Meta‐analysis on pulse disturbances reveals differences in functional and compositional recovery across ecosystems

Most ecosystems are affected by anthropogenic or natural pulse disturbances, which alter the community composition and functioning for a limited period of time. Whether and how quickly communities recover from such pulses is central to our understanding of biodiversity dynamics and ecosystem organisation, but also to nature conservation and management. Here, we present a meta‐analysis of 508 (semi‐)natural field experiments globally distributed across marine, terrestrial and freshwater ecosystems. We found recovery to be significant yet incomplete. At the end of the experiments, disturbed treatments resembled controls again when considering abundance (94%), biomass (82%), and univariate diversity measures (88%). Most disturbed treatments did not further depart from control after the pulse, indicating that few studies showed novel trajectories induced by the pulse. Only multivariate community composition on average showed little recovery: disturbed species composition remained dissimilar to the control throughout most experiments. Still, when experiments revealed a higher compositional stability, they tended to also show higher functional stability. Recovery was more complete when systems had high resistance, whereas resilience and resistance were negatively correlated. The overall results were highly consistent across studies, but significant differences between ecosystems and organism groups appeared. Future research on disturbances should aim to understand these differences, but also fill obvious gaps in the empirical assessments for regions (especially the tropics), ecosystems and organisms. In summary, we provide general evidence that (semi‐)natural communities can recover from pulse disturbances, but compositional aspects are more vulnerable to long‐lasting effects of pulse disturbance than the emergent functions associated to them

Compounded perturbations in coastal areas: contrasting responses to nutrient enrichment and the regime of storm-related disturbance depend on life-history traits

1. Natural systems are exposed to compounded perturbations, whose changes in temporal variance can be as important as those in mean intensity for shaping the structure of assemblages. Specifically, climate-related physical disturbances and nutrient inputs due to natural and/or anthropogenic activities occur concomitantly, but experimental tests of the simultaneous effects of changes in the regime of more than one perturbation are generally lacking. Filling this gap is the key to understand ecological responses of natural assemblages to climate-related change in the intensity and temporal patterning of physical disturbance combined with other global stressors. 2. Responses to factorial manipulations of nutrient enrichment, mean intensity and temporal variability in storm-like mechanical disturbance were examined, using benthic assemblages of tide-pools as model system. 3. Response variables were mean abundance values and temporal variances of taxa with different life-traits. Consistent negative effects of disturbance intensity were observed for the mean cover of long-living taxa (algal canopies and the polychaete Sabellaria alveolata), whose temporal fluctuations were also reduced by more severe mechanical stress. More resilient taxa (ephemeral algae, mostly green of the genus Ulva) increased under enriched conditions, particularly when low-intensity events were irregularly applied over time. Opposite effects of disturbance intensity depending on nutrient availability occurred on filamentous algae (e.g. red of the genus Ceramium). This was probably due to the fact that, although nutrient enrichment stimulated the abundance of both algal groups, when this condition was combined with relatively mild physical disturbance the competitively superior ephemeral green algae tended to become dominant over filamentous red algae. The same did not occur under high intensity of disturbance since it likely damaged large, foliose fronds of Ulva-like forms more than small, filamentous fronds of Ceramium-like forms. Grazers were positively affected by nutrients, likely responding indirectly to more food available. 4. A direct relationship between the mean abundance of most organisms and their temporal fluctuations was documented. However, all organisms persisted throughout the study, even under experimental conditions associated to the largest temporal variation in their abundance, likely due to their ability to resist to/quickly recover from, the applied perturbations. Therefore, in systems with great recovery abilities of dominant organisms (e.g. rocky intertidal, grasslands), effects of traits of the regime of disturbance and nutrient enrichment may modulate the fluctuations of populations not through the elimination and substitution of species, but through changes in relative abundances of the same species. This contrasts with the theory that temporal variation in abundance would be directly related to the risk of local extinction. Present findings enable more accurate predictions of the consequences of climatic and non-climatic scenarios on the biodiversity of marine and terrestrial systems sharing analogous functional traits of organisms. Future more intense physical disturbances are expected to exert negative effects on slow-growing/recovering species (e.g. habitat-formers) irrespectively of the temporal patterning of the same disturbances and nutrient inputs. On the contrary, more resistant species (e.g. encrusting algae on rocky shores or below-ground vegetation in grasslands) are expected to benefit from intense physical disturbance. Species whose abundance is more directly related to the availability of nutrients (e.g. filamentous and ephemeral algae or herbs) are expected to generally increase under enriched conditions, but their ability to eventually become dominant would depend on their ability to grow fast and attain cover large enough to overwhelm any possible control of concomitant disturbance intensity on their abundance. If, such as in the present examined system, virtually all organisms can persist, over the temporal scale of the experiment, under any combination of physical disturbance and nutrient availability, the resulting overall diversity is not predicted to change drastically. Nevertheless, low-intensity events evenly distributed and high-intensity events irregularly distributed appear as the conditions supporting the highest richness of taxa, independently of the availability of nutrients

Reproducibility in the absence of selective reporting : An illustration from large-scale brain asymmetry research

Altres ajuts: Max Planck Society (Germany).The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes

“Can I wear this?” : blending clothing and digital expression by wearing dynamic fabric

We explore the future scenario of wearing garments with digital display capabilities, or dynamic fabric, in everyday life. Our study, called Greenscreen Dress, investigates the experience of wearing dynamic fabric and how this type of garment quality might alter our daily interactions with clothing and have implications for designers. In the study, we adopt an autoethnographic approach that materially speculates on dynamic fabric by wearing green every day for ten months and using a chroma key (“greenscreen”) mobile application to give the garments a digital display. We reflect on the behavioural and mental shifts that emerge from integrating dynamic fabric into one’s wardrobe with regards to expression through personal style, fashion design processes for and with digital content, social acceptance of dynamic displays on clothes in mass fashion and engagement with digital media for expressive purposes. Broadly, we argue that exploring wearable technologies through the lens of socio-cultural perspectives and clothing practice, as opposed to material or technological developments, can reveal insights with regards to the opportunities and challenges of blending clothing with smart technologies. More specifically, we explore the future notion of dynamic fabric clothing through the act of wearing dynamic fabric in everyday life and an engagement with digital expression

Day-­to-­day speculation: designing and wearing dynamic fabric

In this paper we describe Greenscreen Dress, a material speculation inquiry that investigates the wearing experience of dynamic fabric in everyday life. In this study the researcher has worn a "greenscreen garment" every day for seven months. Coupled with a chroma-key smartphone application, she has photographed the garment and digitally composited upon it multiple digital colours, patterns and videos. The fashion expressions were uploaded to Instagram and so situated within a digital social ecosystem. We argue that combining the wearing of dynamic fabric with design activities, the inquiry of what it might mean to wear dynamic fabric moves speculation into day-to day living by drawing from the interactions of the researcher’s everyday life. As innovations in smart textiles and wearable technologies become more accessible, knowledge gained from this research critically inquires into the everydayness of this breed of technological system. The research draws insights from design, fashion, and material performances in the daily life of the researcher. The project contributes critical insights into fashion and technology for clothing designers and in to new methodological terrains for research through design

Trait‐based life‐history strategies explain succession scenario for complex bacterial communities under varying disturbance

Trait‐based approaches are increasingly gaining importance in community ecology, as a way of finding general rules for the mechanisms driving changes in community structure and function under the influence of perturbations. Frameworks for life‐history strategies have been successfully applied to describe changes in plant and animal communities upon disturbance. To evaluate their applicability to complex bacterial communities, we operated replicated wastewater treatment bioreactors for 35 days and subjected them to eight different disturbance frequencies of a toxic pollutant (3‐chloroaniline), starting with a mixed inoculum from a full‐scale treatment plant. Relevant ecosystem functions were tracked and microbial communities assessed through metagenomics and 16S rRNA gene sequencing. Combining a series of ordination, statistical and network analysis methods, we associated different life‐history strategies with microbial communities across the disturbance range. These strategies were evaluated using tradeoffs in community function and genotypic potential, and changes in bacterial genus composition. We further compared our findings with other ecological studies and adopted a semi‐quantitative competitors, stress‐tolerants, ruderals (CSR) classification. The framework reduces complex data sets of microbial traits, functions and taxa into ecologically meaningful components to help understand the system response to disturbance and hence represents a promising tool for managing microbial communities.NRF (Natl Research Foundation, S’pore)MOE (Min. of Education, S’pore