Using a process-based model to understand dynamics of Chinese agricultural and water technology development from 8000 bc to 1911 ad

Advancements in technology are inextricably bound to our society and the natural environment. However, how the development process of a technology system interacts with both remains unclear. We propose a process model to understand the complex dynamics among technology, society, and the environment via seven interactive elements: technologies, actors, receiving bodies, natural contexts, social contexts, temporal–spatial contexts, and outcomes. The model was applied to agricultural and water technology development in China from 8000 bc to 1911 ad. Our findings show that these elements did not play equally important roles in different periods of the development in ancient China, with social contexts most dominating during the earlier periods and both social and environmental concerns arising towards the later periods. The proposed model, by identifying the elements in the technology development that should be strengthened, can act as an analysis device to assist in reconfiguring a more sustainable socio-technological system.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01424-7) contains supplementary material, which is available to authorized users.     

Engaging stakeholders in research to address water–energy–food (WEF) nexus challenges

The water–energy–food (WEF) nexus has become a popular, and potentially powerful, frame through which to analyse interactions and interdependencies between these three systems. Though the case for transdisciplinary research in this space has been made, the extent of stakeholder engagement in research remains limited with stakeholders most commonly incorporated in research as end-users. Yet, stakeholders interact with nexus issues in a variety of ways, consequently there is much that collaboration might offer to develop nexus research and enhance its application. This paper outlines four aspects of nexus research and considers the value and potential challenges for transdisciplinary research in each. We focus on assessing and visualising nexus systems; understanding governance and capacity building; the importance of scale; and the implications of future change. The paper then proceeds to describe a novel mixed-method study that deeply integrates stakeholder knowledge with insights from multiple disciplines. We argue that mixed-method research designs—in this case orientated around a number of cases studies—are best suited to understanding and addressing real-world nexus challenges, with their inevitable complex, non-linear system characteristics. Moreover, integrating multiple forms of knowledge in the manner described in this paper enables research to assess the potential for, and processes of, scaling-up innovations in the nexus space, to contribute insights to policy and decision making.     

Climate change and forests of the future: managing in the face of uncertainty.

We offer a conceptual framework for managing forested ecosystems under an assumption that future environments will be different from present but that we cannot be certain about the specifics of change. We encourage flexible approaches that promote reversible and incremental steps, and that favor ongoing learning and capacity to modify direction as situations change. We suggest that no single solution fits all future challenges, especially in the context of changing climates, and that the best strategy is to mix different approaches for different situations. Resources managers will be challenged to integrate adaptation strategies (actions that help ecosystems accommodate changes adaptively) and mitigation strategies (actions that enable ecosystems to reduce anthropogenic influences on global climate) into overall plans. Adaptive strategies include resistance options (forestall impacts and protect highly valued resources), resilience options (improve the capacity of ecosystems to return to desired conditions after disturbance), and response options (facilitate transition of ecosystems from current to new conditions). Mitigation strategies include options to sequester carbon and reduce overall greenhouse gas emissions. Priority-setting approaches (e.g., triage), appropriate for rapidly changing conditions and for situations where needs are greater than available capacity to respond, will become increasingly important in the future.     

Survival and sex ratios of the intertidal copepod,Tigriopus californicus,following ultraviolet-B (290–320 nm) radiation exposure

The marine harpacticoid copepod, Tigriopus californicus (Baker), is a successful colonizer of supralittoral splash pools from Torch Bay, Alaska, to Baja California, Mexico. As these pools are subject to abundant amounts of direct solar radiation, it was of interest to determine the sensitivity of T. californicus to ultraviolet-B (UV-B, 290 to 320 nm) radiation. During 1980, copepods were raised under diurnal conditions in the laboratory and fed a mixture of unicellular algae and bacteria. Larval and adult stages were irradiated for 0 to 26 h on a rotating turntable under enhanced ultraviolet radiation. Following irradiation, the copepods were maintained in the culture area and checked daily for survival. All life stages of T. californicus tolerated enhanced UV-B radiation irrespective of exposure period; in contrast, survival of an irradiated planktonic copepod, Acartia clausii (Giesbrecht), was significantly lower. Additionally, there appeared to be asex ratio shift in adults that developed from the youngest naupliar stages (N₁/N₂) of T. californicus that were irradiated. Extraction and tentative identification of the pigment(s) responsible for the bright orange color of the carapace of T. californicus were performed. These pigments may function to absorb UV radiation and protect internal structures from photochemically induced damage.     

How regulations impact innovative environmental technologies: A recent case study

The White House Conference on Environmental Technology, held December 12–14, 1994, is the most recent of many events building toward a national environmental technology strategy, which President Clinton will announce on April 22, 1995, the 25th anniversary of Earth Day. Promoting innovation and eliminating barriers to new environmental technologies are important issues in developing this strategy. Anticipating these developments, EPA launched its own Technology Innovation Strategy in early 1994. EPA's strategy explicitly calls for strengthening incentives for technology innovation within regulatory, policy, and enforcement programs. In this light, it is worthwhile to look at a recent case study showing how regulations impact innovative environmental technologies, particularly because there appears to be a gathering political sentiment for deeper regulatory reform.     

Getting to Grips with Groundwater Pollution Protection in Developing Countries*

Although groundwater is widely and increasingly exploited for potable water-supply in developing countries the threat of groundwater pollution has, as yet, received little attention. Activities currently producing the principal risks are described in some detail. A basis for rapid assessment of the degree of groundwater pollution risk is proposed, based on the evaluation of, and the interaction between, pollutant loading and aquifer vulnerability. Protection zones around individual groundwater supply sources can generally play, at most, only a minor role in overall policy. The strategy proposed is aquifer-oriented and activity-related. The evaluation of aquifer pollution vulnerability, made in the rapid risk assessment and based on three semi-independent criteria, could be used to select the required protection measures in relation to specific land-use activities.     

The One-Migrant-per-Generation Rule in Conservation and Management

In the face of continuing habitat fragmentation and isolation, the optimal level of connectivity between populations has become a central issue in conservation biology. A common rule of thumb holds that one migrant per generation into a subpopulation is sufficient to minimize the loss of polymorphism and heterozygosity within subpopulations while allowing for divergence in allele frequencies among subpopulations. The one-migrant-per-generation rule is based on numerous simplifying assumptions that may not hold in natural populations. We examine the conceptual and theoretical basis of the rule and consider both genetic and nongenetic factors that influence the desired level of connectivity among subpopulations. We conclude that one migrant per generation is a desirable minimum, but it may be inadequate for many natural populations. We suggest that a minimum of 1 and a maximum of 10 migrants per generation would be an appropriate general rule of thumb for genetic purposes, bearing in mind that factors other than genetics may further influence the ideal level of connectivity.     

Soil- and surfactant-enhanced reductive dechlorination of carbon tetrachloride in the presence of Shewanella putrefaciens 200

Sorption of organic contaminants to soils has been shown to limit bioavailability and biodegradation in some systems. Use of surfactants has been proposed to reverse this effect. In this study, the effects of a high organic carbon content soil and a nonionic surfactant (Triton X-100) on the reductive dechlorination of carbon tetrachloride (CCl₄) were examined in anaerobic systems containing Shewanella putrefaciens. Although more than 70% of the added CCl₄ was sorbed to the soil phase in these systems, the reductive dechlorination of CCl₄ was not diminished. Rather, rates of CCl₄ dechlorination in systems containing soil were enhanced relative to systems containing non-sorptive sand slurries. This enhancement was also observed in sterile soil slurries to which a chemical reductant, dithiothreitol was added. It appears that the organic soil used in these experiments contains some catalytic factor capable of transforming CCl₄ in the presence of an appropriate chemical or microbial reductant. The addition of Triton X-100 to sand and soil slurries containing S. putrefaciens resulted in increased CCl₄ degradation in both systems. The effect of Triton could not be explained by: (i) surfactant induced changes in the distribution of CCl₄, (i.e. decreased sorption) or the rate of CCl₄ desorption; (ii) a direct reaction between Triton and CCl₄; or (iii) increased cell numbers resulting from use of the surfactant as a substrate. Rather, it appears that Triton X-100 addition resulted in lysis of bacterial cells, a release of biochemical reductant, and enhanced reductive transformation of CCl₄. These results provide insights to guide the development of more effective direct or indirect bioremediation strategies.