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Conservation Science for a Healthy Planet

Tag Archive: soil

  1. Urban floods intensifying, countryside drying up

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    • An exhaustive global analysis of rainfall and rivers shows signs of a radical shift in streamflow patterns, with more intense flooding in cities and smaller catchments coupled with a drier countryside

    August 14, 2017 University of New South Wales  read full ScienceDaily article here

    Drier soils and reduced water flow in rural areas — but more intense rainfall that overwhelms infrastructure and causes flooding and stormwater overflow in urban centers. That’s the finding of an exhaustive study of the world’s river systems, based on data collected from more than 43,000 rainfall stations and 5,300 river monitoring sites across 160 countries…

    …”The [study] relied on observed flow and rainfall data from across the world, instead of uncertain model simulations, means we are seeing a real-world effect — one that was not at all apparent before.”

    “It’s a double whammy,” said Conrad Wasko, lead author of the paper and postdoctoral fellow at UNSW’s Water Research Centre. “People are increasingly migrating to cities, where flooding is getting worse. At the same time, we need adequate flows in rural areas to sustain the agriculture to supply these burgeoning urban populations.”

    …[the study] found warmer temperatures lead to more intense storms, which makes sense: a warming atmosphere means warmer air, and warmer air can store more moisture…But…why is flooding not increasing at the same rate as the higher rainfall?

    The answer turned out to be the other facet of rising temperatures: more evaporation from moist soils is causing them to become drier before any new rain occurs — moist soils that are needed in rural areas to sustain vegetation and livestock. Meanwhile, small catchments and urban areas, where there are limited expanses of soil to capture and retain moisture, the same intense downpours become equally intense floods, overwhelming stormwater infrastructure and disrupting life.

    Global flood damage cost more than US$50 billion in 2013; this is expected to more than double in the next 20 years as extreme storms and rainfall intensify and growing numbers of people move into urban centres. Meanwhile, global population over the next 20 years is forecast to rise another 23% from today’s 7.3 billion to 9 billion — requiring added productivity and hence greater water security….

    “We need to adapt to this emerging reality,” said Sharma. “We may need to do what was done to make previously uninhabitable places liveable: engineer catchments to ensure stable and controlled access to water. Places such as California, or much of the Netherlands, thrive due to extensive civil engineering. Perhaps a similar effort is needed to deal with the consequences of a changing climate as we enter an era where water availability is not as reliable as before.”…

    Conrad Wasko, Ashish Sharma. Global assessment of flood and storm extremes with increased temperatures. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-08481-1

     

     

  2. Well-managed grazing and grass-finishing systems in Midwest can reduce carbon footprint of beef, while lowering overall CO2

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    Potential mitigation of midwest grass-finished beef production emissions with soil carbon sequestration in the United States of America

    Future of Food: Journal on Food, Agriculture and Society 4 (3) Winter 2016

    Jason E Rowntree Rebecca Ryals +4 more authors  [note that Rebecca Ryals co-authored some of the Marin Carbon Project studies]

    Conclusion: The recent call for improved management of grazing systems as part of an international climate change mitigation strategy is critical, particularly in light of many existing beef LCAs [life cycle assessments] that have concluded that beef cattle produced in grazing systems are a particularly large sources of GHG emissions. To identify the best opportunities to reduce GHG emissions from beef production, a systems approach that considers the potential to increase soil C and reduce ecosystem-level GHG emissions is essential. Using a combination of on-farm collected data, literature values, and IPCC Tier 1 methodology, we generated an LCA that indicates highly-managed grass-finished beef systems in the Upper Midwestern United States can mitigate GHG emissions through SCS while contributing to food provisioning at stocking rates as high as 2.5 AU ha-1. From this data, we conclude that well-managed grazing and grass-finishing systems in environmentally appropriate settings can positively contribute to reducing the carbon footprint of beef cattle, while lowering overall atmospheric CO2 concentrations.

  3. Measuring the Benefits of Regenerative Agriculture- TomKat Ranch and Ag Tech

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    • once the benefits of regenerative ranching can be fully quantified – through soil carbon measurements, forage density, and more [working with Point Blue and others]– it could become a mainstay of both ranching and soil management.
    • Holistic or planned grazing can lead to to increased forage production, soil fertility, resistance to drought, water retention, and sequestration of carbon into the soil..
    • TomKat Ranch is betting that the rise of precision agriculture and big data technologies could help prove the financial viability of regenerative ranching, as well as the environmental benefits/

    August 9 2017 read full article at AgFunder News/Successful Farming

    Regenerative agriculture is a method of farming that aims to restore the fertility of the soil and the overall health of the land it’s conducted on….consistent with sustainable agriculture practices, … limiting the use of synthetic inputs like pesticides and fertilizers and limiting tillage of the soil, which can negatively impact soil health. Often, regenerative agriculture involves livestock.

    This might seem confusing if you’ve read the countless headlines that livestock farming is the biggest culprit of greenhouse gas emissions – according to the FAO it accounts for 18% of emissions – but there is a school of thought that’s gathering momentum and evidence that managing livestock in certain ways not only can reduce the negative impact of livestock farming on the environment but also can actually regenerate the land and have a positive impact….’

    Through what’s called holistic planned grazing, or rotational grazing, ranchers strategically move their cattle around the land so that no one area is too depleted, yet every inch of rangeland is trimmed and fertilized by the cows.

    These methods can lead to increased forage production, soil fertility, resistance to drought, water retention, and the sequestration of carbon from the atmosphere into the soil, among other benefits.

    TomKat Ranch, a proponent of regenerative ranching, is betting that the rise of precision agriculture and big data technologies could help prove the financial viability of regenerative ranching, as well as the environmental benefits. The idea of adding only what is absolutely necessary to an agricultural process is a fundamental principle behind precision farming, and TomKat is working to apply these principles to cattle grazing.

    Kevin Watt, land and livestock manager at TomKat Ranch in California, thinks that once the benefits of regenerative ranching can be fully quantified – through soil carbon measurements, forage density, and more – it could become a mainstay of both ranching and soil management.

    “When you’re doing something that is regenerative, you’re basically saying that your productive asset should not be losing value. Your productive asset should be gaining value, and that appeals to everybody,” Watt told AgFunderNews….We caught up with Watt at the Forbes Agtech Summit in Salinas, California, to find out what kind of technology he’ll need to make his case and what challenges are standing in the way…

    …”We have onsite conservation scientists from Point Blue Conservation Science doing very meticulous technician-driven soil tests, vegetation surveys, and wildlife surveys that we can compare to our very rigorous management records and see what strategies grow us more grass, which ones grow us more beef, which ones keep our streams running longer. For every 1% of soil organic matter change or growth, we get an extra 25,000 gallons of water per acre being stored. That’s a USDA figure so people know about this.

    Climate-SH_Infographicsmall.jpg

    We’ve learned that if you can get that feedback from your landscape, whether or not you share a philosophical interest in environmentalism or humane treatment of animals, you start to see that it really makes sense to evolve with your landscape; to see what the ROI is on every one of your management choices. That’s why precision ranching could be so transformative…”

  4. Restore soil in addition to vegetation; Study results suggest aboveground restoration does not restore soil microbial communities.

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    July 26 2017

    Michael S. Strickland, Mac A. Callaham Jr., Emile S. Gardiner, John A. Stanturf, Jonathan W. Leff, Noah Fierer, Mark A. Bradford. Response of soil microbial community composition and function to a bottomland forest restoration intensity gradientJuly 2017. Applied Soil Ecology 199: 317-326 https://doi.org/10.1016/j.apsoil.2017.07.008

    Comments from Dr. Chelsea Carey, Sr. Soil Ecologist at Point Blue:

    The findings differ from some other papers we have seen recently (where microorganisms rapidly respond to restoration efforts, and are influenced by changes in plant community composition); instead, the results of this study support another view, one which acknowledges the need to directly restore the soil in addition to vegetation.

    Some conclusions from discussion:In fact, from a microbial perspective the act of agricultural cessation likely had the most marked influence on these soil communities, while efforts aimed at rapidly establishing trees had relatively little effect to date. Our results therefore help to validate the emerging use of practices which focus directly on restoring soil biotic communities and their functions, through restoration treatments such as transplanting a thin layer of topsoil – albeit labor intensive – from sites similar to the restoration end-point (Kardol et al., 2009; Pywell et al., 2011; Vecrin and Muller, 2003; Wubs et al., 2016). That is, building a better aboveground community does not ensure that an equivalent belowground community will take the field, and so the focus should be on directly establishing both the aboveground and belowground players in future restoration efforts rather than relying on restoration myths (sensu Hilderbrand et al., 2005).”

    Highlights

    •We examined the effect of intensifying aboveground restoration on soil microbes.
    •Restoration had little influence on soil microbial community composition.
    •Restoration had little influence on soil microbial community function.
    Results suggest aboveground restoration does not restore soil microbial communities.

    Abstract: “Terrestrial ecosystems are globally under threat of loss or degradation. To compensate for the impacts incurred by loss and/or degradation, efforts to restore ecosystems are being undertaken. These efforts often focus on restoring the aboveground plant community with the expectation that the belowground microbial community will follow suit. This ‘Field of Dreams’ expectation – if you build it, they will come – makes untested assumptions about how microbial communities and their functions will respond to aboveground-focused restoration. To determine if restoration of aboveground plant communities equates to restoration of belowground microbial communities, we assessed the effects of four forest restoration treatments – varying in intensity from unmanaged to interplanting tree species – on microbial (i.e. prokaryotic and fungal) community composition and function (i.e. catabolic profiles and extracellular enzyme activities). Additionally, effects of the restoration treatments were compared to both degraded (i.e. active arable cultivation) and target endpoint communities (i.e. remnant bottomland forest) to determine the trajectory of intensifying aboveground restoration efforts on microbial communities. Approximately 16 years after the initiation of the restoration treatments, prokaryotic and fungal community composition, and microbial function in the four restoration treatments were intermediate to the endpoint communities. Surprisingly, intensification of aboveground restoration efforts led to few differences among the four restoration treatments and increasing intensification did not consistently lead to microbial communities with greater similarity in composition and function to the target remnant forest communities. Together these results suggest that belowground microbial community composition and function will respond little to, or will lag markedly behind, intensifying aboveground restoration efforts. Reliance on a ‘Field of Dreams’ approach, even if you build it better, may still lead to belowground microbial communities that remain uncoupled from aboveground communities. Importantly, our findings suggest that restoring aboveground vegetation may not lead to the intended restoration of belowground microbial communities and the ecosystem processes they mediate.”

     

  5. We need biodiversity to save biodiversity in a warmer world

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    July 14, 2017 German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig  see full sciencedaily article here

    Climate change leads to loss of biodiversity worldwide. However, ecosystems with a higher biodiversity in the first place might be less affected a new study. Scientists found that when they experimentally warmed meadows, the diversity of nematode worms living in the soil went down in monocultures, whereas the opposite was true for meadows with many different herbaceous plant species.

    …The last month was recorded as the warmest June ever in many parts of the world. Last year, 2016, was the warmest year in the modern temperature record. … poses direct threats to humans, like extreme weather events and global sea-level rise, but scientists are concerned that it may also affect our well-being indirectly via changes in biodiversity.…Today, ecologists are challenged by the question: what does a warmer world mean for biodiversity? More species, less species, or no change?…”The story is simple; you need biodiversity to conserve biodiversity in a warmer world.”

    The monoculture meadow created for the experiment resembled meadows found in intensively managed agricultural land. These new research findings therefore support conservationists who are advocating for maintaining species-rich ecosystems and farmland to sustain biodiversity, and thus human well-being, in a warmer world. This may help to prevent negative effects of climate warming, although likely with some limitations.

    P. Thakur, D. Tilman, O. Purschke, M. Ciobanu, J. Cowles, F. Isbell, P. D. Wragg, N. Eisenhauer. Climate warming promotes not only species diversity but also taxonomic redundancy in complex environmentsSci. Adv., 2017 DOI: 10.1126/sciadv.1700866

  6. Invasive plants decrease soil microbial activity compared to native grassland communities

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    • Two invasive grasses reduce inorganic nitrate availability, active microbial biomass, and the potential for soil communities to nitrify and denitrify compared to native plant communities in California.
    • These results may help explain why it is difficult to establish native grasses on soils that have been invaded by invasive annual grasses.

    Chelsea J. Carey*, Joseph C. Blankinship, Valerie T. Eviner, Carolyn M. Malmstrom, Stephen C. Hart. Invasive plants decrease microbial capacity to nitrify and denitrify compared to native California grassland communities.  Biol Invasions DOI 10.1007/s10530-017-1497-y Accepted: 26 June 2017

    *Dr. Carey is a Point Blue Senior Soil Scientist

    Abstract: Exotic plant invasions are a major driver of global environmental change that can signicantly alter the availability of limiting nutrients such as nitrogen (N). Beginning with European colonization of California, native grasslands were replaced almost entirely by annual exotic grasses, many of which are now so ubiquitous that they are considered part of the regional ora (‘‘naturalized’’). A new wave of invasive plants, such as Aegilops triuncialis (Barb goatgrass) and Elymus caputmedusae (Med usahead), continue to spread throughout the state today. To determine whether these new-wave invasive plants alter soil N dynamics, we measured inorganic N pools , nitrication and deni trication potentials, and possible mediating factors such as microbial biomass and soil pH in experimental grasslands comprised of A. triuncialis and E. caput medusae. We compared these measure-
    ments with those from experimental grasslands containing: (1) native annuals and perennials and (2) naturalized exotic annuals. We found that A. triuncialis and E. caputmedusae signicantly reduced ion-exchange resin estimates of nitrate (NO3) availability as well as nitrication and denitrication potentials compared to native communities. Active microbial biomass was also lower in invaded soils. In contrast, potential measurements of nitrication and denitrication were similar between invaded and naturalized communities. These results suggest that invasion by A. triuncialis and E. caputmedusae may signicantly alter the capacity for soil microbial communities to nitrify or denitrify, and by extension alter soil N availability and rates of N transformations during
    invasion of remnant native-dominated sites.
  7. California’s Healthy Soils Incentive Program- CalCAN update

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    CA Department of Food & Agriculture Finalizing Healthy Soils Program

    Posted by Brian Shobe, California Agriculture and Climate Network (CalCAN) May 22 2017

    As farmers and ranchers in the U.S. and abroad experience the reality of more extreme and unpredictable weather, soil carbon sequestration is catching national and international attention as a means of climate change mitigation and adaptation. California is poised to lead the way with its soon-to-be-launched Healthy Soils Incentives Program, the nation’s first program to directly incentivize farmers for adopting practices that improve soil health, sequester carbon and reduce greenhouse gas emissions overall.

    According to the California Department of Food and Agriculture’s (CDFA) most recent proposed Healthy Soils program framework, farmers and ranchers will be eligible to apply for up to $50,000 to defray the costs of adopting healthy soils practices (pictured below) over the course of three years...

    …some proposed program details raised significant concerns … CDFA agreed to release the program’s draft request for proposal (RFP) for public comment and subsequent revision before officially launching the program….Below, we outline our recommendations for the proposed program framework.

    -Allow on-farm compost to be eligible for compost application…

    -Clarify how payments and payment timelines will work for different practices, as well as how that will affect the 3rd year matching fund requirement…

    -Simplify the application for applicant feasibility…

    -Require soil tests from award recipients, not applicants…

    -Reward applicants for conservation plans and matching funds, but not so much that it creates a structural disadvantage to limited-resource and small-scale farmers…

    -Shift the demonstration program back to its intended goal of expanding the impact and adoption of Healthy Soils practices

  8. Climate change solutions – the role of healthy soils

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    There’s too much carbon in the atmosphere and not enough in the ground where it’s useful. Healthy soil can help flip the picture.  Full article here

    May 17 2017 UC Davis via Washington Post

    …Scow—a microbial ecologist and director of this experimental farm at the University of California, Davis—sees a living being brimming with potential. The soil beneath this field doesn’t just hold living things—it is itself alive. Scow likens soil to the human body with its own system of “organs” working together for its overall health. And, like us, it needs good food, water and care to live up to its full potential...

    …Soil can potentially store between 1.5 and 5.5 billion tons of carbon a year globally. That’s equivalent to between 5 and 20 billion tons of carbon dioxide. While significant, that’s still just a fraction of the 32 billion tons of carbon dioxide emitted every year from burning fossil fuels. Soil is just one of many solutions needed to confront climate change. But the nice thing about healthy soils, Scow said, is that creating them not only helps fight climate change—it also brings multiple benefits for agricultural, human and environmental health….

    there are more microbes in one teaspoon of soil than there are humans on Earth. Many of them lie dormant, just waiting to be properly fed and watered. A well-fed army of microbes can go to work strengthening the soil so it can grow more food, hold more water, break down pollutants, prevent erosion and, yes, sequester carbon….

    Soil sequesters carbon through a complex process that starts with photosynthesis. A plant draws carbon out of the atmosphere and returns to the soil what isn’t harvested in the form of residue and root secretions. This feeds microbes in the soil. The microbes transform the carbon into the building blocks of soil organic matter and help stabilize it, sequestering the carbon….

    …There’s too much carbon in the atmosphere and not enough in the ground where it can be used. A new effort in California aims to flip that picture. The state’s Healthy Soils Incentives Program is considered the first in the nation to provide state funding to help farmers and ranchers enhance their soils to reduce greenhouse gas emissions. The $7.5 million program, expected to launch this summer, encourages farming practices known to boost microbial communities underground and sequester carbon….

    …Stone is as much a natural resources manager as a rancher, with a protective eye on the ranch’s watersheds, trees, pasture and grass-fed cattle, and a genuine desire to leave the land better than he found it. He rotates his cattle frequently across the pasture to avoid overgrazing. Most of the ranch—7,000 acres—is in a conservation easement. He avoids fertilizer. And, increasingly, he composts.

    ….California loses about 20,000 acres of rangeland each year, much of which become greenhouse-gas-emitting housing developments, shopping centers, roads and parking lots. The remaining 63 million acres of rangeland in the state—part of the 770 million acres nationwide—represent significant opportunities for additional carbon storage, and can help offset some of the emissions for which the meat industry is often criticized.

    Scientists estimate that U.S. rangelands could potentially sequester up to 330 million metric tons of carbon dioxide in their soils, and croplands are estimated to lock up more than twice that amount—up to 770 million metric tons. That’s the CO2 emissions equivalent of powering 114 million homes with electricity for a year.

    When you look at the cow, you think of emissions,” Stone said. “But the whole system is actually sequestering carbon. There are so many opportunities in agriculture to move the needle on climate change.”

  9. Can Meadows Rescue the Planet from CO2?

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    An unusual research project is determining whether restoring California’s meadows can reduce atmospheric carbon dioxide

    By Jane Braxton Little on May 11, 2017 Scientific American

    …Scientists and land managers are heading into the mountains to measure the greenhouse gas activity at 16 hand-picked meadows—some recently restored, others degraded from a century of grazing and logging.

    The four-year study is part of California’s pioneering effort to reduce carbon emissions. The project is designed to determine whether restored meadows hold more carbon than those that have been degraded. The outcome could prove pivotal for California and the planet. Worldwide, soils store three times more carbon than vegetation and the atmosphere combined. If the research shows restored meadows improve carbon storage, it could stimulate meadow restoration around the world….

    A December study published in Nature… found rising temperatures are stimulating a net loss of soil carbon to the atmosphere. Warmer soils accelerate the flux, sending more carbon into the ground and more carbon dioxide back out into the atmosphere. As warmth increases microbial activity, decomposition and respiration outpace photosynthesis, particularly in the world’s colder places. …” The changes could drive a carbon–climate feedback loop that could accelerate climate change.”…

    …The research covers meadows from the base of Lassen Peak in the north to areas nearer to Los Angeles. The meadows range in elevation from 3,045 to nearly 8,700 feet; they include granitic, volcanic and metamorphic soils. A critical facet of the partnership is developing precise procedures for when and how to measure and analyze meadow greenhouse gases.

    ……a limited study conducted by the University of Nevada, Reno (U.N.R.). Scientists collected soil samples at seven meadows in the northern Sierra restored between 2001 and 2016, pairing restored sites with similar, adjacent unrestored sites….found an average of 20 percent more soil carbon in restored meadows, with one site recording an increase of over 80 percent. Meadows immediately begin storing carbon following restoration, with significant increases over 15 years, says Cody Reed, a research assistant working with Ben Sullivan, a U.N.R. soil scientist and assistant professor. The investigation seems to show restored meadows add soil carbon and also slow losses to the atmosphere.

    …[In another study] they found surprised them: Carbon dioxide emissions were unaffected by soil moisture content, and methane sequestration was prevalent, particularly on the dry side of wet meadow. The 2014 study also found plant species richness and soil carbon concentration appeared more important than soil moisture in explaining carbon fluxes.

     

  10. Microscopic soil creatures could orchestrate massive tree ‘migrations

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    May 8, 2017 University of Tennessee at Knoxville  Full ScienceDaily Article Here

    Warming temperatures are prompting some tree species in the Rocky Mountains to ‘migrate’ to higher elevations in order to survive. Researchers have discovered that tiny below-ground organisms play a role in this phenomenon — and could be used to encourage tree migration in order to preserve heat-sensitive species. Their work shows how these invisible biotic communities create ‘soil highways’ for young trees, meaning they could determine how quickly species march uphill, if at all.

    The newfound role of the soil microbiome — the collection of microscopic bacteria, fungi and archaea that interact with plant roots — represents a turning point for research aimed at understanding and predicting where important tree species will reside in the future…

    …”we need to work with the trees near the bottom of the mountain, because they are the ones that will feel the most stress from warming temperatures,” Van Nuland said. “So we have to figure out a way to coax them to move up.” The research could help scientists design specific groups of bacteria and fungi to encourage the migration of trees threatened by warming climates….