Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Evaluating impacts of bottom trawling and hypoxia on benthic communities at the local, habitat, and regional scale using a modelling approach
    Denderen, P.D. Van; Bolam, S.G. ; Friedland, R. ; Hiddink, J.G. ; Norén, K. ; Rijnsdorp, A.D. ; Sköld, M. ; Törnroos, A. ; Virtanen, E.A. ; Valanko, S. - \ 2020
    ICES Journal of Marine Science 77 (2020)1. - ISSN 1054-3139 - p. 278 - 289.
    benthic fauna - bottom fishing - ecosystem-based management - human pressures - impact assessment - oxygen deficiency - seabed disturbance

    Bottom trawling disturbance and hypoxia are affecting marine benthic habitats worldwide. We present an approach to predict their effects on benthic communities, and use the approach to estimate the state, the biomass relative to carrying capacity, of the Baltic Sea at the local, habitat, and regional scale. Responses to both pressures are expected to depend on the longevity of fauna, which is predicted from benthic data from 1558 locations. We find that communities in low-salinity regions mostly consist of short-lived species, which are, in our model, more resilient than those of the saline areas. The model predicts that in 14% of the Baltic Sea region benthic biomass is reduced by at least 50%, whereas an additional 8% of the region has reductions of 10-50%. The effects of hypoxia occur over larger spatial scales and lead to a low state of especially deep habitats. The approach is based on a simple characterization of the benthic community, which comes with high uncertainty, but allows for the identification of benthic habitats that are at greatest risk and prioritization of management actions at the regional scale. This information supports the development of sustainable approaches to manage impact of human activities on benthic ecosystems.

    Assessing bottom trawling impacts based on the longevity of benthic invertebrates
    Hiddink, Jan Geert ; Jennings, Simon ; Sciberras, Marija ; Bolam, Stefan G. ; Cambiè, Giulia ; McConnaughey, Robert A. ; Mazor, Tessa ; Hilborn, Ray ; Collie, Jeremy S. ; Pitcher, C.R. ; Parma, Ana M. ; Suuronen, Petri ; Kaiser, Michel J. ; Rijnsdorp, Adriaan D. - \ 2019
    Journal of Applied Ecology 56 (2019)5. - ISSN 0021-8901 - p. 1075 - 1084.
    benthic invertebrates - bottom trawl - fisheries management - impact assessment - life-history meta-analysis - seabed disturbance - systematic review

    Bottom trawling is the most widespread human activity directly affecting seabed habitats. Assessment and effective management of the effects of bottom trawling at the scale of fisheries requires an understanding of differences in sensitivity of biota to trawling. Responses to disturbance are expected to depend on the intrinsic rate of increase in populations (r), which is expected to be linearly related to the reciprocal of longevity. We examine the relationship between the longevity of benthic invertebrates and their response to bottom trawling; both in terms of the immediate mortality following a trawl pass and their subsequent rates of recovery. We collate all available data from experimental and comparative trawling studies, and test how longevity influences these aspects of sensitivity. The shortest lived organisms (<1 year) increased in abundance shortly after experimental trawling but showed no response to trawling in long-term comparative studies. Conversely, the abundance of biota with a life span >1 year decreased by ~9% immediately following a trawl pass. The effect of bottom trawling in comparative studies increased with longevity, with a 2–3× larger effect on biota living >10 years than on biota living 1–3 years. We attribute this difference to the slower recovery rates of the long-lived biota. The observed relationship between the intrinsic rate of population increase (r, our metric of recovery rate) and the reciprocal of longevity matches theoretical expectation and predicts that the sensitivity of habitats to bottom trawling is higher in habitats with higher proportions of long-lived organisms. Synthesis and applications. Where the longevity of a species or the longevity distribution of a community is known or can be inferred, our estimates of depletion and intrinsic rate of increase can be combined with high-resolution maps of trawling intensity to assess trawling impacts at the scale of the fishery or other defined unit of assessment. Our estimates of r may also be used to estimate recovery times following other forms of seabed disturbance.

    Data from: Assessing bottom-trawling impacts based on the longevity of benthic invertebrates
    Hiddink, Jan Geert ; Jennings, Simon ; Sciberras, Marija ; Bolam, Stefan G. ; Cambiè, Giulia ; Mcconnaughey, Robert A. ; Mazor, Tessa ; Hilborn, Ray ; Collie, Jeremy S. ; Pitcher, C.R. ; Parma, Ana M. ; Suuronen, Petri ; Kaiser, Michel J. ; Rijnsdorp, A.D. - \ 2018
    Bangor University
    fisheries management - bottom trawl - benthic invertebrates - impact assessment - meta-analysis - systematic review - life history - seabed disturbance
    Bottom trawling is the most widespread human activity directly affecting seabed habitats. Assessment and effective management of the effects of bottom trawling at the scale of fisheries requires an understanding of differences in sensitivity of biota to trawling. Responses to disturbance are expected to depend on the intrinsic rate of increase of populations (r), which is expected to be linearly related to the reciprocal of longevity. 2. We examine the relationship between the longevity of benthic invertebrates and their response to bottom trawling; both in terms of the immediate mortality following a trawl pass and their subsequent rates of recovery. We collate all available data from experimental and comparative trawling studies, and test how longevity influences these aspects of sensitivity. 3. The shortest-lived organisms (<1yr) increased in abundance shortly after experimental trawling, but showed no response to trawling in longer-term comparative studies. Conversely, the abundance of biota with a life-span >1yr decreased by ~9% immediately following a trawl pass. The effect of bottom trawling in comparative studies increased with longevity, with a 2-3× larger effect on biota living >10yr than on biota living 1-3yr. We attribute this difference to the slower recovery rates of the longer-lived biota. 4. The observed relationship between the intrinsic rate of population increase (r, our metric of recovery rate) and the reciprocal of longevity matches theoretical expectation and predicts that the sensitivity of habitats to bottom trawling is higher in habitats with higher proportions of long-lived organisms. 5. Synthesis and Applications. Where the longevity of a species or the longevity distribution of a community is known or can be inferred, our estimates of depletion and intrinsic rate of increase can be combined with high-resolution maps of trawling intensity to assess trawling impacts at the scale of the fishery or other defined unit of assessment. Our estimates of r may also be used to estimate recovery times following other forms of seabed disturbance.
    Estimating sensitivity of seabed habitats to disturbance by bottom trawling based on the longevity of benthic fauna
    Rijnsdorp, Adriaan D. ; Bolam, Stefan G. ; Garcia, Clement ; Hiddink, Jan Geert ; Hintzen, Niels T. ; Denderen, P.D. van; Kooten, Tobias van - \ 2018
    Ecological Applications 28 (2018)5. - ISSN 1051-0761 - p. 1302 - 1312.
    benthic fauna - ecosystem-based management - effects of trawling - impact assessment - indicators - sea floor

    Bottom fishing such as trawling and dredging may pose serious risks to the seabed and benthic habitats, calling for a quantitative assessment method to evaluate the impact and guide management to develop mitigation measures. We provide a method to estimate the sensitivity of benthic habitats based on the longevity composition of the invertebrate community. We hypothesize that long-lived species are more sensitive to trawling mortality due to their lower pace of life (i.e., slower growth, late maturation). We analyze data from box-core and grab samples taken from 401 stations in the English Channel and southern North Sea to estimate the habitat-specific longevity composition of the benthic invertebrate community and of specific functional groups (i.e., suspension feeders and bioturbators), and examine how bottom trawling affects the longevity biomass composition. The longevity biomass composition differed between habitats governed by differences in sediment composition (gravel and mud content) and tidal bed-shear stress. The biomass proportion of long-lived species increased with gravel content and decreased with mud content and shear stress. Bioturbators had a higher median longevity than suspension feeders. Trawling, in particular by gears that penetrate the seabed >2 cm, shifted the community toward shorter-lived species. Changes from bottom trawling were highest in habitats with many long-lived species (hence increasing with gravel content, decreasing with mud content). Benthic communities in high shear stress habitats were less affected by bottom trawling. Using these relationships, we predicted the sensitivity of the benthic community from bottom trawling impact at large spatial scale (the North Sea). We derived different benthic sensitivity metrics that provide a basis to estimate indicators of trawling impact on a continuous scale for the total community and specific functional groups. In combination with high resolution data of trawling pressure, our approach can be used to monitor and assess trawling impact and seabed status at the scale of the region or broadscale habitat and to compare the environmental impact of bottom-contacting fishing gears across fisheries.

    Beyond the plot: technology extrapolation domains for scaling out agronomic science
    Rattalino Edreira, Juan I. ; Cassman, Kenneth G. ; Hochman, Zvi ; Ittersum, Martin K. van; Bussel, Lenny van; Claessens, Lieven ; Grassini, Patricio - \ 2018
    Environmental Research Letters 13 (2018)5. - ISSN 1748-9318
    geospatial analysis - impact assessment - research prioritization - technology extrapolation

    Ensuring an adequate food supply in systems that protect environmental quality and conserve natural resources requires productive and resource-efficient cropping systems on existing farmland. Meeting this challenge will be difficult without a robust spatial framework that facilitates rapid evaluation and scaling-out of currently available and emerging technologies. Here we develop a global spatial framework to delineate 'technology extrapolation domains' based on key climate and soil factors that govern crop yields and yield stability in rainfed crop production. The proposed framework adequately represents the spatial pattern of crop yields and stability when evaluated over the data-rich US Corn Belt. It also facilitates evaluation of cropping system performance across continents, which can improve efficiency of agricultural research that seeks to intensify production on existing farmland. Populating this biophysical spatial framework with appropriate socio-economic attributes provides the potential to amplify the return on investments in agricultural research and development by improving the effectiveness of research prioritization and impact assessment.

    Capacity development for food policy analysis: What works best? Adding evidence from IFPRI's experience
    Kuyvenhoven, A. - \ 2018
    Development Policy Review 36 (2018)S1. - ISSN 0950-6764 - p. O113 - O137.
    capacity development - collaborative research - evaluation - food policy - IFPRI - impact assessment - institutional development - training
    This article presents major results of a meta-assessment of experience of the International Food Policy Research Institute (IFPRI) with different kinds of capacity strengthening (CS) activities for food policy analysis. Collaborative research, on-the-job-training, and ID support for building data systems and analysis came up as best-practice approaches. Equally successful were new initiatives such as visiting fellow programmes, thesis support schemes, and delivering CS work embedded in country or thematic programmes. Challenges emerged as well: how to address the low CS impact of formal training and work with local collaborators, the uncertain results for outreach and strengthening capacity of organizations over individuals, especially in the policy cycle, and the best way to enter into partnerships and create incentives to deliver and sustain CS. Some policy implications are indicated.
    Toward a harmonized approach for environmental assessment of human activities in the marine environment
    Tamis, J.E. ; Vries, P. de; Jongbloed, R.H. ; Lagerveld, S. ; Jak, R.G. ; Karman, C.C. ; Wal, J.T. van der; Slijkerman, D.M.E. ; Klok, T.C. - \ 2016
    Integrated Environmental Assessment and Management 12 (2016)4. - ISSN 1551-3793 - p. 632 - 642.
    human activity - impact assessment - multiple pressures - Visualization tool
    With a foreseen increase in maritime activities, and driven by new policies and conventions aiming at sustainable management of the marine ecosystem, spatial management at sea is of growing importance. Spatial management should ensure that the collective pressures caused by anthropogenic activities on the marine ecosystem are kept within acceptable levels. A multitude of approaches to environmental assessment are available to provide insight for sustainable management, and there is a need for a harmonized and integrated environmental assessment approach that can be used for different purposes and variable levels of detail. This article first provides an overview of the main types of environmental assessments: “environmental impact assessment” (EIA), “strategic environmental assessment” (SEA), “cumulative effect assessment” (CEA), and “environmental (or ecological) risk assessment” (ERA). Addressing the need for a conceptual “umbrella” for the fragmented approaches, a generic framework for environmental assessment is proposed: cumulative effects of offshore activities (CUMULEO). CUMULEO builds on the principle that activities cause pressures that may lead to adverse effects on the ecosystem. Basic elements and variables are defined that can be used consistently throughout sequential decision-making levels and diverse methodological implementations. This enables environmental assessment to start at a high strategic level (i.e., plan and/or program level), resulting in early environmental awareness and subsequently more informed, efficient, and focused project-level assessments, which has clear benefits for both industry and government. Its main strengths are simplicity, transparency, flexibility (allowing the use of both qualitative and quantitative data), and visualization, making it a powerful framework to support discussions with experts, stakeholders, and policymakers.
    Tradeoffs around crop residue biomass in smallholder crop-livestock systems - What's next?
    Tittonell, P.A. ; Gérard, B. ; Erenstein, O. - \ 2015
    Agricultural Systems 134 (2015). - ISSN 0308-521X - p. 119 - 128.
    sub-saharan africa - define conservation agriculture - soil fertility management - south-western niger - food-feed crops - ecological intensification - farming systems - impact assessment - appropriate use - 4th principle
    Much has been written on the tradeoffs that smallholder farmers face when having to allocate their biomass resources among competing objectives such as feed, fuel, mulch, compost or the market. This paper summarises yet a new body of evidence from 10 studies on tradeoffs in the allocation of cereal crop residue biomass between soil management and livestock feeding in developing regions, published in the special issue of Agricultural Systems ‘Biomass use tradeoffs in cereal cropping systems: Lessons and implications from the developing world’. The studies cover a diversity of socio-ecological contexts, farming system types and scales of analysis. We reflect on their main findings and methodological progress, and on the new and not-so-new implications of these findings for research and action in the development agenda. We propose stylised graphical models to portray tradeoffs and plausible trajectories towards synergies, in the hope that such generalisations would prevent further efforts to ‘reinvent the wheel’ in the realm of tradeoffs analysis. We advocate an ex-post impact assessment of recent investments in systems research to help focus such research further and clearly define its future role in prioritizing and targeting development interventions.
    Leverages for on-farm innovation from farm typologies? An illustration for family-based dairy farms in north-west Michoacán, Mexico
    Cortez Arriola, J. ; Rossing, W.A.H. ; Amendola Massiotti, R.D. ; Scholberg, J.M.S. ; Groot, J.C.J. ; Tittonell, P.A. - \ 2015
    Agricultural Systems 135 (2015). - ISSN 0308-521X - p. 66 - 76.
    impact assessment - management - diversity - systems - scale - indicators - households - migration
    Knowledge on farm diversity provides insight into differences among farms, enables scaling from individual farm to farm population level and vice versa, and has been used in the definition of recommendation domains for introduction of novel technologies. Farm diversity can be broadly described in terms of resource endowment and resource use strategy, or in other words, in terms of scale and intensity of production. Measuring intensity of production requires much greater monitoring effort than measuring scale of production, and often only proxies of production intensity are used. Using data from a regional farm survey and from intensive on-farm monitoring the question addressed in this paper is to which extent results of farm surveys that measure primarily scale of production can inform on-farm interventions aimed at improving farm performance. The survey included a random sample of 97 out of 664 smallholder dairy farmers in a community in north-west Michoacán, Mexico. Farm types were identified by a combination of Principal Component Analysis to reduce the dimensionality of the dataset, followed by Cluster Analysis. The survey was complemented with detailed analyses of costs, revenues and productivity on 6 farms over the course of one year. Survey results revealed considerable variation among the dairy farms in land area, livestock units, amount of hired labour, and infrastructure and equipment, which led to the distinction of 4 farm types. Indicators for animal health management and feeding strategies were uniform across the 4 types. The farm types matched the distinction of family-based and semi-intensive farm types used in Mexico. The detailed analyses of the individual farms belonging to the different types, however, revealed differences in resource use strategies reflected in differences in animal productivity, labour productivity and return to labour. Differences in animal productivity and labour productivity were explained by stocking rate, albeit in different ways. Return to labour was strongly related to cost of feed. Profitability was negative for all farms and was on most farms related to high external feedstuff costs, which constituted 59–89% of the feed cost of the animal ration. The results indicate that in addition to variables reflecting resource endowment or scale of production, typologies that aim to inform on-farm interventions need to consider farm characteristics that reflect intensity of production. Which variables should be selected will need to be determined in a preliminary assessment. To enhance internal resource use efficiency as was the purpose in the current study, candidate variables expressing intensity could include the share of external feed in the ration and proxies of internal resource use, e.g. reflected in crop and milk yields. Opportunities for on-farm innovation arising from the analyses are discussed from the perspective of labour flexibility, low costs and use of internal resources.
    Sustainability of meat production beyond carbon footprint: a synthesis of case studies from grazing systems in Uruguay
    Picasso, V.D. ; Modernel Hristoff, P.D. ; Becona, G. ; Salvo, L. ; Gutierrez, L. ; Astigarraga, L. - \ 2014
    Meat Science 98 (2014)3. - ISSN 0309-1740 - p. 346 - 354.
    life-cycle assessment - impact assessment - sequestration - emissions - climate - grasslands - balance
    Livestock production has been challenged as a large contributor to climate change, and carbon footprint has become a widely used measure of cattle environmental impact. This analysis of fifteen beef grazing systems in Uruguay quantifies the range of variation of carbon footprint, and the trade-offs with other relevant environmental variables, using a partial life cycle assessment (LCA) methodology. Using carbon footprint as the primary environmental indicator has several limitations: different metrics (GWP vs. GTP) may lead to different conclusions, carbon sequestration from soils may drastically affect the results, and systems with lower carbon footprint may have higher energy use, soil erosion, nutrient imbalance, pesticide ecotoxicity, and impact on biodiversity. A multidimensional assessment of sustainability of meat production is therefore needed to inform decision makers. There is great potential to improve grazing livestock systems productivity while reducing carbon footprint and other environmental impacts, and conserving biodiversity.
    Social Learning, Natural Resource Management, and Participatory Activities: A reflection on construct development and testing
    Rodela, R. - \ 2014
    NJAS Wageningen Journal of Life Sciences 69 (2014). - ISSN 1573-5214 - p. 15 - 22.
    deliberative democracy - public-participation - impact assessment - comanagement - innovation - lessons - trust
    This analysis reflects on the use of multidimensional constructs for the study of social learning in natural resource management. Insight from deliberative democracy and adult learning literature are used to ground the identified four dimensions (the moral dimension the cognitive dimension, the relational dimension and trust). Then, a selection of empirical cases is surveyed with the aim to develop and understanding how well the empirical outcomes reported by these sit against the insights borrowed from the deliberative democracy and pedagogy literature. The paper concludes with some recommendations for future research.
    The social learning discourse: trends, themes and interdisciplinary influences in current research
    Rodela, R. - \ 2013
    Environmental Science & Policy 25 (2013). - ISSN 1462-9011 - p. 157 - 166.
    natural-resource management - deliberative democracy - public-participation - ethical leadership - impact assessment - river-basin - policy - organizations - comanagement - perspective
    The literature on social learning advances a critique to the command-and-control approach to resource management, and often, this critique is made by borrowing insights and ideas from disciplines other than resource management, which led to certain conceptual and methodological turns that now characterise the social learning discourse. This paper is based on an extensive survey of the social learning literature; ninety-seven studies were reviewed and classified by the type of natural resource, its geographical location, type of application and related aspects, which helped to identify some general trends. Disciplinary influences that contributed to shape the research are analysed and discussed. The findings suggest that social learning research is issue-driven and that some types of natural resources and geographical areas prevail over others. This study finds that deliberative democracy, pedagogy and research of complex adaptive systems have contributed the most to shaping the current conceptual base of the discourse. Interdisciplinary engagement, as well as choices in terms of what has been borrowed and how the borrowed concepts have been used, help to explain the heterogeneity of frameworks and definitions in the social learning literature
    Environmental life cycle assessment of Ethiopian rose cultivation
    Sahle, A.H. ; Potting, J. - \ 2013
    Science of the Total Environment 443 (2013). - ISSN 0048-9697 - p. 163 - 172.
    pesticide volatilization - impact assessment - soil - emissions
    A life cycle assessment (LCA) was conducted for Ethiopian rose cultivation. The LCA covered the cradle-togate production of all inputs to Ethiopian rose cultivation up to, and including transport to the Ethiopian airport. Primary data were collected about materials and resources used as inputs to, and about the product outputs from 21 farms in 4 geographical regions (i.e. Holleta, Sebeta, Debre Ziet, and Ziway). The primary data were imported in, and analyzed with the SimaPro7.3 software. Data for the production of used inputs were taken from the EcoInvent®2.0 database. Emissions from input use on the farms were quantified based on estimates and emission factors from various studies and guidelines. The resulting life cycle inventory (LCI) table was next evaluated with the CML 2 baseline 2000 V2/world, 1990/characterization method to quantify the contribution of the rose cultivation chain to 10 environmental impact categories. The set of collected primary data was comprehensive and of high quality. The data point to an intensive use of fertilizers, pesticides, and greenhouse plastic. Production and use of these inputs also represent the major contributors in all environmental impact categories. The largest contribution comes from the production of the used fertilizers, specifically nitrogen-based fertilizers. The use of calcium nitrate dominates Abiotic Depletion (AD), Global Warming (GW), Human Toxicity (HT) and Marine Aquatic Ecotoxicity (MAET). It also makes a large contribution to Ozone Depletion (OD), Acidification (AD) and Fresh water Aquatic Ecotoxicity (FAET). Acidification (AC) and Eutrophication (EU) are dominated by the emission of fertilizers. The emissions from the use of pesticides, especially insecticides dominate Terrestrial Ecotoxicity (TE) and make a considerable contribution to Freshwater Aquatic Ecotoxicity (FAET) and Photochemical Oxidation (PhO). There is no visible contribution from the use of pesticides to the other toxicity categories. Production and use of greenhouse plastic are another important contributors, and just a bit less than the contribution of calcium nitrate to Abiotic Depletion (AD). The results of this study clearly indicate nutrient management and emissions from pesticide use, especially insecticides, as a focus point for environmental optimization of the rose cultivation sector in Ethiopia.
    A proposal for a new scenario framework to support research and assessment in different climate research communities
    Vuuren, D.P. van; Riahi, K. ; Moss, R. ; Edmonds, J. ; Thomson, A. ; Nakicenovic, N. ; Kram, T. ; Berkhout, F. ; Swart, R.J. ; Janetos, A. ; Rose, S.K. ; Arnell, N. - \ 2012
    Global environmental change : human and policy dimensions 22 (2012)1. - ISSN 0959-3780 - p. 21 - 35.
    expert judgments - impact assessment - vulnerability - costs - stabilization - adaptation - strategies
    In this paper, we propose a scenario framework that could provide a scenario "thread" through the different climate research communities (climate change - vulnerability, impact, and adaptation - and mitigation) in order to support assessment of mitigation and adaptation strategies and climate impacts. The scenario framework is organized around a matrix with two main axes: radiative forcing levels and socio-economic conditions. The radiative forcing levels (and the associated climate signal) are described by the new Representative Concentration Pathways. The second axis, socio-economic developments comprises elements that affect the capacity for mitigation and adaptation, as well as the exposure to climate impacts. The proposed scenarios derived from this framework are limited in number, allow for comparison across various mitigation and adaptation levels, address a range of vulnerability characteristics, provide information across climate forcing and vulnerability states and span a full century time scale. Assessments based on the proposed scenario framework would strengthen cooperation between integrated-assessment modelers, climate modelers and vulnerability, impact and adaptation researchers, and most importantly, facilitate the development of more consistent and comparable research within and across these research communities.
    Advancing the deliberative turn in natural resource management: An analysis of discourses on the use of local resources
    Rodela, R. - \ 2012
    Journal of Environmental Management 96 (2012)1. - ISSN 0301-4797 - p. 26 - 34.
    public-participation - citizen participation - impact assessment - democracy - slovenia - policy - power
    The natural resource management literature stresses the need for public participation and community involvement in resource management and planning. Recently, some of this literature turned to the theory on deliberative democracy and demonstrated that a deliberative perspective on participation can help to challenge established practices and contribute with new ideas about how to conduct participation. The purpose of this paper is to consider the latest developments in deliberative democracy and outline the implications arising from these insights for a "deliberative turn" in resource management. A bottom-up protected area establishment, the Goricko Landscape Park, is examined. The empirical case is discussed from a discursive perspective, which relied on John Dryzek's approach to discourse analysis here used to explore the construction of discourses on the use of local natural resources. Two discourses are identified and the way these interfaced with the participatory park establishment process is considered. Findings indicate that advocates of the two discourses engaged differently with the participatory tools used and this had important implications for the park establishment. The case study suggests that, in contexts where participation has been recently introduced, knowledge of discourses on the use of local natural resources and of mobilization strategies actors may pursue could usefully assist in the design and implementation of participatory processes.
    Selecting the sharpest tools to explore the food-feed-fuel debate: Sustainability assessment of family farmers producing food, feed and fuel in Brazil
    Florin, M.J. ; Ittersum, M.K. van; Ven, G.W.J. van de - \ 2012
    Ecological Indicators 20 (2012). - ISSN 1470-160X - p. 108 - 120.
    soil fertility decline - land-use - brachiaria pastures - impact assessment - cropping systems - farming systems - scale - agriculture - indicators - framework
    Continuing interest in sustainable biofuel production is linked with sustainable farming and begs for insights from farming systems research on sustainability assessment and the role of family farms. The aims of this work were two-fold. First, to present a tools and methods selection framework supporting indicator-based sustainability assessment. Second, to apply the framework to the case of castor beans (Ricinus communis L.), family farmers and the biodiesel industry in the southeast of Brazil. The framework synthesizes existing work on sustainability assessment within the agricultural domain. Transparent selection of tools and methods is supported by sequentially accounting for the context of sustainability, dealing with space, classifying the ‘nature of research’ and the degree of integration of different facets of sustainability. The framework is demonstrated with an exploratory assessment of the potential for castor bean cultivation within the current farm type of extensive pasture and fodder crops for dairy cattle. The study accounted for the range of productivity levels within the current farm type and for different management decisions when including castor beans. Assessment was made against economic development, livelihood stability and soil fertility criteria. Selected tools and methods included farm surveys, alternative farming system design and input–output calculations. The results demonstrate the greatest opportunity for castor bean cultivation by currently low productive farms. There is a trade-off of income derived from milk production that is supported by fodder production, and income from castor beans. Decisions regarding areal extent of castor beans and supplementing animal feed, are shown to be farm-specific, and depend upon the interactions between current farm productivity and prioritisation of sustainability criteria. However, generally it is shown that castor bean cultivation should be linked to animal production so that current risk management and income levels can be supported and improved. Further, to maintain soil fertility, castor bean cultivation with nitrogen inputs is necessary. The cyclic nature of the framework supports the next contextualisation of the sustainability question. For our application, constructive future work in a next cycle could include extending to regional level and accounting for temporal variability. --------------------------------------------------------------------------------
    Social Learning and Natural Resource Management: The Emergence of Three Research Perspectives
    Rodela, R. - \ 2011
    Ecology and Society 16 (2011)4. - ISSN 1708-3087
    adaptive comanagement - ecological systems - impact assessment - participation - knowledge - risk
    A review is presented of research contributions that use social learning in research on natural resource management. The review is based on an extensive survey of peer-reviewed journal articles appraised against the following selected analytical items: (1) characterizing features, (2) level of analysis, and (3) operational measures. Together, these allowed for an assessment of underlying assumptions and emerging themes. The findings suggest that, within natural resource management literature, three research approaches to social learning have been developed, each with its own assumptions about the learning process, learning outcomes, and operational practices. Hence, we find that a group of publications showed an interest for participants' learning experiences and focused on the type of outcomes that arise from their attendance in participatory workshops and similar activities. Also, findings indicate that a second group of publications showing an interest for learning in other types of settings, such as groups, networks, and associations, have framed social learning as a process that results in a change in resource management practices, or in how things are done. On the other hand, a third group of publications showed an interest in social-ecological systems emphasizing learning as an emergent property.
    Life cycle assessment of intensive striped catfish farming in the Mekong Delta for screening hotspots as input to environmental policy and research agenda
    Bosma, R.H. ; Pham Thi Ahn, ; Potting, J. - \ 2011
    The International Journal of Life Cycle Assessment 16 (2011)9. - ISSN 0948-3349 - p. 903 - 915.
    production systems - impact assessment - water-use - aquaculture - ponds - fish - lca
    Purpose Intensive striped catfish production in the Mekong Delta has, in recent years, raised environmental concerns. We conducted a stakeholder-based screening life cycle assessment (LCA) of the intensive farming system to determine the critical environmental impact and their causative processes in producing striped catfish. Additional to the LCA, we assessed water use and flooding hazards in the Mekong Delta. Materials and methods The goal and scope of the LCA were defined in a stakeholder workshop. It was decided there to include all processes up to the exit-gate of the fish farm in the inventory and to focus life cycle impact assessment on global warming, acidification, eutrophication, human toxicity, and marine (MAET) and freshwater aquatic ecotoxicity (FWET). A survey was used to collect primary inventory data from 28 farms on fish grow-out, and from seven feed mills. Hatching and nursing of striped catfish fingerlings were not included in the assessment due to limited data availability and low estimated impact. Average feed composition for all farms had to be applied due to limitation of budget and data availability. Results and discussion Feed ingredient production, transport and milling dominated most of the impact categories in the LCA except for eutrophication and FWET. Most feed ingredients were produced outside Vietnam, and the impact of transport was important. Because of the screening character of this LCA, generic instead of specific inventory data were used for modelling feed ingredient production. However, the use of generic data is unlikely to have affected the main findings, given the dominance of feed production in all impact categories. Of the feed ingredients, rice bran contributed the most to global warming and acidification, while wheat bran contributed the most to eutrophication. The dominance of both was mainly due to the amounts used. Fishmeal production, transport and energy contributed the most to MAET. The biggest impacts of grow-out farming in Vietnam are on eutrophication and FWET. Water nutrient discharge from grow-out farming was high but negligible compared with the natural nutrient content of the Mekong River. The discharge from all grow-out farms together hardly modified river water quality compared with that before sector expansion. Conclusions Feed production, i.e. ingredient production and transport and milling, remains the main contributor to most impact categories. It contributes indirectly to eutrophication and FWET through the pond effluents. The environmental impact of Pangasius grow-out farming can be reduced by effectively managing sludge and by using feeds with lower feed conversion ratio and lower content of fishery products in the feed. To consider farm variability, a next LCA of aquaculture should enlist closer collaboration from several feed-milling companies and sample farms using their feeds. Future LCAs should also preferably collect specific instead of generic inventory data for feed ingredient production, and include biodiversity and primary production as impact categories.
    Correlation between temperature and phenology prediction error in rice (Oryza sativa L.)
    Oort, P.A.J. van; Zhang, T. ; Vries, M.E. de; Heinemann, A.B. ; Meinke, H.B. - \ 2011
    Agricultural and Forest Meteorology 151 (2011)12. - ISSN 0168-1923 - p. 1545 - 1555.
    diverse agro-environments - fed lowland rice - climate-change - irrigated rice - photothermal responses - water temperature - upland rice - spikelet sterility - impact assessment - cool climate
    For rice (Oryza sativa L.), simulation models like ORYZA2000 and CERES-Rice have been used to explore adaptation options to climate change and weather-related stresses (drought, heat). Output of these models is very sensitive to accurate modelling of crop development, i.e. phenology. What has to date received little attention in phenology calibration is the temperature range within which phenological models are accurate. Particularly the possible correlation between temperature and phenology prediction error has received little attention, although there are indications that such correlation exists, in particular in the study by Zhang et al., 2008 T. Zhang, J. Zhu and X. Yang, Non-stationary thermal time accumulation reduces the predictability of climate change effects on agriculture. Agricultural and Forest Meteorology, 148 10 (2008), pp. 1412–1418. Zhang et al. (2008). The implication of such correlation is that a phenology model that is accurate within the calibration temperature range can be less accurate at higher temperatures where it can systematically overestimate or underestimate the duration of the phase from emergence to flowering. We have developed a new rice phenology calibration program that is consistent with ORYZA2000 concepts and coding. The existing calibration program DRATES of ORYZA2000 requires an assumption of default cardinal temperatures (8, 30 and 42 °C) and then calculates cultivar specific temperature sums and development rates. Our new program estimates all phenological parameters simultaneously, including the cardinal temperatures. Applied to nine large datasets from around the world we show that the use of default cardinal temperatures can lead to correlation between temperature and phenology prediction error and temperature and RMSE values in the order of 4–18 days for the period from emergence to flowering. Our new program avoids such correlation and reduces phenology prediction errors to 3–7 days (RMSE). Our results show that the often made assumption of a rapid decrease in development rate above the optimal temperature can lead to poorer predictions and systematic errors. We therefore caution against using default phenological parameters for studies where temperatures may fall outside the range for which the phenological models have been calibrated. In particular, this applies to climate change studies, were this could lead to highly erroneous conclusions. More phenological research with average growing season temperatures above the optimum, in the range of 32–40 °C, is needed to establish which phenological model best describes phenology in this temperature range.
    Scale changes and model linking methods for integrated assessment of agri-environmental systems
    Ewert, F. ; Ittersum, M.K. van; Heckelei, T. ; Therond, O. ; Bezlepkina, I. ; Andersen, E. - \ 2011
    Agriculture, Ecosystems and Environment 142 (2011)1-2. - ISSN 0167-8809 - p. 6 - 17.
    climate-change - management options - impact assessment - scenarios - tools - productivity - variability - performance - ecosystems - framework
    Agricultural systems and problems of sustainability are complex, covering a range of organisational levels and spatial and temporal scales. Integrated assessment (IA) and modelling (IAM) is an attempt to capture complex multi-scale problems. Scale changes and model linking methods (referred to as scaling methods) are important in dealing with these problems but they are often not well understood. The present study aims to analyse scaling methods used in the recently developed multi-scale IA model SEAMLESS-IF which is applied to two case studies of complex agri-environmental problems. The analysis is based on a classification of up- and down-scaling methods which is extended for the purpose of this study. Our analysis shows that scale changes refer to different spatial, temporal and functional scales with changes in extent, resolution, and coverage rate. Accordingly, SEAMLESS-IF uses a number of different scaling methods including data extrapolation, aggregation and disaggregation, sampling, nested simulation and employs descriptive response functions and technical coefficients derived from explanatory models. Despite the satisfactory results obtained from SEAMLESS-IF, a comparative quantitative analysis of alternative scaling methods is still pending and requires further attention. Improved integration of scaling methods may also help to overcome limitations of IA models related to high data demand, complexity of models and scaling methods considered, and the accumulation of uncertainty due to the use of multiple models. In the case studies, the most challenging scaling problem refers to the appropriate consideration of the farm level as intermediate level between the field and market levels. Among the scaling methods analysed, summary models are hardly applied. This is because they are often unavailable due to limited systems understanding and because they may differ depending on the question at stake. The classification of scaling methods used has been helpful to structure this analysis.
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