
Among species, the biggest losers are cold-weather crops such as strawberry (-32% in areas suitable for cultivation), wheat (-18%), rye (-16%), apple (-12%) and oats (-12%). Among the winners are pearl millet (+31%), sunflower (+18%), common millet (+16%), chick pea (+15%) and soybean (+14%).
Quite often, however, the gains occur in places that have no cultural history to making use of those species. Land suitable for pearl millet is predicted to increase by more than 10% in Europe and the Caribbean, where it is an insignificant food, but not in Africa, where it is widely cultivated and an important element in food security. It is going to be small comfort to know that one can grow a crop that one has no idea how to cultivate, process or eat.
A2 (left) is business as usual, B1 (right) reflects moderate reduction in emissions. Above, risk of novel climates, below risk of disappearing climates, both constrained to 500 km. From Williams et al. (2007). Click to enlarge.
Ah, but people and their crops can move, can’t they? Back to Williams et al. As well as asking whether there is an analogous climate somewhere on Earth, they also asked whether there is an analogous climate less than 500 km away from the target grid cell. That makes things a whole lot worse, with “no-analog” climates right across the tropics and way into the polar regions. And 500 kilometres is quite a distance for agricultural systems to migrate in less than 100 years.
Will that make itself felt? You bet it will. John F. Morton, of the Natural Resources Institute in the United Kingdom, has a paper in PNAS entitled “The impact of climate change on smallholder and subsistence agriculture”.2 You might expect there to be a clear answer, but Morton’s main point is that we don’t really know enough about smallholder and subsistence agriculture to plug it into climate change models. Morton concludes:
Smallholder and subsistence farmers will suffer impacts of climate change that will be locally specific and hard to predict. The variety of crop and livestock species produced by any one household and their interactions, and the importance of nonmarket relations in production and marketing, will increase the complexity both of the impacts and of subsequent adaptations, relative to commercial farms with more restricted ranges of crops. Small farm sizes, low technology, low capitalization, and diverse nonclimate stressors will tend to increase vulnerability, but the resilience factors—family labor, existing patterns of diversification away from agriculture, and possession of a store of indigenous knowledge—should not be underestimated.
Which is a kind of we know what we don’t know plea for more research.
How, then, might one best help smallholder and subsistence farmers to weather the changes ahead? Perhaps predictably, the big boys are all in favour of setting their talented breeders to work to come up with varieties that are resistant to climate change. But there may be a better way. Give farmers access to a far greater range of diversity and improve their ability to select populations that will be adapted and adaptable.
This gets to the heart of one of the big questions of theoretical biology: which is faster, evolution based on new mutations arising, or evolution based on selection from existing variability. Rowan Barrett and Dolph Schluter, of the University of British Columbia, have a review in Trends in Ecology and Evolution that makes a convincing case for the superiority, in many cases, of adaptation from standing genetic variation.3 To cut a long (and very interesting) story short, there is every reason to believe that standing variation has played a role in the adaptation of some wild populations in the recent past. Would that be true in an agricultural setting, with artificial rather than natural selection? Probably even more so, given the very strong selection pressure that people can exercise over their crops and livestock.
To summarize: global warming will create entirely new climates; these will put enormous strains on agriculture, changing where crops grow best and what crops and animals people will be able to cultivate; and farmers may do better to find as much genetic variation as they can and select from that, rather than waiting for breeders to supply them with varieties that will be at best only narrowly adapted.
Williams, J. W., Jackson, S. T., & Kutzbach, J. E. (2007). Projected distributions of novel and disappearing climates by 2100 AD. Proceedings of the National Academy of Sciences of the United States of America, 104(14), 5738-5742. [↩]
Morton, J. F. (2007). The impact of climate change on smallholder and subsistence agriculture. Proceedings of the National Academy of Sciences of the United States of America, 104(50), 19680-19685. [↩]
Barrett, R. D. & Schluter, D. (2007). Adaptation from standing genetic variation. Trends Ecol Evol. [↩]
Posted 12:42 PM by Tevita
Acta Horticulturae: campus-wide online access
From : Acta Horticulturae
Acta Horticulturae update: New optional free campus-wide online access for institutional subscribers
From 2008 all Acta Horticulturae subscriptions will come with optional free online campus-wide acces to the complete Acta Horticulturae article archives available from http://www.blogger.com/www.actahort.org (currently 40.000+ full text articles). For those of you whose institution currently already subscribes to Acta Horticulturae note that by now your librarian will have received all the information (either directly from ISHS or through your subscription agent) on how to activate this extra service for your subscription in 2008. For those who do not yet subscribe this may well be the right moment to consider a subscription to Acta Horticulturae. Most of the details can be found online at www.ishs.org/subscriptions/ but do not hesitate to contact the ISHS Secretariat with any further questions you might have. Certainly also take this occasion to recommend Acta Horticulturae to your librarian who sure will be most positively impressed with the low subscription cost and the overall cost per article for Acta Horticulturae. The fact that ISHS is the world's leading independent organization of horticultural scientists is still your guarantee to get the best subscription value for money on the market. On top of this we do offer considerable discounts to subscribers who apply for Institutional Membership with ISHS (see http://www.blogger.com/www.ishs.org/members/ for further details).
Posted 12:31 PM by Tevita
Vavilov–Frankel Fellowships 2008
Bioversity International established the Fellowship Fund in 1989, to commemorate the unique
contributions to plant science of Academician Nikolai Ivanovich Vavilov and Sir Otto Frankel. To
date, 31 scientists from 21 developing countries have received awards to carry out innovative
research related to the conservation and use of plant genetic resources, outside of their home
countries for a period of three months to one year. Two Fellowship opportunities will be available for 2008 to carry out research on topics such as new conservation technologies and strategies, socioeconomic and human aspects of conservation and use including community
based conservation, the role of traditional knowledge in management and conservation of PGR and contribution of plant genetic resources to improved nutrition, the role of intra and inter-specific diversity in production systems, germplasm management, forest genetic resources, policy development, genetic erosion assessment and mitigation, pre-breeding and base broadening, development of trait based collections and conservation and utilization of specific
crops, particularly those that are neglected and under-utilized. Work solely on plant breeding or molecular characterization will not be selected. Applicants must show in the proposal how the knowledge and expertise gained will be applied after the Fellowship in the framework of a national or regional programme or in a developing country. The maximum award per Fellow will be US$20 000 which is intended to cover travel, stipend, bench fees, equipment, conference participation, publications and so on. One of the Fellowships will be supported by Pioneer Hi-Bred International, Inc., United States. The second Fellowship is supported by the Grains Research and Development Corporation, Australia. Proposals for the second Fellowship should address any of the above topics, should be carried out at an Australian research institute and meet at least one of the following four additional criteria:
Target a species that is a priority for both Australia and the home country
Target an alternative, neglected or underutilized species with either environmental or economic potential for Australia
Work on any of the following specific crops: wheat, barley, oats, sorghum, cereal rye, triticale, maize, canary
seed, millets/panicum, canola, linseed, safflower, soybeans, sunflowers, chickpeas, cowpeas, fababeans,
field peas, lentils, lupins, mung beans, navy beans, peanuts, pigeon peas and vetch
Use biotechnology in support of efficient use of plant genetic resources
Applications are invited from nationals of developing countries, aged 35 or under, holding a masters degree (or equivalent) and/or doctorate in a relevant subject area. The list of eligible countries is available on the World Bank web site http://siteresources.worldbank.org/DATASTATISTICS/Resources/CLASS.XLS (“Income group”: “lowincome” and “lower-middle income” only). Application forms and guidelines for preparation of research proposals (in English, French and Spanish) can be downloaded from Bioversity International web site http://www.bioversityinternational.org/About_Us/Fellowships/Vavilov-
Frankel_Fellowship/index.asp#2008_Call_for_Application or send a request to: Vavilov-Frankel Fellowships, Bioversity International, Via dei Tre Denari 472/a, 00057 Maccarese, Rome, Italy; Fax:(39)0661979661; Email email@example.com. Applications must be in English, French or Spanish and should include a covering letter, completed application form, full curriculum vitae, research proposal (which should follow the guidelines provided), a letter of acceptance from the proposed host institute indicating agreement with the content of the research proposal and other agreements as specified in the “Guidelines for preparation of research proposal” and a letter of support from an institute in a developing country (preferably the home institute) which should specify why the research is important to the institute, how the research will be applied to the benefit of the institute and/or country and should also identify the support that will be provided to the applicant upon return. Applications should be sent by mail, fax or email to the above address. Applications must be received at Bioversity International by 5 November 2007 and the selections will be finalized by 31 March 2008. The successful applicants will be informed by 30 April 2008 and are required to take up their Fellowships before 31 December 2008. Awards can be held concurrently with other sources of support. IPGRI and INIBAP operate under the name of Bioversity International is a Future Harvest Centre supported by the Consultative Group on International Agricultural Research (CGIAR)
Este anuncio está disponible en español. Cette annonce est disponible en français
Monday, December 10, 2007
Posted 9:19 PM by Tevita
RECENT PUBLICATIONS FROM UH-CTAHR'S OFFICE OF COMMUNICATION SERVICES
From : Jim Holleyer
*** Free Publications ***
The publications listed below by their subject category are now available for downloading from the CTAHR free publications Web page, http://www.ctahr.hawaii.edu/freepubs
Unless a publication is indicated to be Web only, printed copies, when available, are circulated to departments and Hawaii libraries, and copies for starter inventories are sent to CES offices.
Place orders for additional quantities of printed copies of free publications by e-mail to firstname.lastname@example.org.
Hawaii avocado industry analysis, part 1: Supply focus
Catherine Chan-Halbrendt, Jyotsna Krishnakumar, Ken Love,
Pauline Sullivan, EI-12, 7 p.
Food Safety and Technology
Clostridium botulinum in foods
Aurora Saulo, FST-28, 4 p.
Fruits and Nuts
Twelve fruits with potential value-added and culinary uses
Ken Love, Richard Bowen, Kent Fleming
56 p. in color
Ornamentals and Flowers
Ornamental ginger, red and pink
Kent Kobayashi, Jan McEwen, Andy Kaufman, OF-37, 8 p.
Kent Kobayashi, James McConnell, John Griffis, OF-38, 12 p.
Using houseplants to clean indoor air
Kent Kobayashi, Andy Kaufman, John Griffis, James McConnell
OF-39, 7 p.
Soil and Crop Management
Phosphorus fertilizer management for romaine lettuce grown in
fertile volcanic ash soils of Hawaii
Jonathan Deenik, Randy Hamasaki, Robin Shimabuku, Ray Uchida
SCM-19, 3 p.
Soils of Hawaii
Jonathan Deenik, T. McClellan, SCM-20, 8 p.
The impact of sunn hemp cover cropping on belowground organisms
and nutrient status associated with a cucumber agroecosystem
Cerruti Hooks, Khamphout Chandara, Declan Fallon, Koon-Hui Wang,
Roshan Manandhar SCM-21, 7 p.
Posted 3:54 PM by Tevita
$5.2 million grant from Moore Foundation funds ambitious project to barcode an entire ecosystem
From : UC Berkeley News
By Sarah Yang, Media Relations 06 December 2007 tages - CMS-->
BERKELEY – In the middle of the South Pacific, about 12 miles west of Tahiti, is a tropical island that soon will emerge as a model ecosystem, thanks to the efforts of a U.S.-French research team led by University of California, Berkeley, biologists.
Moorea, home of the UC Berkeley Richard B. Gump South Pacific Research Station and France's Centre de Recherches Insulaires et Observatoire de l'Environnement (CRIOBE), will be the site of an ambitious project to create a comprehensive inventory of all non-microbial life on the island. Supported by a new $5.2 million grant from the Gordon and Betty Moore Foundation, the Moorea Biocode Project over the next three years will send researchers climbing up jagged peaks, trekking through lush forests and diving down to coral reefs to sample the French Polynesian island's animal and plant life.
"This is the first effort to catalog and barcode an entire tropical ecosystem, from the bottom of the ocean to the top of the mountains," said George Roderick, UC Berkeley professor of environmental science, policy and management, curator of the campus's Essig Museum of Entomology and co-principal investigator of the project.
"We're constructing a library of genetic markers and physical identifiers for every species of plant, animal and fungi on the island, then making that database publicly available as a resource for ecologists and evolutionary biologists around the world," he said. Roderick is a former director of the Gump Station, where the National Science Foundation has established one of its 26 Long Term Ecological Research sites (the Moorea Coral Reef LTER).
Posted 2:45 PM by Tevita
Environment: 2007 --A VOYAGE OF LEGACIES
But greatest gift: sustainable environment
From : Islands Business
As we come to the end of our voyage through 2007 and steer towards 2008, it is a time to reflect on several of the positive legacies the year brought us.
With Christmas just around the corner, from SPREP’s perspective the best gift that many of us can give our loved ones is one that will lead to a sustainable environment. The Secretariat of the Pacific Regional Environment Programme (SPREP) has had an environmentally prosperous year ‘hand in hand’ with our wider Pacific community. It has been our communities, government members, donors, non-governmental organisations (NGOs), and people who care, that have worked with us to leave these legacies.In 2007, the new developments with the Global Environment Facility Pacific Alliance for Sustainability (GEF-PAS) saw the announcement of a total of US$100 million to go towards environmental projects in the region for the next four years. A special highlight for this year was the visit to SPREP and Samoa by the GEF CEO and Chairperson Monique Barbut, to meet with GEF country officials in the region. Having listened to Pacific concerns, the evolving GEF-PAS is the legacy to approach these concerns. It will now cover four areas of concern: biodiversity; climate change mitigation and adaptation; international waters; and cross-cutting issues integrated across sectors such as land and water management. Madame Barbut has invited us to wayfind with her on the journey ahead and commit to evolving the GEF-Pacific Alliance for sustainability. This year, Samoa staged a successful South Pacific Games. Over 6000 Pacific islanders came together and competed in good spirit on the sports field. Samoa as the host, took on board a national ‘Play it clean and green’ campaign during the games, a partnership effort between the Ministry of Natural Resources and Environment (MNRE) of the Government of Samoa, SPREP and the United Nations agencies in the Pacific. The campaign encouraged ideal environmental habits with a treeplanting venture, requests to recycle and reuse wherever possible. From this campaign a valuable inheritance was born, it has become the start of better environmental practices for Pacific sports events. The Cook Islands held a ‘Keep it clean and green’ campaign during their Vaka Eiva canoeing festival in November. Over 500 canoe enthusiasts came together from throughout the Pacific to compete in Rarotonga waters under a ‘Keep it clean and green’ campaign teaching the Reduce, Reuse and Recycle philosophy. SPREP can only hope this campaign grows to become parallel with all Pacific sporting events in the future.The 18th SPREP Meeting in Samoa saw the endorsement of the Marine Species Programme Framework for 2008 - 2012. Our marine life is an important integral part of our biodiversity that was also stressed during the Pacific’s biggest biodiversity conference held this year. Held every five years, the 8th Pacific Islands Conference on Nature Conservation and Biodiversity had over 400 stakeholders in Pacific biodiversity who met to discuss a way forward for the next five years. Papua New Guinea (PNG), as host of the event, also launched its national biodiversity strategy and action plan (NBSAP). It is estimated that PNG hosts five to seven percent of the world’s terrestrial species and also has the world’s third largest block of unbroken tropical rainforest. Act now for tomorrowIt seemed fitting that this biodiversity hotspot was home to the Nature Conservation Conference, a memorable event that had strong conservation community presence and the site of the 10th anniversary for the Roundtable for Nature Conservation. In five years time, the Marshall Islands will host the 9th Pacific Islands Conference on Nature Conservation and Protected Areas in coordination with the Roundtable for Nature Conservation and with support from SPREP.Chairperson of the roundtable, Taholo Kami ended the conference with the challenge for us to act now for tomorrow. He encourages us to choose a path of sustainability to live in peace with each other and in harmony with our environment so conservation will be an achievable outcome. I urge us all to rise to this challenge so we can sustain our natural resources together, for our Pacific people in the future. The Pacific has started its work towards alleviating climate change by embarking on removing the barriers to renewable energy technology. The Pacific Islands Greenhouse Gas Abatement through Renewable Energy Project (PIGGAREP) held its inception workshop for 11 Pacific nations this year. The Global Environment Facility (GEF) through the United Nations Development Programme (UNDP) Samoa Multi-Country Office funds the project. SPREP is its executing agency. The more we use renewable energy the less fossil fuel is burnt forming carbon dioxide (CO2). It is this gas which accounts for 75% of all greenhouse gas emissions around the world. There is value in reducing greenhouse gas emissions, a major factor of climate change. Working together to bring about more renewable energy projects in the Pacific is a positive legacy, both for our environment and our economy. Samoa currently generates approximately 45% of its electricity from hydropower. The nation launched its energy policy this year which highlights the priority of renewable energy. Flame of renewableThis is just one member of our Pacific family that has helped light the flame of renewable energy and PIGGAREP will work towards spreading this light in our region. 2007 is a special year for phasing out the ozone depleting substances in the Pacific. SPREP, the United Nations Environment Programme (UNEP) and the government of Australia have partnered together to implement the Pacific strategy of the Montreal Protocol, which is the global effort to help restore our ozone layer. This year, Niue has passed its own ozone protection legislation that will help those at border patrol to stop ozone depleting substances from entering the nation. The Cook Islands, Solomon Islands, Tuvalu and Kiribati are working towards developing a similar legislation.Waste management has invested in the future of our Pacific nations with capacity building workshops held in-country and awareness work at all levels. Marine pollution, chemicals management, landfill use and waste management in general are just some of the issues that we have worked on to ensure positive legacies are in place for our future generations. The ‘Rubbish is a Resource’ kit was also launched to help spread awareness. It’s not easy working against the challenges of waste management that development brings our way, but SPREP is helping in this area to address these challenges. For 2007, one of the biggest focuses has been with empowering our pacific people with the knowledge to better manage their waste. Kiribati remains in the forefront as an example of how this legacy is at work in our region with their ‘cash back’ recycling scheme that encourages recycling and provides an income for those involved. At Christmas time many of us celebrate our families and memories that the year brought us. As a Pacific Islander first and foremost, I ask that this month, amongst the many different family traditions you have, to start a new one. Begin to strengthen your recycling habits, plant a tree together, or use less fossil fuel, as every effort made by us all brings greater environment awareness and leads us one-step closer to a sustainable environment for our Pacific communities. Have a safe and blessed Christmas this year.
• Asterio Takesy is the director of SPREP, based in Apia, Samoa.
Posted 2:32 PM by Tevita
Forests are not green
From : Bulletin
The Amazon may not help in the battle against rising temperatures. By Mac Margolis.
Think of global warming and the usual set of apocalyptic images comes to mind, from glaciers crashing into the sea to Biblical deluges. But what does climate change sound like? "Usually when you walk through the rain forest you hear a squishy sound from all the moist leaves and organic debris on the forest floor," says ecologist Daniel Nepstad, a researcher at the Woods Hole Research Center and longtime scholar of the Amazon rain forest. "Now we increasingly get rustle and crunch. That's the sound of a dying forest."
Predictions of the collapse of the tropical rain forests have been around for years. Yet until recently the worst forecasts were almost exclusively linked to direct human predation, such as clear-cutting and burning for pastures or farms. Left alone, it was assumed, the world's rain forests would not only flourish but might even rescue us from greater folly by sopping up the excess carbon dioxide and other planet-warming greenhouse gases. Now it turns out that may be wishful thinking. Some scientists believe that the rise in carbon levels means that the Amazon and other rain forests in Asia and Africa may go from being assets in the battle against rising temperatures to liabilities. Amazon flora, for instance, holds more than 100 billion metric tons of carbon, equal to 15 years of tailpipe and smokestack emissions. If the collapse of the rain forests speeds up dramatically, it could eventually release 3.5 billion to 5 billion metric tons of carbon into the atmosphere each year - making forests the leading source of greenhouse gases.
The issue casts a pall over the United Nations' climate talks in Bali this week, where experts are discussing how to cut emissions after the Kyoto Protocol winds down in 2012. The evidence is worrisome. Uncommonly severe droughts brought on by global climate change have led to forest-eating wildfires from Australia to Indonesia, but nowhere more acutely than in the Amazon. Some experts say that the rain forest is already at the brink of collapse. The direst predictions come from the British meteorological office's Hadley Center, where a team led by Peter Cox forecast a massive "dieback" of plants, killing the rain forest by 2100. Critics dismissed these claims as too pessimistic, but Hadley's scientists went beyond the research norm by plotting not only temperature and rainfall but how carbon from the forest - say from fires or rotting trees - feeds back into the atmosphere.
Because the "carbon cycle" is vexing to plot, most meteorologists leave it out of their computer models. Yet extreme weather and rogue development are conspiring against the rain forest in ways that scientists have never seen. Trees need more water as temperatures rise, but the prolonged droughts have robbed them of moisture, making whole forests easy marks for the pioneers' cocktail of chainsaws and kerosene. The picture worsens with each round of El Ni?o, the unusually warm currents in the Pacific Ocean that drive up temperatures and invariably presage droughts and fires in the rain forest. Runaway fires pour even more carbon into the air, which jacks up temperatures, starting the whole vicious cycle all over again. Understanding the Amazon now means tracking the assault on the ground and from the air, and the view isn't pretty. "With the synergy between climate change and deforestation, you don't have to invent any numbers to show that over half the Amazon will be cleared or crippled by 2030," Nepstad says.
More than paradise lost, a perishing rain forest could trigger a domino effect - sending winds and rains kilometers off course and loading the skies with even greater levels of greenhouse gases - that will be felt far beyond the Amazon basin. In a sense, we are already getting a glimpse of what's to come. Each burning season in the Amazon, fires deliberately set by frontier settlers, ranchers and developers hurl up almost half a billion metric tons of carbon a year, placing Brazil among the top five contributors to greenhouse gases.
The prospect of collapse is forcing a profound change in environmental thinking. Not long ago, those who lobbied for the rain forests did so on the earnest but limited argument that biodiversity was at risk. Conservation groups raised funds to rescue imperiled species, like the jaguar or the blue macaw, and pressured governments to stop razing ecological "hot spots." Climate change has widened the focus. The ecological hot spot today is the biosphere. "The loss of biodiversity and the composition of landscapes are important, but as symptoms, not determinants of life on this planet," says Nepstad. "It's the big cycles that are running the show, and that's where the rain forests come in."
Not everyone believes the rain forests are fated to desiccate and die. Among the two dozen computer climate models, some say the Amazon will hold its own, and a few predict even more rainfall. Arizona State University ecologist Scott Saleska found that the Amazon bounced back impressively after the withering 2005 drought, "greening up" as intense sunlight penetrated through to the normally shadowy understory. But a greener canopy is not the same thing as a flourishing forest. "Greening comes from the leaves, not the big trees," says Philip Fearnside, a scholar at the Brazilian Institute for Amazon Research. "Drought kills the big trees first."
Too much carbon in the air could also pose a double threat. At first, the forests may flourish; since plants need carbon to grow, processing it into life-giving sugars and chemicals through photosynthesis, the extra dose of CO2 will jolt them into overdrive. "But the forest cannot expand forever," says Scott Lewis, a scientist at Leeds University. Eventually, the overworked machinery of trees will fail, along with the nutrients in the soils. Trees sated with carbon also tend to shut down their stomates, tiny pores on the leaves that take in CO2 and exhale oxygen and water vapor - leading to even drier forests.
The best-case scenario for the Amazon shows temperatures rising 3 to 5 degrees Celsius this century, well above world averages, with rainfall dropping by as much as 15 percent, according to Brazilian climate expert Jos? Antonio Marengo. That means even more blistering droughts, and with every drought, the forest's talent for pumping vapor into the air grows feebler, opening the door to the next drought.
The experts will surely continue to quibble over the details, but no one doubts anymore that keeping the planet habitable will be a lot easier with the rain forests than without them.
© Newsweek, Inc.
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