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Soil at The Nature Conservancy A shared science agenda: activities and priorities2 Soil at The Nature Conservancy Soil is intrinsically connected to the wellbeing of people and the environment. Soil at The Nature Conservancy 3 Introduction 4 Importance of soil for conservation 5 Types of soil management practices 6 Biophysical management practices 6 Implementation and outcomes 7 Priorities and practices related to soil 7 Regional distribution of TNC soil projects 9 Ground level: TNC soil projects 12 reThink Soil Roadmap 12 Northern Rangelands T rust partnership 13 Water Funds projects 13 A first soil science agenda for TNC 14 Priority areas for soil science 16 Emerging topics 17 Soil science agenda: impacts 18 Contents This document was prepared by Deborah Bossio and Stephen Wood in collaboration with staff at The Nature Conservancy. Acknowledgements A large part of the value in this document was the process of preparing it and the conversations focused on soil that it instigated across the Conservancy. We want to acknowledge the contributions of the more than 100 staff who participated in phone calls, surveys and virtual meetings. We also want to thank the Craig and Susan McCaw Foundation for generously supporting soil science at The Nature Conservancy. October 20184 Soil at The Nature Conservancy Centuries of research and direct experience show that soil is intrinsically connected to the wellbeing of people and the environment. The Sustainable Development Goals (SDGs), adopted by United Nations Member States in 2015, established a clear mandate to manage the planet for both human and environmental wellbeing. This thinking is reflected in The Nature Conservancys missionto achieve a world in which “the diversity of life thrives, and people act to conserve nature for its own sake, and its ability to fulfill our needs and enrich our lives.” Any viable approach to achieving thisand hence achieving the SDGsrequires addressing soil as the foundation of both agricultural and healthy, natural ecosystems. Introduction OVER THE PAST DECADE, soil has gained greater attention in research, practice and policy arenas. In 2012 the UN Food and Agriculture Organization launched the Global Soil Partnership, and then celebrated the International Y ear of Soil in 2015. At the 2015 UN Climate Change Conference in Paris we saw national governments engage with soil, as reflected in the 4 per 1000 initiative launched by the French government to build soil carbon for climate and food security. In recognition of the importance of soil for global conservation work, and the need to accelerate progress, The Nature Conservancy (TNC) has decided to invest in soil science to improve how we manage land and scale up our conservation impact. This work aims to ensure that the best possible soil science is available to TNC and its partners and collaborators. TNCs audience for this science is TNC conservationists and scientists, and external partners in non-profits, government, and private enterprise who look to TNC for guidance on ways to meet their conservation, sustainability, and climate goals. Having clear goals and priorities for soil science at the Conservancy is a prerequisite for ensuring that these partnerships achieve the greatest possible impact, and better alignment with broader Conservancy goals and science. This was the motivation behind developing the shared soil science agenda. Here we present this shared soil science agenda. Our agenda is shared because it is the result of months of conversations with TNC staff, ranging from property managers to global leads, and therefore rooted in the priorities of staff across the Conservancy. It is built on our existing, extensive work to manage soils for conservation outcomes. And it is a soil science agenda as our priority is to catalyze and carry out science that directly and indirectly supports conservation implementation by facilitating and influencing decision-making by practitioners and investors. We begin with an overview of the importance of soil for conservation and the relationship between soil management and TNCs conservation agenda. We also introduce current practice, give a snapshot of the regional distribution of soil-related projects at TNC, and summarize the range of conservation outcomes soil management can support going forward. The final section presents the overarching conservation objectives and the science approach needed. We also lay out the types of actions that will be supported by this science agenda. The shared soil science agenda provides the what and the why. With this in hand, specific initiatives to address the where, how and with whom will be developed moving forward. Soil at The Nature Conservancy 5 Importance of soil for conservation TNCs conservation priorities include tackling climate change, sustainable food production, and protecting habitat and biodiversity; soil is critical to all three. 1. T ackle climate change Soil is the largest terrestrial stock of carbon, containing twice as much carbon as the atmosphere. Current land use degrades and threatens this important carbon pool, and future climate change will only amplify this. Retaining and building soil carbon is therefore important to a multi-pronged natural climate solution approach to mitigating climate change. Sequestering carbon in soils of crop and grazing lands, preserving it in peatlands and grasslands, and building soil carbon stocks through reforestation are all important pathways for land-based climate action. Soil is also an important source of methane and nitrous oxide, which are potent greenhouse gases. Reducing these non-CO 2emissions is another key aspect of natural climate solutions. 2. Sustainable food production Fertile soil is necessary for long-term, productive agriculture. The living ecosystem that is soil provides nutrients to grasslands and crops through the weathering of sediments and mineralization of organic matter. It retains water, which can support crop yield productivity, resilience, and stability. And the right mix of soil biodiversity is important to avoid damage from pests and pathogens. New science is even showing that soil management can impact the nutritional content and flavor of food. In grazing lands, changes in soil propertieslike the dramatic loss of soil carbon or erosion can be important indicators of land degradation. 3. Protect habitat and biodiversity Soils regulate water cycles and control nutrients that pass through soil en route to water systems. Nutrients leave soil by leaching through the soil profile and into groundwater systems, and are lost when water flows on top of the soil surface, eroding surface soil particles (with nutrients attached), and depositing those sediments and nutrients in nearby water systems. Excess nutrients can lead to lower aquatic diversity, lower recreational value, and in some cases impact water quality for human consumption. Sediments can also clog components of hydroelectric dams and reduce the lifespan of reservoirs. Wind loss of soil sediments can create air pollution hazards. Soil is also key to managing lands for biodiversity, which is core to TNCs work. Many of the practices that protect habitat and biodiversitysuch as changing vegetation communities and fire regimeshave strong impacts on soil properties. These changes feedback and impact on habitat restoration efforts because many soil microorganisms exist in close association with plants and can give certain species a leg up by helping with nutrient and water acquisition.6 Soil at The Nature Conservancy Types of soil management practices PracticeConservation outcome Climate Food Biodiversity Agroforestry Biochar Cover cropping Crop diversification Fire management Grass strips Grazing management Intermittent rice flooding Mangrove restoration Nutrient management Organic matter input to agriculture Reduced tillage Reforestation T erracing Vegetation restoration Wetland and riparian restoration Avoided conversion T able 1. Types of biophysical conservation practices that could impact soil. This is not an exhaustive list but a sample of common types of practices. Many management practices have been identified and promoted to improve soil properties. Generally, these practices fall into groups that target soil physical properties, soil chemical properties, or soil biological properties, bearing in mind that many practices affect multiple types of properties. Practices aimed at impacting physical properties, such as terracing, agroforestry windbreaks, or cover cropping, are usually designed to reduce erosion. Practices targeting soil chemical properties could include the adoption of leguminous crops to increase nitrogen, or the addition of organic amendments to increase carbon and other nutrients. Management practices designed to impact the biological properties are those that are aimed at influencing the biotic activity of soil, either by promoting organisms regarded as beneficial, such as mycorrhizal fungi, or by reducing the effect of harmful organisms, such as root pathogens. Different practiceswhether physical, chemical, or biologicalcan be adopted for different conservation goals (T able 1). Some soil management practices are well suited to addressing climate change and others to reducing sedimentation, while many fall into a happy coincidence category where they impact several outcomes. Similarly, many outcomes of soil management may contribute to multiple conservation priorities. For example, forest restoration contributes to protecting land and water at the same time as tackling climate change through carbon sequestration. Reduced nutrient loading to waterways can protect important aquatic habitats and improve drinking water quality. Biophysical management practices In this summary we focus on biophysical management practices that impact soil. Therefore T able 1 does not include decision-making practices, which are essential underpinning for many strategies and programs at the Conservancy. Decision-making practices, as embodied in TNCs Conservation by Design approach, drive planning and change processes in systems and include the concepts of adaptive management, continuous improvement, action planning and landscape planning.Soil at The Nature Conservancy 7 Implementation and outcomes Figure 1. Average priority ranking of target outcomes in projects impacting soil; higher numbers indicate higher priority based on survey of TNC staff. The Nature Conservancy is already implementing many of the practices highlighted in T able 1, but to date there has been no synthesis regarding where they are being adopted and for what goals. In this section, we capture a snapshot of soil projects and priorities at the Conservancy based on conversations with TNC staff and survey responses from project managers, regional conservation leaders and scientists. Some Conservancy projects directly target soil outcomes, while others adopt management practices that impact soil outcomes but for non-soil reasons. An example of a direct soil project is the Northern Rangelands T rust partnership in northern Kenya (see soil project, page 13), which is using rangeland management to increase soil carbon, leverage carbon markets, and provide revenue for community rangeland trusts as part of efforts to improve rangeland productivity for both livestock and wildlife. An example of indirect impact is Matador Ranch in Montana, where TNC is protecting grassland biodiversity through grassbanks and indirectly preserving soil carbon by avoiding conversion to wheat agriculture. A greater number of TNC project managers identify as being involved with projects that are indirectly impacting soil, rather than directly targeting soil outcomes. Priorities and practices related to soil At the Conservancy, soil management practices are implemented to achieve a range of outcomes, including biodiversity restoration, carbon sequestration, crop productivity, and the others listed in Figure 1. According to the survey of TNC staff, the highest priorities are currently biodiversity restoration and protecting water quality by reducing nutrient loading and lowering sedimentation. T ackling climate changethrough sequestering carbon and reducing greenhouse gasesis the next most important priority area, while agricultural productivity outcomes have a somewhat lower priority. The lower rankings of rangeland and crop productivity do not imply that productivity outcomes are not an important component of TNC projects, but that productivity outcomes are less often ranked as the most important. This reflects the mission of the Conservancy, and the role that agriculture plays as a part of strategies for achieving ecosystem services beyond production of food. Biodiversity restoration Lower nutrient loading Carbon sequestration Crop productivity Lower sedimentation GHG avoidance Rangeland productivity 1 2 3 4 5 6 7 w m G h 2R w G h m f F m m G G z m m N m m T V W 3P % 3% S 8% 5% 4 m G h L P 34% 33% 33% 40% 60% 0% 20% 20% 20% 30% 25% 40% 8% 4% 8% 3% 2% 5 f F m m G G z m m N m m T V W 0% % 4% 7% 4% 0% 3% 8% 5% 7% 7% 6% 23% 7% 5% 5% 9% 2% 9% L % 34% 22% 22% % 25% 25% 25% 25% P % S W (w
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