Specifying information needs: improving the working methodology

Specification of information needs is an important step in the design of monitoring networks. Within the framework of Monitoring Strategy 2000+, a programme of the Dutch Directorate General of Public Works and Water Management (Rijkswaterstaat) which seeks to provide innovation in the monitoring sector, a method has been developed to link water management policy to monitoring through specification of information needs. Over the past 2 years, this method has been applied in several projects within the Rijkswaterstaat organisation. Use of this method has led to improvements in the monitoring practice and was judged very positively by the people involved. Nevertheless, the main obstacle to employing the method was the actual translation of policy matters into information products. A special study is carried out, focusing on this aspect within the method, to provide the participants of a project with a mental framework that enables them to clearly specify their information needs. The major requirements for this mental framework are that all participants have a clear view of the process (system), and that they are able to relate their contribution to this process and to the contributions of others (transparency). The first step of the process is to focus the attention of stakeholders on the information they will actually need for decision-making. The next step is to confront the different expressed opinions through the method of the 'devil's advocate', which implies criticising the results of the first step by finding as many as possible arguments against these opinions. This should force the stakeholders to better specify their arguments. The method, its improvements and the results of one pilot project will be discussed in this paper. Electronic Publication     

Induced defenses in herbivores and plants differentially modulate a trophic cascade

Inducible defenses are dynamic traits that modulate the strength of both plant-herbivore and herbivore-carnivore interactions. Surprisingly few studies have considered the relative contributions of induced plant and herbivore defenses to the overall balance of bottom-up and top-down control. Here we compare trophic cascade strengths using replicated two-level and three-level plankton communities in which we systematically varied the presence or absence of induced defenses at the plant and/or herbivore levels. Our results show that a trophic cascade, i.e., significantly higher plant biomass in three-level than in two-level food chains, occurred whenever herbivores were undefended against carnivores. Trophic cascades did not occur when herbivores exhibited an induced defense. This pattern was obtained irrespective of the presence or absence of induced defenses at the plant level. We thus found that herbivore defenses, not plant defenses, had an overriding effect on cascade strength. We discuss these results in relation to variation in cascade strengths in natural communities.     

Assessment and review of organochlorine pesticide pollution in Kyrgyzstan

The current study describes the preliminary assessment and securing activities of the largest and most hazardous POPs-contaminated sites in Kyrgyzstan. In 2010, cattle died and population were found with high pesticide levels in blood, human milk, and placenta. In the first phase of the study, a historic assessment of the pesticide dumping at the landfill/dump sites have been conducted. In the second phase, soil analysis for organochlorine pesticides in the areas of the pesticide disposal sites, the former pesticides storehouses, agro-air strips, and the cotton-growing fields were conducted. By this assessment, a first overview of the types and sources of pollution and of the scale of the problem is compiled including information gaps. From major pesticides used, DDT, DDE, and HCH were measured in the highest concentrations. With the limited analytical capacity present, a reasonable risk assessment could be performed. This paper also reports on practical risk reduction measures that have been carried out recently at the two major pesticide disposal sites with support of a Dutch environmental engineering company, an international NGO (Green Cross Switzerland) and local authorities from the Suzak region within an UN project. Local population living near the sites of the former pesticide storehouses and agro-airstrips are advised not to cultivate vegetables and melons or to raise cattle on these areas. Instead, it is recommended to grow technical crops or plant trees. Further recommendations on monitoring and assessment is given including the suggestion to consider the findings in the National Implementation Plan of Kyrgyzstan.     

KNOWLEDGE UTILIZATION IN WATER MANAGEMENT IN THE NETHERLANDS RELATED TO DESICCATION1

ABSTRACT: The use of scientific knowledge in environmental policy making is an important topic. However, the relation between knowledge producers and policy makers is not a straightforward producer-user relationship. The development of a national desiccation policy in the Netherlands and the implementation of desiccation plans in local situations are used as a case study to investigate the knowledge policy relationship. Three theoretical explanations were used to analyze this case: a difference between the cultures of producers and users; a different rationality of the policy making and research processes; and processes of social construction of problem definitions which imply that different knowledge stocks are used depending on the framing of the policy problem. Emergence of the policy issue at the national level is demonstrated to develop in close interaction between knowledge producers and policy makers, while the interactions at the local level were more based on integration of expert knowledge through personal expertise and closely tied to the development of management plans. This case study thus reveals a difference between general knowledge supporting measures at the national policy level and the way in which specific knowledge is applied in local cases. Therefore more attention should be paid to the translation of policy problems from rather high levels of political authority to the conceptualization at lower management levels. A final conclusion is that knowledge use in Dutch desiccation policy can be understood by pointing to multiple theoretical perspectives. The rational actor model and a construc-tivist perspective turned out to be especially useful in explaining the different ways knowledge was used at the national and the local level.     

Species diversity modulates predation

Predation occurs in a context defined by both prey and non-prey species. At present it is largely unknown how species diversity in general, and species that are not included in a predator's diet in particular, modify predator-prey interactions. Therefore we studied how both the density and diversity of non-prey species modified predation rates in experimental microcosms. We found that even a low density of a single nonprey species depressed the asymptote of a predator's functional response. Increases in the density and diversity of non-prey species further reduced predation rates to very low levels. Controls showed that this diversity effect was not due to the identity of any of the non-prey species. Our results establish that both the density and diversity of species outside a predator's diet can significantly weaken the strength of predator-prey interactions. These results have major implications for ecological theory on species interactions in simple vs. complex communities. We discuss our findings in terms of the relationship between diversity and stability.