General Response Patterns Research Articles

Prey responses to direct and indirect predation risk cues reveal the importance of multiple information sources.

Prey can use several information sources (cues) to assess predation risk and avoid predation with a variety of behavioural responses (e.g., changes in activity, foraging, vigilance, social behaviour, space use, and reproductive behaviour). Direct cues produced by predators and indirect cues from environmental features or conspecific and heterospecific prey generally provide different types of information about predation risk. Despite widespread interest in understanding behavioural antipredator responses to direct and indirect cues, a clear general pattern of relative response strength across taxa and environments has yet to emerge. We conducted a meta-analysis of studies (N = 113 articles and 999 effect sizes taken from a search of over 7500 articles) testing behavioural responses to direct and indirect cues of predation risk, and their combination, across terrestrial and aquatic ecosystems. We further contrasted if effects were moderated by ecosystem type (terrestrial, marine, or freshwater), cue source (predator, conspecific, heterospecific, or environmental feature), or sensory modality (visual, auditory, or chemosensory). Overall, there were strong effects of risk cues on prey behaviour. We found that prey responded more strongly when both types of cues were presented together compared with either cue in isolation, which was driven by changes in prey activity levels but not other behaviours. There was no general pattern in response strength to direct compared with indirect cues. Responses to these cues were moderated by interactions between environment, cue source, and cue sensory modality (e.g., visual cues elicited stronger responses than other modalities, and responses to conspecific chemosensory cues were stronger than those to predator chemosensory cues in aquatic systems). These results suggest that rather than a broad framework of direct and indirect cues, the specific context of the system should be considered in tests and predictions of how prey respond to risk to elucidate general patterns of antipredator responses.

Specific responses in soil metabolite alteration and fungal community decline to the long-term monocropping of lisianthus

Continuous cropping obstacle (CCO) is becoming a serious threat to the quality production of lisianthus (Eustoma grandiflorum). However, investigations of the causal mechanism of CCO in lisianthus are still lacking. To this end, soil biotic dynamics and metabolites alterations were illuminated using metagenomic sequencing and metabolomic profiling along a chronosequence that has cultivated lisianthus from 2 weeks to 6 years. Soil EC and nutrient contents increased significantly as the cultivation duration prolonged. Fungal community has undergone significant decline in their diversity and biomass. Nevertheless, no apparent accumulation of pathogenicity-related microbes was observed along the investigated chronosequence. The alterations of soil metabolites along the chronosequence reflect the decline of microbial activity, the accumulation of phytotoxic compounds and the loss of metabolite involved in beneficial plant-microbe interactions. As a result, lisianthus plants in the longer continuous cropping soil experienced stressful condition as evidenced by the increasing trend of stress responsive metabolites and the overall soil function deterioration as indicated by soil enzymes. Hierarchical partitioning analysis showed that the investigated factors can explain a total of 92.25 % of the variations in the soil function degradation. Of which, soil metabolite alteration was the most important factor in explaining the CCO development, covering 24.55 % of the explainable variations. Spearman's correlation results further implied that soil metabolite alteration is the main driver in the development of CCO in lisianthus, especially by mediating the plant-microbes interactions. Our findings revealed a general pattern of soil biotic and abiotic response to the continuous monocropping of lisianthus and suggest that the overcome of the CCO in lisianthus requires further studies focusing on the crucial metabolites and their interactions with microbes.

Soil moisture alters the responses of alpine ecosystem productivity to environmental factors, especially VPD, on the Qinghai-Tibetan Plateau

Water availability, which can be represented by soil water content (SWC), plays a crucial role in plant growth and productivity across the cold and arid Qinghai-Tibetan Plateau. However, the indirect effects of SWC are less well understood, and a more comprehensive understanding of its regulating effects may enhance the recognition of its importance, as this factor is pivotal for accurately predicting the future response of alpine ecosystems to climate change. In this study, in situ eddy covariance observation data from typical alpine ecosystems and satellite data covering the Qinghai-Tibetan region were used to comprehensively reveal the effects of SWC on ecosystem productivity. The results indicated that SWC played an important role in regulating the responses of gross primary productivity (GPP) to other environmental factors over both time and space, especially in terms of the responses of GPP to vapor pressure deficit (VPD). The regulating effect can be summarized as follows: there was a specific SWC value (SWC = 0.24 m3 m−3 on the Qinghai-Tibetan Plateau) above which SWC was no longer the primary limiting factor. The responses of GPP to certain environmental factors shifted from negative to positive when the SWC increased above this value. The responses of GPP to VPD exhibited the highest sensitivity to the regulating effects of SWC, with a general response pattern found across different temporal and spatial scales. The findings revealed divergent responses of GPP to environmental factors under different SWC conditions and between arid and humid regions, emphasizing the importance of soil water conditions. These findings suggest that water conditions should be given primary consideration in global change studies.

Food quantity and quality modulates inducible defenses in a common predator–prey system

AbstractZooplankton displays different inducible defenses against invertebrate and vertebrate predators. The response pattern to gape‐limited invertebrate predators involves increased somatic growth and offspring body size but delayed maturity and reduced offspring numbers. In contrast to this general pattern, the freshwater model organism Daphnia magna has been reported to exhibit a different response when encountering the gape‐limited tadpole shrimp Triops cancriformis. Under laboratory conditions, D. magna showed increased somatic growth, earlier maturation, and an increase in both offspring number and size. We propose here that the discrepancy between the previously observed and the theory‐based response patterns against invertebrate predators is due to differences in food availability in the applied laboratory settings and assessed whether the defensive response of D. magna against T. cancriformis is modulated differently by food quantity and quality. We found a strong impact of food quantity and quality on the defense response of D. magna to T. cancriformis kairomones. The prey seem to be able to overcome trade‐offs between morphological defense traits and reproductive traits, but distinctly between high food quantity and high food quality. Thereby, reproductive traits were preferred over morphological defenses. Furthermore, the removal of particles from the T. cancriformis‐conditioned water caused a defense pattern in D. magna that was consistent with the general response pattern known from other invertebrate predators, thus explaining the described discrepancy to previous studies with T. cancriformis. Our study highlights the importance of assessing food‐related effects on predator–prey interactions to understand trophic relationships and food web processes.

Global plant responses to intensified fire regimes

AbstractAimGlobal change factors, such as warming, heatwaves, droughts and land‐use changes, are intensifying fire regimes (defined here as increasing frequency or severity of fires) in many ecosystems worldwide. A large body of local‐scale research has shown that such intensified fire regimes can greatly impact on ecosystem structure and function through altering plant communities. Here, we aim to find general patterns of plant responses to intensified fire regimes across climates, habitats and fire regimes at the global scale.LocationWorldwide.Time periodStudies published 1962–2023.Major taxa studiedWoody plants, herbs and bryophytes.MethodsWe carried out a global systematic review and meta‐analysis of the response of plant abundance, diversity and fitness to increased fire frequency or severity. To assess the context dependency of those responses, we tested the effect of the following variables: fire regime component (fire frequency or severity), time since the last fire, fire type (wildfire or prescribed fire), historical fire regime type (surface or crown fire), plant life form (woody plant, herb or bryophyte), habitat type and climate.ResultsIntensified fire regimes reduced overall plant abundance (Hedges' d = −0.24), diversity (d = −0.27), and fitness (d = −0.69). Generally, adverse effects of intensified fire regimes on plants were stronger due to increased severity than frequency, in wildfires compared to prescribed fires, and at shorter times since fire. Adverse effects were also stronger for woody plants than for herbs, and in conifer and mixed forests than in open ecosystems (e.g. grasslands and shrublands).Main conclusionsIntensified fire regimes can substantially alter plant communities in many ecosystems worldwide. Plant responses are influenced by the specific fire regime component that is changing and by the biotic and abiotic conditions.

Elucidating cellular response to treatment with viral immunotherapies in pediatric high-grade glioma and medulloblastoma

HSV G207, a double-stranded, DNA virus, and the polio:rhinovirus chimera, PVSRIPO, a single positive-strand RNA virus, are viral immunotherapies being used to treat pediatric malignant brain tumors in clinical trials. The purpose of this work is to elucidate general response patterns and putative biomarkers of response. Multiple pediatric high-grade glioma and medulloblastoma cell lines were treated with various multiplicities of infection of G207 or PVSRIPO. There was a significant inverse correlation between expression of one HSV cellular receptor, CD111, and the lethal dose of 50% of cells (LD50) of cells treated with G207 (r = -0.985, P<0.001) but no correlation between PVSRIPO cellular receptor expression (CD155) and LD50. RNA sequencing of control cells and cells treated for 8 and 24 h revealed that there were few shared differentially expressed (DE) genes between cells treated with PVSRIPO and G207: GCLM, LANCL2, and RBM3 were enriched whilst ADAMTS1 and VEGFA were depleted. Likewise, there were few shared DE genes enriched between medulloblastoma and high-grade glioma cell lines treated with G207: GPSM2, CHECK2, SEPTIN2, EIF4G2, GCLM, GDAP1, LANCL2, and PWP1. Treatment with G207 and PVSRIPO appear to cause disparate gene enrichment and depletion suggesting disparate molecular mechanisms in malignant pediatric brain tumors.

The impact of urbanisation on chipmunks, arboreal and flying squirrels: a global systematic review

Abstract The current, rapid urbanisation process impacts global biodiversity and can be a driver for phenotypic changes in mammals that persist in cities. Animals display different response strategies in urban environments compared to natural areas, but patterns may differ among species. To better comprehend this process, we focused on a limited number of species that are present in many urban green spaces around the globe. The aim of this systematic review is to investigate which response strategies chipmunks, arboreal and flying squirrels use to cope with urban environments, exploring whether there are general response patterns, and to reveal potential adaptations to life in urban areas. We included studies that compared trait differences among conspecifics living in different areas along an urbanisation gradient (rural–urban) and studies comparing individuals or populations between urban areas with different environmental characteristics. The effects of urbanisation on chipmunks, arboreal and flying squirrels, at the individual and at the population levels, were identified in nine topics. Included articles explored at least one of these topics and their key findings were described. Effects of urbanisation are evident in all considered topics. However, we found contrasting patterns between species or even among individuals of the same species studied in different geographical areas. Overall, we reported two knowledge gaps: some phenotypic traits were considered in few studies, and many species, especially those living in the Global South, where urban growth rate is higher, have not been studied. This systematic review suggests that urbanisation can be an important driver for adaptation in small mammals, underlining the complexity and differentiation of response patterns. Since target species have important ecological and social roles, additional comparative studies, increasing our understanding of processes that determine their presence in cities, are essential for urban green planning which aims to conserve biodiversity.

Soil microorganisms buffer the reduction in plant growth and physiological performance under combined abiotic stress in the halophyte Salicornia ramosissima

The impact of multifactorial abiotic stress combinations on plant functional responses remains controversial, and general patterns of response are yet to emerge. This knowledge gap is particularly relevant for species with innate tolerance to environmental stress. Using the halophyte Salicornia ramosissima as a model species, we performed a multifactorial study with 16 experimental scenarios that included or not beneficial microorganisms in order to quantify their impact on plant growth, photosynthetic performance, osmotic adjustment and ion homeostasis. The experimental scenarios were characterized by the combination of four factors with two levels (salinity: 171 and 510 mM NaCl; water stress: yes and no; temperature min/max range: 14/25 and 18/29ºC and atmospheric CO2 concentration: 400 and 700 ppm). A plant growth-promoting rhizobacteria (PGPR) consortium was used as a proxy for positive biological interaction. The results revealed that the multifactorial stress combinations triggered unique functional responses, depending on the stress factors involved. However, there was an overall more negative impact on plant functional traits under the most extreme scenario (i.e., 510 mM NaCl + water stress + high temperature). Interestingly, the presence of PGPR was able to reverse this negative influence, although this effect was negligible under non-stressful conditions. Furthermore, the positive effect of PGPR was even magnified when coexisting with elevated atmospheric CO2 concentration. This response is associated with mitigation of the negative impacts of suboptimal factor combinations on plant growth, photosynthetic performance/efficiency, and water/nutrient homeostasis. Therefore, we conclude that the positive impact of microorganisms on halophyte tolerance in complex environmental matrices would only be determinant under extreme conditions in which plant intrinsic tolerance mechanisms would not be sufficient. Remarkably, this effect could be accentuated by increasing atmospheric CO2 concentration.

5 Translating developmental neurotoxicity for the public: A large, international, randomized-control trial investigating children's environmental health literacy

Objective:Exposure to toxic chemicals during early brain development increases the risk of neurodevelopmental problems in children. Parents' and prospective parents' understanding of the impact of toxic chemicals on brain development and the efficacy of translation tools for children's environmental health literacy are poorly understood. We developed and validated a questionnaire, PRevention of Toxic chemicals in the Environment for Children Tool (PRoTECT) to assess knowledge of toxic chemicals and neurodevelopment, intentions to reduce exposures to toxic chemicals, and preferences for actions by government and industry to prevent neurodevelopmental disorders. Using PRoTECT, we surveyed people of child-bearing age across five countries (Canada, United States (US), United Kingdom (UK), India, and Australia) to identify general patterns of responses on this questionnaire by demographic characteristics, including country, age, gender, parental status, pregnancy status, and education. We also employed a randomized control design to examine the efficacy of a knowledge translation video to instill knowledge and prompt behavioral changes to reduce exposures to toxic chemicals immediately following its presentation and after a six-week follow-up period.Participants and Methods:We recruited 15,594 participants, ages 18 to 45, via CloudResearch's Prime Panels between October-December 2021. After completing the PRoTECT survey, participants were randomly assigned to watch the video Little Things Matter: Impact of Toxic Chemicals on Brain Development (i.e., the experimental group) or to serve as the control group. Next, both groups answered a series of questions to assess their knowledge of toxic chemicals, their intentions to reduce exposures to toxic chemicals, and barriers to changing their behaviours. After six-weeks, we recontacted a subset (N=4,842) of participants to repeat PRoTECT and answer the same series of behavioural questions assessing whether they modified any of their behaviours to reduce exposure and why or why not.Results:Most participants (i.e., 75-85%) agreed that toxic chemicals can impact brain development and endorsed preferences (∼85%) for allocating more resources to prevent neurodevelopmental disorders, especially people with higher education, parents and pregnant women, and people who lived in India. Despite this, a large proportion of participants (∼50%) trusted industry and believed that government effectively regulated toxic chemicals. After the six-week follow-up, experimental participants showed greater changes in scores on PRoTECT (i.e., between 5-15% change), indicating greater knowledge about harms posed by toxic chemicals, more intentions to reduce exposure, and stronger preferences for prevention as compared to the control group. Differences were larger among people from the US, those who were more highly educated, and people in their thirties. However, the differences between groups in making behavioural changes to reduce exposures were attenuated at the six-week follow up as compared to baseline. Significant barriers to reduce exposure to toxic chemicals were reported by both groups and included cost, inconvenience, and not knowing how to determine whether a product is non-toxic or where to purchase non-toxic products.Conclusions:We observed greater knowledge and concerns about toxic chemicals among more affluent respondents, pregnant women and parents, and people living in India across both groups. While the video enhanced participants' knowledge about toxic chemicals and intentions to reduce exposure, they indicated that barriers hindered them from making behavioral changes.

Examining the latent structure and correlates of sensory reactivity in autism: a multi-site integrative data analysis by the autism sensory research consortium

BackgroundDifferences in responding to sensory stimuli, including sensory hyperreactivity (HYPER), hyporeactivity (HYPO), and sensory seeking (SEEK) have been observed in autistic individuals across sensory modalities, but few studies have examined the structure of these “supra-modal” traits in the autistic population.MethodsLeveraging a combined sample of 3868 autistic youth drawn from 12 distinct data sources (ages 3–18 years and representing the full range of cognitive ability), the current study used modern psychometric and meta-analytic techniques to interrogate the latent structure and correlates of caregiver-reported HYPER, HYPO, and SEEK within and across sensory modalities. Bifactor statistical indices were used to both evaluate the strength of a “general response pattern” factor for each supra-modal construct and determine the added value of “modality-specific response pattern” scores (e.g., Visual HYPER). Bayesian random-effects integrative data analysis models were used to examine the clinical and demographic correlates of all interpretable HYPER, HYPO, and SEEK (sub)constructs.ResultsAll modality-specific HYPER subconstructs could be reliably and validly measured, whereas certain modality-specific HYPO and SEEK subconstructs were psychometrically inadequate when measured using existing items. Bifactor analyses supported the validity of a supra-modal HYPER construct (ωH = .800) but not a supra-modal HYPO construct (ωH = .653), and supra-modal SEEK models suggested a more limited version of the construct that excluded some sensory modalities (ωH = .800; 4/7 modalities). Modality-specific subscales demonstrated significant added value for all response patterns. Meta-analytic correlations varied by construct, although sensory features tended to correlate most with other domains of core autism features and co-occurring psychiatric symptoms (with general HYPER and speech HYPO demonstrating the largest numbers of practically significant correlations).LimitationsConclusions may not be generalizable beyond the specific pool of items used in the current study, which was limited to caregiver report of observable behaviors and excluded multisensory items that reflect many “real-world” sensory experiences.ConclusionOf the three sensory response patterns, only HYPER demonstrated sufficient evidence for valid interpretation at the supra-modal level, whereas supra-modal HYPO/SEEK constructs demonstrated substantial psychometric limitations. For clinicians and researchers seeking to characterize sensory reactivity in autism, modality-specific response pattern scores may represent viable alternatives that overcome many of these limitations.

Hypothesis-generating analysis of the impact of non-damaging metabolic acidosis on the transcriptome of different cell types: Integrated stress response (ISR) modulation as general transcriptomic reaction to non-respiratory acidic stress?

Extracellular pH is an important parameter influencing cell function and fate. Microenvironmental acidosis accompanies different pathological situations, including inflammation, hypoxia and ischemia. Research focussed mainly on acidification of the tumour micromilieu and the possible consequences on proliferation, migration and drug resistance. Much less is known regarding the impact of microenvironmental acidosis on the transcriptome of non-tumour cells, which are exposed to local acidosis during inflammation, hypoxia, ischemia or metabolic derailment. In the present hypothesis-generating study, we investigated the transcriptional impact of extracellular acidosis on five non-tumour cell types of human and rat origin, combining RNA-Sequencing and extensive bioinformatics analyses. For this purpose, cell type-dependent acidosis resiliences and acidosis-induced transcriptional changes within these resilience ranges were determined, using 56 biological samples. The RNA-Sequencing results were used for dual differential-expression analysis (DESeq and edgeR) and, after appropriate homology mapping, Gene Ontology enrichment analysis (g:Profiler), Ingenuity Pathway Analysis (IPA®), as well as functional enrichment analysis for predicted upstream regulators, were performed. Extracellular acidosis led to substantial, yet different, quantitative transcriptional alterations in all five cell types. Our results identify the regulator of the transcriptional activity NCOA5 as the only general acidosis-responsive gene. Although we observed a species- and cell type-dominated response regarding gene expression regulation, Gene Ontology enrichment analysis and upstream regulator analysis predicted a general acidosis response pattern. Indeed, they suggested the regulation of four general acidosis-responsive cellular networks, which comprised the integrated stress response (ISR), TGF-β signalling, NFE2L2 and TP53. Future studies will have to extend the results of our bioinformatics analyses to cell biological and cell physiological validation experiments, in order to test the refined working hypothesis here.

Changes in the activity of soil enzymes after fire

Fire can have widespread impacts on biogeochemical processes of carbon (C) and nutrient cycling. Soil extracellular enzyme activity (EEA) plays crucial roles in biogeochemical processes, while the general response pattern of EEAs to fire remains elusive. Here, we synthesized 1064 paired observations of fire effects on eight soil EEAs of β-D-Cellobiosidase (CB), β-1,4-Glucosidase (BG), β-1,4-Xylosidase (XYL), N-acetyl-glucosaminidase (NAG), urease (URE), phosphatase (PHO), peroxidase (PER), and phenol oxidase (POX) from 51 publications on a global scale. Results showed that fire significantly decreased hydrolases of C acquisition (sum of CB, BG, and XYL), N acquisition (sum of URE and NAG), and P acquisition (PHO) EEAs by 21.0%, 25.5%, and 29.9%, respectively. In contrast, fire significantly enhanced oxidative enzyme (sum of PER and POX) activities by 12.4%. Among all experimental, environmental, and soil variables, ecosystem type and soil C and N had greater effects on the various responses of EEAs to fire across studies. In addition, changes in soil C and N pools and microbial biomass were positively correlated with changes in hydrolytic EEAs but negatively correlated with changes in oxidative EEAs. These results suggest that the differential fire effects on soil hydrolytic and oxidative EEAs may be a crucial mechanism regulating soil C and nutrient cycling following fire events.

Single-cell RNA sequencing reveals the local cell landscape in mouse epididymal initial segment during aging

BackgroundMorphological and functional alterations in aging reproductive organs result in decreased male fertility. The epididymis functions as the transition region for post-testicular sperm maturation. And we have previously demonstrated that the epididymal initial segment (IS), a region of the reproductive tract essential for sperm maturation and capacitation, undergoes considerable histological changes and chronic immune activation in mice during aging. However, the local aging-associated cellular and molecular changes in the aged epididymal IS are poorly understood.ResultsWe conducted single-cell RNA sequencing analysis on the epididymal IS of young (3-month-old) and old (21-month-old) mice. In total, 10,027 cells from the epididymal IS tissues of young and old mice were obtained and annotated. The cell composition, including the expansion of a principal cell subtype and Ms4a4bHiMs4a6bHi T cells, changed with age. Aged principal cells displayed multiple functional gene expression changes associated with acrosome reaction and sperm maturation, suggesting an asynchronous process of sperm activation and maturation during epididymal transit. Meanwhile, aging-related altered pathways in immune cells, especially the “cell chemotaxis” in Cx3cr1Hi epididymal dendritic cells (eDCs), were identified. The monocyte-specific expression of chemokine Ccl8 increased with age in eDCs. And the aged epididymal IS showed increased inflammatory cell infiltration and cytokine secretion. Furthermore, cell–cell communication analysis indicated that age increased inflammatory signaling in the epididymal IS.ConclusionContrary to the general pattern of lower immune responses in the male proximal genital tract, we revealed an inflammaging status in mouse epididymal initial segment. These findings will allow future studies to enable the delay of male reproductive aging via immune regulation.

Sex-specific innate immunity and ageing in long-lived fresh water turtles (Kinosternon flavescens: Kinosternidae)

BackgroundThe progressive deregulation of the immune system with age, termed immunosenescence, has been well studied in mammalian systems, but studies of immune function in long-lived, wild, non-mammalian populations are scarce. In this study we leverage a 38-year mark-recapture study to quantify the relationships among age, sex, survival, reproductive output and the innate immune system in a long-lived reptile, yellow mud turtles (Kinosternon flavescens; Testudines; Kinosternidae).MethodsWe estimated rates of survival and age-specific mortality by sex based on mark-recapture data for 1530 adult females and 860 adult males over 38 years of captures. We analyzed bactericidal competence (BC), and two immune responses to foreign red blood cells - natural antibody-mediated haemagglutination (NAbs), and complement-mediated haemolysis ability (Lys) - in 200 adults (102 females; 98 males) that ranged from 7 to 58 years of age captured in May 2018 during their emergence from brumation, and for which reproductive output and long-term mark-recapture data were available.ResultsWe found that females are smaller and live longer than males in this population, but the rate of accelerating mortality across adulthood is the same for both sexes. In contrast, males exhibited higher innate immunity than females for all three immune variables we measured. All immune responses also varied inversely with age, indicating immunosenescence. For females that reproduced in the preceding reproductive season, egg mass (and therefore total clutch mass) increased with age,. In addition to immunosenescence of bactericidal competence, females that produced smaller clutches also had lower bactericidal competence.ConclusionsContrary to the general vertebrate pattern of lower immune responses in males than females (possibly reflecting the suppressive effects of androgens), we found higher levels of all three immune variables in males. In addition, contrary to previous work that found no evidence of immunosenescence in painted turtles or red-eared slider turtles, we found a decrease in bactericidal competence, lysis ability, and natural antibodies with age in yellow mud turtles.

Variations in leaf anatomical characteristics drive the decrease of mesophyll conductance in poplar under elevated ozone.

Decline in mesophyll conductance (gm ) plays a key role in limiting photosynthesis in plants exposed to elevated ozone (O3 ). Leaf anatomical traits are known to influence gm , but the potential effects of O3 -induced changes in leaf anatomy on gm have not yet been clarified. Here, two poplar clones were exposed to elevated O3 . The effects of O3 on the photosynthetic capacity and anatomical characteristics were assessed to investigate the leaf anatomical properties that potentially affect gm . We also conducted global meta-analysis to explore the general response patterns of gm and leaf anatomy to O3 exposure. We found that the O3 -induced reduction in gm was critical in limiting leaf photosynthesis. Changes in liquid-phase conductance rather than gas-phase conductance drive the decline in gm under elevated O3, and this effect was associated with thicker cell walls and smaller chloroplast sizes. The effects of O3 on palisade and spongy mesophyll cell traits and their contributions to gm were highly genotype-dependent. Our results suggest that, while anatomical adjustments under elevated O3 may contribute to defense against O3 stress, they also cause declines in gm and photosynthesis. These results provide the first evidence of anatomical constraints on gm under elevated O3 .

Contrasting responses of early‐ and late‐season plant phenophases to altered precipitation

Precipitation is a key driver of plant phenology in addition to temperature and photoperiod. Although a few studies have explored phenological responses to altered precipitation, the general patterns of sequential phenophase responses and their potential drivers remain elusive. Here, we conducted a meta‐analysis of the responses of ten phenophases to altered precipitation from 63 manipulative experiments. We show that early‐season (leaf out, first flowering, last flowering and first fruiting) and late‐season phenophases (last fruiting and leaf colouring) shifted in opposite directions with precipitation changes. Advanced early‐season phenophases and delayed late‐season phenophases led to extensions of the reproductive phase and growing season with precipitation increases. Similarly, delayed leaf out and advanced leaf colouring resulted in a shorter length of the growing season with precipitation decreases. We further found that the responses of phenophases were less pronounced in wetter regions than in drier regions, regardless of the precipitation increase or decrease treatments. In addition, the phenophase responses were mediated by the seasons when the precipitation changes were imposed. For instance, early‐season phenophases were more responsive to winter or spring precipitation increases, but late‐season phenophases were only significantly affected by spring–autumn precipitation increases. These findings will help improve the forecasts of plant phenological responses to precipitation changes and will assist in the incorporation of precipitation representations into next‐generation phenological models.

A research agenda for nonvascular photoautotrophs under climate change.

Nonvascular photoautotrophs (NVP), including bryophytes, lichens, terrestrial algae, and cyanobacteria, are increasingly recognized as being essential to ecosystem functioning in many regions of the world. Current research suggests that climate change may pose a substantial threat to NVP, but the extent to which this will affect the associated ecosystem functions and services is highly uncertain. Here, we propose a research agenda to address this urgent question, focusing on physiological and ecological processes that link NVP to ecosystem functions while also taking into account the substantial taxonomic diversity across multiple ecosystem types. Accordingly, we developed a new categorization scheme, based on microclimatic gradients, which simplifies the high physiological and morphological diversity of NVP and world-wide distribution with respect to several broad habitat types. We found that habitat-specific ecosystem functions of NVP will likely be substantially affected by climate change, and more quantitative process understanding is required on (1) potential for acclimation, (2) response to elevated CO2 , (3) role of the microbiome, and (4) feedback to (micro)climate. We suggest an integrative approach of innovative, multimethod laboratory and field experiments and ecophysiological modelling, for which sustained scientific collaboration on NVP research will be essential.

Anatomical, physiological, biochemical and molecular responses of Eucalyptus spp. under water deficit conditions and characteristics of Tunisian arid species: an overview

The genus Eucalyptus occurs in a large range of environmental conditions, mainly arid/semi-arid areas. It includes species with high capacity to survive with extremely low water potential. For that, our review shows an important effect of drought on Eucalyptus spp. plants’ resistance mechanisms and management strategies. In fact, water stress acts directly on growth, productivity, yield, it affects also response to pests and diseases, disturbs wood formation and essential oil yield. However, the general patterns of response to water stress varied among species, genotypes, hybrids and clones. To assume, reducing water loss in eucalyptus species is manifested by reducing leaves area, reducing gas exchange, increasing water uptake thanks to a prolific and deep root systems. A greater accumulation of osmolytes that gives rise to osmotic adjustment including carbohydrates especially cyclitols and quercitol, other amino acids and organic acids, also some proteins which play a vital role in sustaining cellular functions under drought conditions. More than that, water stress increases mainly the levels of pigments, chlorophyll fluorescence parameters, malondialdehyde (MDA), abscisic acid (ABA) and the biosynthesis of triacylglycerols (TAGs) in Eucalyptus species.

Soil enzyme activities after application of fungicide Quadris&lt;sup&gt;R&lt;/sup&gt; at increasing concentration rates

The study aimed to assess the effects of fungicide QuadrisR on activities of soil enzymes contributed to soil nutrient turnover. A batch laboratory experiment with QuadrisR-amended (0 mg/kg ds (dry soil) – 35.00 mg/kg ds) loamy sand soil was conducted, and shifts in soil physical environments and enzyme activities (beta-glucosidase, urease, acid and alkaline phosphatases, arylsulfatase and dehydrogenase) were evaluated on experimental days 1, 30, 60, 90 and 120. The results indicated that QuadrisR changed both soil properties and enzyme activities. The most sensitive environmental parameter to fungicide input was soil pH. The most suscaptable to QuadrisR enzymes were dehydrogenase and arylsulfatase, and the most resistant – urease. The mean overall dehydrogenase activity decreased by 33%, whereas the profile of arylsulfatase activity tended to permanent decrease over time. The general pattern of enzyme responses to QuadrisR was an immediate-early (days 1 – 30) decline of enzyme activities after fungicide application, except that of arylsulfatase. Beta-glucosidase manifested a temporal profile of steady-state stimulation under the lowest (2.90 mg/kg ds) and low sensitivity to the higher (14.65 mg/kg ds and 35.00 mg/kg ds) fungicide concentrations.

General trends of different inter-row vegetation management affecting vine vigor and grape quality across European vineyards

Cover crops in vineyards do provide many important ecosystem functions, however wine growers are often reluctant to incorporate cover crops into their vineyard management as they are concerned about competition regarding water and nutrient availability. The objective of this study was to define the effects of three standard inter-row vegetation management strategies on vine growth and grape quality in different European regions. We hypothesize that general patterns of responses to different inter-row management can be identified across European vine growing regions independent of local climate and soil conditions. Data were collected in 2016 and 2017 in commercial vineyards located in five European temperate wine growing regions directly comparing standard inter-row vegetation management strategies in parallel in vineyards ranging from cover crops to bare ground through tillage or herbicide application. Vegetation management strongly influenced leaf chlorophyll content, shoot pruning weight and yeast assimilable nitrogen (YAN) in grape juice. Across countries, grape varieties and varying soil conditions, YAN consistently showed higher values in grapes separated by bare ground inter-rows as compared to inter-rows with a permanent vegetation cover. Other grape quality parameters, total soluble solids, total titratable acidity and berry weight were not or inconsistently affected across countries, preventing the prediction of generalized trends. We also observed higher values of soil organic matter in complete vegetation inter-rows. In conclusion, we identified general effects of inter-row vegetation management on vine vigor and grape quality across countries and grape varieties in different pedo-climatic conditions. Our study provides general response patterns as a basis for functional studies to develop local inter-row vegetation management strategies.