Margaret A. Slein

Extreme weather events are increasing in frequency and intensity, but their ecological impacts remain less well understood than those of gradual climate change, largely owing to the challenge of studying unpredictable, short-lived events. The 2021 western North American heatwave is among the most extreme on record globally, yet a broad assessment of its ecological consequences is lacking. Here we synthesize meteorological, ecological, hydrological and wildfire data, along with process-based modelling, to quantify the heatwave and its impacts across the region. Our meta-analysis of 32 terrestrial and marine taxa reveals that over 75% were negatively impacted, but species responses ranged widely, from 99% declines to 89% increases. This variability reflects differences in organisms’ thermal sensitivities, response capacities and exposures, with the latter dependent on geography, microclimate and refugia. Impacts tended to be greater for sessile marine invertebrates, algae and plants than for birds and mammals. At the ecosystem scale, changes in gross primary productivity ranged from 30% increases in cooler, wetter areas to 75% decreases in warmer, arid ones. Streamflow from snow and ice melt increased 40% during the heatwave before dropping below average, whereas wildfire activity surged 37% during the heatwave and 395% the following week. Our results underscore the urgent need for enhanced coordinated approaches to predict, detect and manage increasing heatwaves.

Biological nitrogen fixation (BNF) provides half of global new nitrogen annually and plays an important role in biodiversity patterns and global biological carbon uptake processes. BNF rates accelerate with warming, with known implications for ecological functioning, yet the strength of this temperature sensitivity and its context dependence are not well understood. Here we synthesized 70 controlled experimental tests of the acute temperature dependence of nitrogen fixation rates and found that BNF rates accelerate with temperature in a consistent way across levels of biological organization from enzyme to community, mirroring scaling of metabolic temperature dependence across levels of organization for respiration, photosynthesis and methane production. This BNF temperature dependence is also remarkably consistent across biological systems. This analysis shows multiple lines of evidence for general, scalable effects of temperature on nitrogen fixation rates, in line with previous suggestions of a strong enzyme-level constraint. This widespread pattern may be important for understanding effects of warming on coupled carbon-nitrogen systems with ongoing global change.

Open science skills are increasingly important for a career in ecology and evolutionary biology (EEB) as efforts to make data and analyses publicly available continue to become more commonplace. While learning core concepts in EEB, students are also expected to gain skills in conducting open science to prepare for future careers. Core open science skills like programming, data sharing, and practices that promote reproducibility can be taught to undergraduate students alongside core concepts in EEB. Yet, these skills are not always taught in biology undergraduate programs, and a major challenge in developing open science skills and learning EEB concepts simultaneously is the high cognitive load associated with learning multiple disparate concepts at the same time. One solution is to provide students with easily digestible, scaffolded, pre‐formatted code in the form of vignettes and interactive tutorials. Here, we present six open source teaching tutorials for undergraduate students in EEB. These tutorials teach fundamental ecological concepts, data literacy, programming (using R software), and analysis skills using publicly available datasets while introducing students to open science concepts and tools. Spanning a variety of EEB topics and skill levels, these tutorials serve as examples and resources for educators to integrate open science tools, programming, and data literacy into teaching EEB at the undergraduate level.

Thermal variability is a key driver of ecological processes, affecting organisms and populations across multiple temporal scales. Despite the ubiquity of variation, biologists lack a quantitative synthesis of the observed ecological consequences of thermal variability across a wide range of taxa, phenotypic traits and experimental designs. Here, we conduct a meta-analysis to investigate how properties of organisms, their experienced thermal regime and whether thermal variability is experienced in either the past (prior to an assay) or present (during the assay) affect performance relative to the performance of organisms experiencing constant thermal environments. Our results—which draw upon 1712 effect sizes from 75 studies—indicate that the effects of thermal variability are not unidirectional and become more negative as mean temperature and fluctuation range increase. Exposure to variation in the past decreases performance to a greater extent than variation experienced in the present and increases the costs to performance more than diminishing benefits across a broad set of empirical studies. Further, we identify life-history attributes that predictably modify the ecological response to variation. Our findings demonstrate that effects of thermal variability on performance are context-dependent, yet negative outcomes may be heightened in warmer, more variable climates.