Solving Problems in Social–Ecological Systems: Definition, Practice and Barriers of Transdisciplinary Research

Translating policies about sustainable development as a social process and sustainability outcomes into the real world of social–ecological systems involves several challenges. Hence, research policies advocate improved innovative problem-solving capacity. One approach is transdisciplinary research that integrates research disciplines, as well as researchers and practitioners. Drawing upon 14 experiences of problem-solving, we used group modeling to map perceived barriers and bridges for researchers’ and practitioners’ joint knowledge production and learning towards transdisciplinary research. The analysis indicated that the transdisciplinary research process is influenced by (1) the amount of traditional disciplinary formal and informal control, (2) adaptation of project applications to fill the transdisciplinary research agenda, (3) stakeholder participation, and (4) functional team building/development based on self-reflection and experienced leadership. Focusing on implementation of green infrastructure policy as a common denominator for the delivery of ecosystem services and human well-being, we discuss how to diagnose social–ecological systems, and use knowledge production and collaborative learning as treatments.     

Assessing Landscape Condition Relative to Water Resources in the Western United States: A Strategic Approach

The Environmental Monitoring and Assessment Program (EMAP) is proposing an ambitious agenda to assess the status of streams and estuaries in a 12-State area of the western United States by the end of 2003. Additionally, EMAP is proposing to access landscape conditions as they relate to stream and estuary conditions across the west. The goal of this landscape project is to develop a landscape model that can be used to identify the relative risks of streams and estuaries to potential declines due to watershed-scale, landscape conditions across the west. To do so, requires an understanding of quantitative relationships between landscape composition and pattern metrics and parameters of stream and estuary conditions. This paper describes a strategic approach for evaluating the degree to which landscape composition and pattern influence stream and estuary condition, and the development and implementation of a spatially-distributed, landscape analysis approach.     

Market aspects in product life cycle inventory methodology

In planning a product life cycle inventory analysis, the correct choice of methodology often depends on market information. This paper discusses a number of points in the life cycle inventory methodology (choice of product alternatives, geographical system boundaries, technological levels and co-product allocation rules) where the market aspect becomes obvious and where a disregard for these aspects may lead to serious flaws in the results.     

Growth and mortality in young larval herring (Clupea harengus); effects of repetitive changes in food availability

Following yolk resorption, laboratory-reared larval Baltic herring (Clupea harengus L.) were exposed to two sequences of food restriction for 5 d and re-alimentation for 10 d. Comparisons regarding larval growth (standard length and content of water-soluble protein), mortality and content of the sum of trypsin and trypsinogen were made with larvae at a continuous high ration. Larvae exposed to varying prey abundance grew less in length than the control, and during the second high-ration period (Day 22 to 32) growth in length ceased. From the first low-ration period onwards, the content of water-soluble protein in these larvae was lower than that of the control larvae, and the survival rate of the low-high ration group was 59% compared to 77% in the larvae at a continuous high ration. In contrast, the effects of varying food availability were minor on larval content of trypsin and trypsinogen. Results are compared with previous findings in larval Clyde herring, and the effects of larval stock and timing and duration of food restriction on larval growth performance are discussed.     

Sustainable management of shellfish resources in Bandon Bay, Gulf of Thailand

Bandon Bay (Surat Thani Province) is one of the most productive coastal areas in southern Thailand. The Tapi River and 18 channels are the main sources of freshwater, nutrients, organic matter and sediment to the bay and the loading of freshwater and nutrients provide essential support for the production of phytoplankton in the estuarine ecosystem. Bandon Bay is important as natural spawning, nursery and feeding grounds for shellfish such as oysters, blood cockles, green mussels, short-necked clams, mud crabs and shrimps, and the estuary also serves as an excellent area for mariculturing of shellfish. In fact, oysters and blood cockles cultured in Bandon Bay are now being exported worldwide. However, Bandon Bay is also a textbook example of overexploitation of coastal resources in the tropics including all the derived changes in the estuarial ecosystem with severe socio-economic consequences. Hence, there is an urgent need for setting up an integrated management plant for a sustainable use of shellfish resources in Bandon Bay. The present study attempts to integrate water quality simulation results, socio-economic data and information on existing shellfish resource use in the process of proposing a set of sustainable management strategies for shellfish resources in Bandon Bay. These strategies involve: (1) using water quality modeling to monitor ecological and environmental changes in shellfish culture beds and their natural habitats in the process of setting up a master plan for management of waste water discharge into Bandon Bay; (2) zoning of shellfish mariculture in the coastal area in order to solve conflicts between resource users; (3) setting up a clear system for taxation of mariculture where the revenue may be used for (4) setting up and managing mangrove strips as filters of pollution and sediment around Bandon Bay; and finally (5) it is suggested to form a committee with members representing all relevant stakeholders plus the local government in order to work on resolving the existing and potential future conflicts over resource usage in Bandon Bay. This methodology may be seen as an important contribution towards a Bandon Bay sustainable management approach, based on the principles of integrated coastal zone management because it is science-based and takes into consideration the needs and perceptions of people involved in coastal resource extraction.     

Using multi-objective classification to model communities of soil microarthropods

In agricultural soil, a suite of anthropogenic events shape the ecosystem processes and populations. However, the impact from anthropogenic sources on the soil environment is almost exclusively assessed for chemicals, although other factors like crop and tillage practices have an important impact as well. Thus, the farming system as a whole should be evaluated and ranked according to its environmental benefits and impacts. Our starting point is a data set describing agricultural events and soil biological parameters. Using machine learning methods for inducing regression and model trees, we produce empirical models able to predict the soil quality from agricultural measures in terms of quantities describing the soil microarthropod community. We are also interested in discovering additional higher level knowledge. In particular, we have identified the most important factors influencing the population densities of springtails and mites and their biodiversity. We also identify to which agricultural actions different microarthropods react distinctly. To obtain this higher level knowledge, we employ multi-objective regression trees.     

Regulation of parental effort in a long-lived seabird an experimental manipulation of the cost of reproduction in the antarctic petrel,Thalassoica antarctica

Summary The fitness of a parent in an altricial bird species is likely to be a function of the proportion of resources allocated to offspring production in relation to the amount spent on its own survival. Here we report an experiment on the Antarctic petrel in which we manipulated the costs of rearing an offspring by placing small lead loads on the legs of one parent. The bird could then either decrease its own body reserves or reduce the food load to the chick. The manipulated birds decreased their food load and increased the feeding interval, compared with unmanipulated birds. Consequently, the rate of chick loss increased. No significant difference was found between the body weights of experimental and control birds during the experiment.Publication no. 113 from the Norwegian Antarctic Research Expedition (NARE) 1989/90 Correspondence to: B.-E. Sæther     

Effects of a transitory,low food supply in the early life of larval herring (Clupea harengus) on mortality,growth and digestive capacity

In order to assess possible effects of a transitory, low food supply on later development, three groups of Clyde herring larvae (Clupea harengus L.) were exposed in 1989 to different feeding regimes immediately after yolk resorption. Group 1 received a high daily ration of 80 copepods larvae^–1 for 31 d, Group 2 a low daily ration of 15 copepods larva^–1 for 10 d followed by a high ration (80 copepods larva^–1) for 21 d and Group 3 a low ration of 15 to 20 copepods larva^–1 for 31 d. After 31 d of feeding, digestive capacity, expressed as the sum of trypsin and trypsinogen, was markedly reduced in Group 2 compared to Group 1, while Group 3 had an even lower digestive capacity. After the switch from low to high ration Group 2 exhibited compensatory growth and caught up with Group 1 both in standard length and content of soluble protein. Group 3 had the lowest growth rates. Mortality was equal in Groups 1 and 2, while Group 3 showed an excess mortality of 40% of the start population. Although Group 2 larvae had caught up with Group 1 in growth at the end of the study, content of trypsin and trypsinogen in Group 2 was only half of that found in Group 1. Thus, comparing effects of a short period of food limitation on future growth, mortality and content of digestive enzymes, the study indicates content of trypsin and trypsinogen to be the most sensitive variable for detection of food limitation in the early stages of exogenous feeding.     

Trypsin content in intestines of herring larvae,Clupea harengus,ingesting inert polystyrene spheres or live crustacea prey

In 1986, at the Danish Institute of Fisheries and Marine Research, Denmark, Clupea harengus L. larvae from three different herring stocks were offered either non-biodegradable polystyrene spheres, nauplii and copepodites of Acartia tonsa or Artemia ssp. nauplii. Ingestion of polystyrene spheres induced trypsin secretion to a higher level than in non-feeding fish. Larvae ingesting live food of the same width as the polystyrene spheres exhibited the highest trypsin content in the intestines. Mechanisms responsible for the regulation of pancreatic enzyme secretion are discussed.     

Positive association of queen number and queen-mating frequency Myrmica ants: a challenge to the genetic-variability hypotheses

Detailed knowledge of the mating system in specific social insect populations is essential for testing general evolutionary hypotheses of multiple paternity in eusocial Hymenoptera. We have studied the mating frequency of queens in a polygynous population of the red ant Myrmica sulcinodis. Genetic mother-offspring analysis showed that double mating occurred at a considerable frequency, but that the effective number of queen-mates remained close to one. After quantifying the effects of multiple maternity (polygyny) and multiple paternity (polyandry) on the genetic diversity of workers, we conclude that multiple paternity in M. sulcinodis did not evolve as an adaptation to increase genetic variation within colonies. Contrary to the predictions from `genetic variability' hypotheses, we found a positive correlation between colony-specific queen number and the average number of mates per queen. Such positive association of queen number and frequency of multiple mating was also found after analysing comparative data across six species of Myrmica ants. These results suggest that resticted dispersal of young queens may be a common factor promoting both polygyny and polyandry at the same time, and that moderate degrees of multiple mating may be an unselected consequence of (1) mating at low cost when mating occurs close to the nest and (2) mating in swarms with a highly male biased operational sex ratio. Future comparative tests of genetic-variability hypotheses should therefore not include species with such evolutionary derived mating system characteristics. Received: 30 April 1998 / Accepted after revision: 19 August 1998