49 research outputs found

    Germination of small bengal dayflower (Commelina benghalensis) aerial seeds

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    O conhecimento científico sobre a biologia de plantas daninhas relacionado ao fluxo de emergência das plântulas, às causas de dormência das sementes e à profundidade máxima de emergência contribui significativamente para a utilização de estratégias racionais de manejo dessas plantas na agricultura. Assim, este trabalho foi desenvolvido com o objetivo de avaliar a germinação de sementes e a emergência da plântula de sementes aéreas pequenas de trapoeraba (Commelina benghalensis). Para isso, as sementes foram submetidas à superação de dormência em solução de ácido sulfúrico (por períodos de 1, 2, 3, 4 e 5 minutos), em diferentes condições de temperaturas (temperaturas médias de 16,1; 18,6; 20,6; 23,1; 25,0; 26,9; 29,2; 31,1; e 33,6 ºC), de luz (com e sem) e de profundidade de semeadura (0, 5, 10, 20, 40 e 80 mm). A temperatura ótima para germinação da trapoeraba foi de 25 ºC. Não houve efeito da luz na germinação das sementes. Não se observou interferência positiva na germinação por consequência do tratamento das sementes com ácido sulfúrico, em diferentes períodos de exposição, indicando que as sementes de trapoeraba não possuem impermeabilidade do tegumento à água. A emergência das plântulas de trapoeraba é influenciada negativamente e de forma linear pela profundidade de semeadura dos propágulos no substrato. Não houve emergência das plântulas quando as sementes foram depositadas a 80 mm de profundidade. O substrato areia favorece a emergência das plântulas.Understanding basic information on weed biology related to plant emergence fluxes, seed dormancy causes and maximum depth for emergence may significantly contribute to creating rational strategies for weed management in agriculture. Thus, this work was developed to evaluate seed germination and seedling emergence of small aerial seeds of Bengal dayflower (Commelina benghalensis).Seeds were submitted to dormancy overcoming in sulfuric acid (periods of 1, 2, 3, 5 and 5 minutes) under different conditions of temperature (mean temperatures of 16.1; 18.6; 20.6; 23.1; 25.0; 26.9; 29.2; 31.1 and 33.6ºC), light (with or without), and seeding depth in the substrate (0, 5, 10, 20, 40 and 80 mm). The optimal temperature for Bengal dayflower germination was 25ºC. Light effects were not observed on seed germination. Positive consequences of seed treatment with sulfuric acid were not identified, considering different periods of exposure; indicating that Bengal dayflower seeds do not have tegument water impermeability. Seedling emergence is negative and linearly influenced by seeding depth in the substrate. Seedling emergence was not observed when seeds were 80 mm depth placed. Sand substrate favored seedling emergence.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Adding forests to the water–energy–food nexus

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    Forest and landscape restoration is a promising strategy for improving water, energy and food securities. We advocate that ‘forest security’ should form a fourth, foundational dimension of a novel water, energy, food and forest security nexus framework. Key principles of this new framework support an integrated role of forests in sustainable development, and engagement of local communities in nature-based solutions, particularly in the Global South. We believe that this new approach can help to accelerate the pace and magnitude of changes needed for achieving the United Nations Sustainable Development Goals. © 2020, Springer Nature Limited

    Ten golden rules for reforestation to optimize carbon sequestration, biodiversity recovery and livelihood benefits

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    Urgent solutions to global climate change are needed. Ambitious tree-planting initiatives, many already underway, aim to sequester enormous quantities of carbon to partly compensate for anthropogenic CO2 emissions, which are a major cause of rising global temperatures. However, tree planting that is poorly planned and executed could actually increase CO2 emissions and have long-term, deleterious impacts on biodiversity, landscapes and livelihoods. Here, we highlight the main environmental risks of large-scale tree planting and propose 10 golden rules, based on some of the most recent ecological research, to implement forest ecosystem restoration that maximizes rates of both carbon sequestration and biodiversity recovery while improving livelihoods. These are as follows: (1) Protect existing forest first; (2) Work together (involving all stakeholders); (3) Aim to maximize biodiversity recovery to meet multiple goals; (4) Select appropriate areas for restoration; (5) Use natural regeneration wherever possible; (6) Select species to maximize biodiversity; (7) Use resilient plant material (with appropriate genetic variability and provenance); (8) Plan ahead for infrastructure, capacity and seed supply; (9) Learn by doing (using an adaptive management approach); and (10) Make it pay (ensuring the economic sustainability of the project). We focus on the design of long-term strategies to tackle the climate and biodiversity crises and support livelihood needs. We emphasize the role of local communities as sources of indigenous knowledge, and the benefits they could derive from successful reforestation that restores ecosystem functioning and delivers a diverse range of forest products and services. While there is no simple and universal recipe for forest restoration, it is crucial to build upon the currently growing public and private interest in this topic, to ensure interventions provide effective, long-term carbon sinks and maximize benefits for biodiversity and people

    Explore before you restore : incorporating complex systems thinking in ecosystem restoration

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    DATA AVAILABILITY STATEMENT : No new data were used for this manuscript.SUPPLEMENTARY MATERIAL : APPENDIX S1: Extended glossary. APPENDIX S2: Problem statement. APPENDIX S3: Restoration project cycle.The global movement for ecosystem restoration has gained momentum in response to the Bonn Challenge (2010) and the UN Decade on Ecosystem Restoration (UNDER, 2021–2030). While several science-based guidelines exist to aid in achieving successful restoration outcomes, significant variation remains in the outcomes of restoration projects. Some of this disparity can be attributed to unexpected responses of ecosystem components to planned interventions. Given the complex nature of ecosystems, we propose that concepts from Complex Systems Science (CSS) that are linked to non-linearity, such as regime shifts, ecological resilience and ecological feedbacks, should be employed to help explain this variation in restoration outcomes from an ecological perspective. Our framework, Explore Before You Restore, illustrates how these concepts impact restoration outcomes by influencing degradation and recovery trajectories. Additionally, we propose incorporating CSS concepts into the typical restoration project cycle through a CSS assessment phase and suggest that the need for such assessment is explicitly included in the guidelines to improve restoration outcomes. To facilitate this inclusion and make it workable by practitioners, we describe indicators and methods available for restoration teams to answer key questions that should make up such CSS assessment. In doing so, we identify key outstanding science and policy tasks that are needed to further operationalize CSS assessment in restoration. Synthesis and applications. By illustrating how key Complex Systems Science (CSS) concepts linked to non-linear threshold behaviour can impact restoration outcomes through influencing recovery trajectories, our framework Explore Before You Restore demonstrates the need to incorporate Complex Systems thinking in ecosystem restoration. We argue that inclusion of CSS assessment into restoration project cycles, and more broadly, into international restoration guidelines, may significantly improve restoration outcomes.UK Centre for Ecology and Hydrology; Fonds Wetenschappelijk Onderzoek; Svenska Forskningsrådet Formas; Science & Engineering Research Board, Govt of India.http://wileyonlinelibrary.com/journal/jpehj2024Zoology and EntomologySDG-15:Life on lan
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