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Tag Archive: forests

  1. Mapping biodiversity of forests with remote sensing; the more diverse, the more resilient

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    Posted: 13 Nov 2017 06:55 AM PST  read full ScienceDaily article here

    Productivity and stability of forest ecosystems strongly depend on the functional diversity of plant communities. Researchers have developed a new method to measure and map functional diversity of forests at different scales — from individual trees to whole communities — using remote sensing by aircraft [paving] the way for future airborne and satellite missions to monitor global plant functional diversity.

    Ecological studies have demonstrated positive relationships between plant diversity and ecosystem functioning. Forests with higher functional diversity are generally more productive and stable over long timescales than less diverse forests. Diverse plant communities ….can better cope with changing environmental conditions — an insurance effect of biodiversity. They are also less vulnerable to diseases, insect attacks, fire and storms.

    Researchers from the UZH and the California Institute of Technology / NASA Jet Propulsion Laboratory have now developed a new remote-sensing method to map functional diversity of forests from small to large scales, independent of any predefined vegetation units or species information and without the need for ground-based calibration….

    With airborne laser scanning, the scientists measured morphological characteristics of the forest canopy such as canopy height, foliage and branch densities. These measurements indicate how the sunlight is taken up by the canopy to assimilate carbon dioxide from the air and use the carbon to grow. In a canopy with a more diverse structure, light can better spread between different vertical canopy layers and among individual tree crowns, allowing for a more efficient capture of light. The researchers also characterized the forest with regards to its biochemical properties using airborne imaging spectroscopy. By measuring how leaves reflect the light in many spectral bands, they were able to derive physiological traits such as the content of leaf pigments (chlorophylls, carotenoids) and leaf water content

    We can see, for example, if a tree is suffering water stress, and what resource allocation strategy a tree is following or how it adapts to the environment,”

    Fabian D. Schneider et al. Mapping functional diversity from remotely sensed morphological and physiological forest traits. Nature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-01530-3


  2. Carbon feedback from forest soils accelerates global warming

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    • Soil warming stimulates periods of abundant carbon release from the soil to the atmosphere alternating with periods of no detectable loss in soil carbon stores
    • Humans release about 10 billion metric tons (Gt) of carbon into the atmosphere each year and Earth’s soils contain about 3500 billion metric tons (Gt) of carbon which if added to atmosphere could accelerate global warming
    • Over the course of the 26-year experiment (which still continues), the warmed plots lost 17 percent of the carbon that had been stored in organic matter in the top 60 centimeters of soil
    • Study demonstrates value of long term data sets

    October 5, 2017  Marine Biological Laboratory  read full ScienceDaily article here

    After 26 years, the world’s longest-running experiment to discover how warming temperatures affect forest soils has revealed a surprising, cyclical response: Soil warming stimulates periods of abundant carbon release from the soil to the atmosphere alternating with periods of no detectable loss in soil carbon stores. The study indicates that in a warming world, a self-reinforcing and perhaps uncontrollable carbon feedback will occur between forest soils and the climate system, accelerating global warming.

    ….each year, mostly from fossil fuel burning, we are releasing about 10 billion metric tons of carbon into the atmosphere. That’s what’s causing the increase in atmospheric carbon dioxide concentration and global warming. The world’s soils contain about 3,500 billion metric tons of carbon. If a significant amount of that soil carbon is added to the atmosphere, due to microbial activity in warmer soils, that will accelerate the global warming process. And once this self-reinforcing feedback begins, there is no easy way to turn it off. There is no switch to flip.”…

    ….”if the microbes in all landscapes respond to warming in the same way as we’ve observed in mid-latitude forest soils, this self-reinforcing feedback phenomenon will go on for a while and we are not going to be able to turn those microbes off. Of special concern is the big pool of easily decomposed carbon that is frozen in Arctic soils. As those [Arctic] soils thaw out, this feedback phenomenon would be an important component of the climate system, with climate change feeding itself in a warming world….”

    Heated and control plots in a long-term soil warming study at Harvard Forest, Petersham, Mass. Jerry Melillo of the Marine Biological Laboratory, Woods Hole, Mass., and colleagues began the study in 1991.
    Credit: Audrey Barker-Plotkin
    …Melillo and colleagues began this pioneering experiment in 1991 in a deciduous forest stand at the Harvard Forest in Massachusetts. They buried electrical cables in a set of plots and heated the soil 5° C above the ambient temperature of control plots. Over the course of the 26-year experiment (which still continues), the warmed plots lost 17 percent of the carbon that had been stored in organic matter in the top 60 centimeters of soil….
    J. M. Melillo, S. D. Frey, K. M. DeAngelis, W. J. Werner, M. J. Bernard, F. P. Bowles, G. Pold, M. A. Knorr, A. S. Grandy. Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world. Science, 2017; 358 (6359): 101 DOI: 10.1126/science.aan2874
  3. Finally, a focus on saving the great forests of the Sierra. But is it too late? SacBee Editorial

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    • “There is an urgent need to reform policy and management to ensure that Californians continue to benefit from these forests for generations to come,” a new Public Policy Institute of California report says
    • Reducing forest density could have the side benefit of increasing run-off by as much as 9 percent, filling streams and rivers for the good of fisheries and for residential, agriculture and industrial use, the PPIC report says.

    Sacramento Bee Editorial  September 21, 2017 read full SacBee editorial here

    We Californians take for granted the great forests of the Sierra Nevada. It is where we ski and hike, and breathe fresh air, and it’s the primary source of our water.

    It’s all at risk. Drought and bark beetle infestation are the proximate cause of death of more than 100 million trees in California since 2010. But the forests were weakened by climate change, combined with mismanagement that includes well-intentioned wildfire prevention efforts and logging in past decades of old-growth trees, which are most resistant to fire and disease.

    [Governor] Brown and the Legislature approved another $225 million in cap-and-trade revenue, reserved for the fight against climate change, for forests. That underscored one of California’s inconvenient truths. Like refineries, diesel engines and cars powered by internal combustion, burning and decaying forests spew greenhouse gases.

    In April, the Governor’s Tree Mortality Task Force reported that the 2013 Rim Fire at Yosemite emitted 12.06 million tons of carbon dioxide, three times more than all the greenhouse gas reductions achieved that year in all other sectors in California. Worse, the detritus decomposing in the burn area will unleash four times that amount of greenhouse gas in coming decades.

    In much of the 15 million acres of mountains from Kern to Siskiyou counties, forests are choking with 400 sickly trees per acre, four times the number in healthy forests. Tools to heal the forests are at hand, but forest management is fraught.

    …Some environmentalists oppose logging, while some conservative politicians advocate unraveling environmental restrictions to allow for far more logging. Neither extreme is helpful. Flexibility is needed. The Clean Air Act could, for example, allow for the use of prescribed fires.

    …Reducing forest density could have the side benefit of increasing run-off by as much as 9 percent, filling streams and rivers for the good of fisheries and for residential, agriculture and industrial use, the PPIC report says.

    The report says the cost of wise forest management might not be astronomical. In time, it might pay for itself, assuming mills are retooled or built to accommodate smaller and mid-size timber. Such mills could provide jobs in parts of the state where unemployment is chronically high.

    …Our re-engineered state of 40 million people faces many problems. The water delivery system is oversubscribed and antiquated. Billions of dollars should be spent to reinforce California against floods.

    But there is cause for optimism. Laird last month announced the Tahoe-Central Sierra Initiative with other top officials, and some significant environmental groups are joining longtime advocates to focus on Sierra restoration. There is some support in Congress for wiser forest management.

    And now comes an infusion of state money, not to be taken for granted, and none too soon.

  4. Maximizing successful forest restoration in tropical dry forests

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    • tests maximizing success of tree replanting efforts in degraded soils in tropics
    • tree species that were drought tolerant did better
    • soil amendments only helped to get seedlings off to good start

    September 21, 2017 University of Minnesota read full ScienceDaily article here

    A new study has uncovered some valuable information on ways to maximize the success of replanting efforts [in tropical dry forests], bringing new hope for restoring these threatened ecosystems.

    …Over the past century most of these forests, which help keep water clean and provide valuable habitat for wildlife, were replaced by farms and cattle pastures. Now, as conservationists work to replant deforested areas, they’re finding that the already challenging, high-clay soils underlying them have been degraded to an extent that makes it hard for tree seedlings to sink their roots.

    …To find out what works best for reestablishing tropical dry forests, the researchers planted seedlings of 32 native tree species in degraded soil or degraded soil amended with sand, rice hulls, rice hull ash or hydrogel (an artificial water-holding material). After two years, they found that tree species known for traits that make them drought tolerant, such as enhanced ability to use water and capture sunlight, survived better than other species. Some of the soil amendments helped get seedlings off to a good start, but by the end of the experiment there was no difference in survival with respect to soil condition

    Leland K. Werden, Pedro Alvarado J., Sebastian Zarges, Erick Calderón M., Erik M. Schilling, Milena Gutiérrez L., Jennifer S. Powers. Using soil amendments and plant functional traits to select native tropical dry forest species for the restoration of degraded Vertisols. Journal of Applied Ecology, 2017; DOI: 10.1111/1365-2664.12998

  5. ‘Keep it local’ approach more effective than government schemes at protecting rainforest

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    September 12, 2017 University of Cambridge  read full ScienceDaily article here

    Conservation initiatives led by local and indigenous groups can be just as effective as schemes led by government, according to new research. In some cases in the Amazon rainforest, grassroots initiatives can be even more effective at protecting this vital ecosystem

    …”Policy makers must focus on a more diverse set of mechanisms for protecting the rapidly disappearing tropical forests,” said Schleicher. “Our analysis shows that local stewardship of the forest can be very effective at curtailing forest degradation and conversion in the Peruvian Amazon. Local conservation initiatives deserve more political, financial and legal support than they currently receive.”

    “Our analysis shows that there is no single way of protecting tropical forests, and multiple approaches are required to stem the relentless tide of forest conversion and degradation,” said co-author Professor Carlos Peres from UEA’s School of Environmental Sciences.

    Judith Schleicher, Carlos A. Peres, Tatsuya Amano, William Llactayo, Nigel Leader-Williams. Conservation performance of different conservation governance regimes in the Peruvian Amazon. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-10736-w

  6. Warming may quickly drive forest-eating beetles north, says study

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    • Pines in Canada and much of US at risk

    August 28, 2017 Lamont-Doherty Earth Observatory, Columbia University  read full ScienceDaily article here

    Over the next few decades, global warming-related rises in winter temperatures could significantly extend the range of the southern pine beetle — one of the world’s most aggressive tree-killing insects — through much of the northern United States and southern Canada, says a new study. The beetle’s range is sharply limited by annual extreme temperature lows, but these lows are rising much faster than average temperatures — a trend that will probably drive the beetles’ spread, say the authors. The study was published today in the journal Nature Climate Change.

    …Until recently, southern pine beetles lived from Central America up into the southeastern United States, but in the past decade or so they have also begun appearing in parts of the Northeast and New England…

    …”We could see loss of biodiversity and iconic regional forests. There would be damage to tourism and forestry industries in already struggling rural areas.” Coauthor Radley Horton, a researcher at Columbia University’s Lamont-Doherty Earth Observatory, said infested forests could also dry out and burn, endangering property and emitting large amounts of carbon into the atmosphere

    Corey Lesk, Ethan Coffel, Anthony W. D’Amato, Kevin Dodds, Radley Horton. Threats to North American forests from southern pine beetle with warming winters. Nature Climate Change, 2017; DOI: 10.1038/nclimate3375

  7. Paying people to protect forests is worth it to reduce deforestation, carbon emissions

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    Posted: 20 Jul 2017 11:23 AM PDT  see full ScienceDaily article here

    A new study suggests that paying people to conserve their trees could be a highly cost-effective way to reduce deforestation and carbon emissions and should be a key part of the global strategy to fight climate change. The study sought to evaluate how effective ‘Payments for Ecosystems’ (PES) is at reducing deforestation.

    …the study applies the method of field experiments, or randomized controlled trials, to the question of how effective PES is. The study design helped the researchers accurately measure the averted deforestation caused by the program…

    The findings highlight the advantages of focusing on developing countries when working to reduce global carbon emissions. While the benefit of conserving a tree is the same regardless of the location, paying individuals to conserve forests in developing countries like Uganda is less expensive, making it cheaper to reduce overall emissions

    Seema Jayachandran, Joost de Laat, Eric F. Lambin, Charlotte Y. Stanton, Robin Audy, Nancy E. Thomas. Cash for carbon: A randomized trial of payments for ecosystem services to reduce deforestation. Science, 2017; 357 (6348): 267 DOI: 10.1126/science.aan0568

     

  8. Adapting Forests to Climate Change- new UC guide

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    UC helps forest owners adapt to climate change

    By Jeannette E. Warnert April 5, 2017 University of California Division of Agriculture and Natural Resources Blog

    The new publication, Adapting Forests to Climate Change, can be downloaded free from the UC ANR Catalog. It is the 25th in the Forest Stewardship series, developed to help forest landowners in California learn how to manage their land. It was written by Adrienne Marshall, a doctoral student at the University of Idaho; Susie Kocher, UC Cooperative Extension forestry and natural resources advisor; Amber Kerr, postdoctoral scholar with the UC John Muir Institute of the Environment; and Peter Stine, U.S. Forest Service.

    The document provides specific recommendations for care of three common types of forest in California: mixed conifer, oak woodland and coastal redwood forests… see page 12 for specific management recommendations.

  9. Local cooling value of forests: fighting global warming more than previously understood

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    Local cooling value of forests affirms need for greater forest conservation, protection

    Posted: 27 Mar 2017 08:46 AM PDT  ScienceDaily article here

    Forests take up carbon dioxide from the atmosphere. At the same time, forests promote the turbulent mixing of air near the surface and transpire large amounts of moisture to the atmosphere. A new study exposes the importance of these processes in keeping much of the planet’s surface cool….

    Ryan M. Bright, Edouard Davin, Thomas O’Halloran, Julia Pongratz, Kaiguang Zhao, Alessandro Cescatti. Local temperature response to land cover and management change driven by non-radiative processes. Nature Climate Change, 2017; DOI: 10.1038/nclimate3250