Life Distribution Research Articles

Diversity and distribution of Raunkiær's life forms in European vegetation

AbstractAimsThe Raunkiær's system classifies vascular plants into life forms based on the position of renewal buds during periods unfavourable for plant growth. Despite the importance of Raunkiær's system for ecological research, a study exploring the diversity and distribution of life forms on a continental scale is missing. We aim to (i) map the diversity and distribution of life forms in European vegetation and (ii) test for effects of bioclimatic variables while controlling for habitat‐specific responses.LocationEurope.MethodsWe used data on life forms of 8883 species recorded in 546,501 vegetation plots of different habitats (forest, grassland, scrub and wetland). For each plot, we calculated: (i) the proportion of species of each life form and (ii) the richness and evenness of life forms. We mapped these plot‐level metrics averaged across 50 km × 50 km grid cells and modelled their response to bioclimatic variables.ResultsHemicryptophytes were the most widespread life form, especially in the temperate zone of Central Europe. Conversely, therophyte and chamaephyte species were more common in the Mediterranean as well as in the dry temperate regions. Moreover, chamaephytes were also more common in the boreal and arctic zones. Higher proportions of phanerophytes were found in the Mediterranean. Overall, a higher richness of life forms was found at lower latitudes while evenness showed more spatially heterogeneous patterns. Habitat type was the main discriminator for most of the responses analysed, but several moisture‐related predictors still showed a marked effect on the diversity of therophytes and chamaephytes.ConclusionsOur maps can be used as a tool for future biogeographic and macro‐ecological research at a continental scale. Habitat type and bioclimatic conditions are key for regulating the diversity and distribution of plant life forms, with concomitant consequences for the response of functional diversity in European vegetation to global environmental changes.

The attribution of causality, perception of responsibility, and preferred generic means of life distribution

The attribution of causality, a central concept in human cognition theory, is the principal instrument for investigating functional links between events and phenomena. Although the links between causality and moral responsibility are commonly recognized, the scope of studies analysing the practical implications of causality attribution is minimal. This study examines the effect of causality perception on the desired distribution of the generic means of life by utilising thought experiment data collection methodology and non-parametric statistical analysis. The results indicate that: (i) causality perception affects the desired distribution, and (ii) individuals show no tendency to modify their perception of causality.

A novel refined maintenance strategy for full life cycle of high‐speed automatic train protection system

AbstractAutomatic train protection (ATP) system is essential for ensuring the safe operation of high‐speed trains. However, the existing extensive and fixed maintenance mode of the ATP system results in a waste of resources. To achieve a state of operation and maintenance that ensures both protection capability and economic efficiency, a lean method in a dynamic maintenance mode for the full life cycle of the ATP system is proposed. Firstly, reliability tests are carried out based on historical failure data. The parameter values of the possible life distribution are estimated by maximum likelihood method, and the optimal life distribution of different devices is obtained through the Kolmogorov–Smirnov hypothesis test. Secondly, a dynamic failure rate function is introduced to describe the impact of maintenance on device performance. A refined maintenance model is then established within the life cycle, and the dynamically changing preventive maintenance intervals and frequencies are obtained using a genetic algorithm. Finally, to mitigate the impact of the intermittent operation of ATP system on maintenance, the multidimensional relationships among the maintenance strategy, service time and operation mileage are revealed. The effectiveness of the proposed method is verified through an example test on a type of driver machine interface device.

Notes on the distribution and colouration in life of Stenomacra tungurahuana Brailovsky & Mayorga, 1997 (Hemiptera: Largidae)

The hemipteran Stenomacra tungurahuana Brailovsky & Mayorga, 1997 (Hemiptera, Heteroptera, Largidae) remains known from just two localities in the inter-Andean valley of Ecuador. No ecological information nor description of its colouration in life have been reported. In this contribution, I provide the first record of S. tungurahuana on the northeastern slopes of the Eastern Cordillera of the Andes and the first description of its colouration in life, including photographs, based on a specimen from San Isidro Lodge, province of Napo, ca. 108 km from the species’ type locality.

Reliability-Centered Preventive Maintenance Optimization for a Single-Component Mechanical Equipment

Due to the high failure rates of mechanical equipment with complex structures and numerous moving parts, devising an effective preventive maintenance (PM) plan and avoiding the influence brought by failure is crucial. However, some PM efforts are disorganized, unpractical, and unscientific, leading to prolonged downtime and significant cost losses. The challenge in creating PM plans is exacerbated by the asymmetry between maintenance and failure data. Therefore, focusing on single-unit mechanical equipment, the reliability-centered maintenance (RCM) idea is put forward to find out the key parts to implement preventive maintenance, and PM models are built to draw up a more reasonable PM plan. Such strategies aim to lower maintenance costs and enhance economic performance. Data on past maintenance and failures are analyzed to determine the life distribution and maintenance effect functions, helping to quantify the uncertainty caused by data asymmetry. Two PM optimization models considering time-varying failure rates are proposed: one focuses on minimizing costs, while the other aims to maximize availability. A PM plan example is demonstrated using a component from a tire-building machine including six parts, which proves the validity of the models. The availability results of two parts corresponding to the maintenance strategy obtained by the availability maximization model are above 0.99, and the results of total costs per unit time of the remaining four parts obtained by the cost minimization model are under 5.69.

Astroecology: bridging the gap between ecology and astrobiology

Abstract Although astrobiology studies how life functions and evolves, ecology is still largely overlooked in astrobiology research. Here we present an argument for astroecology, a merger of ecology and astrobiology, a self-aware scientific endeavour. Ecology is rarely mentioned in influential documents like the NASA Astrobiology Strategy (2015), and terms such as ‘niche’ can end up being used in a less precise fashion. As ecology deals with sequential levels of organization, we suggest astrobiologically-relevant problems for each of these levels. Organismal ecology provides ecological niche modelling, which can aid in evaluating the probability that Earth-like life would survive in extraterrestrial environments. Population ecology provides a gamut of models on the consequences of dispersal, and if lithopanspermia can be validated as a form of space dispersal for life, then metabiospheres and similar astrobiological models could be developed to understand such complex structure and dynamics. From community ecology, the discussion of habitability should include the concept of true vacant habitats (a misnomer, perhaps better called ‘will-dwells’) and contributions from the blossoming field of microbial ecology. Understanding ecosystems by focusing on abiotic properties is also key to extrapolating from analogue environments on Earth to extraterrestrial ones. Energy sources and their distribution are relevant for ecological gradients, such as the biodiversity latitudinal gradient – would tropics be species-rich in other inhabited planets? Finally, biosphere ecology deals with integration and feedback between living and non-living systems, which can generate stabilized near-optimal planetary conditions (Gaia); but would this work for other inhabited planets? Are there ‘strong’ (like Earth) and ‘weak’ (perhaps like Mars) biospheres? We hope to show ecology can contribute relevant ideas to the interdisciplinary field of astrobiology, helping conceptualize further levels of integration. We encourage new partnerships and for astrobiologists to take ecology into account when studying the origin, evolution and distribution of life in the universe.

AUTOMATIC VIDEO DETECTION FOR GOLDEN MONKEYS IN SHENNONGJIA NATIONAL PARK, CHINA

Abstract. Infrared-triggered cameras serve as essential tools for wildlife resource surveys, allowing camera traps to capture wildlife activity while minimizing the impact on the ecosystem. Traditional monitoring methods heavily rely on human resources for visual discrimination, which is inefficient and susceptible to environmental influences. Therefore, this paper focuses on Shennongjia National Park as a case study to address the limitations of traditional approaches. We constructed a Shennongjia wildlife object detection dataset using video data from the fixed-erected infrared cameras and proposed a supervised learning-based automatic monitoring method for golden monkeys, aiming to achieve intelligent target detection. With these processing results, we were able to capture golden monkeys' tracks and conduct statistical analysis of their life range and distribution characteristics. Through the integration of sensors and deep learning techniques, we developed a golden monkeys detection monitoring system to visualize the monitoring results and assess the spatial and temporal distribution characteristics of golden monkeys’ activities.

Crack tip mechanics of multiscale change

Singularity representation at the crack tip and/or smaller region will be considered using six scale transitional physical parameters: three assigned for the nano/micro range (*na/mi, *na/mi, d*na/mi) and three assigned for the micro/macro range (*mi/ma, *mi/ma, d* mi/ma). The subscripts nano, micro, and macro are self-evident. Only the ratio of two successive scale sensitive parameters are needed. Although time dependent physical parameters at the lower scale can be found analytical, they regarded as fictitious, mainly because they are not conducible to measurements. The transitional character of multiscale changes according to nano→micro→ macro with the respective singularity strength of  are given by 1.00/0.75/0.50. Since =0.5 corresponds to the inverse square root r-0.5, where r is the distance from the macro singular point. The micro and nano singular point possess the singularities r-0.75 and r-1.00, respectively. For example, a critical device component may be designed to operate at the nano/micro/macro scale with a life distribution of 2.5+ /3.5+ /5.5+ and total life of 11.5 + years. Progressive changes are assumed to occur in the direction of nano→micro→macro.

Microstructure analysis and life prediction of DD6 superalloy under 760 °C combined high and low cycle fatigue conditions

The impact of high and low cycle combined loads on the fatigue performance of DD6 alloy was investigated in this work. Specifically, the combined high- and low-cycle fatigue response of DD6 alloy was examined at a temperature of 760 °C under different low cycle stress amplitudes (960, 1000, and 1040 MPa). The findings revealed that higher low cycle stress amplitudes result in shorter combined high and low cycle fatigue life and less dispersion in life. Correlations between the microstructural features (crystal plane distribution, fracture elevation difference, and the area proportion of crack propagation zone) and fatigue performance were accurately established, demonstrating a linear relationship between these microstructural features and the logarithm of fatigue life. The study also uncovered the evolution rule of microstructural features in high- and low-cycle combined fatigue. Furthermore, the fracture mechanism was analyzed and the distribution of high and low cycle combined fatigue life of DD6 alloy at 760 °C was statistically validated using the dual-parameter Weibull distribution theory. Building upon the crystal plasticity theory, a fatigue life prediction model was developed, and the combined cycle fatigue lifespan under various low cycle stress amplitudes was compared. The comparison between the predicted life and actual fatigue life indicated that the predicted lifespan falls in three times the scatter band.

Novel iterative Ragone plot-based optimization of low pass filter for hybrid power sources electric vehicles

The growing demand for eco-friendly transportation has led to the emergence of electric vehicles (EVs). To meet driving requirements and enhance the performance of EVs, researchers combine Energy Storage Systems (ESS) to form Hybrid-ESS (HESS). Efficient power distribution within HESS relies on an effective Energy Management Strategy (EMS). While various EMS methods exist, practical implementation is often hindered by computational complexity. The low-pass filter (LPF) approach is one of the easiest and implementable EMS methods. However, the pivotal challenge lies in determining the optimal cut-off frequency for LPF, a crucial factor influencing energy distribution. Traditional optimization methods, such as Particle Swarm Optimization (PSO) face significant limitations when applied to intricate ESS and DC-DC converter models. Therefore, the iterative method based on the Ragone plot is proposed. Its performance is compared with LPF tuned by PSO. The test results show that the proposed method has a faster process by up to 83.51 % while maintaining comparable performance levels. Compared to battery-only EVs, it is superior in terms of the delta-State of Charge of the battery (delta-SoCB), energy consumption, maximum battery current, and Battery Current Root Means Square (BCRMS). Compared to the Fuzzy Logic Controller (FLC), it outperforms in maximum battery current and BCRMS, with slightly lower delta-SoCB and energy consumption. This highlights the practicality and efficiency of the proposed method, offering a solution for optimizing battery life and power distribution in HESS EVs. Hence advancing the sustainability and performance of eco-friendly transportation systems.

Performance degradation and reliability analysis of a MEMS flow sensor with accelerated degradation testing

In this article, we research the performance degradation of a MEMS flow sensor with accelerated degradation testing (ADT). The degradation of temperature stress (Ts) on sensor is studied. Based on the performance in the aging test, resistance degradation ∆R is selected as a more suitable degradation characteristic parameter. Furthermore, the degradation process of the characteristic parameter results from resistivity decreases, in which Ts leads to stress relief within the bulk of the resistor. By implementing the Constant-stress accelerated degradation test (CSADT), we estimate the lifetime of this MEMS flow sensor based on the Arrhenius model. The calculated lifetime is 6.833 years for the 120°C group, 3.942 years for the150°C group, and 2.492 years for the180°C group. In addition, using statistics analysis, the Weibull distribution (WD) is proved to be the better mode for the MEMS flow sensor acceleration life with the Anderson-Darling (AD) being 235.910. The scale and shape of WD was evaluation. On the other hand, to verify the rationality of the distribution, the Standard residual error method and the Cox-Snell residual error method have been used separately, to perform the Goodness-of-fit tests. The AD value of Standard residual error and Cox-Snell residual error is 3.476. It proves that the selected life distribution model of this MEMS flow sensor is befitting. Finally, in this research the CSADT results are original and novelty. The lifetime distribution results reveal that considering the Goodness-of-fit tests can significantly improve the accuracy of reliability analysis of this MEMS flow sensor. Based on those results, a reliability method for this MEMS flow sensor is established.

Study on life distribution and prediction method of flexible graphite composite reinforced gasket

PurposeThis paper aims to prevent gasket sealing failure in engineering, accurately predict gasket life, extend system life and improve sealing reliability. The accelerated life test method of flexible graphite composite–reinforced gaskets is established, the life distribution law of flexible graphite composite–reinforced gaskets is revealed, and the life prediction method of flexible graphite composite–reinforced gaskets with different allowable leakage rates is proposed, which can provide a reference for the life prediction of other types of gaskets.Design/methodology/approachIn this study, flexible graphite composite–reinforced gaskets were tested for long-term high-temperature sealing performance on a multi-sample gasket accelerated life test rig. The data were also analyzed using the least squares method and the K-S hypothesis calibration method. A gasket time-dependent leakage model and an accelerated life model were also developed. Constant stress-accelerated life tests were conducted on flexible graphite composite–reinforced gaskets. On this basis, a gasket life prediction method at different allowable leakage rates was proposed.FindingsThe life distribution law of flexible graphite composite–reinforced gaskets is revealed. The results show that the life of the gasket obeys the Weibull distribution. The time-correlated leakage model and accelerated life model of the gasket were established. And the accelerated life test method of the flexible graphite composite–reinforced gasket was established. The life distribution parameters, accelerated life model parameters and life estimates of gaskets were obtained through tests. On this basis, a gasket life prediction method under different leakage rates was proposed, which can be used as a reference for other types of gaskets.Practical implicationsThe research in this paper can better provide guidance for the use and replacement of gaskets in the project, which is also very meaningful for predicting the leakage condition of gaskets in the bolted flange connection system and taking corresponding control measures to reduce energy waste and pollution and ensure the safe operation of industrial equipment.Originality/valueA multi-specimen gasket-accelerated life test device has been developed, and the design parameters of the device have reached the international advanced level. The life distribution law of the flexible graphite composite–reinforced gasket was revealed. The accelerated life test method for the flexible graphite composite–reinforced gasket was established. The life prediction method of the flexible graphite composite–reinforced gasket under different allowable leakage rates was proposed.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2023-0254/

Statistical Analysis of Step Stress Acceleration Test Data

The step stress accelerated life test is the selection of a set of accelerated stress levels that are higher than normal stress levels. At the beginning of the test, a certain number of samples are placed under a certain stress level for life testing. After some time, the stress level is increased, and this continues until a certain number of samples fail. In this paper, the acceleration coefficient is used to convert the failure data under each acceleration stress level into life data. The life distribution is exponential distribution, Weibull distribution, and logarithmic normal distribution. Under a certain number of samples, the statistical analysis of step stress accelerated life test data is completed, and the estimation of each reliability index is calculated.

Clustering as a mechanism for enhanced reaction of buoyant species

Buoyant material has a tendency to form dense clusters at the ocean surface. This has been observed in distributions of marine life and floating plastic contaminants. The main mechanism behind this is that particles with positive/neutral buoyancy do not behave as passive tracers in stratified flows. It could be expected that coextensive clustering between plankton and toxic ocean contaminants could lead to enhanced ecological risk. However, such interactions cannot be sufficiently modelled in a standard passive tracer approximation. Given the large uncertainty in the form of converging currents and how to model interactions of buoyant tracers, we opt for an idealised modelling approach. The simplicity of our model allows easy interpretation of the novel physical considerations. We demonstrate that the global dynamics of our biogeochemical model are significantly altered by clustering forces. Most notably, a new balance in the ecosystem exists in which reactions are dominated entirely by those within the dense clusters. This greatly enhances the impact of destructive pollutants through efficient mixing. There is evidence that this equilibrium will be robust moving to more complex and realistic models.

In Situ Real-Time Monitoring for Aseptic Drilling: Lessons Learned from the Atacama Rover Astrobiology Drilling Studies Contamination Control Strategy and Implementation and Application to the Icebreaker Mars Life Detection Mission.

In 2019, the Atacama Rover Astrobiology Drilling Studies (ARADS) project field-tested an autonomous rover-mounted robotic drill prototype for a 6-Sol life detection mission to Mars (Icebreaker). ARADS drilled Mars-like materials in the Atacama Desert (Chile), one of the most life-diminished regions on Earth, where mitigating contamination transfer into life-detection instruments becomes critical. Our Contamination Control Strategy and Implementation (CCSI) for the Sample Handling and Transfer System (SHTS) hardware (drill, scoop and funnels) included out-of-simulation protocol testing (out-of-sim) for hardware decontamination and verification during the 6-Sol simulation (in-sim). The most effective five-step decontamination combined safer-to-use sterilants (3%_hydrogen-peroxide-activated 5%_sodium-hypochlorite), and in situ real-time verification by adenosine triphosphate (ATP) and Signs of Life Detector (SOLID) Fluorescence Immunoassay for characterization hardware bioburden and airborne contaminants. The 20- to 40-min protocol enabled a 4-log bioburden reduction down to <0.1 fmoles ATP detection limit (funnels and drill) to 0.2-0.7 fmoles (scoop) of total ATP. The (post-cleaning) hardware background was 0.3 to 1-2 attomoles ATP/cm2 (cleanliness benchmark background values) equivalent to ca. 1-10 colony forming unit (CFU)/cm2. Further, 60-100% of the in-sim hardware background was ≤3-4 bacterial cells/cm2, the threshold limit for Class <7 aseptic operations. Across the six Sols, the flux of airborne contaminants to the drill sites was ∼5 and ∼22 amoles ATP/(cm2·day), accounting for an unexpectedly high Fluorescence Intensity (FI) signal (FI: ∼6000) against aquatic cyanobacteria, but negligible anthropogenic contribution. The SOLID immunoassay also detected microorganisms from multiple habitats across the Atacama Desert (anoxic, alkaline/acidic microenvironments in halite fields, playas, and alluvial fans) in both airborne and post-cleaning hardware background. Finally, the hardware ATP background was 40-250 times lower than the ATP in cores. Similarly, the FI peaks (FImax) against the microbial taxa and molecular biomarkers detected in the post-cleaned hardware (FI: ∼1500-1600) were 5-10 times lower than biomarkers in drilled sediments, excluding significant interference with putative biomarker found in cores. Similar protocols enable the acquisition of contamination-free materials for ultra-sensitive instruments analysis and the integrity of scientific results. Their application can augment our scientific knowledge of the distribution of cryptic life on Mars-like grounds and support life-detection robotic and human-operated missions to Mars.

Moisture evaporation effect on pore structure and microbial distribution during sludge biodrying

Biodrying of dewatered sludge is an eco-friendly and efficient technology to decrease the sludge moisture content (MC) by metabolic heat generated from sludge organic matter degradation. By analyzing the water states and visualizing the sludge pore structure during the biodrying process, it was found that the bound water accounted for 96.5–97.9% of the sludge water and interstitial water was only 2.0–3.5%. The microscopic and dispersed sludge pores were transformed into larger and linked ones by the transformation of bound water into interstitial water and the subsequent evaporation. As a result, the depth of live bacteria distribution thickened, reaching 0–180 µm, 0–330 µm, and 0–350 µm during the temperature ramp-up to 45.6 °C, the peak temperature of 70.7 °C, and the cool-down to 45.6 °C, respectively. Briefly, as moisture evaporated, the pore structure of the sludge expanded and the microbial distribution deepened. Moreover, the phylum of anaerobic bacteria was drastically decreased.

1492. Gender-Specific Targets for Primary Prevention in People Living with HIV : Applying Life's Simple 7 to a Gender-Stratified Population of ART-Naive People Living with HIV in Tanzania

Abstract Background Cardiovascular disease (CVD) represents a major cause of premature mortality in people living with HIV (PLWH). However, morbidity is not equal between males and females. There is a need to better understand how gender influences cardiovascular health (CVH) in PLWH in order to identify targets for intervention. Therefore, we applied the Life's Simple Seven (LS7) scale to a gender-stratified cohort of ART-Naive PLWH and HIV-uninfected controls in adults. Methods A cross-sectional analysis was conducted on a cohort of ART-naive PLWH and HIV-uninfected adults recruited from HIV clinics between June 2016 and August 2019 in Mwanza, Tanzania (HIV&amp;HTN cohort). We applied modified Life's Simple Seven (LS7) definitions (Table 1) and compared the distribution of Ideal LS7 metrics between males and females of both study groups. Each LS7 metric was categorized as ideal (2 points), intermediate (1 point) and poor (0 point) and ordinal regressions were employed to investigate associations between gender and each individual LS7 metric. Regressions were adjusted for HIV status, age, income, education level. Results Our study included 997 participants, with 493 PLWH (68.7% female) and 504 HIV-uninfected (66.4% female). As displayed in Figure 1, the distribution of Ideal LS7 metrics differed between the males and females in both study groups. Males had a higher prevalence of ideal physical activity (aOR=4.12 [95%CI=3.11 to 5.44], p&amp;lt; 0.001) and ideal BMI (aOR=5.10 [3.47 to 7.49], p&amp;lt; 0.001) but lower prevalence of ideal smoking (aOR=0.037 [0.021 to 0.065], p&amp;lt; 0.001) and ideal blood pressure (aOR= 0.65 [0.50 to 0.85], p=0.002). The magnitude of these differences also varied by HIV status such that they were larger in PLWH than HIV-uninfected group for smoking (41.3% vs 26.4%), physical activity (41.6% vs 24.8%) and blood pressure (12.7% vs 9.2%) metrics. By contrast, these differences were less pronounced in PLWH vs HIV-uninfected group for the BMI metric (23.1% vs 29.7%). Figure 1: Distribution of Ideal Life's Simple 7 metrics, stratified by gender for both PLWH and HIV-uninfected controls Conclusion Cardiovascular health profiles vary by gender and HIV status, with stark differences between male and female PLWH for most metrics. Gender-specific interventions targeting smoking cessation, blood pressure control in male PLWH and physical activity, weight loss in female PLWH are warranted to mitigate CVD risk. Disclosures All Authors: No reported disclosures

Complementarity between urban land uses: a temporal analysis

ABSTRACT Despite great interest in land use mix and the set of benefits that it supposedly provides, there still is a gap in the understanding of how land uses interact to promote urban vitality. This article examines land use from a temporal perspective, analysing both the frequency of visits throughout the day and the average duration of visits. The results show that even land uses in the same conventional functional category have different daily visitation patterns. Furthermore, the temporal combination and complementarity of some land uses seemed to directly influence the intensity and distribution of urban life.

Statistical Fuzzy Reliability Analysis: An Explanation with Generalized Intuitionistic Fuzzy Lomax Distribution

To illustrate data uncertainty, intuitionistic fuzzy sets simply use membership and non-membership degrees. However, in some cases, a more complex strategy is required to deal with imprecise data. One of these techniques is generalized intuitionistic fuzzy sets (GIFSs), which provide a comprehensive framework by adding extra factors that provide a more realistic explanation for uncertainty. GIFSs contain generalized membership, non-membership, and hesitation degrees for establishing symmetry around a reference point. In this paper, we applied a generalized intuitionistic fuzzy set approach to investigate ambiguity in the parameter of the Lomax life distribution, seeking a more symmetric assessment of the reliability measurements. Several reliability measurements and associated cut sets for a novel L-R type fuzzy sets are derived after establishing the scale parameter as a generalized intuitionistic fuzzy number. Additionally, the study includes a range of reliability measurements, such as odds, hazards, reliability functions, etc., that are designed for the Lomax distribution within the framework of generalized intuitionistic fuzzy sets. These reliability measurements are an essential tool for evaluating the reliability characteristics of various types of complex systems. For the purpose of interpretation and application, the results are visually displayed and compared across different cut set values using a numerical example.

Temperate species underfill their tropical thermal potentials on land

Understanding how temperature determines the distribution of life is necessary to assess species’ sensitivities to contemporary climate change. Here, we test the importance of temperature in limiting the geographic ranges of ectotherms by comparing the temperatures and areas that species occupy to the temperatures and areas species could potentially occupy on the basis of their physiological thermal tolerances. We find that marine species across all latitudes and terrestrial species from the tropics occupy temperatures that closely match their thermal tolerances. However, terrestrial species from temperate and polar latitudes are absent from warm, thermally tolerable areas that they could potentially occupy beyond their equatorward range limits, indicating that extreme temperature is often not the factor limiting their distributions at lower latitudes. This matches predictions from the hypothesis that adaptation to cold environments that facilitates survival in temperate and polar regions is associated with a performance trade-off that reduces species’ abilities to contend in the tropics, possibly due to biotic exclusion. Our findings predict more direct responses to climate warming of marine ranges and cool range edges of terrestrial species.