Climatic Limits Research Articles

Modeling biomimetic absorbent compounds for capturing carbon dioxide

Carbon capture and storage is a critical component of negative emission technologies for achieving economy-wide carbon neutrality to mitigate climate change and limit global temperature increase. Removal of CO2 can be undertaken after the standard pollution controls. Yet, the separation of CO2 from flue gas via CO2 capture processes is challenging because a high volume of gas must be treated, the CO2 is dilute, the flue gas is at atmospheric pressure, trace impurities can degrade capture media, and the captured CO2 must be compressed. We present a computational study of a novel family of biomimetic materials for such carbon capture processes based on the Crassulacean Acid Metabolism. Phosphoenolpyruvate serves as a template for designing similar molecules for use as CO2 solvents with designed thermochemical properties.

Safety Work Climate and Performance Limitations among Intensive Care Nurses: A Comparative Study

Safety Work Climate and Performance Limitations among Intensive Care Nurses: A Comparative Study

Climatic limitations of nearly endangered Juniperus rigida populations at their range edges in semiarid China

The treat of climate warming is expected to increase the frequency and severity of droughts and significantly affect tree growth and distribution ranges, particularly in regions without monsoons. The distribution limits of tree species are highly susceptible to climate change. A deeper understanding of how tree species respond to climate across their distribution ranges is crucial for accurately predicting forest dynamics in the face of climate warming. Using tree ring width data from 586 trees at 19 sites spanning the northernmost and southernmost limits of Juniperus rigida (near-threatened, IUCN: NT), we assessed the growth responses of J. rigida to climate at different distribution range limits. We observed significant differences in tree-growth variability between the southern and northern populations of J. rigida, characterized by an increasing growth trend at the southern range limit, but a decreasing trend at the northern limit since 1996. Moreover, tree growth at their northern limit was hindered by high temperatures and SPEI during summer months, whereas it was constrained by low temperatures in March and precipitation in June at the southern limit. Particularly noteworthy is the increased sensitivity of growth to SPEI and precipitation in recent decades (1996–2018) compared to previous decades (1961–1995), particularly at their northern distribution edge. We therefore conclude that the growth of J. rigida trees at the southern limit could benefit from climate warming, while increasing warming and drought could limit tree growth or even cause tree mortality at the northern range limits. These findings may serve as an early warning for the growth and survival of J. rigida trees in open forests at their northern distribution edges in the face of future climate warming.

Dispersal limits poleward expansion of mangroves on the west coast of North America

While much attention has been paid to the climatic controls of species' range limits, other factors such as dispersal limitation are also important. Temperature is an important control of the distribution of coastal mangrove forests, and mangrove expansion at multiple poleward range limits has been linked to increasing temperatures. However, mangrove abundances at other poleward range limits have been surprisingly insensitive to climate change, indicating other drivers of range limitation. For example, along the west coast of North America, the poleward mangrove range limits are found on the Baja California and mainland coasts of Mexico, between 26°48ʹ and 30°18ʹN. Non‐climatic factors may play an important role in setting these range limits as 1) the abundance of range limit populations has been relatively insensitive to climate variability and 2) an introduced population of mangroves has persisted hundreds of kilometers north of the natural range limits. We combined a species distribution model with a high‐resolution oceanographic transport model to identify the roles of climate and dispersal limitation in controlling mangrove distributions. We identified estuarine habitat that is likely climatically suitable for mangroves north of the current range limits. However, propagules from current mangrove populations are unlikely to reach these suitable locations due to prevailing ocean currents and geomorphic factors that create a patchy distribution of estuarine habitat with large between‐patch distances. Thus, although climate change is driving range shifts of mangroves in multiple regions around the world, dispersal is currently limiting poleward mangrove expansion at several range limits, including the west coast of North America.

Assisted tree migration can preserve the European forest carbon sink under climate change

AbstractClimate change threatens the role of European forests as a long-term carbon sink. Assisted migration aims to increase the resilience of forest tree populations to climate change, using species-specific climatic limits and local adaptations through transferring seed provenances. We modelled assisted migration scenarios for seven main European tree species and analysed the effects of species and seed provenance selection, accounting for environmental and genetic variations, on the annual above-ground carbon sink of regrowing juvenile forests. To increase forest resilience, coniferous trees need to be replaced by deciduous species over large parts of their distribution. If local seed provenances are used, this would result in a decrease of the current carbon sink (40 TgC yr−1) by 34–41% by 2061–2080. However, if seed provenances adapted to future climates are used, current sinks could be maintained or even increased to 48–60 TgC yr−1.

Direct Cooling of Electric Machines for Vehicles under Long-term Testing in Climatic Limit Operation on a Test Bench

Direct Cooling of Electric Machines for Vehicles under Long-term Testing in Climatic Limit Operation on a Test Bench

Rapid advance of climatic tree limits in the Eastern Alps explained by on-site temperatures

In the European Alps, mean temperature has risen by 2.5 K since the end of the nineteenth century. A 2 K warming of the growing season has taken place in the last 4 decades only. The 2.5 K warming should rise the position of the climatic treeline by about 400 m. Actual shifts in uppermost tree positions reported here for the Austrian Defereggen Valley and the Swiss Lower Engadine region of the Eastern Alps reach only around 140 m of elevation above the limit of old trees that date back to the nineteenth century. Uppermost Pinus cembra trees of > 2 m height currently occur at c. 2500 m, representing elevation records for the Eastern Alps. In situ temperature records for 2022–2023 revealed seasonal mean temperatures for uppermost trees that are 1–3 K higher than the equilibrium treeline isotherm of c. 6 °C in both regions (corrected for temperature anomalies from long-term records). The 2 K span reflects microhabitat differences and two ways to define the season. Thus, tree advances lag behind the upslope shift of the treeline isotherm, on average, by more than 200 m. The uppermost trees currently grow under quite warm conditions with annual shoot length increments frequently reaching 20 cm. Even without additional future warming, the new steady-state climatic treeline will exceed the Holocene maximum elevation in the Eastern Alps substantially.

Symbionts out of sync: Decoupled physiological responses are widespread and ecologically important in lichen associations.

A core vulnerability in symbioses is the need for coordination between the symbiotic partners, which are often assumed to be closely physiologically integrated. We critically re-examine this assumed integration between symbionts in lichen symbioses, recovering a long overlooked yet fundamental physiological asymmetry in carbon balance. We examine the physiological, ecological, and transcriptional basis of this asymmetry in the lichen Evernia mesomorpha. This carbon balance asymmetry depends on hydration source and aligns with climatic range limits. Differences in gene expression across the E. mesomorpha symbiosis suggest that the physiologies of the primary lichen symbionts are decoupled. Furthermore, we use gas exchange data to show that asymmetries in carbon balance are widespread and common across evolutionarily disparate lichen associations. Using carbon balance asymmetry as an example, we provide evidence for the wide-ranging importance of physiological asymmetries in symbioses.

Subjective evaluation of thermal comfort of tropically acclimatized subjects in air conditioned, naturally ventilated and radiant cooling environments

The thermal sensation of people is subjective. It depends on the external climatic condition and thermal history of a person. Thermal comfort standards suggest a narrow temperature range to assert an environment as comfortable or otherwise. It is important to evaluate people’s thermal perception in different climatic regions and set comfort limits based on their thermal perception. This study evaluates the thermal perception of subjects in hot and humid climatic regions at higher indoor temperatures and air velocities. Three different thermal environments chosen for the study are air conditioned (AC), naturally ventilated (NV), and radiant cooling (RC) thermal environments. The study shows that more than 80% of subjects voted as comfortable in AC and RC thermal environments for the measured Top and va range of 25.3 – 28.4℃/0.1 – 0.3m/s and 25.9 – 29.1℃/0.1 – 0.9m/s respectively. The findings gathered from the study in NV environment indicate that 68% of subjects opt for the use of table fans over ceiling fans. The subjects' free control of air movement improves their thermal sensation over no control of air movement, indicating that they prefer table fans and free control of air movement. In AC, NV, and RC thermal environments, humidity and air quality remain uncontrolled. In AC and RC thermal environments, less than 20% of subjects voted unacceptable for the humidity sensation and Perceived air quality (PAQ) scales in nearly all the studied experimental conditions. In NV thermal environment, the percentage of subjects voting dissatisfied on the humidity sensation scale and PAQ scale is 30-52% and 26-37%, respectively. This outcome shows that a thermally comfortable environment with air movement improves subjects' humidity sensation and PAQ even when humidity and air quality are unaltered. The study points out that air velocity played a vital role in influencing the thermal sensation, humidity sensation and perceived air quality of subjects in the three studied thermal environments. Further the study shows that with free control of air movement will significantly aid in rising the comfort temperature band of tropically acclimatized subjects. Practical application The study shows the variation in limits of thermal comfort indices such as operative temperature and air velocity for tropically acclimatized subjects in three thermal environments. The same group of subjects participated in the subject study conducted in air conditioned, naturally ventilated and radiant cooling thermal environments. The outcomes indicate that subjects are comfortable at higher indoor temperature and air velocity. Further the outcomes showed that the humidity and air quality sensation of subjects is influenced by the subjects’ thermal sensation and air velocity.

Unifying functional and population ecology to test the adaptive value of traits.

Plant strategies are phenotypes shaped by natural selection that enable populations to persist in a given environment. Plant strategy theory is essential for understanding the assembly of plant communities, predicting plant responses to climate change, and enhancing the restoration of our degrading biosphere. However, models of plant strategies vary widely and have tended to emphasize either functional traits or life-history traits at the expense of integrating both into a general framework to improve our ecological and evolutionary understanding of plant form and function. Advancing our understanding of plant strategies will require investment in two complementary research agendas that together will unify functional ecology and population ecology. First, we must determine what is phenotypically possible by quantifying the dimensionality of plant traits. This step requires dense taxonomic sampling of traits on species representing the broad diversity of phylogenetic clades, environmental gradients, and geographical regions found across Earth. It is important that we continue to sample traits locally and share data globally to fill biased gaps in trait databases. Second, we must test the power of traits for explaining species distributions, demographic rates, and population growth rates across gradients of resource limitation, disturbance regimes, temperature, vegetation density, and frequencies of other strategies. This step requires thoughtful, theory-driven empiricism. Reciprocal transplant experiments beyond the native range and synthetic demographic modelling are the most powerful methods to determine how trait-by-environment interactions influence fitness. Moving beyond easy-to-measure traits and evaluating the traits that are under the strongest ecological selection within different environmental contexts will improve our understanding of plant adaptations. Plant strategy theory is poised to (i) unpack the multiple dimensions of productivity and disturbance gradients and differentiate adaptations to climate and resource limitation from adaptations to disturbance, (ii) distinguish between the fundamental and realized niches of phenotypes, and (iii) articulate the distinctions and relationships between functional traits and life-history traits.

Climatically robust multiscale species distribution models to support pronghorn recovery in California.

We combined two climate-based distribution models with three finer-scale suitability models to identify habitat for pronghorn recovery in California now and into the future. We used a consensus approach to identify areas of suitable climate now and future for pronghorn in California. We compared the results of climate models from two separate hypotheses about their historical ecology in the state. Under the migration hypothesis, pronghorn were expected to be limited climatically by extreme cold in winter and extreme heat in summer; under the niche reduction hypothesis, historical pronghorn of distribution would have better represented the climatic limitations of the species. We combined occurrences from GPS collars distributed across three populations of pronghorn in the state to create three distinct habitat suitability models: (1) an ensemble model using random forests, Maxent, classification and regression Trees, and a generalized linear model; (2) a step selection function; and (3) an expert-driven model. We evaluated consensus among both the climate models and the suitability models to prioritize areas for, and evaluate the prospects of, pronghorn recovery. Climate suitability for pronghorn in the future depends heavily on model assumptions. Under the migration hypothesis, our model predicted that there will be no suitable climate in California in the future. Under the niche reduction hypothesis, by contrast, suitable climate will expand. Habitat suitability also depended on the methods used, but areas of consensus among all three models exist in large patches throughout the state. Identifying habitat for a species which has undergone extreme range collapse, and which has very fine scale habitat needs, presents novel challenges for spatial ecologists. Our multimethod, multihypothesis approach can allow habitat modelers to identify areas of consensus and, perhaps more importantly, fill critical knowledge gaps that could resolve disagreements among the models. For pronghorn, a better understanding of their upper thermal tolerances and whether historical populations migrated will be crucial to their potential recovery in California and throughout the arid Southwest.

Climate change may reveal currently unavailable parts of species' ecological niches.

The ability of climatic niche models to predict species extinction risks can be hampered if niches are incompletely quantified. This can occur when niches are estimated considering only currently available climatic conditions, disregarding the fact that climate change can open up portions of the fundamental niche that are currently inaccessible to species. Using a new metric, we estimate the prevalence of potential situations of fundamental niche truncation by measuring whether current ecological niche limits are contiguous to the boundaries of currently available climatic conditions for 24,944 species at the global scale in both terrestrial and marine realms and including animals and plants. We show that 12,172 (~49%) species are showing niche contiguity, particularly those inhabiting tropical ecosystems and the marine realm. Using niche expansion scenarios, we find that 86% of species showing niche contiguity could have a fundamental niche potentially expanding beyond current climatic limits, resulting in lower-yet still alarming-rates of predicted biodiversity loss, particularly within the tropics. Caution is therefore advised when forecasting future distributions of species presenting niche contiguity, particularly towards climatic limits that are predicted to expand in the future.

The sensitivity of root water uptake to cold root temperature follows species-specific upper elevational distribution limits of temperate tree species.

Physiological water stress induced by low root temperatures might contribute to species-specific climatic limits of tree distribution. We investigated the low temperature sensitivity of root water uptake and transport in seedlings of 16 European tree species which reach their natural upper elevation distribution limits at different distances to the alpine treeline. We used 2H-H2O pulse-labelling to quantify the water uptake and transport velocity from roots to leaves in seedlings exposed to constant 15°C, 7°C or 2°C root temperature, but identical aboveground temperatures between 20°C and 25°C. In all species, low root temperatures reduced the water transport rate, accompanied by reduced stem water potentials and stomatal conductance. At 7°C root temperature, the relative water uptake rates among species correlated positively with the species-specific upper elevation limits, indicating an increasingly higher sensitivity to lower root zone temperatures, the lower a species'natural elevational distribution limit. Conversely, 2°C root temperature severely inhibited water uptake in all species, irrespective of the species'thermal elevational limits. We conclude that low temperature-induced hydraulic constraints contribute to the cold distribution limits of temperate tree species and are a potential physiological cause behind the low temperature limits of plant growth in general.

Toposequence effect on soil properties and suitability rating for selected crops in Northern Guinea Savanna, Nigeria

A toposequence at Giwa, Kaduna State was studied with the aim of assessing the effect of topography on soil properties and suitability ratings for rainfed rice, cowpea, and tomato. Three slope positions namely, lower slope (LS), middle slope (MS) and upper slope (US) were delineated, and their properties were assessed. Results indicated that soils on all locations were very deep (167 – 192 cm) with occurrence of plinthite at subsurface of MS and US. Slope position of the soils was noted to influence morphological, physical and chemical properties. Content of silt and sand fractions, available water content and moisture retention at field capacity were all significantly influenced by slope. Melanization, braunification, plinthization and argilluviation were some pedogenetic process notable in the soils. Suitability studies revealed that 29.12% of the area was moderately suitable (S2) for rice cultivation with limitations of climate, soil physical property and fertility, while 70.88% of the area were marginally suitable (S3), with an additional limitation in wetness. For cowpea, 68.13% of the soils were S2 with limitations in fertility, while MS was highly suitable (S1). Tomato was rated S2 for the entire area with general limitations in climate and fertility. Suitability for rice increased down the slope from US, while that of cowpea and tomato increased along the slope from LS to US. This effect was attributed to distribution of nutrient and water, as preconditioned by topography. Management practice suggests the use of LS for rice, while MS and US may be rotated for cultivating tomato and cowpea.

Climate-limited vegetation change in the conterminous United States of America.

The effects of climate change on vegetation composition and distribution are evident in different ecosystems around the world. Although some climate-derived alterations on vegetation are expected to result in changes in lifeform fractional cover, disentangling the direct effects of climate change from different non-climate factors, such as land-use change, is challenging. By applying "Liebig's law of the minimum" in a geospatial context, we determined the climate-limited potential for tree, shrub, herbaceous, and non-vegetation fractional cover change for the conterminous United States and compared these potential rates to observed change rates for the period 1986 to 2018. We found that 10% of the land area of the conterminous United States appears to have climate limitations on the change in fractional cover, with a high proportion of these sites located in arid and semiarid ecosystems in the Southwest part of the country. The rates of change in lifeform fractional cover for the remaining area of the country are likely limited by non-climate factors such as the disturbance regime, land management, land-use history, soil conditions, and species interactions and adaptations.

Engineering Yarrowia lipolytica for Sustainable Production of the Pomegranate Seed Oil-Derived Punicic Acid.

Punicic acid is a conjugated linolenic acid with various biological activities including antiobesity, antioxidant, anticancer, and anti-inflammatory effects. It is often used as a nutraceutical, dietary additive, and animal feed. Currently, punicic acid is primarily extracted from pomegranate seed oil, but it is restricted due to the extended growth cycle, climatic limitations, and low recovery level. There have also been reports on the chemical synthesis of punicic acid, but it resulted in a mixture of structurally similar isomers, requiring additional purification/separation steps. In this study, a comprehensive strategy for the production of punicic acid in Yarrowia lipolytica was implemented by pushing the supply of linoleic acid precursors in a high-oleic oil strain, expressing multiple copies of the fatty acid conjugase gene from Punica granatum, engineering the acyl-editing pathway to improve the phosphatidylcholine pool, and promoting the assembly of punicic acid in the form of triglycerides. The optimal strain with high oil production capacity and a significantly increased punicic acid ratio accumulated 3072.72 mg/L punicic acid, accounting for 6.19% of total fatty acids in fed-batch fermentation, providing a viable, sustainable, and green approach for punicic acid production to substitute plant extraction and chemical synthesis production.

Strengthening the Quest for Sustainable Development Through Persuasive Climate Argumentation

This study explored the nexus between framing, persuasion and the quest for sustainable development in a competitive policy debate setting using content analysis approach. Evidence from the analysis reveals several insights about the underlying mechanism that governs persuasive climate argumentation which shapes sustainable development trajectory. First, the study showed that arguers construct arguments that appeals to logos as a major persuasion strategy. Second, it demonstrated how persuasion strategy entrench a culture of persuasion in climate debates. Third, it found a discordant relationship between fallacies and persuasion strategy in climate argumentation, which jeopardises arguments' persuasive power. Finally, the study evaluated how tensions in the mainstream socio-economic and environmental ecosystem creeps into climate arguments and limit persuasive power of climate arguments. These are regarded as reflective pattern of climate argumentation that are capable of stimulating behavioural change and communication strategies for sustainable development.

Pool bio-oxidation and fitting analysis of low-grade arsenic-containing refractory gold ore

To overcome the limitations of geography, climate, and ore characteristics on the ore beneficiation process, bio-oxidation studies on low-grade arsenic-bearing refractory gold ore by pool leaching were carried out, as well as process fitting analysis. The gold particles are encapsulated by pyrite and arsenopyrite. After 60 days of bio-oxidation, the oxidation rates of arsenic, sulfur, and gold were 39%∼69%, 24%∼41%, and 49%∼83%, respectively. The inoculated Acidithiobacillus ferrooxidans, Ferroplasma acidiphilum, and Leptospirillum ferrodiazotrophum could all mediate the initial pyrite/arsenopyrite oxidation and the Fe2+ oxidation reaction, but only the former could mediate the subsequent sulfur compound oxidation. When compared to daily bacterial circulation and bacterial replacement every ten days, aeration improved the gold leaching rate by 14%∼22%. The Boltzmann model could fit both the arsenic and sulfur bio-oxidation, with model fit variances greater than 0.98. Based on the experimental and fitting results, the bio-oxidation cycle was determined to be 60 days, and the bio-oxidation mechanisms are summarized. This study has significant practical implications for the rational utilization of gold resources and provides theoretical and practical guidance for similar gold ores.

Planning for climate change with the best of intentions... Analyzing the content of plans and planners’ rationale for adaptation

In France, local urban plans (PLUi) can convey drivers for climate change adaptation, e.g. greening and limitation of soil sealing to reinforce stormwater management. However, translating adaptation measures into plans is not always easy for planners to effectively communicate adaptation. We create an analysis method, specifically designed for the sustainable development project (PADD), a key document of the PLUi, in order to understand its adaptation approach. The PADD examined is that of the PLUi of Nantes metropolis in France. The first part of the method has been published; here, we develop the last two steps of the method, which consist of a thematic analysis applied to the corpus and a cross-analysis of results. The findings reveal seven major intentions for adaptation. Specific actions were more difficult to identify; however, four areas of practical application emerged: vegetation, water, soil and building. Furthermore, we questioned local planners to get a complete sense of their rationale to address adaptation. Creators and agents result in being aware of the challenges and can identify concrete and synergistic adaptive actions; however, it is unclear how they would measure achievement of PADD objectives. The results may provide useful information to determine whether PADDs are conducive to adaptation.

Limited influence of air temperature and precipitation on six-year survival and growth of non-native tree species in a Central European multi-site field trial

The biggest challenge for forest management in the near future will be the silvicultural adaptation of forests on sites where climate change will increase the risk for drought induced tree mortality and for a decrease of the growth performance. One management option is the diversification by promoting climate change adapted non-native tree species. Currently, we have in depth experience with only a few non-native tree species in Central Europe. Other tree species that may complement the species pool in Central Europe need to be carefully selected by a range of criteria. Before establishing larger silvicultural experiments at stand-level, the suitability of species to grow well with a low risk of failure under expected future climatic conditions as well as a good performance already today should be tested, amongst other aspects. We present results of a multi-site common garden experiment where growth and survival of five non-native tree species (Abies bornmuelleriana, Cedrus libani, Fagus orientalis, Tilia tomentosa, and Tsuga heterophylla) and one climate adapted local native species per site are tested in five field trials in Austria, Germany and Switzerland along a temperature (7.9–10.4 °C mean annual Temperature) and precipitation (490–1147 mm annual precipitation) gradient. Each species was replicated on three plots per site using a block-wise design. Lower survival and growth of the non-native species as the native reference on most sites indicate that the studied non-native species are today not as well adapted to current climatic conditions as native species. However, the performance of the non-native species was sufficiently high to justify further trials. Survival and growth rates were mostly equally high on the two sites at the opposing ends of the temperature and humidity gradient and lower on all other sites. Height growth and survival were only marginally affected by the strong summer drought in 2018 in all except one site, presumably due to the low water storage capacity of the sandy soils on this site. This indicates that the tested non-native tree species grow well in the wide range of climatically changing weather conditions from our transnational study sites across Central Europe. So far, the tested tree species did not reach their climatic growth limitation. However, edaphic site conditions may have influenced the performance of the tested non-native species as well and must be considered when discussing the suitability of these tree species.