A review of open top chamber (OTC) performance across the ITEX Network

Open top chambers (OTCs) were adopted as the recommended warming mechanism by the International Tundra Experiment (ITEX) network in the early 1990’s. Since then, OTCs have been deployed across the globe. Hundreds of papers have reported the impacts of OTCs on the abiotic environment and the biota. Here we review the impacts of the OTC on the physical environment, with comments on the appropriateness of using OTCs to characterize the response of biota to warming. The purpose of this review is to guide readers to previously published work and to provide recommendations for continued use of OTCs to understand the implications of warming on low stature ecosystems. In short, the OTC is a useful tool to experimentally manipulate temperature, however the characteristics and magnitude of warming varies greatly in different environments, therefore it is important to document chamber performance to maximize the interpretation of biotic response. When coupled with long-term monitoring, warming experiments are a valuable means to understand the impacts of climate change on natural ecosystems

(A)synchrony of above- and below-ground productivity in a warming tundra biome

Arctic and alpine tundra ecosystems are experiencing accelerated warming compared to the global average, causing significant changes in plant productivity and the timing of life histories of tundra species, with cascading effects on trophic interactions and carbon cycling. However, the sparsity of long-term and spatially-varied observations hinders our understanding of how these dynamics may continue to change in a warming tundra biome. Specific knowledge gaps, often borne from limitations on year-round travel to tundra sites, hamper our ability to accurately predict the long-term trajectory of tundra phenology change, both above-ground and below-ground. In this PhD thesis, I use above- and below-ground ecological observations across spatial and temporal scales to resolve key questions about how heterogeneous tundra landscapes may respond to future warming and ecosystem change. My findings have implications for biome-scale carbon cycling and wildlife habitats. In Chapter 2, I used a geographically varied time-lapse camera imagery to analyse tundra phenology variations across microclimates and snowmelt gradients. I found that while growing seasons were consistently longer at warmer, lower-latitude sites (11 extra days for each additional 1°C in mean summer temperature). Growing season lengths did not significantly vary across warmer or colder summers and earlier or later snowmelt timing despite warmer spring temperatures consistently advancing spring green-up. I found that early-season phenology constrained the timing of much of the mid-season phenology and early senescence, but not full senescence. Green-up, mid-season, and early senescence phenophases generally occurred earlier in warmer microclimates and tracked snowmelt, although initial community-scale bud-burst and full community senescence was not related to microclimate. Across sites, I found that green-up occurred more slowly when snowmelt was earlier and faster when snowmelt was later. If growing season length remains relatively stable across space and time and is not extending into the longer snow-free autumn season, this indicates that tundra productivity and carbon sink capacity may not necessarily increase much as the climate warms. I recommend that terrestrial carbon and ecosystem modellers incorporate microclimate, interannual variations and varying metrics of phenological time into their model designs in order to more precisely forecast long-term vegetation change and carbon flux. In Chapter 3, I combined above- and below-ground plant phenology metrics to compare the relative timings and magnitudes of leaf and root growth and senescence across microclimates and plant communities at five sites across the tundra biome. I observed asynchronous growth between above-ground and below-ground plant tissue, with the below-ground season extending up to 74% beyond the onset of above-ground leaf senescence. Community type, rather than microclimate, was a key factor controlling the timing, productivity and growth rates of roots, with graminoid roots exhibiting a distinct growth ‘pulse’ later into the growing season than shrub and forb roots. My findings indicate the potential for greater below-ground carbon storage as roots grow into thawed soils that remain unfrozen for longer as the climate warms. Taken together, long-term vegetation change, an indirect response to climate warming, is more likely than climate warming alone to impact below-ground productivity and carbon cycling in the tundra biome. In Chapter 4, I used the Tea Bag Index protocol to investigate the microenvironmental controls on litter decomposition in tundra soils. I examined the extent to which the thermal sum of surface air temperature, soil moisture and permafrost thaw depth influenced litter mass loss and decomposition rates (k), and at which spatial thresholds an environmental variable becomes a reliable predictor of decomposition, Overall, I found that litter decomposition was faster and litter mass loss higher in the warmer and wetter parts of the landscape. Spatially heterogeneous belowground conditions (soil moisture and active layer depth) explained variation in decomposition metrics at local scales (< 50 m2) better than thermal sum. Surprisingly, there was no strong control of elevation or slope on litter decomposition. My results reveal that there is considerable scale dependency in the environmental controls of tundra litter decomposition, with moisture playing a greater role than the thermal sum at < 50 m2 scales. My findings indicate that variation in microenvironmental conditions will influence litter decomposition in ways that are not currently incorporated into models estimating carbon cycling with warming. In Chapter 5, I explored how animal husbandry affected changes in tundra land-surface greenness from 1985 to 2021 using Landsat satellite observations from 31 sites in Svalbard. I assessed changes in annual maximum NDVI at contemporary and historical animal husbandry sites using the Normalized Difference Vegetation Index (NDVI) to extract dates of peak-season NDVI, green-up, and plant senescence. I found that while peak-season greenness increased across all of our study sites, the greening signal was enhanced at active dog-yards and historic animal husbandry sites. In addition, the greening signal was stronger at all animal husbandry sites compared to reference ‘non-disturbed’ tundra sites. Across sites, the date of tundra vegetation greening shifted up to 0.81 days earlier, and the date of plant senescence shifted slightly later from 1985 to 2021. My analysis shows nutrient enrichment from animal husbandry can stimulate long-term increases in tundra vegetation productivity, with a lasting impact of nutrient enrichment at abandoned animal husbandry sites. In this PhD thesis, I highlight complex and interconnected factors influencing tundra plant phenology, productivity and decomposition in a period of rapid and accelerating climate change. My research demonstrates that by accounting for spatio-temporal variability across Arctic and alpine tundra landscapes, we will improve forecasts of future ecosystem change and more precisely quantify the contribution of tundra warming to the global carbon cycle

Cassiope tetragona as a dendroecological proxy : a retrospective analysis of experimental warming in the Arctic Tundra

Annual stem growth and reproductive effort of the evergreen dwarf-shrub, Cassiope tetragona, exhibit a strong positive relationship to summer temperature and have been used in dendroclimatological analyses to reconstruct climate in the High Arctic through the application of transfer function equations. Retrospective analysis of the annual growth increments have also previously been used to examine the impact of short term warming in a few tundra sites. This thesis presents a full retrospective analysis approach to reconstruct the impact of long-term experimental warming in tundra communities at Alexandra Fiord (Ellesmere Island) from before the installation of open-top-chambers in 1992 to the present day, using a before-after-control-intervention design on growth and reproduction variables. We found a positive, significant effect of experimental warming on the stem growth of C. tetragona and revealed that phenology stages (such as bud break, flowering, and fruit production) take place significantly earlier in the warming plots in comparison to the control plots. Furthermore, the relationship between both July Average and August Maximum air temperature time series at Alexandra Fiord and the annual stem growth and reproductive chronologies from the control plots were used to construct summer air temperature models with good predictive abilities, explaining up to 68% of the variance. We compared chronologies of C. tetragona samples from multiple International Tundra Experiment sites to investigate the extent to which growth and reproductive responses to experimental warming vary across the Arctic. An effect size analysis and linear mixed effects model was used to determine the fact that experimental warming has a significant and positive effect on plant growth, increasing annual stem growth by an average of 0.665 mm across the Arctic, with 60% of the overall variance in the stem growth data being explained by Region. This regional signal was also revealed in a Principal Components Analysis which included descriptive stem characteristics statistics at 23 circumarctic sites. These findings complement existing research about the warming effect of treatment on tundra plant growth and phenology, and provide novel information on the value of C. tetragona as a dendroecological proxy and the regional differences in C. tetragona growth and reproduction patterns.Arts, Faculty ofGeography, Department ofGraduat

Emotion and its management: the lens of language and social psychology

In this paper, we briefly review the large research literature on emotion in social psychology, and show how it is now firmly embedded in language and communication. As a springboard, we look at the history of emotion studies in\ua0JLSP. Then, we consider theory and methodology, and evaluate how standard and more recent methods of measurement have led to new ways of looking at the communication of emotion, including in real-life contexts. We conclude with suggestions for a research agenda that takes the study of emotion forward into the heartland of research in language and social psychology

Microclimate, an inseparable part of ecology and biogeography

Abstract Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography, and where this field is heading next. We showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping, and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling, and solutions for computational challenges that have pushed the state-of-the-art of the field. We highlight the latest research on interactions between microclimate and organisms, including how microclimate influences individuals, and through them populations, communities, and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimate from the tropics to the poles. Microclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry, and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity. We identify major knowledge gaps that need to be filled for further advancing microclimate methods, investigations, and applications. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management. &nbsp; Biosketch The authors are participants of the Microclimate Ecology and Biogeography conference held in Antwerp, Belgium in 2022. Together they collaboratively wrote this perspective paper that brings together 97 experts and their views on the recent advancements and knowledge gaps in terrestrial microclimate. The paper was coordinated by Julia Kemppinen, Jonas Lembrechts, Koenraad Van Meerbeek, and Pieter De Frenne, and writing different sections was led by Jofre Carnicer, Nathalie Chardon, Paul Kardol, Jonathan Lenoir, Daijun Liu, Ilya Maclean, Jan Pergl, Patrick Saccone, Rebecca Senior, Ting Shen, Sandra Słowińska, Vigdis Vandvik, and Jonathan von Oppen. For more details on authors statistics and how the work was organised, please see Supplementary information Figures S1-3.</p

Microclimate, an important part of ecology and biogeography

Brief introduction: What are microclimates and why are they important?: Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography in terrestrial ecosystems, and where this field is heading next. Microclimate investigations in ecology and biogeography: We highlight the latest research on interactions between microclimates and organisms, including how microclimates influence individuals, and through them populations, communities and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimates from the tropics to the poles. Microclimate applications in ecosystem management: Microclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity. Methods for microclimate science: We showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling and solutions for computational challenges that have pushed the state‐of‐the‐art of the field. What's next?: We identify major knowledge gaps that need to be filled for further advancing microclimate investigations, applications and methods. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management

Active Surveillance Program to Increase Awareness on Invasive Fungal Diseases: the French RESSIF Network (2012 to 2018)

International audienceThe French National Reference Center for Invasive Mycoses and Antifungals leads an active and sustained nationwide surveillance program on probable and proven invasive fungal diseases (IFDs) to determine their epidemiology in France. Between 2012 and 2018, a total of 10,886 IFDs were recorded. The incidence increased slightly over time (2.16 to 2.36/10,000 hospitalization days, P = 0.0562) in relation with an increase of fungemia incidence (1.03 to 1.19/10,000, P = 0.0023), while that of other IFDs remained stable. The proportion of ≥65-year-old patients increased from 38.4% to 45.3% (P 60% of the cases) with a global mortality rate of 42.5% and 59.3%, respectively, at 3 months and significant changes in diagnosis procedure over time. More concurrent infections were also diagnosed over time (from 5.4% to 9.4% for mold IFDs, P = 0.0115). In conclusion, we observed an aging of patients with IFD with a significant increase in incidence only for yeast fungemia, a trend toward more concurrent infections, which raises diagnostic and therapeutic issues. Overall, global survival associated with IFDs has not improved despite updated guidelines and new diagnostic tools.IMPORTANCE The epidemiology of invasive fungal diseases (IFDs) is hard to delineate given the difficulties in ascertaining the diagnosis that is often based on the confrontation of clinical and microbiological criteria. The present report underlines the interest of active surveillance involving mycologists and clinicians to describe the global incidence and that of the main IFDs. Globally, although the incidence of Pneumocystis pneumonia, invasive aspergillosis, and mucormycosis remained stable over the study period (2012 to 2018), that of yeast fungemia increased slightly. We also show here that IFDs seem to affect older people more frequently. The most worrisome observation is the lack of improvement in the global survival rate associated with IFDs despite the increasing use of more sensitive diagnostic tools, the availability of new antifungal drugs very active in clinical trials, and a still low/marginal rate of acquired in vitro resistance in France. Therefore, other tracks of improvement should be investigated actively

Rapid Improvement after Starting Elexacaftor–Tezacaftor–Ivacaftor in Patients with Cystic Fibrosis and Advanced Pulmonary Disease

International audienceRationale: Elexacaftor-tezacaftor-ivacaftor is a CFTR (cystic fibrosis [CF] transmembrane conductance regulator) modulator combination, developed for patients with CF with at least one Phe508del mutation. Objectives: To evaluate the effects of elexacaftor-tezacaftor- ivacaftor in patients with CF and advanced respiratory disease. Methods: A prospective observational study, including all patients aged ⩾12 years and with a percent-predicted FEV1 (ppFEV1) <40 who initiated elexacaftor-tezacaftor-ivacaftor from December 2019 to August 2020 in France was conducted. Clinical characteristics were collected at initiation and at 1 and 3 months. Safety and effectiveness were evaluated by September 2020. National-level transplantation and mortality figures for 2020 were obtained from the French CF and transplant centers and registries. Measurements and Main Results: Elexacaftor-tezacaftor- ivacaftor was initiated in 245 patients with a median (interquartile range) ppFEV1 = 29 (24-34). The mean (95% confidence interval) absolute increase in the ppFEV1 was +15.1 (+13.8 to +16.4; P < 0.0001), and the mean (95% confidence interval) in weight was +4.2 kg (+3.9 to +4.6; P < 0.0001). The number of patients requiring long-term oxygen, noninvasive ventilation, and/or enteral tube feeding decreased by 50%, 30%, and 50%, respectively (P < 0.01). Although 16 patients were on the transplant waiting list and 37 were undergoing transplantation evaluation at treatment initiation, only 2 received a transplant, and 1 died. By September 2020, only five patients were still on the transplantation path. Compared with the previous 2 years, a twofold decrease in the number of lung transplantations in patients with CF was observed in 2020, whereas the number of deaths without transplantation remained stable. Conclusions: In patients with advanced disease, elexacaftor-tezacaftor-ivacaftor is associated with rapid clinical improvement, often leading to the indication for lung transplantation being suspended