Intraspecific variation in thermal acclimation and tolerance between populations of the winter ant, Prenolepis imparis.

Thermal phenotypic plasticity, otherwise known as acclimation, plays an essential role in how organisms respond to short-term temperature changes. Plasticity buffers the impact of harmful temperature changes; therefore, understanding variation in plasticity in natural populations is crucial for understanding how species will respond to the changing climate. However, very few studies have examined patterns of phenotypic plasticity among populations, especially among ant populations. Considering that this intraspecies variation can provide insight into adaptive variation in populations, the goal of this study was to quantify the short-term acclimation ability and thermal tolerance of several populations of the winter ant, Prenolepis imparis. We tested for correlations between thermal plasticity and thermal tolerance, elevation, and body size. We characterized the thermal environment both above and below ground for several populations distributed across different elevations within California, USA. In addition, we measured the short-term acclimation ability and thermal tolerance of those populations. To measure thermal tolerance, we used chill-coma recovery time (CCRT) and knockdown time as indicators of cold and heat tolerance, respectively. Short-term phenotypic plasticity was assessed by calculating acclimation capacity using CCRT and knockdown time after exposure to both high and low temperatures. We found that several populations displayed different chill-coma recovery times and a few displayed different heat knockdown times, and that the acclimation capacities of cold and heat tolerance differed among most populations. The high-elevation populations displayed increased tolerance to the cold (faster CCRT) and greater plasticity. For high-temperature tolerance, we found heat tolerance was not associated with altitude; instead, greater tolerance to the heat was correlated with increased plasticity at higher temperatures. These current findings provide insight into thermal adaptation and factors that contribute to phenotypic diversity by revealing physiological variance among populations

Reduced tillage, but not organic matter input, increased nematode diversity and food web stability in European long‐term field experiments

Soil nematode communities and food web indices can inform about the complexity, nutrient flows and decomposition pathways of soil food webs, reflecting soil quality. Relative abundance of nematode feeding and life‐history groups are used for calculating food web indices, i.e., maturity index (MI), enrichment index (EI), structure index (SI) and channel index (CI). Molecular methods to study nematode communities potentially offer advantages compared to traditional methods in terms of resolution, throughput, cost and time. In spite of such advantages, molecular data have not often been adopted so far to assess the effects of soil management on nematode communities and to calculate these food web indices. Here, we used high‐throughput amplicon sequencing to investigate the effects of tillage (conventional vs. reduced) and organic matter addition (low vs. high) on nematode communities and food web indices in 10 European long‐term field experiments and we assessed the relationship between nematode communities and soil parameters. We found that nematode communities were more strongly affected by tillage than by organic matter addition. Compared to conventional tillage, reduced tillage increased nematode diversity (23% higher Shannon diversity index), nematode community stability (12% higher MI), structure (24% higher SI), and the fungal decomposition channel (59% higher CI), and also the number of herbivorous nematodes (70% higher). Total and labile organic carbon, available K and microbial parameters explained nematode community structure. Our findings show that nematode communities are sensitive indicators of soil quality and that molecular profiling of nematode communities has the potential to reveal the effects of soil management on soil quality

Different Patterns of Colonization of \u3cem\u3eOxalis alpina\u3c/em\u3e in the Sky Islands of the Sonoran Desert via Pollen and Seed Flow

Historical factors such as climatic oscillations during the Pleistocene epoch have dramatically impacted species distributions. Studies of the patterns of genetic structure in angiosperm species using molecular markers with different modes of inheritance contribute to a better understanding of potential differences in colonization and patterns of gene flow via pollen and seeds. These markers may also provide insights into the evolution of reproductive systems in plants. Oxalis alpina is a tetraploid, herbaceous species inhabiting the Sky Island region of the southwestern United States and northern Mexico. Our main objective in this study was to analyze the influence of climatic oscillations on the genetic structure of O. alpina and the impact of these oscillations on the evolutionary transition from tristylous to distylous reproductive systems. We used microsatellite markers and compared our results to a previous study using chloroplast genetic markers. The phylogeographic structure inferred by both markers was different, suggesting that intrinsic characteristics including the pollination system and seed dispersal have influenced patterns of gene flow. Microsatellites exhibited low genetic structure, showed no significant association between geographic and genetic distances, and all individual genotypes were assigned to two main groups. In contrast, chloroplast markers exhibited a strong association between geographic and genetic distance, had higher levels of genetic differentiation, and were assigned to five groups. Both types of DNA markers showed evidence of a northward expansion as a consequence of climate warming occurring in the last 10,000 years. The data from both types of markers support the hypothesis for several independent transitions from tristyly to distyly

The effect of intergroup contact on solidarity-based collective action is mediated by reductions in SDO

This paper explores the impact of positive and negative intergroup contact on advantaged group members’ willingness to engage in collective action on behalf of disadvantaged outgroups, and the meditational role of social dominance orientation (SDO) in this process. SDO captures an individuals’ ideological support for inequality. If contact is going to promote collective action to reduce inequality amongst the advantaged group, it must be expected to influence their ideological beliefs about hierarchy. In Study 1 only positive, and not negative contact was found to be associated with Whites’ support for the Black Lives Matter movement, mediated by reductions in SDO. In Study 2, both positive and negative contact were associated respectively, with more or less support for collective action to protect the rights of European immigrants during Brexit negotiations. While positive contact was associated with reduced SDO and more support for collective action amongst British nationals, negative contact was associated with increased SDO and lower support for collective action

Generalist Life Cycle Aids Persistence of Alexandrium ostenfeldii (Dinophyceae) in Seasonal Coastal Habitats of the Baltic Sea(1)

Abstract In seasonal environments, strong gradients of environmental parameters can shape life cycles of phytoplankton. Depending on the rate of environmental fluctuation, specialist or generalist strategies may be favored, potentially affecting life cycle transitions. The present study examined life cycle transitions of the toxin producing Baltic dinoflagellate Alexandrium ostenfeldii and their regulation by environmental factors (temperature and nutrients). This investigation aimed to determine if genetic recombination of different strains is required for resting cyst formation and if newly formed cysts are dormant. Field data (temperature, salinity) and sediment surface samples were collected from a site with recurrent blooms and germination and encystment experiments were conducted under controlled laboratory conditions. Results indicate a lack of seasonal germination pattern, set by an endogenous rhythm, as commonly found with other dinoflagellates from the Baltic Sea. Germination of quiescent cysts was triggered by temperatures exceeding 10°C and combined nutrient limitation of nitrogen and phosphorus or a drop in temperature from 16 to 10°C triggered encystment most efficiently. Genetic recombination was not mandatory for the formation of resting cysts, but supported higher numbers of resistant cysts and enhanced germination capacity after a resting period. Findings from this study confirm that A. ostenfeldii follows a generalist germination and cyst formation strategy, driven by strong seasonality, which may support its persistence and possibly expansion in marginal environments in the future, if higher temperatures facilitate a longer growth season. This article is protected by copyright. All rights reserved.peerReviewe

Anthropogenic N deposition alters soil organic matter biochemistry and microbial communities on decaying fine roots

Fine root litter is a primary source of soil organic matter (SOM), which is a globally important pool of C that is responsive to climate change. We previously established that ~20 years of experimental nitrogen (N) deposition has slowed fine root decay and increased the storage of soil carbon (C; +18%) across a widespread northern hardwood forest ecosystem. However, the microbial mechanisms that have directly slowed fine root decay are unknown. Here, we show that experimental N deposition has decreased the relative abundance of Agaricales fungi (−31%) and increased that of partially ligninolytic Actinobacteria (+24%) on decaying fine roots. Moreover, experimental N deposition has increased the relative abundance of lignin‐derived compounds residing in SOM (+53%), and this biochemical response is significantly related to shifts in both fungal and bacterial community composition. Specifically, the accumulation of lignin‐derived compounds in SOM is negatively related to the relative abundance of ligninolytic Mycena and Kuehneromyces fungi, and positively related to Microbacteriaceae. Our findings suggest that by altering the composition of microbial communities on decaying fine roots such that their capacity for lignin degradation is reduced, experimental N deposition has slowed fine root litter decay, and increased the contribution of lignin‐derived compounds from fine roots to SOM. The microbial responses we observed may explain widespread findings that anthropogenic N deposition increases soil C storage in terrestrial ecosystems. More broadly, our findings directly link composition to function in soil microbial communities, and implicate compositional shifts in mediating biogeochemical processes of global significance.Experimental nitrogen deposition (ca. 20 years) has slowed fine root decay and increased soil carbon across a widespread northern hardwood forest ecosystem, but the microbial mechanisms underlying this response are unknown. Here, we show that experimental N deposition has reduced the relative abundance of ligninolytic fungi and increased that of bacteria with weaker ligninolytic capacity on decaying fine root litter. These responses are correlated with an accumulation of lignin‐derived compounds in soil organic matter, of which fine root litter is the primary source. Thus, anthropogenic nitrogen deposition may enhance terrestrial carbon storage by altering microbial community composition on decaying fine roots.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151954/1/gcb14770.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151954/2/gcb14770_am.pd

Optimising time-limited non-pharmaceutical interventions for COVID-19 outbreak control

Retrospective analyses of the non-pharmaceutical interventions (NPIs) used to combat the ongoing COVID-19 outbreak have highlighted the potential of optimizing interventions. These optimal interventions allow policymakers to manage NPIs to minimize the epidemiological and human health impacts of both COVID-19 and the intervention itself. Here, we use a susceptible-infectious-recovered (SIR) mathematical model to explore the feasibility of optimizing the duration, magnitude and trigger point of five different NPI scenarios to minimize the peak prevalence or the attack rate of a simulated UK COVID-19 outbreak. An optimal parameter space to minimize the peak prevalence or the attack rate was identified for each intervention scenario, with each scenario differing with regard to how reductions to transmission were modelled. However, we show that these optimal interventions are fragile, sensitive to epidemiological uncertainty and prone to implementation error. We highlight the use of robust, but suboptimal interventions as an alternative, with these interventions capable of mitigating the peak prevalence or the attack rate over a broader, more achievable parameter space, but being less efficacious than theoretically optimal interventions. This work provides an illustrative example of the concept of intervention optimization across a range of different NPI strategies. This article is part of the theme issue 'Modelling that shaped the early COVID-19 pandemic response in the UK'

Factors affecting young adults’ willingness to try novel health-enhancing nature-based products

One of the megatrends that affects consumers' preferences is a growing interest in health, well-being and self-care. This study explores consumer perceptions of a health-enhancing nature-based substance. Based on a survey data (N = 944) collected among national and international students in Finland, we examined factors that affect young adults' willingness to try products containing the substance. The results showed a relatively high willingness to try the products, particularly among female and non-Finnish respondents. Relationship to nature and beliefs related to the health benefits or risks of soil microbes influenced willingness to try products. The results highlight the importance of accounting for consumer perceptions in the innovation process.Peer reviewe

Application of a novel molecular method to age free-living wild Bechstein's bats

The age profile of populations fundamentally affects their conservation status. Yet, age is frequently difficult to assess in wild animals. Here, we assessed the use of DNA methylation of homologous genes to establish the age structure of a rare and elusive wild mammal: the Bechstein's bat (Myotis bechsteinii). We collected 62 wing punches from individuals whose ages were known as a result of a long‐term banding study. DNA methylation was measured at seven CpG sites from three genes, which have previously shown age‐associated changes in humans and laboratory mice. All CpG sites from the tested genes showed a significant relationship between DNA methylation and age, both individually and in combination (multiple linear regression R2 = 0.58, p < 0.001). Despite slight approximation around estimates, the approach is sufficiently precise to place animals into practically useful age cohorts. This method is of considerable practical benefit as it can reliably age individual bats. It is also much faster than traditional capture–mark–recapture techniques, with the potential to collect information on the age structure of an entire colony from a single sampling session to better inform conservation actions for Bechstein's bats. By identifying three genes where DNA methylation correlates with age across distantly related species, this study also suggests that the technique can potentially be applied across a wide range of mammals