2,135 research outputs found

    Survey among Belgian pig producers about the introduction of group housing systems for gestating sows

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    There is a global move from individual to group housing of gestating sows. In the European Union, individual gestating stalls will be banned by 2013. Just like in other industrialized regions, these stalls have been the standard housing system for intensively kept sows from the 1960s onward in the Flemish region of Belgium. Because the socioeconomic consequences for the pig industry may be far-reaching and because farmer attitude may influence the realization of the hoped-for improvement in animal welfare in practice, we conducted a survey from 2003 until 2009 among representative samples of Flemish pig producers every 2 yr. The share of farms with group housing increased from 10.5% in 2003 to 29.8% in 2007, but then dropped to 24.6% in 2009. It appears that after 2005 users of old group housing systems in particular stopped farming. Because sow herd size increased more on farms with vs. without group housing and because the proportion of the herd that was group-housed also tended to increase between 2003 to 2009, the change to group housing took place faster when expressed at the level of the sow (from 9.1% in 2003 to 34.1% in 2009) instead of farm. The percentage of farmers planning to convert to group housing within 2 yr was 4.1% in 2003, and 6 to 7% thereafter. These were typically young farmers (P = 0.006) with a large sow herd (P < 0.001) and with a likely successor (P = 0.03). Free access stalls were the most common group housing system (31% of farms, 37% of sows). Their popularity is expected to increase further at the expense of electronic feeding stations, ad libitum feeding, and stalls/troughs with manual feed delivery. User satisfaction was generally high but depended on whether or not all gestating sows were kept in group (P < 0.001), the provisioning of environmental enrichment (P = 0.057), and the age (P = 0.012) and type (P = 0.016) of system. The main criteria for choosing a certain group housing system were the investment costs and sow health and welfare. The importance of economic reasons (P = 0.007) and type of labor (P = 0.043) decreased with the age of the system. In 2003 and 2005 the main reason for not having converted to group housing was that farmers would stop keeping sows by 2013. In 2007 and 2009 the reasons mainly concerned uncertainty about the future and maximally delaying the conversion. Belgium is one of the European Union countries where the pig industry is expected to undergo drastic changes during the few years remaining before the ban on individual housing

    Demystifying Governance and its Role for Transitions in Urban Social–Ecological Systems

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    Governance is key to sustainable urban transitions. Governance is a system of social, power, and decision‐making processes that acts as a key driver of resource allocation and use, yet ecologists—even urban ecologists–seldom consider governance concepts in their work. Transitions to more sustainable futures are becoming increasingly important to the management of many ecosystems and landscapes, and particularly so for urban systems. We briefly identify and synthesize important governance dimensions of urban sustainability transitions, using illustrations from cities in which long‐term social–ecological governance research is underway. This article concludes with a call to ecologists who are interested in environmental stewardship, and to urban ecologists in particular, to consider the role of governance as a driver in the dynamics of the systems they study

    Assessment the flood hazard arising from land use change in a forested catchment in northern Iran

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    The provinces of northern Iran that border the Caspian Sea are forested and may be prone to increased risks of flooding due to deforestation and other land use changes, in addition to climate change effects. This research investigated changes in runoff from a small forested catchment in northern Iran for several land use change scenarios and the effects of higher rainfall and high antecedent soil moisture. Peak discharges and total runoff volumes from the catchment were estimated using the US Soil Conservation Service 'Curve Number' (SCS-CN) method and the SCS dimensionless unit hydrograph. This method was selected for reasons of data availability and operational simplicity for flood managers. A GIS was used to manipulate spatial data for use in the catchment runoff modelling. The results show that runoff is predicted to increase as a result of deforestation, which is dependent on the proportion of the catchment area affected. However, climate change presents a significant flood hazard even in the absence of deforestation. Other land use changes may reduce the peak discharges of all return period floods. Therefore a future ban on timber extraction, combined with agricultural utilisation of rangeland, could prove effective as 'nature-based' flood reduction measures throughout northern Iran

    Effects of the Structure of Water Rights on Agricultural Production During Drought: A Spatiotemporal Analysis of California\u27s Central Valley

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    California’s Central Valley region has been called the “bread-basket” of the United States. The region is home to one of the most productive agricultural systems on the planet. Such high levels of agricultural productivity require large amounts of fresh water for irrigation. However, the long-term availability of water required to sustain high levels of agricultural production is being called into question following the latest drought in California. In this paper, we use Bayesian multilevel spatiotemporal modeling techniques to examine the influence of the structure of surface water rights in the Central Valley on agricultural production during the recent drought. California is an important place to study these dynamics as it is the only state to recognize the two dominant approaches to surface water management in the United States: riparian and appropriative rights. In this study, Bayesian spatiotemporal modeling is employed to account for spatial processes that have the potential to influence the effects of water right structures on agricultural production. Results suggest that, after accounting for spatiotemporal dependencies in the data, seniority in surface water access significantly improves crop health and productivity on cultivated lands, but does not independently affect the ability to maintain cultivated extent. In addition, agricultural productivity in watersheds with more junior surface water rights show less sensitivity to cumulative drought exposure than other watersheds, however the extent of cultivation in these same watersheds is relatively more sensitive to cumulative drought exposure

    Lengthening of maize maturity time is not a widespread climate change adaptation strategy in the US Midwest

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    Increasing temperatures in the US Midwest are projected to reduce maize yields because warmer temperatures hasten reproductive development and, as a result, shorten the grain fill period. However, there is widespread expectation that farmers will mitigate projected yield losses by planting longer season hybrids that lengthen the grain fill period. Here, we ask: (a) how current hybrid maturity length relates to thermal availability of the local climate, and (b) if farmers are shifting to longer season hybrids in response to a warming climate. To address these questions, we used county‐level Pioneer brand hybrid sales (Corteva Agriscience) across 17 years and 650 counties in 10 Midwest states (IA, IL, IN, MI, MN, MO, ND, OH, SD, and WI). Northern counties were shown to select hybrid maturities with growing degree day (GDD°C) requirements more closely related to the environmentally available GDD compared to central and southern counties. This measure, termed “thermal overlap,” ranged from complete 106% in northern counties to a mere 63% in southern counties. The relationship between thermal overlap and latitude was fit using split‐line regression and a breakpoint of 42.8°N was identified. Over the 17‐years, hybrid maturities shortened across the majority of the Midwest with only a minority of counties lengthening in select northern and southern areas. The annual change in maturity ranged from −5.4 to 4.1 GDD year−1 with a median of −0.9 GDD year−1. The shortening of hybrid maturity contrasts with widespread expectations of hybrid maturity aligning with magnitude of warming. Factors other than thermal availability appear to more strongly impact farmer decision‐making such as the benefit of shorter maturity hybrids on grain drying costs, direct delivery to ethanol biorefineries, field operability, labor constraints, and crop genetics availability. Prediction of hybrid choice under future climate scenarios must include climatic factors, physiological‐genetic attributes, socio‐economic, and operational constraints

    Dietary iron intakes based on food composition data may underestimate the contribution of potentially exchangeable contaminant iron from soil

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    Iron intakes calculated from one-day weighed records were compared with those from same day analyzed duplicate diet composites collected from 120 Malawian women living in two rural districts with contrasting soil mineralogy and where threshing may contaminate cereals with soil iron. Soils and diet composites from the two districts were then subjected to a simulated gastrointestinal digestion and iron availability in the digests measured using a Caco-2 cell model. Median analyzed iron intakes (mg/d) were higher (p < 0.001) than calculated intakes in both Zombwe (16.6 vs. 10.1 mg/d) and Mikalango (29.6 vs. 19.1 mg/d), attributed to some soil contaminant iron based on high Al and Ti concentrations in diet composites. A small portion of iron in acidic soil from Zombwe, but not Mikalango calcareous soil, was bioavailable, as it induced ferritin expression in the cells, and may have contributed to higher plasma ferritin and total body iron for the Zombwe women reported earlier, despite lower iron intakes. In conclusion, iron intakes calculated from food composition data were underestimated, highlighting the importance of analyzing duplicate diet composites where extraneous contaminant iron from soil is likely. Acidic contaminant soil may make a small but useful contribution to iron nutrition

    Satellite‐Based Monitoring of Irrigation Water Use: Assessing Measurement Errors and Their Implications for Agricultural Water Management Policy

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    Reliable accounting of agricultural water use is critical for sustainable water management. However, the majority of agricultural water use is not monitored, with limited metering of irrigation despite increasing pressure on both groundwater and surface water resources in many agricultural regions worldwide. Satellite remote sensing has been proposed as a low-cost and scalable solution to fill widespread gaps in monitoring of irrigation water use in both developed and developing countries, bypassing the technical, socioeconomic, and political challenges that to date have constrained in situ metering. In this paper, we show through a systematic meta-analysis that the relative accuracy of different satellite-based irrigation water use monitoring approaches remains poorly understood, with evidence of large uncertainties when water use estimates are validated against in situ irrigation data at both field and regional scales. Subsequently, we demonstrate that water use measurement errors result in large economic welfare losses for farmers and may negatively impact ability of policies to limit acute and nonlinear externalities of irrigation abstraction on both the environment and other water users. Our findings highlight that water resource planners must consider the trade-offs between accuracy and costs associated with different water use accounting approaches. Remote sensing has an important role to play in supporting improved agricultural water accounting—both independently and in combination with in situ monitoring. However, greater transparency and evidence is needed about underlying uncertainties in satellite-based models, along with how these measurement errors affect the performance of associated policies to manage different short- and long-term externalities of irrigation water use

    Targeting Conservation Investments in Heterogeneous Landscapes: A distance function approach and application to watershed management

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    To achieve a given level of an environmental amenity at least cost, decision-makers must integrate information about spatially variable biophysical and economic conditions. Although the biophysical attributes that contribute to supplying an environmental amenity are often known, the way in which these attributes interact to produce the amenity is often unknown. Given the difficulty in converting multiple attributes into a unidimensional physical measure of an environmental amenity (e.g., habitat quality), analyses in the academic literature tend to use a single biophysical attribute as a proxy for the environmental amenity (e.g., species richness). A narrow focus on a single attribute, however, fails to consider the full range of biophysical attributes that are critical to the supply of an environmental amenity. Drawing on the production efficiency literature, we introduce an alternative conservation targeting approach that relies on distance functions to cost-efficiently allocate conservation funds across a spatially heterogeneous landscape. An approach based on distance functions has the advantage of not requiring a parametric specification of the amenity function (or cost function), but rather only requiring that the decision-maker identify important biophysical and economic attributes. We apply the distance-function approach empirically to an increasingly common, but little studied, conservation initiative: conservation contracting for water quality objectives. The contract portfolios derived from the distance-function application have many desirable properties, including intuitive appeal, robust performance across plausible parametric amenity measures, and the generation of ranking measures that can be easily used by field practitioners in complex decision-making environments that cannot be completely modeled. Working Paper # 2002-01

    Future Dominance by Quaking Aspen Expected Following Short-Interval, Compounded Disturbance Interaction

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    The spatial overlap of multiple ecological disturbances in close succession has the capacity to alter trajectories of ecosystem recovery. Widespread bark beetle outbreaks and wildfire have affected many forests in western North America in the past two decades in areas of important habitat for native ungulates. Bark beetle outbreaks prior to fire may deplete seed supply of the host species, and differences in fire‐related regeneration strategies among species may shift the species composition and structure of the initial forest trajectory. Subsequent browsing of postfire tree regeneration by large ungulates, such as elk (Cervus canadensis), may limit the capacity for regeneration to grow above the browse zone to form the next forest canopy. Five stand‐replacing wildfires burned ~60,000 ha of subalpine forest that had previously been affected by severe ( \u3e90% mortality) outbreaks of spruce beetle (SB, Dendroctonus rufipennis) in Engelmann spruce (Picea engelmannii) in 2012–2013 in southwestern Colorado. Here we examine the drivers of variability in abundance of newly established conifer tree seedlings [spruce and subalpine fir (Abies lasiocarpa)] and resprouts of quaking aspen (Populus tremuloides) following the short‐interval sequence of SB outbreaks and wildfire (2–8 yr between SB outbreak and fire) at sites where we previously reconstructed severities of SB and fire. We then examine the implications of ungulate browsing for forest recovery. We found that abundances of postfire spruce seedling establishment decreased substantially in areas of severe SB outbreak. Prolific aspen resprouting in stands with live aspen prior to fire will favor an initial postfire forest trajectory dominated by aspen. However, preferential browsing of postfire aspen resprouts by ungulates will likely slow the rate of canopy recovery but browsing is unlikely to alter the species composition of the future forest canopy. Collectively, our results show that SB outbreak prior to fire increases the vulnerability of spruce–fir forests to shifts in forest type (conifer to aspen) and physiognomic community type (conifer forest to non‐forest). By identifying where compounded disturbance interactions are likely to limit recovery of forests or tree species, our findings are useful for developing adaptive management strategies in the context of warming climate and shifting disturbance regimes
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