Wageningen University and Research Centre

About: Wageningen University and Research Centre is a education organization based out in Wageningen, Netherlands. It is known for research contribution in the topics: Population & Sustainability. The organization has 23474 authors who have published 54833 publications receiving 2608897 citations.

Dealing with Ambivalence: Farmers' and Consumers' Perceptions of Animal Welfare in Livestock Breeding

Abstract: The results of an empirical study intoperceptions of the treatment of farm animals inthe Netherlands are presented. A qualitativeapproach, based on in-depth interviews withmeat livestock farmers and consumers was chosenin order to assess motivations behindperceptions and to gain insight into the waypeople deal with possible discrepancies betweentheir perceptions and their daily practices.Perceptions are analyzed with the help of aframe of reference, which consists ofvalues, norms, convictions, interests, andknowledge. The perceptions of the interviewed farmersare quite consistent and without exceptionpositive: according to them, nothing is wrongwith animal welfare in livestock breeding. Theperceptions of the consumers we interviewed aremore divergent, but generally negative. Bothgroups show ambivalence as a result ofdiscrepancies between perceptions and behavior.Although the consumers share the impressionthat the living conditions of livestock animalsare far from optimal, most of them still buyand eat meat from the meat industry. Thefarmers believe the welfare of their animals isgood, but, as frequent defensive utterancesshow, they feel uncomfortable with expressed orunexpressed accusations of mistreating animals.The ways the respondents deal with thisambivalence were analysed by drawing ontheories of dissonance reduction and distancing devices. Catherine and Raphael Larrere(Larrere and Larrere, 2000) argue thatanimal rearing is a hierarchical relationshipwhose rules are to be found in the fiction of adomestic contract. We argue that the questionis not whether there should be a domesticcontract, because such a contract seems alreadyaccepted. However, since values and normsdiffer widely, not only among meat livestockfarmers and consumers, but also amongconsumers, the question remains as to whosevalues and norms should form the basis of thedomestic contract.

Heavy metals and soil microbes

Abstract: The discovery in the early 1980s that soil microorganisms, and in particular the symbiotic bacteria Rhizobium, were highly sensitive to heavy metals initiated a new line of research. This has given us important insights into a range of topics: ecotoxicology, bioavailability of heavy metals, the role of soil biodiversity, and the existence of ‘keystone’ organisms. Concurrently, and particularly in Europe, the research led to new approaches to the protection of soils from pollution that take into account the many effects on soil microorganisms. To date these key findings have largely been ignored in the USA, although our results caused considerable controversy there. In the past decade there have been many advances in the ecotoxicological assessment of metals and their effects on soil organisms but major gaps in knowledge and theory remain with regard to how microorganisms are exposed and respond to metals in soils. In this brief review we emphasise the need for long-term experiments and basic research to forge this understanding and improve environmental protection policies.

Multiple successional pathways in human-modified tropical landscapes: New insights from forest succession, forest fragmentation and landscape ecology research

Abstract: Old-growth tropical forests are being extensively deforested and fragmented worldwide. Yet forest recovery through succession has led to an expansion of secondary forests in human-modified tropical landscapes (HMTLs). Secondary forests thus emerge as a potential repository for tropical biodiversity, and also as a source of essential ecosystem functions and services in HMTLs. Such critical roles are controversial, however, as they depend on successional, landscape and socio-economic dynamics, which can vary widely within and across landscapes and regions. Understanding the main drivers of successional pathways of disturbed tropical forests is critically needed for improving management, conservation, and restoration strategies. Here, we combine emerging knowledge from tropical forest succession, forest fragmentation and landscape ecology research to identify the main driving forces shaping successional pathways at different spatial scales. We also explore causal connections between land-use dynamics and the level of predictability of successional pathways, and examine potential implications of such connections to determine the importance of secondary forests for biodiversity conservation in HMTLs. We show that secondary succession (SS) in tropical landscapes is a multifactorial phenomenon affected by a myriad of forces operating at multiple spatio-temporal scales. SS is relatively fast and more predictable in recently modified landscapes and where well-preserved biodiversity-rich native forests are still present in the landscape. Yet the increasing variation in landscape spatial configuration and matrix heterogeneity in landscapes with intermediate levels of disturbance increases the uncertainty of successional pathways. In landscapes that have suffered extensive and intensive human disturbances, however, succession can be slow or arrested, with impoverished assemblages and reduced potential to deliver ecosystem functions and services. We conclude that: (i) succession must be examined using more comprehensive explanatory models, providing information about the forces affecting not only the presence but also the persistence of species and ecological groups, particularly of those taxa expected to be extirpated from HMTLs; (ii) SS research should integrate new aspects from forest fragmentation and landscape ecology research to address accurately the potential of secondary forests to serve as biodiversity repositories; and (iii) secondary forest stands, as a dynamic component of HMTLs, must be incorporated as key elements of conservation planning; i.e. secondary forest stands must be actively managed (e.g. using assisted forest restoration) according to conservation goals at broad spatial scales.

Temporal and among-site variability of inherent water-use efficiency at the ecosystem level

Abstract: Half-hourly measurements of the net exchanges of carbon dioxide and water vapor between terrestrial ecosystems and the atmosphere provide estimates of gross primary production (GPP) and evapotranspiration (ET) at the ecosystem level and on daily to annual timescales. The ratio of these quantities represents ecosystem water use efficiency. Its multiplication with mean daylight vapor pressure deficit (VPD) leads to a quantity which we call “inherent water use efficiency” (IWUE*). The dependence of IWUE* on environmental conditions indicates possible adaptive adjustment of ecosystem physiology in response to a changing environment. IWUE* is analyzed for 43 sites across a range of plant functional types and climatic conditions. IWUE* increases during short-term moderate drought conditions. Mean annual IWUE* varied by a factor of 3 among all sites. This is partly explained by soil moisture at field capacity, particularly in deciduous broad-leaved forests. Canopy light interception sets the upper limits to canopy photosynthesis, and explains half the variance in annual IWUE* among herbaceous ecosystems and evergreen needle-leaved forests. Knowledge of IWUE* offers valuable improvement to the representation of carbon and water coupling in ecosystem process models