Short‐term insurance versus long‐term bet‐hedging strategies as adaptations to variable environments

Understanding how organisms adapt to environmental variation is a key challenge of biology. Central to this are bet‐hedging strategies that maximize geometric mean fitness across generations, either by being conservative or diversifying phenotypes. Theoretical models have identified environmental variation across generations with multiplicative fitness effects as driving the evolution of bet‐hedging. However, behavioral ecology has revealed adaptive responses to additive fitness effects of environmental variation within lifetimes, either through insurance or risk‐sensitive strategies. Here, we explore whether the effects of adaptive insurance interact with the evolution of bet‐hedging by varying the position and skew of both arithmetic and geometric mean fitness functions. We find that insurance causes the optimal phenotype to shift from the peak to down the less steeply decreasing side of the fitness function, and that conservative bet‐hedging produces an additional shift on top of this, which decreases as adaptive phenotypic variation from diversifying bet‐hedging increases. When diversifying bet‐hedging is not an option, environmental canalization to reduce phenotypic variation is almost always favored, except where the tails of the fitness function are steeply convex and produce a novel risk‐sensitive increase in phenotypic variance akin to diversifying bet‐hedging. Importantly, using skewed fitness functions, we provide the first model that explicitly addresses how conservative and diversifying bet‐hedging strategies might coexist.     

Policy Strategies to Promote Eco‐Innovation

This article elaborates an integrated policy framework, including policy features and specific measures that can be implemented to mitigate the barriers to eco‐innovations. We claim that factors inhibiting the development and uptake of eco‐innovations are multifaceted and stem from different sources. This systems view, which highlights the multilayered conception of the obstacles to eco‐innovation, calls for a combination of environmental and technology policies adapted to the different barriers and characteristics of the technologies. Drawing on evolutionary economics, the article sheds light on the appropriate combinations of framework conditions and instruments that are most effective to promote eco‐innovation, considering different barriers and eco‐innovation types (process/product, mature/immature, and radical/incremental).     

Idiopathic environmental intolerance attributed to electromagnetic fields (formerly ‘electromagnetic hypersensitivity’): An updated systematic review of provocation studies

Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI‐EMF; formerly ‘electromagetic hypersensitivity’) is a medically unexplained illness in which subjective symptoms are reported following exposure to electrical devices. In an earlier systematic review, we reported data from 31 blind provocation studies which had exposed IEI‐EMF volunteers to active or sham electromagnetic fields and assessed whether volunteers could detect these fields or whether they reported worse symptoms when exposed to them. In this article, we report an update to that review. An extensive literature search identified 15 new experiments. Including studies reported in our earlier review, 46 blind or double‐blind provocation studies in all, involving 1175 IEI‐EMF volunteers, have tested whether exposure to electromagnetic fields is responsible for triggering symptoms in IEI‐EMF. No robust evidence could be found to support this theory. However, the studies included in the review did support the role of the nocebo effect in triggering acute symptoms in IEI‐EMF sufferers. Despite the conviction of IEI‐EMF sufferers that their symptoms are triggered by exposure to electromagnetic fields, repeated experiments have been unable to replicate this phenomenon under controlled conditions. A narrow focus by clinicians or policy makers on bioelectromagnetic mechanisms is therefore, unlikely to help IEI‐EMF patients in the long‐term. Bioelectromagnetics 31:1–11, 2010. © 2009 Wiley‐Liss, Inc.     

Implementing Carbon‐Footprint‐Based Calculation Tools in Municipal Greenhouse Gas Inventories

Policy makers and practitioners working on local climate action continuously strive for improved greenhouse gas (GHG) inventories to support their mitigation strategies. The provision of such inventories, with the sufficient detail and quality needed, has proven to be challenging. This article describes the application of a carbon‐footprint–based (CF‐based) calculation tool to Norwegian municipalities. The aim is to improve the local GHG inventory, with a particular focus on the emissions resulting from the provision of services by local governments. Through selective CF analysis, we aim to illustrate the knowledge gained from implementing these tools in local climate action plans and to further contrast CF‐based calculations with more traditional production‐based accounting. Municipalities report they have revised their understanding of the most important GHG mitigation strategies after implementing this tool.     

Taxonomy‐free molecular diatom index for high‐throughput eDNA biomonitoring

Current biodiversity assessment and biomonitoring are largely based on the morphological identification of selected bioindicator taxa. Recently, several attempts have been made to use eDNA metabarcoding as an alternative tool. However, until now, most applied metabarcoding studies have been based on the taxonomic assignment of sequences that provides reference to morphospecies ecology. Usually, only a small portion of metabarcoding data can be used due to a limited reference database and a lack of phylogenetic resolution. Here, we investigate the possibility to overcome these limitations using a taxonomy‐free approach that allows the computing of a molecular index directly from eDNA data without any reference to morphotaxonomy. As a case study, we use the benthic diatoms index, commonly used for monitoring the biological quality of rivers and streams. We analysed 87 epilithic samples from Swiss rivers, the ecological status of which was established based on the microscopic identification of diatom species. We compared the diatom index derived from eDNA data obtained with or without taxonomic assignment. Our taxonomy‐free approach yields promising results by providing a correct assessment for 77% of examined sites. The main advantage of this method is that almost 95% of OTUs could be used for index calculation, compared to 35% in the case of the taxonomic assignment approach. Its main limitations are under‐sampling and the need to calibrate the index based on the microscopic assessment of diatoms communities. However, once calibrated, the taxonomy‐free molecular index can be easily standardized and applied in routine biomonitoring, as a complementary tool allowing fast and cost‐effective assessment of the biological quality of watercourses.     

Hybrid All‐in‐One Power Source Based on High‐Performance Spherical Triboelectric Nanogenerators for Harvesting Environmental Energy

With the development of the Internet of Things (IoTs), widely distributed electronics in the environment require effective in situ energy harvesting technologies, which is made challenging by the unstable supply and severe conditions in some environments. In this work, a hybrid all‐in‐one power source (AoPS) is demonstrated for widely adaptive environmental energy harvesting. With a novel structure, the AoPS hybridizes high‐performance spherical triboelectric nanogenerators (TENGs) with solar cells, enabling the harvesting of most typical environmental energies from wind, rain drops, and sun light, for complementary supply. The spherical TENG units with a packaged structure can work robustly to collect energy from fluid. Nearly continuous direct current and a high average power of 5.63 mW can be obtained by four TENG units, which is further complemented by solar cells. Typical application scenarios are also demonstrated, achieving self‐powered soil moisture control, forest fire prevention and pipeline monitoring. The work realizes the concept of an environmental power source that can be deployed in the environment with high adaptability to make use of all kinds of surrounding energies for powering electronics in all‐weather conditions, providing a reliable foundation for the era of the IoTs.     

Saltatory Search in Free-Living <Emphasis Type="Italic">Callithrix jacchus</Emphasis>: Environmental and Age Influences

Researchers generally categorize motile foraging behavior into 3 strategies: ambush, cruise, and saltatory searching. During saltatory searches, predators move from one location to the next, frequently pausing to scan for prey that are hard to detect and widely distributed. We investigated whether 1) the foraging strategy of free-living common marmosets conforms to the strategy; 2) scanning occurs solely when the individual is stationary; 3) the environment (dense and sparse vegetation) influences foraging behavior; and 4) the age of the marmosets is related to their foraging behavior. Bezerra carried out the observations in a 32-ha fragment of Atlantic Forest in the Northeast of Brazil and in an adjacent condominium. Using the focal sampling method, we observed 31 common marmosets, including adults, juveniles, and infants, Bezerra recorded the following behaviors (in dense and sparse vegetation): locomotion (subdivided into minor locomotion—moving distances ≤1 m; major locomotion—moving distances >1 m), scan, pause, and capture. The frequency of scanning behavior was significantly greater when individuals were stationary. Adults and juveniles exhibited the clearest differentiation in terms of locomotion, both adjusting the behavior in accordance with the environment; periods of major locomotion were more frequent in sparse vegetation, whereas minor locomotion was more frequent in dense vegetation. In contrast, infants exhibited major locomotion more frequently in dense vegetation. We conclude that common marmosets use a saltatory strategy when foraging, and that their foraging behavior is plastic, changing both with the age of the individual and with the density of the vegetation.     

“Environmental stress” and reproductive success in the common marmoset (Callithrix jacchus jacchus)

The present report documents the breeding success of a new colony of common marmosets (Callithrix jacchus jacchus) and demonstrates a correlation between environmental stress and reproductive success. Environmental conditions ranged chronologically over 40 months, through four periods: I) the initial period, when the colony was formed; II) a phase of relative environmental stability; III) a stage of “environmental stress” (when the colony was disrupted by nearby construction); and IV) a return to a stable environment. Examination of reproductive status during each period indicated that the colony exhibited severe reproductive suppression during the time of the environmental disruption. Parity and the number of live births decreased and the number of spontaneous abortions increased during this period. Reproductive success remained low during period IV. More triplets than twins were born during the period of relative environmental stability.     

Long‐term effects of photoperiod,temperature and their interaction on growth,gill Na+, K+‐ATPase activity,seawater tolerance and plasma growth‐hormone levels in Atlantic salmon Salmo salar

This study was undertaken to examine the long‐term effects of photoperiod, temperature and their interaction on growth, gill Na⁺,K⁺‐ATPase (NKA) activity, seawater tolerance and plasma growth‐hormone levels in Atlantic salmon Salmo salar pre‐smolts and smolts. The fish (mean ± s.e . initial body mass = 15·9 ± 0·4 g) were reared on two photoperiods (continuous light, LL, and simulated natural photoperiod, LDN, 60° 25′ N) and two temperatures (8·3 and 12·7° C) from June to May of the following year. Mean body mass was affected by photoperiod, temperature and their interactions. Both temperature groups on LL developed peak levels in gill NKA activity from October to November, 4–5 months prior to the natural season for the parr–smolt transformation. Fish at 12° C showed peak levels in NKA activity 4–6 weeks before the fish at 8° C. Fish in all four experimental groups showed maximum NKA activity within a similar size range (113–162 g). The present findings further indicate that smoltification in S. salar is to some extent driven by size, and that S. salar will develop smolt characteristics, e.g. a marked increase in NKA activity, within a similar size range. Faster‐growing S. salar will, thus, reach this size threshold at a relatively younger age.     

Effect of species‐counting protocols and the spatial distribution of effort on rarefaction curves in relation to decision making in environmental‐impact assessments

Rarefaction Curves are frequently used in Environmental Impact Assessments to evaluate sampling sufficiency, but without clear guidelines of how to ensure that the assumptions of the methods are met. Infrastructure projects in the Brazilian Amazon and elsewhere often occupy extensive areas in remote locations with difficult access, and random sampling under such conditions is impractical. We tested the influence of sampling unit (sample or individual), and geographic distance between samples on rarefaction curve s, and evaluated the magnitude of errors resulting from the misuse of rarefaction curve in decision making, using frogs from four Amazonian sampling sites. Individual‐based rarefaction curve were steeper than those generated by sample‐based rarefaction curve. Geographic distance influenced the number of exclusive species in a predictable fashion only in one area, and not in the Environmental Impact Assessment site. Misuse of rarefaction curve generated large errors in the identification of vulnerable taxa. Because the rarefaction curve model is sensitive to the assumption of randomness and geographic distance can influence it unpredictably, we suggest that rarefaction curve should generally not be used to estimate sample completeness when making management decisions for environmental licensing purposes.     

生态创新的最新研究进展与述评

生态创新是实现可持续发展的重要方式.它具有“知识溢出”和“环保溢出”双重正外部性,受到了理论和实践界的广泛关注.为了系统把握生态创新的研究现状,本研究梳理了国外近10年生态创新的相关文献,对生态创新的内涵、特性与维度构成进行了系统的回顾,围绕制度理论、利益相关者理论、资源基础观理论等剖析了生态创新的驱动因素;重点探究了生态创新对企业财务绩效的正向和负向影响,以及生态创新影响财务绩效的中介和调节机理.最后,结合现有研究的不足,提出了未来研究展望.     

Influence of streamflow on spawning‐related movements of golden perch Macquaria ambigua in south‐eastern Australia

In this study, linkages were examined between movement and spawning behaviour for golden perch Macquaria ambigua in a lowland river by integrating acoustic telemetry and egg and larval drift sampling over 4 years. Movement was strongly seasonal, being most prevalent during the spawning season (spring to early summer), and occurred primarily downstream into the lower river reaches during elevated flows. A very strong association was found between the occurrence of spawning and long‐distance M. ambigua movement. The results also revealed that targeted environmental water allocation can promote movement and spawning of this species. By integrating multiple analytical approaches and focusing on key life‐history events, this study provides an improved picture of the life history and flow requirements of M. ambigua. The findings can help guide the development of effective environmental flow recommendations.     

EVOLUTION OF PHENOTYPE–ENVIRONMENT ASSOCIATIONS BY GENETIC RESPONSES TO SELECTION AND PHENOTYPIC PLASTICITY IN A TEMPORALLY AUTOCORRELATED ENVIRONMENT

Covariation between population‐mean phenotypes and environmental variables, sometimes termed a “phenotype–environment association” (PEA), can result from phenotypic plasticity, genetic responses to natural selection, or both. PEAs can potentially provide information on the evolutionary dynamics of a particular set of populations, but this requires a full theoretical characterization of PEAs and their evolution. Here, we derive formulas for the expected PEA in a temporally fluctuating environment for a quantitative trait with a linear reaction norm. We compare several biologically relevant scenarios, including constant versus evolving plasticity, and the situation in which an environment affects both development and selection but at different time periods. We find that PEAs are determined not only by biological factors (e.g., magnitude of plasticity, genetic variation), but also environmental factors, such as the association between the environments of development and of selection, and in some cases the level of temporal autocorrelation. We also describe how a PEA can be used to estimate the relationship between an optimum phenotype and an environmental variable (i.e., the environmental sensitivity of selection), an important parameter for determining the extinction risk of populations experiencing environmental change. We illustrate this ability using published data on the predator‐induced morphological responses of tadpoles to predation risk.     

The ‘wet–dry’ in the wet–dry tropics drives river ecosystem structure and processes in northern Australia

1. Northern Australia is characterised by a tropical wet–dry climate that regulates the distinctive character of river flow regimes across the region. There is marked hydrological seasonality, with most flow occurring over only a few months of the year during the wet season. Flow is also characterised by high variability between years, and in the degree of flow cessation, or intermittency, over the dry season. 2. At present, the relatively low human population density and demand for water in the region means that most rivers have largely unmodified flow regimes. These rivers therefore provide a good opportunity to understand the role of natural flow variability in river ecosystem structure and processes. 3. This review describes the major flow regime classes characterising northern Australian rivers, from perennial to seasonally intermittent to extremely intermittent, and how these regimes give rise to marked differences in the ecological character of these tropical rivers, particularly their floodplains. 4. We describe the key features of these flow regimes, namely the wet and dry seasons and the transitions between these seasons, and how they regulate the biophysical heterogeneity, primary productivity and movement of biota in Australia’s wet–dry tropical rivers. 5. We develop a conceptual model that predicts the likely hydrological and ecological consequences of future increases in water abstraction (e.g. for agriculture), and suggest how such impacts can be managed so that the distinctive ecological character of these rivers is maintained.